Merge tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

Pull vfs idmapping updates from Christian Brauner:

 - Last cycle we introduced the dedicated struct mnt_idmap type for
   mount idmapping and the required infrastucture in 256c8aed2b42 ("fs:
   introduce dedicated idmap type for mounts"). As promised in last
   cycle's pull request message this converts everything to rely on
   struct mnt_idmap.

   Currently we still pass around the plain namespace that was attached
   to a mount. This is in general pretty convenient but it makes it easy
   to conflate namespaces that are relevant on the filesystem with
   namespaces that are relevant on the mount level. Especially for
   non-vfs developers without detailed knowledge in this area this was a
   potential source for bugs.

   This finishes the conversion. Instead of passing the plain namespace
   around this updates all places that currently take a pointer to a
   mnt_userns with a pointer to struct mnt_idmap.

   Now that the conversion is done all helpers down to the really
   low-level helpers only accept a struct mnt_idmap argument instead of
   two namespace arguments.

   Conflating mount and other idmappings will now cause the compiler to
   complain loudly thus eliminating the possibility of any bugs. This
   makes it impossible for filesystem developers to mix up mount and
   filesystem idmappings as they are two distinct types and require
   distinct helpers that cannot be used interchangeably.

   Everything associated with struct mnt_idmap is moved into a single
   separate file. With that change no code can poke around in struct
   mnt_idmap. It can only be interacted with through dedicated helpers.
   That means all filesystems are and all of the vfs is completely
   oblivious to the actual implementation of idmappings.

   We are now also able to extend struct mnt_idmap as we see fit. For
   example, we can decouple it completely from namespaces for users that
   don't require or don't want to use them at all. We can also extend
   the concept of idmappings so we can cover filesystem specific
   requirements.

   In combination with the vfs{g,u}id_t work we finished in v6.2 this
   makes this feature substantially more robust and thus difficult to
   implement wrong by a given filesystem and also protects the vfs.

 - Enable idmapped mounts for tmpfs and fulfill a longstanding request.

   A long-standing request from users had been to make it possible to
   create idmapped mounts for tmpfs. For example, to share the host's
   tmpfs mount between multiple sandboxes. This is a prerequisite for
   some advanced Kubernetes cases. Systemd also has a range of use-cases
   to increase service isolation. And there are more users of this.

   However, with all of the other work going on this was way down on the
   priority list but luckily someone other than ourselves picked this
   up.

   As usual the patch is tiny as all the infrastructure work had been
   done multiple kernel releases ago. In addition to all the tests that
   we already have I requested that Rodrigo add a dedicated tmpfs
   testsuite for idmapped mounts to xfstests. It is to be included into
   xfstests during the v6.3 development cycle. This should add a slew of
   additional tests.

* tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits)
  shmem: support idmapped mounts for tmpfs
  fs: move mnt_idmap
  fs: port vfs{g,u}id helpers to mnt_idmap
  fs: port fs{g,u}id helpers to mnt_idmap
  fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
  fs: port i_{g,u}id_{needs_}update() to mnt_idmap
  quota: port to mnt_idmap
  fs: port privilege checking helpers to mnt_idmap
  fs: port inode_owner_or_capable() to mnt_idmap
  fs: port inode_init_owner() to mnt_idmap
  fs: port acl to mnt_idmap
  fs: port xattr to mnt_idmap
  fs: port ->permission() to pass mnt_idmap
  fs: port ->fileattr_set() to pass mnt_idmap
  fs: port ->set_acl() to pass mnt_idmap
  fs: port ->get_acl() to pass mnt_idmap
  fs: port ->tmpfile() to pass mnt_idmap
  fs: port ->rename() to pass mnt_idmap
  fs: port ->mknod() to pass mnt_idmap
  fs: port ->mkdir() to pass mnt_idmap
  ...

293 files changed, 2154 insertions, 2000 deletions

diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index c397c51f80d9..eed551d8555f 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -139,7 +139,7 @@ struct posix_acl *v9fs_iop_get_inode_acl(struct inode *inode, int type, bool rcu
 
 }
 
-struct posix_acl *v9fs_iop_get_acl(struct user_namespace *mnt_userns,
+struct posix_acl *v9fs_iop_get_acl(struct mnt_idmap *idmap,
 				   struct dentry *dentry, int type)
 {
 	struct v9fs_session_info *v9ses;
@@ -151,7 +151,7 @@ struct posix_acl *v9fs_iop_get_acl(struct user_namespace *mnt_userns,
 	return v9fs_get_cached_acl(d_inode(dentry), type);
 }
 
-int v9fs_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int v9fs_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct posix_acl *acl, int type)
 {
 	int retval;
@@ -195,7 +195,7 @@ int v9fs_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 		goto err_out;
 	}
 
-	if (!inode_owner_or_capable(&init_user_ns, inode)) {
+	if (!inode_owner_or_capable(&nop_mnt_idmap, inode)) {
 		retval = -EPERM;
 		goto err_out;
 	}
@@ -206,7 +206,7 @@ int v9fs_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 			struct iattr iattr = {};
 			struct posix_acl *acl_mode = acl;
 
-			retval = posix_acl_update_mode(&init_user_ns, inode,
+			retval = posix_acl_update_mode(&nop_mnt_idmap, inode,
 						       &iattr.ia_mode,
 						       &acl_mode);
 			if (retval)
@@ -225,7 +225,7 @@ int v9fs_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 			 * FIXME should we update ctime ?
 			 * What is the following setxattr update the mode ?
 			 */
-			v9fs_vfs_setattr_dotl(&init_user_ns, dentry, &iattr);
+			v9fs_vfs_setattr_dotl(&nop_mnt_idmap, dentry, &iattr);
 		}
 		break;
 	case ACL_TYPE_DEFAULT:
diff --git a/fs/9p/acl.h b/fs/9p/acl.h
index 4c60a2bce5de..333cfcc281da 100644
--- a/fs/9p/acl.h
+++ b/fs/9p/acl.h
@@ -10,9 +10,9 @@
 int v9fs_get_acl(struct inode *inode, struct p9_fid *fid);
 struct posix_acl *v9fs_iop_get_inode_acl(struct inode *inode, int type,
 				   bool rcu);
-struct posix_acl *v9fs_iop_get_acl(struct user_namespace *mnt_userns,
+struct posix_acl *v9fs_iop_get_acl(struct mnt_idmap *idmap,
 					  struct dentry *dentry, int type);
-int v9fs_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int v9fs_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct posix_acl *acl, int type);
 int v9fs_acl_chmod(struct inode *inode, struct p9_fid *fid);
 int v9fs_set_create_acl(struct inode *inode, struct p9_fid *fid,
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 6acabc2e7dc9..f3f74d197b5d 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -151,7 +151,7 @@ extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 				      unsigned int flags);
 extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
 extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
-extern int v9fs_vfs_rename(struct user_namespace *mnt_userns,
+extern int v9fs_vfs_rename(struct mnt_idmap *idmap,
 			   struct inode *old_dir, struct dentry *old_dentry,
 			   struct inode *new_dir, struct dentry *new_dentry,
 			   unsigned int flags);
diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index bc417da7e9c1..75106b9f293d 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -60,7 +60,7 @@ void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
 int v9fs_uflags2omode(int uflags, int extended);
 
 void v9fs_blank_wstat(struct p9_wstat *wstat);
-int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
+int v9fs_vfs_setattr_dotl(struct mnt_idmap *idmap,
 			  struct dentry *dentry, struct iattr *iattr);
 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
 			 int datasync);
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 27a04a226d97..4344e7a7865f 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -260,7 +260,7 @@ int v9fs_init_inode(struct v9fs_session_info *v9ses,
 {
 	int err = 0;
 
-	inode_init_owner(&init_user_ns, inode, NULL, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, NULL, mode);
 	inode->i_blocks = 0;
 	inode->i_rdev = rdev;
 	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
@@ -672,7 +672,7 @@ error:
 
 /**
  * v9fs_vfs_create - VFS hook to create a regular file
- * @mnt_userns: The user namespace of the mount
+ * @idmap: idmap of the mount
  * @dir: The parent directory
  * @dentry: The name of file to be created
  * @mode: The UNIX file mode to set
@@ -684,7 +684,7 @@ error:
  */
 
 static int
-v9fs_vfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir,
 		struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
@@ -704,14 +704,14 @@ v9fs_vfs_create(struct user_namespace *mnt_userns, struct inode *dir,
 
 /**
  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
- * @mnt_userns: The user namespace of the mount
+ * @idmap: idmap of the mount
  * @dir:  inode that is being unlinked
  * @dentry: dentry that is being unlinked
  * @mode: mode for new directory
  *
  */
 
-static int v9fs_vfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			  struct dentry *dentry, umode_t mode)
 {
 	int err;
@@ -908,7 +908,7 @@ int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 
 /**
  * v9fs_vfs_rename - VFS hook to rename an inode
- * @mnt_userns: The user namespace of the mount
+ * @idmap: The idmap of the mount
  * @old_dir:  old dir inode
  * @old_dentry: old dentry
  * @new_dir: new dir inode
@@ -918,7 +918,7 @@ int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
  */
 
 int
-v9fs_vfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		struct dentry *old_dentry, struct inode *new_dir,
 		struct dentry *new_dentry, unsigned int flags)
 {
@@ -1018,7 +1018,7 @@ error:
 
 /**
  * v9fs_vfs_getattr - retrieve file metadata
- * @mnt_userns: The user namespace of the mount
+ * @idmap: idmap of the mount
  * @path: Object to query
  * @stat: metadata structure to populate
  * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
@@ -1027,7 +1027,7 @@ error:
  */
 
 static int
-v9fs_vfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+v9fs_vfs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	struct dentry *dentry = path->dentry;
@@ -1038,7 +1038,7 @@ v9fs_vfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 	v9ses = v9fs_dentry2v9ses(dentry);
 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
-		generic_fillattr(&init_user_ns, d_inode(dentry), stat);
+		generic_fillattr(&nop_mnt_idmap, d_inode(dentry), stat);
 		return 0;
 	}
 	fid = v9fs_fid_lookup(dentry);
@@ -1051,7 +1051,7 @@ v9fs_vfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 		return PTR_ERR(st);
 
 	v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
-	generic_fillattr(&init_user_ns, d_inode(dentry), stat);
+	generic_fillattr(&nop_mnt_idmap, d_inode(dentry), stat);
 
 	p9stat_free(st);
 	kfree(st);
@@ -1060,13 +1060,13 @@ v9fs_vfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 
 /**
  * v9fs_vfs_setattr - set file metadata
- * @mnt_userns: The user namespace of the mount
+ * @idmap: idmap of the mount
  * @dentry: file whose metadata to set
  * @iattr: metadata assignment structure
  *
  */
 
-static int v9fs_vfs_setattr(struct user_namespace *mnt_userns,
+static int v9fs_vfs_setattr(struct mnt_idmap *idmap,
 			    struct dentry *dentry, struct iattr *iattr)
 {
 	int retval, use_dentry = 0;
@@ -1077,7 +1077,7 @@ static int v9fs_vfs_setattr(struct user_namespace *mnt_userns,
 	struct p9_wstat wstat;
 
 	p9_debug(P9_DEBUG_VFS, "\n");
-	retval = setattr_prepare(&init_user_ns, dentry, iattr);
+	retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (retval)
 		return retval;
 
@@ -1135,7 +1135,7 @@ static int v9fs_vfs_setattr(struct user_namespace *mnt_userns,
 
 	v9fs_invalidate_inode_attr(inode);
 
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 	mark_inode_dirty(inode);
 	return 0;
 }
@@ -1300,7 +1300,7 @@ static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
 
 /**
  * v9fs_vfs_symlink - helper function to create symlinks
- * @mnt_userns: The user namespace of the mount
+ * @idmap: idmap of the mount
  * @dir: directory inode containing symlink
  * @dentry: dentry for symlink
  * @symname: symlink data
@@ -1310,7 +1310,7 @@ static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
  */
 
 static int
-v9fs_vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+v9fs_vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 		 struct dentry *dentry, const char *symname)
 {
 	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
@@ -1356,7 +1356,7 @@ v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
 
 /**
  * v9fs_vfs_mknod - create a special file
- * @mnt_userns: The user namespace of the mount
+ * @idmap: idmap of the mount
  * @dir: inode destination for new link
  * @dentry: dentry for file
  * @mode: mode for creation
@@ -1365,7 +1365,7 @@ v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
  */
 
 static int
-v9fs_vfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+v9fs_vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	       struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index f806b3f11649..3bed3eb3a0e2 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -30,7 +30,7 @@
 #include "acl.h"
 
 static int
-v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, struct inode *dir,
+v9fs_vfs_mknod_dotl(struct mnt_idmap *idmap, struct inode *dir,
 		    struct dentry *dentry, umode_t omode, dev_t rdev);
 
 /**
@@ -211,7 +211,7 @@ int v9fs_open_to_dotl_flags(int flags)
 
 /**
  * v9fs_vfs_create_dotl - VFS hook to create files for 9P2000.L protocol.
- * @mnt_userns: The user namespace of the mount
+ * @idmap: The user namespace of the mount
  * @dir: directory inode that is being created
  * @dentry:  dentry that is being deleted
  * @omode: create permissions
@@ -219,10 +219,10 @@ int v9fs_open_to_dotl_flags(int flags)
  *
  */
 static int
-v9fs_vfs_create_dotl(struct user_namespace *mnt_userns, struct inode *dir,
+v9fs_vfs_create_dotl(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry, umode_t omode, bool excl)
 {
-	return v9fs_vfs_mknod_dotl(mnt_userns, dir, dentry, omode, 0);
+	return v9fs_vfs_mknod_dotl(idmap, dir, dentry, omode, 0);
 }
 
 static int
@@ -356,14 +356,14 @@ out:
 
 /**
  * v9fs_vfs_mkdir_dotl - VFS mkdir hook to create a directory
- * @mnt_userns: The user namespace of the mount
+ * @idmap: The idmap of the mount
  * @dir:  inode that is being unlinked
  * @dentry: dentry that is being unlinked
  * @omode: mode for new directory
  *
  */
 
-static int v9fs_vfs_mkdir_dotl(struct user_namespace *mnt_userns,
+static int v9fs_vfs_mkdir_dotl(struct mnt_idmap *idmap,
 			       struct inode *dir, struct dentry *dentry,
 			       umode_t omode)
 {
@@ -450,7 +450,7 @@ error:
 }
 
 static int
-v9fs_vfs_getattr_dotl(struct user_namespace *mnt_userns,
+v9fs_vfs_getattr_dotl(struct mnt_idmap *idmap,
 		      const struct path *path, struct kstat *stat,
 		      u32 request_mask, unsigned int flags)
 {
@@ -462,7 +462,7 @@ v9fs_vfs_getattr_dotl(struct user_namespace *mnt_userns,
 	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 	v9ses = v9fs_dentry2v9ses(dentry);
 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
-		generic_fillattr(&init_user_ns, d_inode(dentry), stat);
+		generic_fillattr(&nop_mnt_idmap, d_inode(dentry), stat);
 		return 0;
 	}
 	fid = v9fs_fid_lookup(dentry);
@@ -479,7 +479,7 @@ v9fs_vfs_getattr_dotl(struct user_namespace *mnt_userns,
 		return PTR_ERR(st);
 
 	v9fs_stat2inode_dotl(st, d_inode(dentry), 0);
-	generic_fillattr(&init_user_ns, d_inode(dentry), stat);
+	generic_fillattr(&nop_mnt_idmap, d_inode(dentry), stat);
 	/* Change block size to what the server returned */
 	stat->blksize = st->st_blksize;
 
@@ -529,13 +529,13 @@ static int v9fs_mapped_iattr_valid(int iattr_valid)
 
 /**
  * v9fs_vfs_setattr_dotl - set file metadata
- * @mnt_userns: The user namespace of the mount
+ * @idmap: idmap of the mount
  * @dentry: file whose metadata to set
  * @iattr: metadata assignment structure
  *
  */
 
-int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
+int v9fs_vfs_setattr_dotl(struct mnt_idmap *idmap,
 			  struct dentry *dentry, struct iattr *iattr)
 {
 	int retval, use_dentry = 0;
@@ -548,7 +548,7 @@ int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
 
 	p9_debug(P9_DEBUG_VFS, "\n");
 
-	retval = setattr_prepare(&init_user_ns, dentry, iattr);
+	retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (retval)
 		return retval;
 
@@ -597,7 +597,7 @@ int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
 		truncate_setsize(inode, iattr->ia_size);
 
 	v9fs_invalidate_inode_attr(inode);
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 	mark_inode_dirty(inode);
 	if (iattr->ia_valid & ATTR_MODE) {
 		/* We also want to update ACL when we update mode bits */
@@ -687,7 +687,7 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
 }
 
 static int
-v9fs_vfs_symlink_dotl(struct user_namespace *mnt_userns, struct inode *dir,
+v9fs_vfs_symlink_dotl(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, const char *symname)
 {
 	int err;
@@ -817,7 +817,7 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
 
 /**
  * v9fs_vfs_mknod_dotl - create a special file
- * @mnt_userns: The user namespace of the mount
+ * @idmap: The idmap of the mount
  * @dir: inode destination for new link
  * @dentry: dentry for file
  * @omode: mode for creation
@@ -825,7 +825,7 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
  *
  */
 static int
-v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, struct inode *dir,
+v9fs_vfs_mknod_dotl(struct mnt_idmap *idmap, struct inode *dir,
 		    struct dentry *dentry, umode_t omode, dev_t rdev)
 {
 	int err;
diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c
index b6984311e00a..50f7f3f6b55e 100644
--- a/fs/9p/xattr.c
+++ b/fs/9p/xattr.c
@@ -150,7 +150,7 @@ static int v9fs_xattr_handler_get(const struct xattr_handler *handler,
 }
 
 static int v9fs_xattr_handler_set(const struct xattr_handler *handler,
-				  struct user_namespace *mnt_userns,
+				  struct mnt_idmap *idmap,
 				  struct dentry *dentry, struct inode *inode,
 				  const char *name, const void *value,
 				  size_t size, int flags)
diff --git a/fs/Makefile b/fs/Makefile
index 4dea17840761..76abc9e055bd 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -16,7 +16,7 @@ obj-y :=	open.o read_write.o file_table.o super.o \
 		pnode.o splice.o sync.o utimes.o d_path.o \
 		stack.o fs_struct.o statfs.o fs_pin.o nsfs.o \
 		fs_types.o fs_context.o fs_parser.o fsopen.o init.o \
-		kernel_read_file.o remap_range.o
+		kernel_read_file.o mnt_idmapping.o remap_range.o
 
 ifeq ($(CONFIG_BLOCK),y)
 obj-y +=	buffer.o direct-io.o mpage.o
diff --git a/fs/adfs/adfs.h b/fs/adfs/adfs.h
index 06b7c92343ad..223f0283d20f 100644
--- a/fs/adfs/adfs.h
+++ b/fs/adfs/adfs.h
@@ -144,7 +144,7 @@ struct adfs_discmap {
 /* Inode stuff */
 struct inode *adfs_iget(struct super_block *sb, struct object_info *obj);
 int adfs_write_inode(struct inode *inode, struct writeback_control *wbc);
-int adfs_notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
+int adfs_notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
 		       struct iattr *attr);
 
 /* map.c */
diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c
index ee22278b0cfc..c3ac613d0975 100644
--- a/fs/adfs/inode.c
+++ b/fs/adfs/inode.c
@@ -294,7 +294,7 @@ out:
  * later.
  */
 int
-adfs_notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
+adfs_notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
 		   struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -302,7 +302,7 @@ adfs_notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
 	unsigned int ia_valid = attr->ia_valid;
 	int error;
 	
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 
 	/*
 	 * we can't change the UID or GID of any file -
diff --git a/fs/affs/affs.h b/fs/affs/affs.h
index bfa89e131ead..60685ec76d98 100644
--- a/fs/affs/affs.h
+++ b/fs/affs/affs.h
@@ -167,17 +167,17 @@ extern const struct export_operations affs_export_ops;
 extern int	affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len);
 extern struct dentry *affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int);
 extern int	affs_unlink(struct inode *dir, struct dentry *dentry);
-extern int	affs_create(struct user_namespace *mnt_userns, struct inode *dir,
+extern int	affs_create(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, umode_t mode, bool);
-extern int	affs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+extern int	affs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, umode_t mode);
 extern int	affs_rmdir(struct inode *dir, struct dentry *dentry);
 extern int	affs_link(struct dentry *olddentry, struct inode *dir,
 			  struct dentry *dentry);
-extern int	affs_symlink(struct user_namespace *mnt_userns,
+extern int	affs_symlink(struct mnt_idmap *idmap,
 			struct inode *dir, struct dentry *dentry,
 			const char *symname);
-extern int	affs_rename2(struct user_namespace *mnt_userns,
+extern int	affs_rename2(struct mnt_idmap *idmap,
 			struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags);
@@ -185,7 +185,7 @@ extern int	affs_rename2(struct user_namespace *mnt_userns,
 /* inode.c */
 
 extern struct inode		*affs_new_inode(struct inode *dir);
-extern int			 affs_notify_change(struct user_namespace *mnt_userns,
+extern int			 affs_notify_change(struct mnt_idmap *idmap,
 					struct dentry *dentry, struct iattr *attr);
 extern void			 affs_evict_inode(struct inode *inode);
 extern struct inode		*affs_iget(struct super_block *sb,
diff --git a/fs/affs/inode.c b/fs/affs/inode.c
index 2352a75bd9d6..27f77a52c5c8 100644
--- a/fs/affs/inode.c
+++ b/fs/affs/inode.c
@@ -216,7 +216,7 @@ affs_write_inode(struct inode *inode, struct writeback_control *wbc)
 }
 
 int
-affs_notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
+affs_notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
 		   struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -224,7 +224,7 @@ affs_notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 	pr_debug("notify_change(%lu,0x%x)\n", inode->i_ino, attr->ia_valid);
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		goto out;
 
@@ -250,7 +250,7 @@ affs_notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
 		affs_truncate(inode);
 	}
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 
 	if (attr->ia_valid & ATTR_MODE)
diff --git a/fs/affs/namei.c b/fs/affs/namei.c
index bcab18956b4f..d12ccfd2a83d 100644
--- a/fs/affs/namei.c
+++ b/fs/affs/namei.c
@@ -242,7 +242,7 @@ affs_unlink(struct inode *dir, struct dentry *dentry)
 }
 
 int
-affs_create(struct user_namespace *mnt_userns, struct inode *dir,
+affs_create(struct mnt_idmap *idmap, struct inode *dir,
 	    struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct super_block *sb = dir->i_sb;
@@ -274,7 +274,7 @@ affs_create(struct user_namespace *mnt_userns, struct inode *dir,
 }
 
 int
-affs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+affs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	   struct dentry *dentry, umode_t mode)
 {
 	struct inode		*inode;
@@ -313,7 +313,7 @@ affs_rmdir(struct inode *dir, struct dentry *dentry)
 }
 
 int
-affs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+affs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 	     struct dentry *dentry, const char *symname)
 {
 	struct super_block	*sb = dir->i_sb;
@@ -503,7 +503,7 @@ done:
 	return retval;
 }
 
-int affs_rename2(struct user_namespace *mnt_userns, struct inode *old_dir,
+int affs_rename2(struct mnt_idmap *idmap, struct inode *old_dir,
 		 struct dentry *old_dentry, struct inode *new_dir,
 		 struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index b7c1f8c84b38..82690d1dd49a 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -28,17 +28,17 @@ static bool afs_lookup_one_filldir(struct dir_context *ctx, const char *name, in
 				  loff_t fpos, u64 ino, unsigned dtype);
 static bool afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen,
 			      loff_t fpos, u64 ino, unsigned dtype);
-static int afs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int afs_create(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, bool excl);
-static int afs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int afs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry, umode_t mode);
 static int afs_rmdir(struct inode *dir, struct dentry *dentry);
 static int afs_unlink(struct inode *dir, struct dentry *dentry);
 static int afs_link(struct dentry *from, struct inode *dir,
 		    struct dentry *dentry);
-static int afs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int afs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, const char *content);
-static int afs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int afs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		      struct dentry *old_dentry, struct inode *new_dir,
 		      struct dentry *new_dentry, unsigned int flags);
 static bool afs_dir_release_folio(struct folio *folio, gfp_t gfp_flags);
@@ -1332,7 +1332,7 @@ static const struct afs_operation_ops afs_mkdir_operation = {
 /*
  * create a directory on an AFS filesystem
  */
-static int afs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int afs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry, umode_t mode)
 {
 	struct afs_operation *op;
@@ -1630,7 +1630,7 @@ static const struct afs_operation_ops afs_create_operation = {
 /*
  * create a regular file on an AFS filesystem
  */
-static int afs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int afs_create(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct afs_operation *op;
@@ -1760,7 +1760,7 @@ static const struct afs_operation_ops afs_symlink_operation = {
 /*
  * create a symlink in an AFS filesystem
  */
-static int afs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int afs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, const char *content)
 {
 	struct afs_operation *op;
@@ -1897,7 +1897,7 @@ static const struct afs_operation_ops afs_rename_operation = {
 /*
  * rename a file in an AFS filesystem and/or move it between directories
  */
-static int afs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int afs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		      struct dentry *old_dentry, struct inode *new_dir,
 		      struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 6d3a3dbe4928..0167e96e5198 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -737,7 +737,7 @@ error_unlock:
 /*
  * read the attributes of an inode
  */
-int afs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int afs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
@@ -761,7 +761,7 @@ int afs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 
 	do {
 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
-		generic_fillattr(&init_user_ns, inode, stat);
+		generic_fillattr(&nop_mnt_idmap, inode, stat);
 		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
 		    stat->nlink > 0)
 			stat->nlink -= 1;
@@ -870,7 +870,7 @@ static const struct afs_operation_ops afs_setattr_operation = {
 /*
  * set the attributes of an inode
  */
-int afs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int afs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct iattr *attr)
 {
 	const unsigned int supported =
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 2d6d7dae225a..ad8523d0d038 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -1171,9 +1171,9 @@ extern struct inode *afs_iget(struct afs_operation *, struct afs_vnode_param *);
 extern struct inode *afs_root_iget(struct super_block *, struct key *);
 extern bool afs_check_validity(struct afs_vnode *);
 extern int afs_validate(struct afs_vnode *, struct key *);
-extern int afs_getattr(struct user_namespace *mnt_userns, const struct path *,
+extern int afs_getattr(struct mnt_idmap *idmap, const struct path *,
 		       struct kstat *, u32, unsigned int);
-extern int afs_setattr(struct user_namespace *mnt_userns, struct dentry *, struct iattr *);
+extern int afs_setattr(struct mnt_idmap *idmap, struct dentry *, struct iattr *);
 extern void afs_evict_inode(struct inode *);
 extern int afs_drop_inode(struct inode *);
 
@@ -1388,7 +1388,7 @@ extern void afs_cache_permit(struct afs_vnode *, struct key *, unsigned int,
 extern struct key *afs_request_key(struct afs_cell *);
 extern struct key *afs_request_key_rcu(struct afs_cell *);
 extern int afs_check_permit(struct afs_vnode *, struct key *, afs_access_t *);
-extern int afs_permission(struct user_namespace *, struct inode *, int);
+extern int afs_permission(struct mnt_idmap *, struct inode *, int);
 extern void __exit afs_clean_up_permit_cache(void);
 
 /*
diff --git a/fs/afs/security.c b/fs/afs/security.c
index 7c6a63a30394..6a7744c9e2a2 100644
--- a/fs/afs/security.c
+++ b/fs/afs/security.c
@@ -395,7 +395,7 @@ int afs_check_permit(struct afs_vnode *vnode, struct key *key,
  * - AFS ACLs are attached to directories only, and a file is controlled by its
  *   parent directory's ACL
  */
-int afs_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int afs_permission(struct mnt_idmap *idmap, struct inode *inode,
 		   int mask)
 {
 	struct afs_vnode *vnode = AFS_FS_I(inode);
diff --git a/fs/afs/xattr.c b/fs/afs/xattr.c
index 7751b0b3f81d..9048d8ccc715 100644
--- a/fs/afs/xattr.c
+++ b/fs/afs/xattr.c
@@ -97,7 +97,7 @@ static const struct afs_operation_ops afs_store_acl_operation = {
  * Set a file's AFS3 ACL.
  */
 static int afs_xattr_set_acl(const struct xattr_handler *handler,
-			     struct user_namespace *mnt_userns,
+			     struct mnt_idmap *idmap,
                              struct dentry *dentry,
                              struct inode *inode, const char *name,
                              const void *buffer, size_t size, int flags)
@@ -228,7 +228,7 @@ static const struct afs_operation_ops yfs_store_opaque_acl2_operation = {
  * Set a file's YFS ACL.
  */
 static int afs_xattr_set_yfs(const struct xattr_handler *handler,
-			     struct user_namespace *mnt_userns,
+			     struct mnt_idmap *idmap,
                              struct dentry *dentry,
                              struct inode *inode, const char *name,
                              const void *buffer, size_t size, int flags)
diff --git a/fs/attr.c b/fs/attr.c
index f3eb8e57b451..aca9ff7aed33 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -24,7 +24,7 @@
 /**
  * setattr_should_drop_sgid - determine whether the setgid bit needs to be
  *                            removed
- * @mnt_userns:	user namespace of the mount @inode was found from
+ * @idmap:	idmap of the mount @inode was found from
  * @inode:	inode to check
  *
  * This function determines whether the setgid bit needs to be removed.
@@ -34,7 +34,7 @@
  *
  * Return: ATTR_KILL_SGID if setgid bit needs to be removed, 0 otherwise.
  */
-int setattr_should_drop_sgid(struct user_namespace *mnt_userns,
+int setattr_should_drop_sgid(struct mnt_idmap *idmap,
 			     const struct inode *inode)
 {
 	umode_t mode = inode->i_mode;
@@ -43,8 +43,7 @@ int setattr_should_drop_sgid(struct user_namespace *mnt_userns,
 		return 0;
 	if (mode & S_IXGRP)
 		return ATTR_KILL_SGID;
-	if (!in_group_or_capable(mnt_userns, inode,
-				 i_gid_into_vfsgid(mnt_userns, inode)))
+	if (!in_group_or_capable(idmap, inode, i_gid_into_vfsgid(idmap, inode)))
 		return ATTR_KILL_SGID;
 	return 0;
 }
@@ -52,7 +51,7 @@ int setattr_should_drop_sgid(struct user_namespace *mnt_userns,
 /**
  * setattr_should_drop_suidgid - determine whether the set{g,u}id bit needs to
  *                               be dropped
- * @mnt_userns:	user namespace of the mount @inode was found from
+ * @idmap:	idmap of the mount @inode was found from
  * @inode:	inode to check
  *
  * This function determines whether the set{g,u}id bits need to be removed.
@@ -64,7 +63,7 @@ int setattr_should_drop_sgid(struct user_namespace *mnt_userns,
  * Return: A mask of ATTR_KILL_S{G,U}ID indicating which - if any - setid bits
  * to remove, 0 otherwise.
  */
-int setattr_should_drop_suidgid(struct user_namespace *mnt_userns,
+int setattr_should_drop_suidgid(struct mnt_idmap *idmap,
 				struct inode *inode)
 {
 	umode_t mode = inode->i_mode;
@@ -74,7 +73,7 @@ int setattr_should_drop_suidgid(struct user_namespace *mnt_userns,
 	if (unlikely(mode & S_ISUID))
 		kill = ATTR_KILL_SUID;
 
-	kill |= setattr_should_drop_sgid(mnt_userns, inode);
+	kill |= setattr_should_drop_sgid(idmap, inode);
 
 	if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))
 		return kill;
@@ -85,24 +84,24 @@ EXPORT_SYMBOL(setattr_should_drop_suidgid);
 
 /**
  * chown_ok - verify permissions to chown inode
- * @mnt_userns:	user namespace of the mount @inode was found from
+ * @idmap:	idmap of the mount @inode was found from
  * @inode:	inode to check permissions on
  * @ia_vfsuid:	uid to chown @inode to
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then
- * take care to map the inode according to @mnt_userns before checking
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then
+ * take care to map the inode according to @idmap before checking
  * permissions. On non-idmapped mounts or if permission checking is to be
- * performed on the raw inode simply passs init_user_ns.
+ * performed on the raw inode simply pass @nop_mnt_idmap.
  */
-static bool chown_ok(struct user_namespace *mnt_userns,
+static bool chown_ok(struct mnt_idmap *idmap,
 		     const struct inode *inode, vfsuid_t ia_vfsuid)
 {
-	vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
+	vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
 	if (vfsuid_eq_kuid(vfsuid, current_fsuid()) &&
 	    vfsuid_eq(ia_vfsuid, vfsuid))
 		return true;
-	if (capable_wrt_inode_uidgid(mnt_userns, inode, CAP_CHOWN))
+	if (capable_wrt_inode_uidgid(idmap, inode, CAP_CHOWN))
 		return true;
 	if (!vfsuid_valid(vfsuid) &&
 	    ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
@@ -112,28 +111,28 @@ static bool chown_ok(struct user_namespace *mnt_userns,
 
 /**
  * chgrp_ok - verify permissions to chgrp inode
- * @mnt_userns:	user namespace of the mount @inode was found from
+ * @idmap:	idmap of the mount @inode was found from
  * @inode:	inode to check permissions on
  * @ia_vfsgid:	gid to chown @inode to
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then
- * take care to map the inode according to @mnt_userns before checking
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then
+ * take care to map the inode according to @idmap before checking
  * permissions. On non-idmapped mounts or if permission checking is to be
- * performed on the raw inode simply passs init_user_ns.
+ * performed on the raw inode simply pass @nop_mnt_idmap.
  */
-static bool chgrp_ok(struct user_namespace *mnt_userns,
+static bool chgrp_ok(struct mnt_idmap *idmap,
 		     const struct inode *inode, vfsgid_t ia_vfsgid)
 {
-	vfsgid_t vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
-	vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
+	vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
+	vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
 	if (vfsuid_eq_kuid(vfsuid, current_fsuid())) {
 		if (vfsgid_eq(ia_vfsgid, vfsgid))
 			return true;
 		if (vfsgid_in_group_p(ia_vfsgid))
 			return true;
 	}
-	if (capable_wrt_inode_uidgid(mnt_userns, inode, CAP_CHOWN))
+	if (capable_wrt_inode_uidgid(idmap, inode, CAP_CHOWN))
 		return true;
 	if (!vfsgid_valid(vfsgid) &&
 	    ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
@@ -143,7 +142,7 @@ static bool chgrp_ok(struct user_namespace *mnt_userns,
 
 /**
  * setattr_prepare - check if attribute changes to a dentry are allowed
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dentry:	dentry to check
  * @attr:	attributes to change
  *
@@ -153,16 +152,16 @@ static bool chgrp_ok(struct user_namespace *mnt_userns,
  * SGID bit from mode if user is not allowed to set it. Also file capabilities
  * and IMA extended attributes are cleared if ATTR_KILL_PRIV is set.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then
- * take care to map the inode according to @mnt_userns before checking
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then
+ * take care to map the inode according to @idmap before checking
  * permissions. On non-idmapped mounts or if permission checking is to be
- * performed on the raw inode simply passs init_user_ns.
+ * performed on the raw inode simply passs @nop_mnt_idmap.
  *
  * Should be called as the first thing in ->setattr implementations,
  * possibly after taking additional locks.
  */
-int setattr_prepare(struct user_namespace *mnt_userns, struct dentry *dentry,
+int setattr_prepare(struct mnt_idmap *idmap, struct dentry *dentry,
 		    struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -184,34 +183,34 @@ int setattr_prepare(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 	/* Make sure a caller can chown. */
 	if ((ia_valid & ATTR_UID) &&
-	    !chown_ok(mnt_userns, inode, attr->ia_vfsuid))
+	    !chown_ok(idmap, inode, attr->ia_vfsuid))
 		return -EPERM;
 
 	/* Make sure caller can chgrp. */
 	if ((ia_valid & ATTR_GID) &&
-	    !chgrp_ok(mnt_userns, inode, attr->ia_vfsgid))
+	    !chgrp_ok(idmap, inode, attr->ia_vfsgid))
 		return -EPERM;
 
 	/* Make sure a caller can chmod. */
 	if (ia_valid & ATTR_MODE) {
 		vfsgid_t vfsgid;
 
-		if (!inode_owner_or_capable(mnt_userns, inode))
+		if (!inode_owner_or_capable(idmap, inode))
 			return -EPERM;
 
 		if (ia_valid & ATTR_GID)
 			vfsgid = attr->ia_vfsgid;
 		else
-			vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
+			vfsgid = i_gid_into_vfsgid(idmap, inode);
 
 		/* Also check the setgid bit! */
-		if (!in_group_or_capable(mnt_userns, inode, vfsgid))
+		if (!in_group_or_capable(idmap, inode, vfsgid))
 			attr->ia_mode &= ~S_ISGID;
 	}
 
 	/* Check for setting the inode time. */
 	if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) {
-		if (!inode_owner_or_capable(mnt_userns, inode))
+		if (!inode_owner_or_capable(idmap, inode))
 			return -EPERM;
 	}
 
@@ -220,7 +219,7 @@ kill_priv:
 	if (ia_valid & ATTR_KILL_PRIV) {
 		int error;
 
-		error = security_inode_killpriv(mnt_userns, dentry);
+		error = security_inode_killpriv(idmap, dentry);
 		if (error)
 			return error;
 	}
@@ -277,7 +276,7 @@ EXPORT_SYMBOL(inode_newsize_ok);
 
 /**
  * setattr_copy - copy simple metadata updates into the generic inode
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @inode:	the inode to be updated
  * @attr:	the new attributes
  *
@@ -290,23 +289,23 @@ EXPORT_SYMBOL(inode_newsize_ok);
  * Noticeably missing is inode size update, which is more complex
  * as it requires pagecache updates.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then
- * take care to map the inode according to @mnt_userns before checking
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then
+ * take care to map the inode according to @idmap before checking
  * permissions. On non-idmapped mounts or if permission checking is to be
- * performed on the raw inode simply passs init_user_ns.
+ * performed on the raw inode simply pass @nop_mnt_idmap.
  *
  * The inode is not marked as dirty after this operation. The rationale is
  * that for "simple" filesystems, the struct inode is the inode storage.
  * The caller is free to mark the inode dirty afterwards if needed.
  */
-void setattr_copy(struct user_namespace *mnt_userns, struct inode *inode,
+void setattr_copy(struct mnt_idmap *idmap, struct inode *inode,
 		  const struct iattr *attr)
 {
 	unsigned int ia_valid = attr->ia_valid;
 
-	i_uid_update(mnt_userns, attr, inode);
-	i_gid_update(mnt_userns, attr, inode);
+	i_uid_update(idmap, attr, inode);
+	i_gid_update(idmap, attr, inode);
 	if (ia_valid & ATTR_ATIME)
 		inode->i_atime = attr->ia_atime;
 	if (ia_valid & ATTR_MTIME)
@@ -315,15 +314,15 @@ void setattr_copy(struct user_namespace *mnt_userns, struct inode *inode,
 		inode->i_ctime = attr->ia_ctime;
 	if (ia_valid & ATTR_MODE) {
 		umode_t mode = attr->ia_mode;
-		if (!in_group_or_capable(mnt_userns, inode,
-					 i_gid_into_vfsgid(mnt_userns, inode)))
+		if (!in_group_or_capable(idmap, inode,
+					 i_gid_into_vfsgid(idmap, inode)))
 			mode &= ~S_ISGID;
 		inode->i_mode = mode;
 	}
 }
 EXPORT_SYMBOL(setattr_copy);
 
-int may_setattr(struct user_namespace *mnt_userns, struct inode *inode,
+int may_setattr(struct mnt_idmap *idmap, struct inode *inode,
 		unsigned int ia_valid)
 {
 	int error;
@@ -341,8 +340,8 @@ int may_setattr(struct user_namespace *mnt_userns, struct inode *inode,
 		if (IS_IMMUTABLE(inode))
 			return -EPERM;
 
-		if (!inode_owner_or_capable(mnt_userns, inode)) {
-			error = inode_permission(mnt_userns, inode, MAY_WRITE);
+		if (!inode_owner_or_capable(idmap, inode)) {
+			error = inode_permission(idmap, inode, MAY_WRITE);
 			if (error)
 				return error;
 		}
@@ -353,7 +352,7 @@ EXPORT_SYMBOL(may_setattr);
 
 /**
  * notify_change - modify attributes of a filesytem object
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dentry:	object affected
  * @attr:	new attributes
  * @delegated_inode: returns inode, if the inode is delegated
@@ -372,13 +371,13 @@ EXPORT_SYMBOL(may_setattr);
  * the file open for write, as there can be no conflicting delegation in
  * that case.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then
- * take care to map the inode according to @mnt_userns before checking
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then
+ * take care to map the inode according to @idmap before checking
  * permissions. On non-idmapped mounts or if permission checking is to be
- * performed on the raw inode simply passs init_user_ns.
+ * performed on the raw inode simply pass @nop_mnt_idmap.
  */
-int notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
+int notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr, struct inode **delegated_inode)
 {
 	struct inode *inode = dentry->d_inode;
@@ -389,7 +388,7 @@ int notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 	WARN_ON_ONCE(!inode_is_locked(inode));
 
-	error = may_setattr(mnt_userns, inode, ia_valid);
+	error = may_setattr(idmap, inode, ia_valid);
 	if (error)
 		return error;
 
@@ -454,11 +453,11 @@ int notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
 	 * namespace of the superblock.
 	 */
 	if (ia_valid & ATTR_UID &&
-	    !vfsuid_has_fsmapping(mnt_userns, inode->i_sb->s_user_ns,
+	    !vfsuid_has_fsmapping(idmap, inode->i_sb->s_user_ns,
 				  attr->ia_vfsuid))
 		return -EOVERFLOW;
 	if (ia_valid & ATTR_GID &&
-	    !vfsgid_has_fsmapping(mnt_userns, inode->i_sb->s_user_ns,
+	    !vfsgid_has_fsmapping(idmap, inode->i_sb->s_user_ns,
 				  attr->ia_vfsgid))
 		return -EOVERFLOW;
 
@@ -466,13 +465,13 @@ int notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
 	 * gids unless those uids & gids are being made valid.
 	 */
 	if (!(ia_valid & ATTR_UID) &&
-	    !vfsuid_valid(i_uid_into_vfsuid(mnt_userns, inode)))
+	    !vfsuid_valid(i_uid_into_vfsuid(idmap, inode)))
 		return -EOVERFLOW;
 	if (!(ia_valid & ATTR_GID) &&
-	    !vfsgid_valid(i_gid_into_vfsgid(mnt_userns, inode)))
+	    !vfsgid_valid(i_gid_into_vfsgid(idmap, inode)))
 		return -EOVERFLOW;
 
-	error = security_inode_setattr(mnt_userns, dentry, attr);
+	error = security_inode_setattr(idmap, dentry, attr);
 	if (error)
 		return error;
 	error = try_break_deleg(inode, delegated_inode);
@@ -480,13 +479,13 @@ int notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
 		return error;
 
 	if (inode->i_op->setattr)
-		error = inode->i_op->setattr(mnt_userns, dentry, attr);
+		error = inode->i_op->setattr(idmap, dentry, attr);
 	else
-		error = simple_setattr(mnt_userns, dentry, attr);
+		error = simple_setattr(idmap, dentry, attr);
 
 	if (!error) {
 		fsnotify_change(dentry, ia_valid);
-		ima_inode_post_setattr(mnt_userns, dentry);
+		ima_inode_post_setattr(idmap, dentry);
 		evm_inode_post_setattr(dentry, ia_valid);
 	}
 
diff --git a/fs/autofs/root.c b/fs/autofs/root.c
index ca03c1cae2be..6baf90b08e0e 100644
--- a/fs/autofs/root.c
+++ b/fs/autofs/root.c
@@ -10,12 +10,12 @@
 
 #include "autofs_i.h"
 
-static int autofs_dir_permission(struct user_namespace *, struct inode *, int);
-static int autofs_dir_symlink(struct user_namespace *, struct inode *,
+static int autofs_dir_permission(struct mnt_idmap *, struct inode *, int);
+static int autofs_dir_symlink(struct mnt_idmap *, struct inode *,
 			      struct dentry *, const char *);
 static int autofs_dir_unlink(struct inode *, struct dentry *);
 static int autofs_dir_rmdir(struct inode *, struct dentry *);
-static int autofs_dir_mkdir(struct user_namespace *, struct inode *,
+static int autofs_dir_mkdir(struct mnt_idmap *, struct inode *,
 			    struct dentry *, umode_t);
 static long autofs_root_ioctl(struct file *, unsigned int, unsigned long);
 #ifdef CONFIG_COMPAT
@@ -543,7 +543,7 @@ static struct dentry *autofs_lookup(struct inode *dir,
 	return NULL;
 }
 
-static int autofs_dir_permission(struct user_namespace *mnt_userns,
+static int autofs_dir_permission(struct mnt_idmap *idmap,
 				 struct inode *inode, int mask)
 {
 	if (mask & MAY_WRITE) {
@@ -560,10 +560,10 @@ static int autofs_dir_permission(struct user_namespace *mnt_userns,
 			return -EACCES;
 	}
 
-	return generic_permission(mnt_userns, inode, mask);
+	return generic_permission(idmap, inode, mask);
 }
 
-static int autofs_dir_symlink(struct user_namespace *mnt_userns,
+static int autofs_dir_symlink(struct mnt_idmap *idmap,
 			      struct inode *dir, struct dentry *dentry,
 			      const char *symname)
 {
@@ -720,7 +720,7 @@ static int autofs_dir_rmdir(struct inode *dir, struct dentry *dentry)
 	return 0;
 }
 
-static int autofs_dir_mkdir(struct user_namespace *mnt_userns,
+static int autofs_dir_mkdir(struct mnt_idmap *idmap,
 			    struct inode *dir, struct dentry *dentry,
 			    umode_t mode)
 {
diff --git a/fs/bad_inode.c b/fs/bad_inode.c
index 92737166203f..db649487d58c 100644
--- a/fs/bad_inode.c
+++ b/fs/bad_inode.c
@@ -27,7 +27,7 @@ static const struct file_operations bad_file_ops =
 	.open		= bad_file_open,
 };
 
-static int bad_inode_create(struct user_namespace *mnt_userns,
+static int bad_inode_create(struct mnt_idmap *idmap,
 			    struct inode *dir, struct dentry *dentry,
 			    umode_t mode, bool excl)
 {
@@ -51,14 +51,14 @@ static int bad_inode_unlink(struct inode *dir, struct dentry *dentry)
 	return -EIO;
 }
 
-static int bad_inode_symlink(struct user_namespace *mnt_userns,
+static int bad_inode_symlink(struct mnt_idmap *idmap,
 			     struct inode *dir, struct dentry *dentry,
 			     const char *symname)
 {
 	return -EIO;
 }
 
-static int bad_inode_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int bad_inode_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			   struct dentry *dentry, umode_t mode)
 {
 	return -EIO;
@@ -69,13 +69,13 @@ static int bad_inode_rmdir (struct inode *dir, struct dentry *dentry)
 	return -EIO;
 }
 
-static int bad_inode_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int bad_inode_mknod(struct mnt_idmap *idmap, struct inode *dir,
 			   struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	return -EIO;
 }
 
-static int bad_inode_rename2(struct user_namespace *mnt_userns,
+static int bad_inode_rename2(struct mnt_idmap *idmap,
 			     struct inode *old_dir, struct dentry *old_dentry,
 			     struct inode *new_dir, struct dentry *new_dentry,
 			     unsigned int flags)
@@ -89,20 +89,20 @@ static int bad_inode_readlink(struct dentry *dentry, char __user *buffer,
 	return -EIO;
 }
 
-static int bad_inode_permission(struct user_namespace *mnt_userns,
+static int bad_inode_permission(struct mnt_idmap *idmap,
 				struct inode *inode, int mask)
 {
 	return -EIO;
 }
 
-static int bad_inode_getattr(struct user_namespace *mnt_userns,
+static int bad_inode_getattr(struct mnt_idmap *idmap,
 			     const struct path *path, struct kstat *stat,
 			     u32 request_mask, unsigned int query_flags)
 {
 	return -EIO;
 }
 
-static int bad_inode_setattr(struct user_namespace *mnt_userns,
+static int bad_inode_setattr(struct mnt_idmap *idmap,
 			     struct dentry *direntry, struct iattr *attrs)
 {
 	return -EIO;
@@ -146,14 +146,14 @@ static int bad_inode_atomic_open(struct inode *inode, struct dentry *dentry,
 	return -EIO;
 }
 
-static int bad_inode_tmpfile(struct user_namespace *mnt_userns,
+static int bad_inode_tmpfile(struct mnt_idmap *idmap,
 			     struct inode *inode, struct file *file,
 			     umode_t mode)
 {
 	return -EIO;
 }
 
-static int bad_inode_set_acl(struct user_namespace *mnt_userns,
+static int bad_inode_set_acl(struct mnt_idmap *idmap,
 			     struct dentry *dentry, struct posix_acl *acl,
 			     int type)
 {
diff --git a/fs/bfs/dir.c b/fs/bfs/dir.c
index 34d4f68f786b..040d5140e426 100644
--- a/fs/bfs/dir.c
+++ b/fs/bfs/dir.c
@@ -75,7 +75,7 @@ const struct file_operations bfs_dir_operations = {
 	.llseek		= generic_file_llseek,
 };
 
-static int bfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int bfs_create(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, bool excl)
 {
 	int err;
@@ -96,7 +96,7 @@ static int bfs_create(struct user_namespace *mnt_userns, struct inode *dir,
 	}
 	set_bit(ino, info->si_imap);
 	info->si_freei--;
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 	inode->i_blocks = 0;
 	inode->i_op = &bfs_file_inops;
@@ -199,7 +199,7 @@ out_brelse:
 	return error;
 }
 
-static int bfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int bfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		      struct dentry *old_dentry, struct inode *new_dir,
 		      struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 3da1779e8b79..7427449a04a3 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -110,7 +110,7 @@ out:
 	return ret;
 }
 
-int btrfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int btrfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct posix_acl *acl, int type)
 {
 	int ret;
@@ -118,7 +118,7 @@ int btrfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 	umode_t old_mode = inode->i_mode;
 
 	if (type == ACL_TYPE_ACCESS && acl) {
-		ret = posix_acl_update_mode(mnt_userns, inode,
+		ret = posix_acl_update_mode(idmap, inode,
 					    &inode->i_mode, &acl);
 		if (ret)
 			return ret;
diff --git a/fs/btrfs/acl.h b/fs/btrfs/acl.h
index 39bd36e6eeb7..a270e71ec05f 100644
--- a/fs/btrfs/acl.h
+++ b/fs/btrfs/acl.h
@@ -6,7 +6,7 @@
 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 
 struct posix_acl *btrfs_get_acl(struct inode *inode, int type, bool rcu);
-int btrfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int btrfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct posix_acl *acl, int type);
 int __btrfs_set_acl(struct btrfs_trans_handle *trans, struct inode *inode,
 		    struct posix_acl *acl, int type);
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 195c09e20609..7c1527fcc7b3 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -469,7 +469,7 @@ int btrfs_new_inode_prepare(struct btrfs_new_inode_args *args,
 int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
 			   struct btrfs_new_inode_args *args);
 void btrfs_new_inode_args_destroy(struct btrfs_new_inode_args *args);
-struct inode *btrfs_new_subvol_inode(struct user_namespace *mnt_userns,
+struct inode *btrfs_new_subvol_inode(struct mnt_idmap *idmap,
 				     struct inode *dir);
  void btrfs_set_delalloc_extent(struct btrfs_inode *inode, struct extent_state *state,
 			        u32 bits);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 98a800b8bd43..efee6d35af52 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5281,7 +5281,7 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr)
 	return ret;
 }
 
-static int btrfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+static int btrfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 			 struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -5291,7 +5291,7 @@ static int btrfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentr
 	if (btrfs_root_readonly(root))
 		return -EROFS;
 
-	err = setattr_prepare(mnt_userns, dentry, attr);
+	err = setattr_prepare(idmap, dentry, attr);
 	if (err)
 		return err;
 
@@ -5302,12 +5302,12 @@ static int btrfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentr
 	}
 
 	if (attr->ia_valid) {
-		setattr_copy(mnt_userns, inode, attr);
+		setattr_copy(idmap, inode, attr);
 		inode_inc_iversion(inode);
 		err = btrfs_dirty_inode(BTRFS_I(inode));
 
 		if (!err && attr->ia_valid & ATTR_MODE)
-			err = posix_acl_chmod(mnt_userns, dentry, inode->i_mode);
+			err = posix_acl_chmod(idmap, dentry, inode->i_mode);
 	}
 
 	return err;
@@ -6724,7 +6724,7 @@ out_inode:
 	return err;
 }
 
-static int btrfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int btrfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct inode *inode;
@@ -6732,13 +6732,13 @@ static int btrfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	inode = new_inode(dir->i_sb);
 	if (!inode)
 		return -ENOMEM;
-	inode_init_owner(mnt_userns, inode, dir, mode);
+	inode_init_owner(idmap, inode, dir, mode);
 	inode->i_op = &btrfs_special_inode_operations;
 	init_special_inode(inode, inode->i_mode, rdev);
 	return btrfs_create_common(dir, dentry, inode);
 }
 
-static int btrfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int btrfs_create(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct inode *inode;
@@ -6746,7 +6746,7 @@ static int btrfs_create(struct user_namespace *mnt_userns, struct inode *dir,
 	inode = new_inode(dir->i_sb);
 	if (!inode)
 		return -ENOMEM;
-	inode_init_owner(mnt_userns, inode, dir, mode);
+	inode_init_owner(idmap, inode, dir, mode);
 	inode->i_fop = &btrfs_file_operations;
 	inode->i_op = &btrfs_file_inode_operations;
 	inode->i_mapping->a_ops = &btrfs_aops;
@@ -6837,7 +6837,7 @@ fail:
 	return err;
 }
 
-static int btrfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int btrfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode;
@@ -6845,7 +6845,7 @@ static int btrfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 	inode = new_inode(dir->i_sb);
 	if (!inode)
 		return -ENOMEM;
-	inode_init_owner(mnt_userns, inode, dir, S_IFDIR | mode);
+	inode_init_owner(idmap, inode, dir, S_IFDIR | mode);
 	inode->i_op = &btrfs_dir_inode_operations;
 	inode->i_fop = &btrfs_dir_file_operations;
 	return btrfs_create_common(dir, dentry, inode);
@@ -8802,7 +8802,7 @@ out:
 	return ret;
 }
 
-struct inode *btrfs_new_subvol_inode(struct user_namespace *mnt_userns,
+struct inode *btrfs_new_subvol_inode(struct mnt_idmap *idmap,
 				     struct inode *dir)
 {
 	struct inode *inode;
@@ -8813,7 +8813,7 @@ struct inode *btrfs_new_subvol_inode(struct user_namespace *mnt_userns,
 		 * Subvolumes don't inherit the sgid bit or the parent's gid if
 		 * the parent's sgid bit is set. This is probably a bug.
 		 */
-		inode_init_owner(mnt_userns, inode, NULL,
+		inode_init_owner(idmap, inode, NULL,
 				 S_IFDIR | (~current_umask() & S_IRWXUGO));
 		inode->i_op = &btrfs_dir_inode_operations;
 		inode->i_fop = &btrfs_dir_file_operations;
@@ -9004,7 +9004,7 @@ fail:
 	return -ENOMEM;
 }
 
-static int btrfs_getattr(struct user_namespace *mnt_userns,
+static int btrfs_getattr(struct mnt_idmap *idmap,
 			 const struct path *path, struct kstat *stat,
 			 u32 request_mask, unsigned int flags)
 {
@@ -9034,7 +9034,7 @@ static int btrfs_getattr(struct user_namespace *mnt_userns,
 				  STATX_ATTR_IMMUTABLE |
 				  STATX_ATTR_NODUMP);
 
-	generic_fillattr(mnt_userns, inode, stat);
+	generic_fillattr(idmap, inode, stat);
 	stat->dev = BTRFS_I(inode)->root->anon_dev;
 
 	spin_lock(&BTRFS_I(inode)->lock);
@@ -9289,14 +9289,14 @@ out_notrans:
 	return ret;
 }
 
-static struct inode *new_whiteout_inode(struct user_namespace *mnt_userns,
+static struct inode *new_whiteout_inode(struct mnt_idmap *idmap,
 					struct inode *dir)
 {
 	struct inode *inode;
 
 	inode = new_inode(dir->i_sb);
 	if (inode) {
-		inode_init_owner(mnt_userns, inode, dir,
+		inode_init_owner(idmap, inode, dir,
 				 S_IFCHR | WHITEOUT_MODE);
 		inode->i_op = &btrfs_special_inode_operations;
 		init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
@@ -9304,7 +9304,7 @@ static struct inode *new_whiteout_inode(struct user_namespace *mnt_userns,
 	return inode;
 }
 
-static int btrfs_rename(struct user_namespace *mnt_userns,
+static int btrfs_rename(struct mnt_idmap *idmap,
 			struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
@@ -9376,7 +9376,7 @@ static int btrfs_rename(struct user_namespace *mnt_userns,
 		filemap_flush(old_inode->i_mapping);
 
 	if (flags & RENAME_WHITEOUT) {
-		whiteout_args.inode = new_whiteout_inode(mnt_userns, old_dir);
+		whiteout_args.inode = new_whiteout_inode(idmap, old_dir);
 		if (!whiteout_args.inode) {
 			ret = -ENOMEM;
 			goto out_fscrypt_names;
@@ -9545,7 +9545,7 @@ out_fscrypt_names:
 	return ret;
 }
 
-static int btrfs_rename2(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int btrfs_rename2(struct mnt_idmap *idmap, struct inode *old_dir,
 			 struct dentry *old_dentry, struct inode *new_dir,
 			 struct dentry *new_dentry, unsigned int flags)
 {
@@ -9558,7 +9558,7 @@ static int btrfs_rename2(struct user_namespace *mnt_userns, struct inode *old_di
 		ret = btrfs_rename_exchange(old_dir, old_dentry, new_dir,
 					    new_dentry);
 	else
-		ret = btrfs_rename(mnt_userns, old_dir, old_dentry, new_dir,
+		ret = btrfs_rename(idmap, old_dir, old_dentry, new_dir,
 				   new_dentry, flags);
 
 	btrfs_btree_balance_dirty(BTRFS_I(new_dir)->root->fs_info);
@@ -9758,7 +9758,7 @@ out:
 	return ret;
 }
 
-static int btrfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int btrfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			 struct dentry *dentry, const char *symname)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
@@ -9786,7 +9786,7 @@ static int btrfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 	inode = new_inode(dir->i_sb);
 	if (!inode)
 		return -ENOMEM;
-	inode_init_owner(mnt_userns, inode, dir, S_IFLNK | S_IRWXUGO);
+	inode_init_owner(idmap, inode, dir, S_IFLNK | S_IRWXUGO);
 	inode->i_op = &btrfs_symlink_inode_operations;
 	inode_nohighmem(inode);
 	inode->i_mapping->a_ops = &btrfs_aops;
@@ -10075,7 +10075,7 @@ int btrfs_prealloc_file_range_trans(struct inode *inode,
 					   min_size, actual_len, alloc_hint, trans);
 }
 
-static int btrfs_permission(struct user_namespace *mnt_userns,
+static int btrfs_permission(struct mnt_idmap *idmap,
 			    struct inode *inode, int mask)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -10088,10 +10088,10 @@ static int btrfs_permission(struct user_namespace *mnt_userns,
 		if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
 			return -EACCES;
 	}
-	return generic_permission(mnt_userns, inode, mask);
+	return generic_permission(idmap, inode, mask);
 }
 
-static int btrfs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+static int btrfs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 			 struct file *file, umode_t mode)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
@@ -10109,7 +10109,7 @@ static int btrfs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	inode = new_inode(dir->i_sb);
 	if (!inode)
 		return -ENOMEM;
-	inode_init_owner(mnt_userns, inode, dir, mode);
+	inode_init_owner(idmap, inode, dir, mode);
 	inode->i_fop = &btrfs_file_operations;
 	inode->i_op = &btrfs_file_inode_operations;
 	inode->i_mapping->a_ops = &btrfs_aops;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7e348bd2ccde..5ba1ff31713b 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -243,7 +243,7 @@ int btrfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return 0;
 }
 
-int btrfs_fileattr_set(struct user_namespace *mnt_userns,
+int btrfs_fileattr_set(struct mnt_idmap *idmap,
 		       struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
@@ -578,7 +578,7 @@ static unsigned int create_subvol_num_items(struct btrfs_qgroup_inherit *inherit
 	return num_items;
 }
 
-static noinline int create_subvol(struct user_namespace *mnt_userns,
+static noinline int create_subvol(struct mnt_idmap *idmap,
 				  struct inode *dir, struct dentry *dentry,
 				  struct btrfs_qgroup_inherit *inherit)
 {
@@ -623,7 +623,7 @@ static noinline int create_subvol(struct user_namespace *mnt_userns,
 	if (ret < 0)
 		goto out_root_item;
 
-	new_inode_args.inode = btrfs_new_subvol_inode(mnt_userns, dir);
+	new_inode_args.inode = btrfs_new_subvol_inode(idmap, dir);
 	if (!new_inode_args.inode) {
 		ret = -ENOMEM;
 		goto out_anon_dev;
@@ -898,7 +898,7 @@ free_pending:
  *     nfs_async_unlink().
  */
 
-static int btrfs_may_delete(struct user_namespace *mnt_userns,
+static int btrfs_may_delete(struct mnt_idmap *idmap,
 			    struct inode *dir, struct dentry *victim, int isdir)
 {
 	int error;
@@ -909,12 +909,12 @@ static int btrfs_may_delete(struct user_namespace *mnt_userns,
 	BUG_ON(d_inode(victim->d_parent) != dir);
 	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 
-	error = inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
+	error = inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
 	if (error)
 		return error;
 	if (IS_APPEND(dir))
 		return -EPERM;
-	if (check_sticky(mnt_userns, dir, d_inode(victim)) ||
+	if (check_sticky(idmap, dir, d_inode(victim)) ||
 	    IS_APPEND(d_inode(victim)) || IS_IMMUTABLE(d_inode(victim)) ||
 	    IS_SWAPFILE(d_inode(victim)))
 		return -EPERM;
@@ -933,16 +933,16 @@ static int btrfs_may_delete(struct user_namespace *mnt_userns,
 }
 
 /* copy of may_create in fs/namei.c() */
-static inline int btrfs_may_create(struct user_namespace *mnt_userns,
+static inline int btrfs_may_create(struct mnt_idmap *idmap,
 				   struct inode *dir, struct dentry *child)
 {
 	if (d_really_is_positive(child))
 		return -EEXIST;
 	if (IS_DEADDIR(dir))
 		return -ENOENT;
-	if (!fsuidgid_has_mapping(dir->i_sb, mnt_userns))
+	if (!fsuidgid_has_mapping(dir->i_sb, idmap))
 		return -EOVERFLOW;
-	return inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
+	return inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
 }
 
 /*
@@ -951,7 +951,7 @@ static inline int btrfs_may_create(struct user_namespace *mnt_userns,
  * inside this filesystem so it's quite a bit simpler.
  */
 static noinline int btrfs_mksubvol(const struct path *parent,
-				   struct user_namespace *mnt_userns,
+				   struct mnt_idmap *idmap,
 				   const char *name, int namelen,
 				   struct btrfs_root *snap_src,
 				   bool readonly,
@@ -967,12 +967,12 @@ static noinline int btrfs_mksubvol(const struct path *parent,
 	if (error == -EINTR)
 		return error;
 
-	dentry = lookup_one(mnt_userns, name, parent->dentry, namelen);
+	dentry = lookup_one(idmap, name, parent->dentry, namelen);
 	error = PTR_ERR(dentry);
 	if (IS_ERR(dentry))
 		goto out_unlock;
 
-	error = btrfs_may_create(mnt_userns, dir, dentry);
+	error = btrfs_may_create(idmap, dir, dentry);
 	if (error)
 		goto out_dput;
 
@@ -993,7 +993,7 @@ static noinline int btrfs_mksubvol(const struct path *parent,
 	if (snap_src)
 		error = create_snapshot(snap_src, dir, dentry, readonly, inherit);
 	else
-		error = create_subvol(mnt_userns, dir, dentry, inherit);
+		error = create_subvol(idmap, dir, dentry, inherit);
 
 	if (!error)
 		fsnotify_mkdir(dir, dentry);
@@ -1007,7 +1007,7 @@ out_unlock:
 }
 
 static noinline int btrfs_mksnapshot(const struct path *parent,
-				   struct user_namespace *mnt_userns,
+				   struct mnt_idmap *idmap,
 				   const char *name, int namelen,
 				   struct btrfs_root *root,
 				   bool readonly,
@@ -1037,7 +1037,7 @@ static noinline int btrfs_mksnapshot(const struct path *parent,
 
 	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 
-	ret = btrfs_mksubvol(parent, mnt_userns, name, namelen,
+	ret = btrfs_mksubvol(parent, idmap, name, namelen,
 			     root, readonly, inherit);
 out:
 	if (snapshot_force_cow)
@@ -1240,7 +1240,7 @@ out_drop:
 }
 
 static noinline int __btrfs_ioctl_snap_create(struct file *file,
-				struct user_namespace *mnt_userns,
+				struct mnt_idmap *idmap,
 				const char *name, unsigned long fd, int subvol,
 				bool readonly,
 				struct btrfs_qgroup_inherit *inherit)
@@ -1268,7 +1268,7 @@ static noinline int __btrfs_ioctl_snap_create(struct file *file,
 	}
 
 	if (subvol) {
-		ret = btrfs_mksubvol(&file->f_path, mnt_userns, name,
+		ret = btrfs_mksubvol(&file->f_path, idmap, name,
 				     namelen, NULL, readonly, inherit);
 	} else {
 		struct fd src = fdget(fd);
@@ -1283,14 +1283,14 @@ static noinline int __btrfs_ioctl_snap_create(struct file *file,
 			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
 				   "Snapshot src from another FS");
 			ret = -EXDEV;
-		} else if (!inode_owner_or_capable(mnt_userns, src_inode)) {
+		} else if (!inode_owner_or_capable(idmap, src_inode)) {
 			/*
 			 * Subvolume creation is not restricted, but snapshots
 			 * are limited to own subvolumes only
 			 */
 			ret = -EPERM;
 		} else {
-			ret = btrfs_mksnapshot(&file->f_path, mnt_userns,
+			ret = btrfs_mksnapshot(&file->f_path, idmap,
 					       name, namelen,
 					       BTRFS_I(src_inode)->root,
 					       readonly, inherit);
@@ -1317,7 +1317,7 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
 		return PTR_ERR(vol_args);
 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 
-	ret = __btrfs_ioctl_snap_create(file, file_mnt_user_ns(file),
+	ret = __btrfs_ioctl_snap_create(file, file_mnt_idmap(file),
 					vol_args->name, vol_args->fd, subvol,
 					false, NULL);
 
@@ -1377,7 +1377,7 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
 		}
 	}
 
-	ret = __btrfs_ioctl_snap_create(file, file_mnt_user_ns(file),
+	ret = __btrfs_ioctl_snap_create(file, file_mnt_idmap(file),
 					vol_args->name, vol_args->fd, subvol,
 					readonly, inherit);
 	if (ret)
@@ -1422,7 +1422,7 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
 	u64 flags;
 	int ret = 0;
 
-	if (!inode_owner_or_capable(file_mnt_user_ns(file), inode))
+	if (!inode_owner_or_capable(file_mnt_idmap(file), inode))
 		return -EPERM;
 
 	ret = mnt_want_write_file(file);
@@ -1870,7 +1870,7 @@ out:
 	return ret;
 }
 
-static int btrfs_search_path_in_tree_user(struct user_namespace *mnt_userns,
+static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
 				struct inode *inode,
 				struct btrfs_ioctl_ino_lookup_user_args *args)
 {
@@ -1962,7 +1962,7 @@ static int btrfs_search_path_in_tree_user(struct user_namespace *mnt_userns,
 				ret = PTR_ERR(temp_inode);
 				goto out_put;
 			}
-			ret = inode_permission(mnt_userns, temp_inode,
+			ret = inode_permission(idmap, temp_inode,
 					       MAY_READ | MAY_EXEC);
 			iput(temp_inode);
 			if (ret) {
@@ -2101,7 +2101,7 @@ static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
 		return -EACCES;
 	}
 
-	ret = btrfs_search_path_in_tree_user(file_mnt_user_ns(file), inode, args);
+	ret = btrfs_search_path_in_tree_user(file_mnt_idmap(file), inode, args);
 
 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
 		ret = -EFAULT;
@@ -2335,7 +2335,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 	struct btrfs_root *dest = NULL;
 	struct btrfs_ioctl_vol_args *vol_args = NULL;
 	struct btrfs_ioctl_vol_args_v2 *vol_args2 = NULL;
-	struct user_namespace *mnt_userns = file_mnt_user_ns(file);
+	struct mnt_idmap *idmap = file_mnt_idmap(file);
 	char *subvol_name, *subvol_name_ptr = NULL;
 	int subvol_namelen;
 	int err = 0;
@@ -2428,7 +2428,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 			 * anywhere in the filesystem the user wouldn't be able
 			 * to delete without an idmapped mount.
 			 */
-			if (old_dir != dir && mnt_userns != &init_user_ns) {
+			if (old_dir != dir && idmap != &nop_mnt_idmap) {
 				err = -EOPNOTSUPP;
 				goto free_parent;
 			}
@@ -2471,7 +2471,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 	err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 	if (err == -EINTR)
 		goto free_subvol_name;
-	dentry = lookup_one(mnt_userns, subvol_name, parent, subvol_namelen);
+	dentry = lookup_one(idmap, subvol_name, parent, subvol_namelen);
 	if (IS_ERR(dentry)) {
 		err = PTR_ERR(dentry);
 		goto out_unlock_dir;
@@ -2513,13 +2513,13 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		if (root == dest)
 			goto out_dput;
 
-		err = inode_permission(mnt_userns, inode, MAY_WRITE | MAY_EXEC);
+		err = inode_permission(idmap, inode, MAY_WRITE | MAY_EXEC);
 		if (err)
 			goto out_dput;
 	}
 
 	/* check if subvolume may be deleted by a user */
-	err = btrfs_may_delete(mnt_userns, dir, dentry, 1);
+	err = btrfs_may_delete(idmap, dir, dentry, 1);
 	if (err)
 		goto out_dput;
 
@@ -2582,7 +2582,7 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
 		 * running and allows defrag on files open in read-only mode.
 		 */
 		if (!capable(CAP_SYS_ADMIN) &&
-		    inode_permission(&init_user_ns, inode, MAY_WRITE)) {
+		    inode_permission(&nop_mnt_idmap, inode, MAY_WRITE)) {
 			ret = -EPERM;
 			goto out;
 		}
@@ -3907,7 +3907,7 @@ static long btrfs_ioctl_quota_rescan_wait(struct btrfs_fs_info *fs_info,
 }
 
 static long _btrfs_ioctl_set_received_subvol(struct file *file,
-					    struct user_namespace *mnt_userns,
+					    struct mnt_idmap *idmap,
 					    struct btrfs_ioctl_received_subvol_args *sa)
 {
 	struct inode *inode = file_inode(file);
@@ -3919,7 +3919,7 @@ static long _btrfs_ioctl_set_received_subvol(struct file *file,
 	int ret = 0;
 	int received_uuid_changed;
 
-	if (!inode_owner_or_capable(mnt_userns, inode))
+	if (!inode_owner_or_capable(idmap, inode))
 		return -EPERM;
 
 	ret = mnt_want_write_file(file);
@@ -4024,7 +4024,7 @@ static long btrfs_ioctl_set_received_subvol_32(struct file *file,
 	args64->rtime.nsec = args32->rtime.nsec;
 	args64->flags = args32->flags;
 
-	ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_user_ns(file), args64);
+	ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_idmap(file), args64);
 	if (ret)
 		goto out;
 
@@ -4058,7 +4058,7 @@ static long btrfs_ioctl_set_received_subvol(struct file *file,
 	if (IS_ERR(sa))
 		return PTR_ERR(sa);
 
-	ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_user_ns(file), sa);
+	ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_idmap(file), sa);
 
 	if (ret)
 		goto out;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 8a855d5ac2fa..d51b9a2f2f6e 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -6,7 +6,7 @@
 long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 int btrfs_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-int btrfs_fileattr_set(struct user_namespace *mnt_userns,
+int btrfs_fileattr_set(struct mnt_idmap *idmap,
 		       struct dentry *dentry, struct fileattr *fa);
 int btrfs_ioctl_get_supported_features(void __user *arg);
 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode);
diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c
index 181469fc0bb3..ca09cf9afce8 100644
--- a/fs/btrfs/tests/btrfs-tests.c
+++ b/fs/btrfs/tests/btrfs-tests.c
@@ -64,7 +64,7 @@ struct inode *btrfs_new_test_inode(void)
 	BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
 	BTRFS_I(inode)->location.objectid = BTRFS_FIRST_FREE_OBJECTID;
 	BTRFS_I(inode)->location.offset = 0;
-	inode_init_owner(&init_user_ns, inode, NULL, S_IFREG);
+	inode_init_owner(&nop_mnt_idmap, inode, NULL, S_IFREG);
 
 	return inode;
 }
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 0ed4b119a7ca..0ebeaf4e81f9 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -370,7 +370,7 @@ static int btrfs_xattr_handler_get(const struct xattr_handler *handler,
 }
 
 static int btrfs_xattr_handler_set(const struct xattr_handler *handler,
-				   struct user_namespace *mnt_userns,
+				   struct mnt_idmap *idmap,
 				   struct dentry *unused, struct inode *inode,
 				   const char *name, const void *buffer,
 				   size_t size, int flags)
@@ -383,7 +383,7 @@ static int btrfs_xattr_handler_set(const struct xattr_handler *handler,
 }
 
 static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler,
-					struct user_namespace *mnt_userns,
+					struct mnt_idmap *idmap,
 					struct dentry *unused, struct inode *inode,
 					const char *name, const void *value,
 					size_t size, int flags)
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index a69073a1d3f0..40052bdb3365 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -138,7 +138,7 @@ static int cachefiles_adjust_size(struct cachefiles_object *object)
 		newattrs.ia_size = oi_size & PAGE_MASK;
 		ret = cachefiles_inject_remove_error();
 		if (ret == 0)
-			ret = notify_change(&init_user_ns, file->f_path.dentry,
+			ret = notify_change(&nop_mnt_idmap, file->f_path.dentry,
 					    &newattrs, NULL);
 		if (ret < 0)
 			goto truncate_failed;
@@ -148,7 +148,7 @@ static int cachefiles_adjust_size(struct cachefiles_object *object)
 	newattrs.ia_size = ni_size;
 	ret = cachefiles_inject_write_error();
 	if (ret == 0)
-		ret = notify_change(&init_user_ns, file->f_path.dentry,
+		ret = notify_change(&nop_mnt_idmap, file->f_path.dentry,
 				    &newattrs, NULL);
 
 truncate_failed:
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 03ca8f2f657a..82219a8f6084 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -130,7 +130,7 @@ retry:
 			goto mkdir_error;
 		ret = cachefiles_inject_write_error();
 		if (ret == 0)
-			ret = vfs_mkdir(&init_user_ns, d_inode(dir), subdir, 0700);
+			ret = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700);
 		if (ret < 0) {
 			trace_cachefiles_vfs_error(NULL, d_inode(dir), ret,
 						   cachefiles_trace_mkdir_error);
@@ -245,7 +245,7 @@ static int cachefiles_unlink(struct cachefiles_cache *cache,
 
 	ret = cachefiles_inject_remove_error();
 	if (ret == 0) {
-		ret = vfs_unlink(&init_user_ns, d_backing_inode(dir), dentry, NULL);
+		ret = vfs_unlink(&nop_mnt_idmap, d_backing_inode(dir), dentry, NULL);
 		if (ret == -EIO)
 			cachefiles_io_error(cache, "Unlink failed");
 	}
@@ -382,10 +382,10 @@ try_again:
 		cachefiles_io_error(cache, "Rename security error %d", ret);
 	} else {
 		struct renamedata rd = {
-			.old_mnt_userns	= &init_user_ns,
+			.old_mnt_idmap	= &nop_mnt_idmap,
 			.old_dir	= d_inode(dir),
 			.old_dentry	= rep,
-			.new_mnt_userns	= &init_user_ns,
+			.new_mnt_idmap	= &nop_mnt_idmap,
 			.new_dir	= d_inode(cache->graveyard),
 			.new_dentry	= grave,
 		};
@@ -451,7 +451,7 @@ struct file *cachefiles_create_tmpfile(struct cachefiles_object *object)
 
 	ret = cachefiles_inject_write_error();
 	if (ret == 0) {
-		file = vfs_tmpfile_open(&init_user_ns, &parentpath, S_IFREG,
+		file = vfs_tmpfile_open(&nop_mnt_idmap, &parentpath, S_IFREG,
 					O_RDWR | O_LARGEFILE | O_DIRECT,
 					cache->cache_cred);
 		ret = PTR_ERR_OR_ZERO(file);
@@ -714,7 +714,7 @@ bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
 
 	ret = cachefiles_inject_read_error();
 	if (ret == 0)
-		ret = vfs_link(object->file->f_path.dentry, &init_user_ns,
+		ret = vfs_link(object->file->f_path.dentry, &nop_mnt_idmap,
 			       d_inode(fan), dentry, NULL);
 	if (ret < 0) {
 		trace_cachefiles_vfs_error(object, d_inode(fan), ret,
diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c
index 00b087c14995..bcb6173943ee 100644
--- a/fs/cachefiles/xattr.c
+++ b/fs/cachefiles/xattr.c
@@ -65,7 +65,7 @@ int cachefiles_set_object_xattr(struct cachefiles_object *object)
 
 	ret = cachefiles_inject_write_error();
 	if (ret == 0)
-		ret = vfs_setxattr(&init_user_ns, dentry, cachefiles_xattr_cache,
+		ret = vfs_setxattr(&nop_mnt_idmap, dentry, cachefiles_xattr_cache,
 				   buf, sizeof(struct cachefiles_xattr) + len, 0);
 	if (ret < 0) {
 		trace_cachefiles_vfs_error(object, file_inode(file), ret,
@@ -108,7 +108,7 @@ int cachefiles_check_auxdata(struct cachefiles_object *object, struct file *file
 
 	xlen = cachefiles_inject_read_error();
 	if (xlen == 0)
-		xlen = vfs_getxattr(&init_user_ns, dentry, cachefiles_xattr_cache, buf, tlen);
+		xlen = vfs_getxattr(&nop_mnt_idmap, dentry, cachefiles_xattr_cache, buf, tlen);
 	if (xlen != tlen) {
 		if (xlen < 0)
 			trace_cachefiles_vfs_error(object, file_inode(file), xlen,
@@ -150,7 +150,7 @@ int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
 
 	ret = cachefiles_inject_remove_error();
 	if (ret == 0)
-		ret = vfs_removexattr(&init_user_ns, dentry, cachefiles_xattr_cache);
+		ret = vfs_removexattr(&nop_mnt_idmap, dentry, cachefiles_xattr_cache);
 	if (ret < 0) {
 		trace_cachefiles_vfs_error(object, d_inode(dentry), ret,
 					   cachefiles_trace_remxattr_error);
@@ -207,7 +207,7 @@ bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume)
 
 	ret = cachefiles_inject_write_error();
 	if (ret == 0)
-		ret = vfs_setxattr(&init_user_ns, dentry, cachefiles_xattr_cache,
+		ret = vfs_setxattr(&nop_mnt_idmap, dentry, cachefiles_xattr_cache,
 				   buf, len, 0);
 	if (ret < 0) {
 		trace_cachefiles_vfs_error(NULL, d_inode(dentry), ret,
@@ -249,7 +249,7 @@ int cachefiles_check_volume_xattr(struct cachefiles_volume *volume)
 
 	xlen = cachefiles_inject_read_error();
 	if (xlen == 0)
-		xlen = vfs_getxattr(&init_user_ns, dentry, cachefiles_xattr_cache, buf, len);
+		xlen = vfs_getxattr(&nop_mnt_idmap, dentry, cachefiles_xattr_cache, buf, len);
 	if (xlen != len) {
 		if (xlen < 0) {
 			trace_cachefiles_vfs_error(NULL, d_inode(dentry), xlen,
diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c
index c7e8dd5b58d4..6945a938d396 100644
--- a/fs/ceph/acl.c
+++ b/fs/ceph/acl.c
@@ -85,7 +85,7 @@ retry:
 	return acl;
 }
 
-int ceph_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ceph_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type)
 {
 	int ret = 0, size = 0;
@@ -105,7 +105,7 @@ int ceph_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 	case ACL_TYPE_ACCESS:
 		name = XATTR_NAME_POSIX_ACL_ACCESS;
 		if (acl) {
-			ret = posix_acl_update_mode(&init_user_ns, inode,
+			ret = posix_acl_update_mode(&nop_mnt_idmap, inode,
 						    &new_mode, &acl);
 			if (ret)
 				goto out;
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 6c7026cc8988..0ced8b570e42 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -845,7 +845,7 @@ int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
 	return PTR_ERR(result);
 }
 
-static int ceph_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int ceph_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
@@ -905,13 +905,13 @@ out:
 	return err;
 }
 
-static int ceph_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int ceph_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
-	return ceph_mknod(mnt_userns, dir, dentry, mode, 0);
+	return ceph_mknod(idmap, dir, dentry, mode, 0);
 }
 
-static int ceph_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int ceph_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, const char *dest)
 {
 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
@@ -970,7 +970,7 @@ out:
 	return err;
 }
 
-static int ceph_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int ceph_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
@@ -1269,7 +1269,7 @@ out:
 	return err;
 }
 
-static int ceph_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int ceph_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		       struct dentry *old_dentry, struct inode *new_dir,
 		       struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index e22e631cb115..8e5f41d45283 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -2227,7 +2227,7 @@ int __ceph_setattr(struct inode *inode, struct iattr *attr)
 /*
  * setattr
  */
-int ceph_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ceph_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -2240,7 +2240,7 @@ int ceph_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (ceph_inode_is_shutdown(inode))
 		return -ESTALE;
 
-	err = setattr_prepare(&init_user_ns, dentry, attr);
+	err = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (err != 0)
 		return err;
 
@@ -2255,7 +2255,7 @@ int ceph_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	err = __ceph_setattr(inode, attr);
 
 	if (err >= 0 && (attr->ia_valid & ATTR_MODE))
-		err = posix_acl_chmod(&init_user_ns, dentry, attr->ia_mode);
+		err = posix_acl_chmod(&nop_mnt_idmap, dentry, attr->ia_mode);
 
 	return err;
 }
@@ -2397,7 +2397,7 @@ out:
  * Check inode permissions.  We verify we have a valid value for
  * the AUTH cap, then call the generic handler.
  */
-int ceph_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int ceph_permission(struct mnt_idmap *idmap, struct inode *inode,
 		    int mask)
 {
 	int err;
@@ -2408,7 +2408,7 @@ int ceph_permission(struct user_namespace *mnt_userns, struct inode *inode,
 	err = ceph_do_getattr(inode, CEPH_CAP_AUTH_SHARED, false);
 
 	if (!err)
-		err = generic_permission(&init_user_ns, inode, mask);
+		err = generic_permission(&nop_mnt_idmap, inode, mask);
 	return err;
 }
 
@@ -2444,7 +2444,7 @@ static int statx_to_caps(u32 want, umode_t mode)
  * Get all the attributes. If we have sufficient caps for the requested attrs,
  * then we can avoid talking to the MDS at all.
  */
-int ceph_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ceph_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	struct inode *inode = d_inode(path->dentry);
@@ -2465,7 +2465,7 @@ int ceph_getattr(struct user_namespace *mnt_userns, const struct path *path,
 			return err;
 	}
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	stat->ino = ceph_present_inode(inode);
 
 	/*
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 07c6906cda70..6ecca2c6d137 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -1050,12 +1050,12 @@ static inline int ceph_do_getattr(struct inode *inode, int mask, bool force)
 {
 	return __ceph_do_getattr(inode, NULL, mask, force);
 }
-extern int ceph_permission(struct user_namespace *mnt_userns,
+extern int ceph_permission(struct mnt_idmap *idmap,
 			   struct inode *inode, int mask);
 extern int __ceph_setattr(struct inode *inode, struct iattr *attr);
-extern int ceph_setattr(struct user_namespace *mnt_userns,
+extern int ceph_setattr(struct mnt_idmap *idmap,
 			struct dentry *dentry, struct iattr *attr);
-extern int ceph_getattr(struct user_namespace *mnt_userns,
+extern int ceph_getattr(struct mnt_idmap *idmap,
 			const struct path *path, struct kstat *stat,
 			u32 request_mask, unsigned int flags);
 void ceph_inode_shutdown(struct inode *inode);
@@ -1128,7 +1128,7 @@ void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx);
 #ifdef CONFIG_CEPH_FS_POSIX_ACL
 
 struct posix_acl *ceph_get_acl(struct inode *, int, bool);
-int ceph_set_acl(struct user_namespace *mnt_userns,
+int ceph_set_acl(struct mnt_idmap *idmap,
 		 struct dentry *dentry, struct posix_acl *acl, int type);
 int ceph_pre_init_acls(struct inode *dir, umode_t *mode,
 		       struct ceph_acl_sec_ctx *as_ctx);
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index f31350cda960..f65b07cc33a2 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -1285,7 +1285,7 @@ static int ceph_get_xattr_handler(const struct xattr_handler *handler,
 }
 
 static int ceph_set_xattr_handler(const struct xattr_handler *handler,
-				  struct user_namespace *mnt_userns,
+				  struct mnt_idmap *idmap,
 				  struct dentry *unused, struct inode *inode,
 				  const char *name, const void *value,
 				  size_t size, int flags)
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index bbf58c2439da..9a2d390bd06f 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -1674,7 +1674,7 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode,
 	return rc;
 }
 
-struct posix_acl *cifs_get_acl(struct user_namespace *mnt_userns,
+struct posix_acl *cifs_get_acl(struct mnt_idmap *idmap,
 			       struct dentry *dentry, int type)
 {
 #if defined(CONFIG_CIFS_ALLOW_INSECURE_LEGACY) && defined(CONFIG_CIFS_POSIX)
@@ -1738,7 +1738,7 @@ out:
 #endif
 }
 
-int cifs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int cifs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type)
 {
 #if defined(CONFIG_CIFS_ALLOW_INSECURE_LEGACY) && defined(CONFIG_CIFS_POSIX)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index f052f190b2e8..cb7c5460a80b 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -346,7 +346,7 @@ static long cifs_fallocate(struct file *file, int mode, loff_t off, loff_t len)
 	return -EOPNOTSUPP;
 }
 
-static int cifs_permission(struct user_namespace *mnt_userns,
+static int cifs_permission(struct mnt_idmap *idmap,
 			   struct inode *inode, int mask)
 {
 	struct cifs_sb_info *cifs_sb;
@@ -362,7 +362,7 @@ static int cifs_permission(struct user_namespace *mnt_userns,
 		on the client (above and beyond ACL on servers) for
 		servers which do not support setting and viewing mode bits,
 		so allowing client to check permissions is useful */
-		return generic_permission(&init_user_ns, inode, mask);
+		return generic_permission(&nop_mnt_idmap, inode, mask);
 }
 
 static struct kmem_cache *cifs_inode_cachep;
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index 63a0ac2b9355..b58cd737b21e 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -49,7 +49,7 @@ extern void cifs_sb_deactive(struct super_block *sb);
 /* Functions related to inodes */
 extern const struct inode_operations cifs_dir_inode_ops;
 extern struct inode *cifs_root_iget(struct super_block *);
-extern int cifs_create(struct user_namespace *, struct inode *,
+extern int cifs_create(struct mnt_idmap *, struct inode *,
 		       struct dentry *, umode_t, bool excl);
 extern int cifs_atomic_open(struct inode *, struct dentry *,
 			    struct file *, unsigned, umode_t);
@@ -57,12 +57,12 @@ extern struct dentry *cifs_lookup(struct inode *, struct dentry *,
 				  unsigned int);
 extern int cifs_unlink(struct inode *dir, struct dentry *dentry);
 extern int cifs_hardlink(struct dentry *, struct inode *, struct dentry *);
-extern int cifs_mknod(struct user_namespace *, struct inode *, struct dentry *,
+extern int cifs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
 		      umode_t, dev_t);
-extern int cifs_mkdir(struct user_namespace *, struct inode *, struct dentry *,
+extern int cifs_mkdir(struct mnt_idmap *, struct inode *, struct dentry *,
 		      umode_t);
 extern int cifs_rmdir(struct inode *, struct dentry *);
-extern int cifs_rename2(struct user_namespace *, struct inode *,
+extern int cifs_rename2(struct mnt_idmap *, struct inode *,
 			struct dentry *, struct inode *, struct dentry *,
 			unsigned int);
 extern int cifs_revalidate_file_attr(struct file *filp);
@@ -72,9 +72,9 @@ extern int cifs_revalidate_dentry(struct dentry *);
 extern int cifs_invalidate_mapping(struct inode *inode);
 extern int cifs_revalidate_mapping(struct inode *inode);
 extern int cifs_zap_mapping(struct inode *inode);
-extern int cifs_getattr(struct user_namespace *, const struct path *,
+extern int cifs_getattr(struct mnt_idmap *, const struct path *,
 			struct kstat *, u32, unsigned int);
-extern int cifs_setattr(struct user_namespace *, struct dentry *,
+extern int cifs_setattr(struct mnt_idmap *, struct dentry *,
 			struct iattr *);
 extern int cifs_fiemap(struct inode *, struct fiemap_extent_info *, u64 start,
 		       u64 len);
@@ -124,7 +124,7 @@ extern struct vfsmount *cifs_dfs_d_automount(struct path *path);
 /* Functions related to symlinks */
 extern const char *cifs_get_link(struct dentry *, struct inode *,
 			struct delayed_call *);
-extern int cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
+extern int cifs_symlink(struct mnt_idmap *idmap, struct inode *inode,
 			struct dentry *direntry, const char *symname);
 
 #ifdef CONFIG_CIFS_XATTR
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 1207b39686fb..b8a47704a6ef 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -225,9 +225,9 @@ extern struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *, struct inode *,
 				      const char *, u32 *, u32);
 extern struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *,
 				const struct cifs_fid *, u32 *, u32);
-extern struct posix_acl *cifs_get_acl(struct user_namespace *mnt_userns,
+extern struct posix_acl *cifs_get_acl(struct mnt_idmap *idmap,
 				      struct dentry *dentry, int type);
-extern int cifs_set_acl(struct user_namespace *mnt_userns,
+extern int cifs_set_acl(struct mnt_idmap *idmap,
 			struct dentry *dentry, struct posix_acl *acl, int type);
 extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *,
 				const char *, int);
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index ad4208bf1e32..2b6076324ffc 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -529,7 +529,7 @@ out_free_xid:
 	return rc;
 }
 
-int cifs_create(struct user_namespace *mnt_userns, struct inode *inode,
+int cifs_create(struct mnt_idmap *idmap, struct inode *inode,
 		struct dentry *direntry, umode_t mode, bool excl)
 {
 	int rc;
@@ -579,7 +579,7 @@ out_free_xid:
 	return rc;
 }
 
-int cifs_mknod(struct user_namespace *mnt_userns, struct inode *inode,
+int cifs_mknod(struct mnt_idmap *idmap, struct inode *inode,
 	       struct dentry *direntry, umode_t mode, dev_t device_number)
 {
 	int rc = -EPERM;
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index f145a59af89b..11cdc7cfe0ba 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1910,7 +1910,7 @@ posix_mkdir_get_info:
 }
 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 
-int cifs_mkdir(struct user_namespace *mnt_userns, struct inode *inode,
+int cifs_mkdir(struct mnt_idmap *idmap, struct inode *inode,
 	       struct dentry *direntry, umode_t mode)
 {
 	int rc = 0;
@@ -2138,7 +2138,7 @@ do_rename_exit:
 }
 
 int
-cifs_rename2(struct user_namespace *mnt_userns, struct inode *source_dir,
+cifs_rename2(struct mnt_idmap *idmap, struct inode *source_dir,
 	     struct dentry *source_dentry, struct inode *target_dir,
 	     struct dentry *target_dentry, unsigned int flags)
 {
@@ -2496,7 +2496,7 @@ int cifs_revalidate_dentry(struct dentry *dentry)
 	return cifs_revalidate_mapping(inode);
 }
 
-int cifs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int cifs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	struct dentry *dentry = path->dentry;
@@ -2537,7 +2537,7 @@ int cifs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 			return rc;
 	}
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	stat->blksize = cifs_sb->ctx->bsize;
 	stat->ino = CIFS_I(inode)->uniqueid;
 
@@ -2752,7 +2752,7 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM)
 		attrs->ia_valid |= ATTR_FORCE;
 
-	rc = setattr_prepare(&init_user_ns, direntry, attrs);
+	rc = setattr_prepare(&nop_mnt_idmap, direntry, attrs);
 	if (rc < 0)
 		goto out;
 
@@ -2859,7 +2859,7 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
 		fscache_resize_cookie(cifs_inode_cookie(inode), attrs->ia_size);
 	}
 
-	setattr_copy(&init_user_ns, inode, attrs);
+	setattr_copy(&nop_mnt_idmap, inode, attrs);
 	mark_inode_dirty(inode);
 
 	/* force revalidate when any of these times are set since some
@@ -2903,7 +2903,7 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM)
 		attrs->ia_valid |= ATTR_FORCE;
 
-	rc = setattr_prepare(&init_user_ns, direntry, attrs);
+	rc = setattr_prepare(&nop_mnt_idmap, direntry, attrs);
 	if (rc < 0)
 		goto cifs_setattr_exit;
 
@@ -3058,7 +3058,7 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 		fscache_resize_cookie(cifs_inode_cookie(inode), attrs->ia_size);
 	}
 
-	setattr_copy(&init_user_ns, inode, attrs);
+	setattr_copy(&nop_mnt_idmap, inode, attrs);
 	mark_inode_dirty(inode);
 
 cifs_setattr_exit:
@@ -3068,7 +3068,7 @@ cifs_setattr_exit:
 }
 
 int
-cifs_setattr(struct user_namespace *mnt_userns, struct dentry *direntry,
+cifs_setattr(struct mnt_idmap *idmap, struct dentry *direntry,
 	     struct iattr *attrs)
 {
 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index a5a097a69983..4510dea77be3 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -569,7 +569,7 @@ cifs_hl_exit:
 }
 
 int
-cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
+cifs_symlink(struct mnt_idmap *idmap, struct inode *inode,
 	     struct dentry *direntry, const char *symname)
 {
 	int rc = -EOPNOTSUPP;
diff --git a/fs/cifs/xattr.c b/fs/cifs/xattr.c
index 5f2fb2fd2e37..50e762fa1a14 100644
--- a/fs/cifs/xattr.c
+++ b/fs/cifs/xattr.c
@@ -89,7 +89,7 @@ static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
 }
 
 static int cifs_xattr_set(const struct xattr_handler *handler,
-			  struct user_namespace *mnt_userns,
+			  struct mnt_idmap *idmap,
 			  struct dentry *dentry, struct inode *inode,
 			  const char *name, const void *value,
 			  size_t size, int flags)
diff --git a/fs/coda/coda_linux.h b/fs/coda/coda_linux.h
index 9be281bbcc06..dd6277d87afb 100644
--- a/fs/coda/coda_linux.h
+++ b/fs/coda/coda_linux.h
@@ -46,12 +46,12 @@ extern const struct file_operations coda_ioctl_operations;
 /* operations shared over more than one file */
 int coda_open(struct inode *i, struct file *f);
 int coda_release(struct inode *i, struct file *f);
-int coda_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int coda_permission(struct mnt_idmap *idmap, struct inode *inode,
 		    int mask);
 int coda_revalidate_inode(struct inode *);
-int coda_getattr(struct user_namespace *, const struct path *, struct kstat *,
+int coda_getattr(struct mnt_idmap *, const struct path *, struct kstat *,
 		 u32, unsigned int);
-int coda_setattr(struct user_namespace *, struct dentry *, struct iattr *);
+int coda_setattr(struct mnt_idmap *, struct dentry *, struct iattr *);
 
 /* this file:  helpers */
 char *coda_f2s(struct CodaFid *f);
diff --git a/fs/coda/dir.c b/fs/coda/dir.c
index 328d7a684b63..8450b1bd354b 100644
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -73,7 +73,7 @@ static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, unsig
 }
 
 
-int coda_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int coda_permission(struct mnt_idmap *idmap, struct inode *inode,
 		    int mask)
 {
 	int error;
@@ -133,7 +133,7 @@ static inline void coda_dir_drop_nlink(struct inode *dir)
 }
 
 /* creation routines: create, mknod, mkdir, link, symlink */
-static int coda_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int coda_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *de, umode_t mode, bool excl)
 {
 	int error;
@@ -166,7 +166,7 @@ err_out:
 	return error;
 }
 
-static int coda_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int coda_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *de, umode_t mode)
 {
 	struct inode *inode;
@@ -228,7 +228,7 @@ static int coda_link(struct dentry *source_de, struct inode *dir_inode,
 }
 
 
-static int coda_symlink(struct user_namespace *mnt_userns,
+static int coda_symlink(struct mnt_idmap *idmap,
 			struct inode *dir_inode, struct dentry *de,
 			const char *symname)
 {
@@ -295,7 +295,7 @@ static int coda_rmdir(struct inode *dir, struct dentry *de)
 }
 
 /* rename */
-static int coda_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int coda_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		       struct dentry *old_dentry, struct inode *new_dir,
 		       struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/coda/inode.c b/fs/coda/inode.c
index 2185328b65c7..d661e6cf17ac 100644
--- a/fs/coda/inode.c
+++ b/fs/coda/inode.c
@@ -251,16 +251,16 @@ static void coda_evict_inode(struct inode *inode)
 	coda_cache_clear_inode(inode);
 }
 
-int coda_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int coda_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	int err = coda_revalidate_inode(d_inode(path->dentry));
 	if (!err)
-		generic_fillattr(&init_user_ns, d_inode(path->dentry), stat);
+		generic_fillattr(&nop_mnt_idmap, d_inode(path->dentry), stat);
 	return err;
 }
 
-int coda_setattr(struct user_namespace *mnt_userns, struct dentry *de,
+int coda_setattr(struct mnt_idmap *idmap, struct dentry *de,
 		 struct iattr *iattr)
 {
 	struct inode *inode = d_inode(de);
diff --git a/fs/coda/pioctl.c b/fs/coda/pioctl.c
index cb9fd59a688c..36e35c15561a 100644
--- a/fs/coda/pioctl.c
+++ b/fs/coda/pioctl.c
@@ -24,7 +24,7 @@
 #include "coda_linux.h"
 
 /* pioctl ops */
-static int coda_ioctl_permission(struct user_namespace *mnt_userns,
+static int coda_ioctl_permission(struct mnt_idmap *idmap,
 				 struct inode *inode, int mask);
 static long coda_pioctl(struct file *filp, unsigned int cmd,
 			unsigned long user_data);
@@ -41,7 +41,7 @@ const struct file_operations coda_ioctl_operations = {
 };
 
 /* the coda pioctl inode ops */
-static int coda_ioctl_permission(struct user_namespace *mnt_userns,
+static int coda_ioctl_permission(struct mnt_idmap *idmap,
 				 struct inode *inode, int mask)
 {
 	return (mask & MAY_EXEC) ? -EACCES : 0;
diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h
index c0395363eab9..e710a1782382 100644
--- a/fs/configfs/configfs_internal.h
+++ b/fs/configfs/configfs_internal.h
@@ -77,7 +77,7 @@ extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
 
 extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
 extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
-extern int configfs_setattr(struct user_namespace *mnt_userns,
+extern int configfs_setattr(struct mnt_idmap *idmap,
 			    struct dentry *dentry, struct iattr *iattr);
 
 extern struct dentry *configfs_pin_fs(void);
@@ -91,7 +91,7 @@ extern const struct inode_operations configfs_root_inode_operations;
 extern const struct inode_operations configfs_symlink_inode_operations;
 extern const struct dentry_operations configfs_dentry_ops;
 
-extern int configfs_symlink(struct user_namespace *mnt_userns,
+extern int configfs_symlink(struct mnt_idmap *idmap,
 			    struct inode *dir, struct dentry *dentry,
 			    const char *symname);
 extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index ec6519e1ca3b..4afcbbe63e68 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -1251,7 +1251,7 @@ out_root_unlock:
 }
 EXPORT_SYMBOL(configfs_depend_item_unlocked);
 
-static int configfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int configfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			  struct dentry *dentry, umode_t mode)
 {
 	int ret = 0;
diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
index b601610e9907..1c15edbe70ff 100644
--- a/fs/configfs/inode.c
+++ b/fs/configfs/inode.c
@@ -32,7 +32,7 @@ static const struct inode_operations configfs_inode_operations ={
 	.setattr	= configfs_setattr,
 };
 
-int configfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int configfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct iattr *iattr)
 {
 	struct inode * inode = d_inode(dentry);
@@ -60,7 +60,7 @@ int configfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	}
 	/* attributes were changed atleast once in past */
 
-	error = simple_setattr(mnt_userns, dentry, iattr);
+	error = simple_setattr(idmap, dentry, iattr);
 	if (error)
 		return error;
 
diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c
index 0623c3edcfb9..69133ec1fac2 100644
--- a/fs/configfs/symlink.c
+++ b/fs/configfs/symlink.c
@@ -137,7 +137,7 @@ static int get_target(const char *symname, struct path *path,
 }
 
 
-int configfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+int configfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry, const char *symname)
 {
 	int ret;
@@ -196,7 +196,7 @@ int configfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 	if (dentry->d_inode || d_unhashed(dentry))
 		ret = -EEXIST;
 	else
-		ret = inode_permission(&init_user_ns, dir,
+		ret = inode_permission(&nop_mnt_idmap, dir,
 				       MAY_WRITE | MAY_EXEC);
 	if (!ret)
 		ret = type->ct_item_ops->allow_link(parent_item, target_item);
diff --git a/fs/coredump.c b/fs/coredump.c
index a25ecec9ca7c..68619329ec65 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -644,7 +644,7 @@ void do_coredump(const kernel_siginfo_t *siginfo)
 			goto close_fail;
 		}
 	} else {
-		struct user_namespace *mnt_userns;
+		struct mnt_idmap *idmap;
 		struct inode *inode;
 		int open_flags = O_CREAT | O_RDWR | O_NOFOLLOW |
 				 O_LARGEFILE | O_EXCL;
@@ -722,8 +722,8 @@ void do_coredump(const kernel_siginfo_t *siginfo)
 		 * a process dumps core while its cwd is e.g. on a vfat
 		 * filesystem.
 		 */
-		mnt_userns = file_mnt_user_ns(cprm.file);
-		if (!vfsuid_eq_kuid(i_uid_into_vfsuid(mnt_userns, inode),
+		idmap = file_mnt_idmap(cprm.file);
+		if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode),
 				    current_fsuid())) {
 			pr_info_ratelimited("Core dump to %s aborted: cannot preserve file owner\n",
 					    cn.corename);
@@ -736,7 +736,7 @@ void do_coredump(const kernel_siginfo_t *siginfo)
 		}
 		if (!(cprm.file->f_mode & FMODE_CAN_WRITE))
 			goto close_fail;
-		if (do_truncate(mnt_userns, cprm.file->f_path.dentry,
+		if (do_truncate(idmap, cprm.file->f_path.dentry,
 				0, 0, cprm.file))
 			goto close_fail;
 	}
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index 893661b52376..fa09c925bda8 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -506,7 +506,7 @@ int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
 		return -EFAULT;
 	policy.version = version;
 
-	if (!inode_owner_or_capable(&init_user_ns, inode))
+	if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
 		return -EACCES;
 
 	ret = mnt_want_write_file(filp);
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 2e8e112b1993..bf397f6a6a33 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -42,7 +42,7 @@ static unsigned int debugfs_allow __ro_after_init = DEFAULT_DEBUGFS_ALLOW_BITS;
  * so that we can use the file mode as part of a heuristic to determine whether
  * to lock down individual files.
  */
-static int debugfs_setattr(struct user_namespace *mnt_userns,
+static int debugfs_setattr(struct mnt_idmap *idmap,
 			   struct dentry *dentry, struct iattr *ia)
 {
 	int ret;
@@ -52,7 +52,7 @@ static int debugfs_setattr(struct user_namespace *mnt_userns,
 		if (ret)
 			return ret;
 	}
-	return simple_setattr(&init_user_ns, dentry, ia);
+	return simple_setattr(&nop_mnt_idmap, dentry, ia);
 }
 
 static const struct inode_operations debugfs_file_inode_operations = {
@@ -837,7 +837,7 @@ struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
 
 	take_dentry_name_snapshot(&old_name, old_dentry);
 
-	error = simple_rename(&init_user_ns, d_inode(old_dir), old_dentry,
+	error = simple_rename(&nop_mnt_idmap, d_inode(old_dir), old_dentry,
 			      d_inode(new_dir), dentry, 0);
 	if (error) {
 		release_dentry_name_snapshot(&old_name);
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index e3f5d7f3c8a0..bd3f3c755b24 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1105,7 +1105,7 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry,
 	}
 
 	inode_lock(lower_inode);
-	rc = __vfs_setxattr(&init_user_ns, lower_dentry, lower_inode,
+	rc = __vfs_setxattr(&nop_mnt_idmap, lower_dentry, lower_inode,
 			    ECRYPTFS_XATTR_NAME, page_virt, size, 0);
 	if (!rc && ecryptfs_inode)
 		fsstack_copy_attr_all(ecryptfs_inode, lower_inode);
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index f3cd00fac9c3..144ace9e0dd9 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -139,7 +139,7 @@ static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
 		if (d_unhashed(lower_dentry))
 			rc = -EINVAL;
 		else
-			rc = vfs_unlink(&init_user_ns, lower_dir, lower_dentry,
+			rc = vfs_unlink(&nop_mnt_idmap, lower_dir, lower_dentry,
 					NULL);
 	}
 	if (rc) {
@@ -180,7 +180,7 @@ ecryptfs_do_create(struct inode *directory_inode,
 
 	rc = lock_parent(ecryptfs_dentry, &lower_dentry, &lower_dir);
 	if (!rc)
-		rc = vfs_create(&init_user_ns, lower_dir,
+		rc = vfs_create(&nop_mnt_idmap, lower_dir,
 				lower_dentry, mode, true);
 	if (rc) {
 		printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
@@ -191,7 +191,7 @@ ecryptfs_do_create(struct inode *directory_inode,
 	inode = __ecryptfs_get_inode(d_inode(lower_dentry),
 				     directory_inode->i_sb);
 	if (IS_ERR(inode)) {
-		vfs_unlink(&init_user_ns, lower_dir, lower_dentry, NULL);
+		vfs_unlink(&nop_mnt_idmap, lower_dir, lower_dentry, NULL);
 		goto out_lock;
 	}
 	fsstack_copy_attr_times(directory_inode, lower_dir);
@@ -253,7 +253,7 @@ out:
  * Returns zero on success; non-zero on error condition
  */
 static int
-ecryptfs_create(struct user_namespace *mnt_userns,
+ecryptfs_create(struct mnt_idmap *idmap,
 		struct inode *directory_inode, struct dentry *ecryptfs_dentry,
 		umode_t mode, bool excl)
 {
@@ -434,7 +434,7 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
 	lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
 	rc = lock_parent(new_dentry, &lower_new_dentry, &lower_dir);
 	if (!rc)
-		rc = vfs_link(lower_old_dentry, &init_user_ns, lower_dir,
+		rc = vfs_link(lower_old_dentry, &nop_mnt_idmap, lower_dir,
 			      lower_new_dentry, NULL);
 	if (rc || d_really_is_negative(lower_new_dentry))
 		goto out_lock;
@@ -456,7 +456,7 @@ static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
 	return ecryptfs_do_unlink(dir, dentry, d_inode(dentry));
 }
 
-static int ecryptfs_symlink(struct user_namespace *mnt_userns,
+static int ecryptfs_symlink(struct mnt_idmap *idmap,
 			    struct inode *dir, struct dentry *dentry,
 			    const char *symname)
 {
@@ -478,7 +478,7 @@ static int ecryptfs_symlink(struct user_namespace *mnt_userns,
 						  strlen(symname));
 	if (rc)
 		goto out_lock;
-	rc = vfs_symlink(&init_user_ns, lower_dir, lower_dentry,
+	rc = vfs_symlink(&nop_mnt_idmap, lower_dir, lower_dentry,
 			 encoded_symname);
 	kfree(encoded_symname);
 	if (rc || d_really_is_negative(lower_dentry))
@@ -495,7 +495,7 @@ out_lock:
 	return rc;
 }
 
-static int ecryptfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int ecryptfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			  struct dentry *dentry, umode_t mode)
 {
 	int rc;
@@ -504,7 +504,7 @@ static int ecryptfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 
 	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
 	if (!rc)
-		rc = vfs_mkdir(&init_user_ns, lower_dir,
+		rc = vfs_mkdir(&nop_mnt_idmap, lower_dir,
 			       lower_dentry, mode);
 	if (rc || d_really_is_negative(lower_dentry))
 		goto out;
@@ -533,7 +533,7 @@ static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
 		if (d_unhashed(lower_dentry))
 			rc = -EINVAL;
 		else
-			rc = vfs_rmdir(&init_user_ns, lower_dir, lower_dentry);
+			rc = vfs_rmdir(&nop_mnt_idmap, lower_dir, lower_dentry);
 	}
 	if (!rc) {
 		clear_nlink(d_inode(dentry));
@@ -548,7 +548,7 @@ static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
 }
 
 static int
-ecryptfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+ecryptfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	       struct dentry *dentry, umode_t mode, dev_t dev)
 {
 	int rc;
@@ -557,7 +557,7 @@ ecryptfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 
 	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
 	if (!rc)
-		rc = vfs_mknod(&init_user_ns, lower_dir,
+		rc = vfs_mknod(&nop_mnt_idmap, lower_dir,
 			       lower_dentry, mode, dev);
 	if (rc || d_really_is_negative(lower_dentry))
 		goto out;
@@ -574,7 +574,7 @@ out:
 }
 
 static int
-ecryptfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+ecryptfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		struct dentry *old_dentry, struct inode *new_dir,
 		struct dentry *new_dentry, unsigned int flags)
 {
@@ -616,10 +616,10 @@ ecryptfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
 		goto out_lock;
 	}
 
-	rd.old_mnt_userns	= &init_user_ns;
+	rd.old_mnt_idmap	= &nop_mnt_idmap;
 	rd.old_dir		= d_inode(lower_old_dir_dentry);
 	rd.old_dentry		= lower_old_dentry;
-	rd.new_mnt_userns	= &init_user_ns;
+	rd.new_mnt_idmap	= &nop_mnt_idmap;
 	rd.new_dir		= d_inode(lower_new_dir_dentry);
 	rd.new_dentry		= lower_new_dentry;
 	rc = vfs_rename(&rd);
@@ -856,7 +856,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
 		struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
 
 		inode_lock(d_inode(lower_dentry));
-		rc = notify_change(&init_user_ns, lower_dentry,
+		rc = notify_change(&nop_mnt_idmap, lower_dentry,
 				   &lower_ia, NULL);
 		inode_unlock(d_inode(lower_dentry));
 	}
@@ -864,16 +864,16 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
 }
 
 static int
-ecryptfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
+ecryptfs_permission(struct mnt_idmap *idmap, struct inode *inode,
 		    int mask)
 {
-	return inode_permission(&init_user_ns,
+	return inode_permission(&nop_mnt_idmap,
 				ecryptfs_inode_to_lower(inode), mask);
 }
 
 /**
  * ecryptfs_setattr
- * @mnt_userns: user namespace of the target mount
+ * @idmap: idmap of the target mount
  * @dentry: dentry handle to the inode to modify
  * @ia: Structure with flags of what to change and values
  *
@@ -884,7 +884,7 @@ ecryptfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
  * All other metadata changes will be passed right to the lower filesystem,
  * and we will just update our inode to look like the lower.
  */
-static int ecryptfs_setattr(struct user_namespace *mnt_userns,
+static int ecryptfs_setattr(struct mnt_idmap *idmap,
 			    struct dentry *dentry, struct iattr *ia)
 {
 	int rc = 0;
@@ -939,7 +939,7 @@ static int ecryptfs_setattr(struct user_namespace *mnt_userns,
 	}
 	mutex_unlock(&crypt_stat->cs_mutex);
 
-	rc = setattr_prepare(&init_user_ns, dentry, ia);
+	rc = setattr_prepare(&nop_mnt_idmap, dentry, ia);
 	if (rc)
 		goto out;
 	if (ia->ia_valid & ATTR_SIZE) {
@@ -965,14 +965,14 @@ static int ecryptfs_setattr(struct user_namespace *mnt_userns,
 		lower_ia.ia_valid &= ~ATTR_MODE;
 
 	inode_lock(d_inode(lower_dentry));
-	rc = notify_change(&init_user_ns, lower_dentry, &lower_ia, NULL);
+	rc = notify_change(&nop_mnt_idmap, lower_dentry, &lower_ia, NULL);
 	inode_unlock(d_inode(lower_dentry));
 out:
 	fsstack_copy_attr_all(inode, lower_inode);
 	return rc;
 }
 
-static int ecryptfs_getattr_link(struct user_namespace *mnt_userns,
+static int ecryptfs_getattr_link(struct mnt_idmap *idmap,
 				 const struct path *path, struct kstat *stat,
 				 u32 request_mask, unsigned int flags)
 {
@@ -982,7 +982,7 @@ static int ecryptfs_getattr_link(struct user_namespace *mnt_userns,
 
 	mount_crypt_stat = &ecryptfs_superblock_to_private(
 						dentry->d_sb)->mount_crypt_stat;
-	generic_fillattr(&init_user_ns, d_inode(dentry), stat);
+	generic_fillattr(&nop_mnt_idmap, d_inode(dentry), stat);
 	if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
 		char *target;
 		size_t targetsiz;
@@ -998,7 +998,7 @@ static int ecryptfs_getattr_link(struct user_namespace *mnt_userns,
 	return rc;
 }
 
-static int ecryptfs_getattr(struct user_namespace *mnt_userns,
+static int ecryptfs_getattr(struct mnt_idmap *idmap,
 			    const struct path *path, struct kstat *stat,
 			    u32 request_mask, unsigned int flags)
 {
@@ -1011,7 +1011,7 @@ static int ecryptfs_getattr(struct user_namespace *mnt_userns,
 	if (!rc) {
 		fsstack_copy_attr_all(d_inode(dentry),
 				      ecryptfs_inode_to_lower(d_inode(dentry)));
-		generic_fillattr(&init_user_ns, d_inode(dentry), stat);
+		generic_fillattr(&nop_mnt_idmap, d_inode(dentry), stat);
 		stat->blocks = lower_stat.blocks;
 	}
 	return rc;
@@ -1033,7 +1033,7 @@ ecryptfs_setxattr(struct dentry *dentry, struct inode *inode,
 		goto out;
 	}
 	inode_lock(lower_inode);
-	rc = __vfs_setxattr_locked(&init_user_ns, lower_dentry, name, value, size, flags, NULL);
+	rc = __vfs_setxattr_locked(&nop_mnt_idmap, lower_dentry, name, value, size, flags, NULL);
 	inode_unlock(lower_inode);
 	if (!rc && inode)
 		fsstack_copy_attr_all(inode, lower_inode);
@@ -1099,7 +1099,7 @@ static int ecryptfs_removexattr(struct dentry *dentry, struct inode *inode,
 		goto out;
 	}
 	inode_lock(lower_inode);
-	rc = __vfs_removexattr(&init_user_ns, lower_dentry, name);
+	rc = __vfs_removexattr(&nop_mnt_idmap, lower_dentry, name);
 	inode_unlock(lower_inode);
 out:
 	return rc;
@@ -1110,26 +1110,26 @@ static int ecryptfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return vfs_fileattr_get(ecryptfs_dentry_to_lower(dentry), fa);
 }
 
-static int ecryptfs_fileattr_set(struct user_namespace *mnt_userns,
+static int ecryptfs_fileattr_set(struct mnt_idmap *idmap,
 				 struct dentry *dentry, struct fileattr *fa)
 {
 	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
 	int rc;
 
-	rc = vfs_fileattr_set(&init_user_ns, lower_dentry, fa);
+	rc = vfs_fileattr_set(&nop_mnt_idmap, lower_dentry, fa);
 	fsstack_copy_attr_all(d_inode(dentry), d_inode(lower_dentry));
 
 	return rc;
 }
 
-static struct posix_acl *ecryptfs_get_acl(struct user_namespace *mnt_userns,
+static struct posix_acl *ecryptfs_get_acl(struct mnt_idmap *idmap,
 					  struct dentry *dentry, int type)
 {
-	return vfs_get_acl(mnt_userns, ecryptfs_dentry_to_lower(dentry),
+	return vfs_get_acl(idmap, ecryptfs_dentry_to_lower(dentry),
 			   posix_acl_xattr_name(type));
 }
 
-static int ecryptfs_set_acl(struct user_namespace *mnt_userns,
+static int ecryptfs_set_acl(struct mnt_idmap *idmap,
 			    struct dentry *dentry, struct posix_acl *acl,
 			    int type)
 {
@@ -1137,7 +1137,7 @@ static int ecryptfs_set_acl(struct user_namespace *mnt_userns,
 	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
 	struct inode *lower_inode = d_inode(lower_dentry);
 
-	rc = vfs_set_acl(&init_user_ns, lower_dentry,
+	rc = vfs_set_acl(&nop_mnt_idmap, lower_dentry,
 			 posix_acl_xattr_name(type), acl);
 	if (!rc)
 		fsstack_copy_attr_all(d_inode(dentry), lower_inode);
@@ -1190,7 +1190,7 @@ static int ecryptfs_xattr_get(const struct xattr_handler *handler,
 }
 
 static int ecryptfs_xattr_set(const struct xattr_handler *handler,
-			      struct user_namespace *mnt_userns,
+			      struct mnt_idmap *idmap,
 			      struct dentry *dentry, struct inode *inode,
 			      const char *name, const void *value, size_t size,
 			      int flags)
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 19af229eb7ca..373c3e5747e6 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -428,7 +428,7 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode)
 	if (size < 0)
 		size = 8;
 	put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt);
-	rc = __vfs_setxattr(&init_user_ns, lower_dentry, lower_inode,
+	rc = __vfs_setxattr(&nop_mnt_idmap, lower_dentry, lower_inode,
 			    ECRYPTFS_XATTR_NAME, xattr_virt, size, 0);
 	inode_unlock(lower_inode);
 	if (rc)
diff --git a/fs/efivarfs/inode.c b/fs/efivarfs/inode.c
index 617f3ad2485e..b973a2c03dde 100644
--- a/fs/efivarfs/inode.c
+++ b/fs/efivarfs/inode.c
@@ -70,7 +70,7 @@ bool efivarfs_valid_name(const char *str, int len)
 	return uuid_is_valid(s);
 }
 
-static int efivarfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int efivarfs_create(struct mnt_idmap *idmap, struct inode *dir,
 			   struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct inode *inode = NULL;
@@ -163,7 +163,7 @@ efivarfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 }
 
 static int
-efivarfs_fileattr_set(struct user_namespace *mnt_userns,
+efivarfs_fileattr_set(struct mnt_idmap *idmap,
 		      struct dentry *dentry, struct fileattr *fa)
 {
 	unsigned int i_flags = 0;
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index d3b8736fa124..a194e8ee5861 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -353,7 +353,7 @@ struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid)
 	return inode;
 }
 
-int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int erofs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, u32 request_mask,
 		  unsigned int query_flags)
 {
@@ -366,7 +366,7 @@ int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 	stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
 				  STATX_ATTR_IMMUTABLE);
 
-	generic_fillattr(mnt_userns, inode, stat);
+	generic_fillattr(idmap, inode, stat);
 	return 0;
 }
 
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index bb8501c0ff5b..e05ae61069e8 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -494,7 +494,7 @@ extern const struct inode_operations erofs_symlink_iops;
 extern const struct inode_operations erofs_fast_symlink_iops;
 
 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid);
-int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int erofs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, u32 request_mask,
 		  unsigned int query_flags);
 
diff --git a/fs/exec.c b/fs/exec.c
index ab913243a367..3d2b80d8d58e 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1414,15 +1414,15 @@ EXPORT_SYMBOL(begin_new_exec);
 void would_dump(struct linux_binprm *bprm, struct file *file)
 {
 	struct inode *inode = file_inode(file);
-	struct user_namespace *mnt_userns = file_mnt_user_ns(file);
-	if (inode_permission(mnt_userns, inode, MAY_READ) < 0) {
+	struct mnt_idmap *idmap = file_mnt_idmap(file);
+	if (inode_permission(idmap, inode, MAY_READ) < 0) {
 		struct user_namespace *old, *user_ns;
 		bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
 
 		/* Ensure mm->user_ns contains the executable */
 		user_ns = old = bprm->mm->user_ns;
 		while ((user_ns != &init_user_ns) &&
-		       !privileged_wrt_inode_uidgid(user_ns, mnt_userns, inode))
+		       !privileged_wrt_inode_uidgid(user_ns, idmap, inode))
 			user_ns = user_ns->parent;
 
 		if (old != user_ns) {
@@ -1596,7 +1596,7 @@ static void check_unsafe_exec(struct linux_binprm *bprm)
 static void bprm_fill_uid(struct linux_binprm *bprm, struct file *file)
 {
 	/* Handle suid and sgid on files */
-	struct user_namespace *mnt_userns;
+	struct mnt_idmap *idmap;
 	struct inode *inode = file_inode(file);
 	unsigned int mode;
 	vfsuid_t vfsuid;
@@ -1612,15 +1612,15 @@ static void bprm_fill_uid(struct linux_binprm *bprm, struct file *file)
 	if (!(mode & (S_ISUID|S_ISGID)))
 		return;
 
-	mnt_userns = file_mnt_user_ns(file);
+	idmap = file_mnt_idmap(file);
 
 	/* Be careful if suid/sgid is set */
 	inode_lock(inode);
 
 	/* reload atomically mode/uid/gid now that lock held */
 	mode = inode->i_mode;
-	vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
-	vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
+	vfsuid = i_uid_into_vfsuid(idmap, inode);
+	vfsgid = i_gid_into_vfsgid(idmap, inode);
 	inode_unlock(inode);
 
 	/* We ignore suid/sgid if there are no mappings for them in the ns */
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index bc6d21d7c5ad..1bf16abe3c84 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -450,9 +450,9 @@ int exfat_trim_fs(struct inode *inode, struct fstrim_range *range);
 extern const struct file_operations exfat_file_operations;
 int __exfat_truncate(struct inode *inode);
 void exfat_truncate(struct inode *inode);
-int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr);
-int exfat_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, unsigned int request_mask,
 		  unsigned int query_flags);
 int exfat_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);
diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index f5b29072775d..1fdb0a64b91d 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -226,14 +226,14 @@ write_size:
 	mutex_unlock(&sbi->s_lock);
 }
 
-int exfat_getattr(struct user_namespace *mnt_uerns, const struct path *path,
+int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, unsigned int request_mask,
 		  unsigned int query_flags)
 {
 	struct inode *inode = d_backing_inode(path->dentry);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	exfat_truncate_atime(&stat->atime);
 	stat->result_mask |= STATX_BTIME;
 	stat->btime.tv_sec = ei->i_crtime.tv_sec;
@@ -242,7 +242,7 @@ int exfat_getattr(struct user_namespace *mnt_uerns, const struct path *path,
 	return 0;
 }
 
-int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr)
 {
 	struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
@@ -266,7 +266,7 @@ int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 				ATTR_TIMES_SET);
 	}
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	attr->ia_valid = ia_valid;
 	if (error)
 		goto out;
@@ -293,7 +293,7 @@ int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (attr->ia_valid & ATTR_SIZE)
 		inode->i_mtime = inode->i_ctime = current_time(inode);
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	exfat_truncate_atime(&inode->i_atime);
 
 	if (attr->ia_valid & ATTR_SIZE) {
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
index 5f995eba5dbb..02aab4c3a5f7 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -551,7 +551,7 @@ out:
 	return ret;
 }
 
-static int exfat_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int exfat_create(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct super_block *sb = dir->i_sb;
@@ -834,7 +834,7 @@ unlock:
 	return err;
 }
 
-static int exfat_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int exfat_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode)
 {
 	struct super_block *sb = dir->i_sb;
@@ -1285,7 +1285,7 @@ out:
 	return ret;
 }
 
-static int exfat_rename(struct user_namespace *mnt_userns,
+static int exfat_rename(struct mnt_idmap *idmap,
 			struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 3204bd33e4e8..ab88d33d106c 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -145,7 +145,7 @@ static struct dentry *reconnect_one(struct vfsmount *mnt,
 	if (err)
 		goto out_err;
 	dprintk("%s: found name: %s\n", __func__, nbuf);
-	tmp = lookup_one_unlocked(mnt_user_ns(mnt), nbuf, parent, strlen(nbuf));
+	tmp = lookup_one_unlocked(mnt_idmap(mnt), nbuf, parent, strlen(nbuf));
 	if (IS_ERR(tmp)) {
 		dprintk("lookup failed: %ld\n", PTR_ERR(tmp));
 		err = PTR_ERR(tmp);
@@ -524,7 +524,7 @@ exportfs_decode_fh_raw(struct vfsmount *mnt, struct fid *fid, int fh_len,
 		}
 
 		inode_lock(target_dir->d_inode);
-		nresult = lookup_one(mnt_user_ns(mnt), nbuf,
+		nresult = lookup_one(mnt_idmap(mnt), nbuf,
 				     target_dir, strlen(nbuf));
 		if (!IS_ERR(nresult)) {
 			if (unlikely(nresult->d_inode != result->d_inode)) {
diff --git a/fs/ext2/acl.c b/fs/ext2/acl.c
index 440d5f1e9d47..82b17d7fc93f 100644
--- a/fs/ext2/acl.c
+++ b/fs/ext2/acl.c
@@ -219,7 +219,7 @@ __ext2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
  * inode->i_mutex: down
  */
 int
-ext2_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+ext2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	     struct posix_acl *acl, int type)
 {
 	int error;
@@ -228,7 +228,7 @@ ext2_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 	umode_t mode = inode->i_mode;
 
 	if (type == ACL_TYPE_ACCESS && acl) {
-		error = posix_acl_update_mode(&init_user_ns, inode, &mode,
+		error = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode,
 					      &acl);
 		if (error)
 			return error;
diff --git a/fs/ext2/acl.h b/fs/ext2/acl.h
index 3841becb94ff..4a8443a2b8ec 100644
--- a/fs/ext2/acl.h
+++ b/fs/ext2/acl.h
@@ -56,7 +56,7 @@ static inline int ext2_acl_count(size_t size)
 
 /* acl.c */
 extern struct posix_acl *ext2_get_acl(struct inode *inode, int type, bool rcu);
-extern int ext2_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+extern int ext2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 			struct posix_acl *acl, int type);
 extern int ext2_init_acl (struct inode *, struct inode *);
 
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index 28de11a22e5f..5b52306e2e95 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -753,8 +753,8 @@ extern struct inode *ext2_iget (struct super_block *, unsigned long);
 extern int ext2_write_inode (struct inode *, struct writeback_control *);
 extern void ext2_evict_inode(struct inode *);
 extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
-extern int ext2_setattr (struct user_namespace *, struct dentry *, struct iattr *);
-extern int ext2_getattr (struct user_namespace *, const struct path *,
+extern int ext2_setattr (struct mnt_idmap *, struct dentry *, struct iattr *);
+extern int ext2_getattr (struct mnt_idmap *, const struct path *,
 			 struct kstat *, u32, unsigned int);
 extern void ext2_set_inode_flags(struct inode *inode);
 extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
@@ -762,7 +762,7 @@ extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 
 /* ioctl.c */
 extern int ext2_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-extern int ext2_fileattr_set(struct user_namespace *mnt_userns,
+extern int ext2_fileattr_set(struct mnt_idmap *idmap,
 			     struct dentry *dentry, struct fileattr *fa);
 extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
 extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);
diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c
index 78b8686d9a4a..a4e1d7a9c544 100644
--- a/fs/ext2/ialloc.c
+++ b/fs/ext2/ialloc.c
@@ -545,7 +545,7 @@ got:
 		inode->i_uid = current_fsuid();
 		inode->i_gid = dir->i_gid;
 	} else
-		inode_init_owner(&init_user_ns, inode, dir, mode);
+		inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 
 	inode->i_ino = ino;
 	inode->i_blocks = 0;
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 69aed9e2359e..26f135e7ffce 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1592,7 +1592,7 @@ int ext2_write_inode(struct inode *inode, struct writeback_control *wbc)
 	return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
 }
 
-int ext2_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ext2_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
@@ -1614,28 +1614,28 @@ int ext2_getattr(struct user_namespace *mnt_userns, const struct path *path,
 			STATX_ATTR_IMMUTABLE |
 			STATX_ATTR_NODUMP);
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	return 0;
 }
 
-int ext2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ext2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct iattr *iattr)
 {
 	struct inode *inode = d_inode(dentry);
 	int error;
 
-	error = setattr_prepare(&init_user_ns, dentry, iattr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (error)
 		return error;
 
-	if (is_quota_modification(mnt_userns, inode, iattr)) {
+	if (is_quota_modification(&nop_mnt_idmap, inode, iattr)) {
 		error = dquot_initialize(inode);
 		if (error)
 			return error;
 	}
-	if (i_uid_needs_update(mnt_userns, iattr, inode) ||
-	    i_gid_needs_update(mnt_userns, iattr, inode)) {
-		error = dquot_transfer(mnt_userns, inode, iattr);
+	if (i_uid_needs_update(&nop_mnt_idmap, iattr, inode) ||
+	    i_gid_needs_update(&nop_mnt_idmap, iattr, inode)) {
+		error = dquot_transfer(&nop_mnt_idmap, inode, iattr);
 		if (error)
 			return error;
 	}
@@ -1644,9 +1644,9 @@ int ext2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		if (error)
 			return error;
 	}
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 	if (iattr->ia_valid & ATTR_MODE)
-		error = posix_acl_chmod(&init_user_ns, dentry, inode->i_mode);
+		error = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
 	mark_inode_dirty(inode);
 
 	return error;
diff --git a/fs/ext2/ioctl.c b/fs/ext2/ioctl.c
index e8340bf09b10..cc87d413eb43 100644
--- a/fs/ext2/ioctl.c
+++ b/fs/ext2/ioctl.c
@@ -27,7 +27,7 @@ int ext2_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return 0;
 }
 
-int ext2_fileattr_set(struct user_namespace *mnt_userns,
+int ext2_fileattr_set(struct mnt_idmap *idmap,
 		      struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
@@ -66,7 +66,7 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	case EXT2_IOC_SETVERSION: {
 		__u32 generation;
 
-		if (!inode_owner_or_capable(&init_user_ns, inode))
+		if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
 			return -EPERM;
 		ret = mnt_want_write_file(filp);
 		if (ret)
@@ -99,7 +99,7 @@ setversion_out:
 		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 			return -ENOTTY;
 
-		if (!inode_owner_or_capable(&init_user_ns, inode))
+		if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
 			return -EACCES;
 
 		if (get_user(rsv_window_size, (int __user *)arg))
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index c056957221a2..81808e3d11c1 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -99,7 +99,7 @@ struct dentry *ext2_get_parent(struct dentry *child)
  * If the create succeeds, we fill in the inode information
  * with d_instantiate(). 
  */
-static int ext2_create (struct user_namespace * mnt_userns,
+static int ext2_create (struct mnt_idmap * idmap,
 			struct inode * dir, struct dentry * dentry,
 			umode_t mode, bool excl)
 {
@@ -119,7 +119,7 @@ static int ext2_create (struct user_namespace * mnt_userns,
 	return ext2_add_nondir(dentry, inode);
 }
 
-static int ext2_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+static int ext2_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 			struct file *file, umode_t mode)
 {
 	struct inode *inode = ext2_new_inode(dir, mode, NULL);
@@ -133,7 +133,7 @@ static int ext2_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	return finish_open_simple(file, 0);
 }
 
-static int ext2_mknod (struct user_namespace * mnt_userns, struct inode * dir,
+static int ext2_mknod (struct mnt_idmap * idmap, struct inode * dir,
 	struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct inode * inode;
@@ -154,7 +154,7 @@ static int ext2_mknod (struct user_namespace * mnt_userns, struct inode * dir,
 	return err;
 }
 
-static int ext2_symlink (struct user_namespace * mnt_userns, struct inode * dir,
+static int ext2_symlink (struct mnt_idmap * idmap, struct inode * dir,
 	struct dentry * dentry, const char * symname)
 {
 	struct super_block * sb = dir->i_sb;
@@ -225,7 +225,7 @@ static int ext2_link (struct dentry * old_dentry, struct inode * dir,
 	return err;
 }
 
-static int ext2_mkdir(struct user_namespace * mnt_userns,
+static int ext2_mkdir(struct mnt_idmap * idmap,
 	struct inode * dir, struct dentry * dentry, umode_t mode)
 {
 	struct inode * inode;
@@ -315,7 +315,7 @@ static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
 	return err;
 }
 
-static int ext2_rename (struct user_namespace * mnt_userns,
+static int ext2_rename (struct mnt_idmap * idmap,
 			struct inode * old_dir, struct dentry * old_dentry,
 			struct inode * new_dir, struct dentry * new_dentry,
 			unsigned int flags)
diff --git a/fs/ext2/xattr_security.c b/fs/ext2/xattr_security.c
index ebade1f52451..db47b8ab153e 100644
--- a/fs/ext2/xattr_security.c
+++ b/fs/ext2/xattr_security.c
@@ -19,7 +19,7 @@ ext2_xattr_security_get(const struct xattr_handler *handler,
 
 static int
 ext2_xattr_security_set(const struct xattr_handler *handler,
-			struct user_namespace *mnt_userns,
+			struct mnt_idmap *idmap,
 			struct dentry *unused, struct inode *inode,
 			const char *name, const void *value,
 			size_t size, int flags)
diff --git a/fs/ext2/xattr_trusted.c b/fs/ext2/xattr_trusted.c
index 18a87d5dd1ab..995f931228ce 100644
--- a/fs/ext2/xattr_trusted.c
+++ b/fs/ext2/xattr_trusted.c
@@ -26,7 +26,7 @@ ext2_xattr_trusted_get(const struct xattr_handler *handler,
 
 static int
 ext2_xattr_trusted_set(const struct xattr_handler *handler,
-		       struct user_namespace *mnt_userns,
+		       struct mnt_idmap *idmap,
 		       struct dentry *unused, struct inode *inode,
 		       const char *name, const void *value,
 		       size_t size, int flags)
diff --git a/fs/ext2/xattr_user.c b/fs/ext2/xattr_user.c
index 58092449f8ff..dd1507231081 100644
--- a/fs/ext2/xattr_user.c
+++ b/fs/ext2/xattr_user.c
@@ -30,7 +30,7 @@ ext2_xattr_user_get(const struct xattr_handler *handler,
 
 static int
 ext2_xattr_user_set(const struct xattr_handler *handler,
-		    struct user_namespace *mnt_userns,
+		    struct mnt_idmap *idmap,
 		    struct dentry *unused, struct inode *inode,
 		    const char *name, const void *value,
 		    size_t size, int flags)
diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index a9f89539aeee..27fcbddfb148 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -225,7 +225,7 @@ __ext4_set_acl(handle_t *handle, struct inode *inode, int type,
 }
 
 int
-ext4_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+ext4_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	     struct posix_acl *acl, int type)
 {
 	handle_t *handle;
@@ -249,7 +249,7 @@ retry:
 		return PTR_ERR(handle);
 
 	if ((type == ACL_TYPE_ACCESS) && acl) {
-		error = posix_acl_update_mode(mnt_userns, inode, &mode, &acl);
+		error = posix_acl_update_mode(idmap, inode, &mode, &acl);
 		if (error)
 			goto out_stop;
 		if (mode != inode->i_mode)
diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h
index 09c4a8a3b716..0c5a79c3b5d4 100644
--- a/fs/ext4/acl.h
+++ b/fs/ext4/acl.h
@@ -56,7 +56,7 @@ static inline int ext4_acl_count(size_t size)
 
 /* acl.c */
 struct posix_acl *ext4_get_acl(struct inode *inode, int type, bool rcu);
-int ext4_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ext4_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type);
 extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
 
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 140e1eb300d1..43e26e6f6e42 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2845,7 +2845,7 @@ extern int ext4fs_dirhash(const struct inode *dir, const char *name, int len,
 
 /* ialloc.c */
 extern int ext4_mark_inode_used(struct super_block *sb, int ino);
-extern struct inode *__ext4_new_inode(struct user_namespace *, handle_t *,
+extern struct inode *__ext4_new_inode(struct mnt_idmap *, handle_t *,
 				      struct inode *, umode_t,
 				      const struct qstr *qstr, __u32 goal,
 				      uid_t *owner, __u32 i_flags,
@@ -2853,11 +2853,11 @@ extern struct inode *__ext4_new_inode(struct user_namespace *, handle_t *,
 				      int nblocks);
 
 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner, i_flags)          \
-	__ext4_new_inode(&init_user_ns, (handle), (dir), (mode), (qstr),       \
+	__ext4_new_inode(&nop_mnt_idmap, (handle), (dir), (mode), (qstr),      \
 			 (goal), (owner), i_flags, 0, 0, 0)
-#define ext4_new_inode_start_handle(mnt_userns, dir, mode, qstr, goal, owner, \
+#define ext4_new_inode_start_handle(idmap, dir, mode, qstr, goal, owner, \
 				    type, nblocks)		    \
-	__ext4_new_inode((mnt_userns), NULL, (dir), (mode), (qstr), (goal), (owner), \
+	__ext4_new_inode((idmap), NULL, (dir), (mode), (qstr), (goal), (owner), \
 			 0, (type), __LINE__, (nblocks))
 
 
@@ -2976,14 +2976,14 @@ extern struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,
 	__ext4_iget((sb), (ino), (flags), __func__, __LINE__)
 
 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
-extern int  ext4_setattr(struct user_namespace *, struct dentry *,
+extern int  ext4_setattr(struct mnt_idmap *, struct dentry *,
 			 struct iattr *);
 extern u32  ext4_dio_alignment(struct inode *inode);
-extern int  ext4_getattr(struct user_namespace *, const struct path *,
+extern int  ext4_getattr(struct mnt_idmap *, const struct path *,
 			 struct kstat *, u32, unsigned int);
 extern void ext4_evict_inode(struct inode *);
 extern void ext4_clear_inode(struct inode *);
-extern int  ext4_file_getattr(struct user_namespace *, const struct path *,
+extern int  ext4_file_getattr(struct mnt_idmap *, const struct path *,
 			      struct kstat *, u32, unsigned int);
 extern int  ext4_sync_inode(handle_t *, struct inode *);
 extern void ext4_dirty_inode(struct inode *, int);
@@ -3024,7 +3024,7 @@ extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
 /* ioctl.c */
 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
-int ext4_fileattr_set(struct user_namespace *mnt_userns,
+int ext4_fileattr_set(struct mnt_idmap *idmap,
 		      struct dentry *dentry, struct fileattr *fa);
 int ext4_fileattr_get(struct dentry *dentry, struct fileattr *fa);
 extern void ext4_reset_inode_seed(struct inode *inode);
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 63f9bb6e8851..157663031f8c 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -921,7 +921,7 @@ static int ext4_xattr_credits_for_new_inode(struct inode *dir, mode_t mode,
  * For other inodes, search forward from the parent directory's block
  * group to find a free inode.
  */
-struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
+struct inode *__ext4_new_inode(struct mnt_idmap *idmap,
 			       handle_t *handle, struct inode *dir,
 			       umode_t mode, const struct qstr *qstr,
 			       __u32 goal, uid_t *owner, __u32 i_flags,
@@ -972,10 +972,10 @@ struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
 		i_gid_write(inode, owner[1]);
 	} else if (test_opt(sb, GRPID)) {
 		inode->i_mode = mode;
-		inode_fsuid_set(inode, mnt_userns);
+		inode_fsuid_set(inode, idmap);
 		inode->i_gid = dir->i_gid;
 	} else
-		inode_init_owner(mnt_userns, inode, dir, mode);
+		inode_init_owner(idmap, inode, dir, mode);
 
 	if (ext4_has_feature_project(sb) &&
 	    ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9d9f414f99fe..be664dc9b991 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5434,7 +5434,7 @@ static void ext4_wait_for_tail_page_commit(struct inode *inode)
  *
  * Called with inode->i_rwsem down.
  */
-int ext4_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ext4_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -5454,7 +5454,7 @@ int ext4_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 				  ATTR_GID | ATTR_TIMES_SET))))
 		return -EPERM;
 
-	error = setattr_prepare(mnt_userns, dentry, attr);
+	error = setattr_prepare(idmap, dentry, attr);
 	if (error)
 		return error;
 
@@ -5466,14 +5466,14 @@ int ext4_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (error)
 		return error;
 
-	if (is_quota_modification(mnt_userns, inode, attr)) {
+	if (is_quota_modification(idmap, inode, attr)) {
 		error = dquot_initialize(inode);
 		if (error)
 			return error;
 	}
 
-	if (i_uid_needs_update(mnt_userns, attr, inode) ||
-	    i_gid_needs_update(mnt_userns, attr, inode)) {
+	if (i_uid_needs_update(idmap, attr, inode) ||
+	    i_gid_needs_update(idmap, attr, inode)) {
 		handle_t *handle;
 
 		/* (user+group)*(old+new) structure, inode write (sb,
@@ -5490,7 +5490,7 @@ int ext4_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		 * counts xattr inode references.
 		 */
 		down_read(&EXT4_I(inode)->xattr_sem);
-		error = dquot_transfer(mnt_userns, inode, attr);
+		error = dquot_transfer(idmap, inode, attr);
 		up_read(&EXT4_I(inode)->xattr_sem);
 
 		if (error) {
@@ -5499,8 +5499,8 @@ int ext4_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		}
 		/* Update corresponding info in inode so that everything is in
 		 * one transaction */
-		i_uid_update(mnt_userns, attr, inode);
-		i_gid_update(mnt_userns, attr, inode);
+		i_uid_update(idmap, attr, inode);
+		i_gid_update(idmap, attr, inode);
 		error = ext4_mark_inode_dirty(handle, inode);
 		ext4_journal_stop(handle);
 		if (unlikely(error)) {
@@ -5630,7 +5630,7 @@ out_mmap_sem:
 	if (!error) {
 		if (inc_ivers)
 			inode_inc_iversion(inode);
-		setattr_copy(mnt_userns, inode, attr);
+		setattr_copy(idmap, inode, attr);
 		mark_inode_dirty(inode);
 	}
 
@@ -5642,7 +5642,7 @@ out_mmap_sem:
 		ext4_orphan_del(NULL, inode);
 
 	if (!error && (ia_valid & ATTR_MODE))
-		rc = posix_acl_chmod(mnt_userns, dentry, inode->i_mode);
+		rc = posix_acl_chmod(idmap, dentry, inode->i_mode);
 
 err_out:
 	if  (error)
@@ -5668,7 +5668,7 @@ u32 ext4_dio_alignment(struct inode *inode)
 	return 1; /* use the iomap defaults */
 }
 
-int ext4_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ext4_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
@@ -5725,18 +5725,18 @@ int ext4_getattr(struct user_namespace *mnt_userns, const struct path *path,
 				  STATX_ATTR_NODUMP |
 				  STATX_ATTR_VERITY);
 
-	generic_fillattr(mnt_userns, inode, stat);
+	generic_fillattr(idmap, inode, stat);
 	return 0;
 }
 
-int ext4_file_getattr(struct user_namespace *mnt_userns,
+int ext4_file_getattr(struct mnt_idmap *idmap,
 		      const struct path *path, struct kstat *stat,
 		      u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
 	u64 delalloc_blocks;
 
-	ext4_getattr(mnt_userns, path, stat, request_mask, query_flags);
+	ext4_getattr(idmap, path, stat, request_mask, query_flags);
 
 	/*
 	 * If there is inline data in the inode, the inode will normally not
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 8067ccda34e4..b0dc7212694e 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -358,12 +358,12 @@ void ext4_reset_inode_seed(struct inode *inode)
  * important fields of the inodes.
  *
  * @sb:         the super block of the filesystem
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @inode:      the inode to swap with EXT4_BOOT_LOADER_INO
  *
  */
 static long swap_inode_boot_loader(struct super_block *sb,
-				struct user_namespace *mnt_userns,
+				struct mnt_idmap *idmap,
 				struct inode *inode)
 {
 	handle_t *handle;
@@ -393,7 +393,7 @@ static long swap_inode_boot_loader(struct super_block *sb,
 	}
 
 	if (IS_RDONLY(inode) || IS_APPEND(inode) || IS_IMMUTABLE(inode) ||
-	    !inode_owner_or_capable(mnt_userns, inode) ||
+	    !inode_owner_or_capable(idmap, inode) ||
 	    !capable(CAP_SYS_ADMIN)) {
 		err = -EPERM;
 		goto journal_err_out;
@@ -979,7 +979,7 @@ int ext4_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return 0;
 }
 
-int ext4_fileattr_set(struct user_namespace *mnt_userns,
+int ext4_fileattr_set(struct mnt_idmap *idmap,
 		      struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
@@ -1217,7 +1217,7 @@ static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);
 	struct super_block *sb = inode->i_sb;
-	struct user_namespace *mnt_userns = file_mnt_user_ns(filp);
+	struct mnt_idmap *idmap = file_mnt_idmap(filp);
 
 	ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
 
@@ -1234,7 +1234,7 @@ static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		__u32 generation;
 		int err;
 
-		if (!inode_owner_or_capable(mnt_userns, inode))
+		if (!inode_owner_or_capable(idmap, inode))
 			return -EPERM;
 
 		if (ext4_has_metadata_csum(inode->i_sb)) {
@@ -1376,7 +1376,7 @@ mext_out:
 	case EXT4_IOC_MIGRATE:
 	{
 		int err;
-		if (!inode_owner_or_capable(mnt_userns, inode))
+		if (!inode_owner_or_capable(idmap, inode))
 			return -EACCES;
 
 		err = mnt_want_write_file(filp);
@@ -1398,7 +1398,7 @@ mext_out:
 	case EXT4_IOC_ALLOC_DA_BLKS:
 	{
 		int err;
-		if (!inode_owner_or_capable(mnt_userns, inode))
+		if (!inode_owner_or_capable(idmap, inode))
 			return -EACCES;
 
 		err = mnt_want_write_file(filp);
@@ -1417,7 +1417,7 @@ mext_out:
 		err = mnt_want_write_file(filp);
 		if (err)
 			return err;
-		err = swap_inode_boot_loader(sb, mnt_userns, inode);
+		err = swap_inode_boot_loader(sb, idmap, inode);
 		mnt_drop_write_file(filp);
 		return err;
 	}
@@ -1542,7 +1542,7 @@ resizefs_out:
 
 	case EXT4_IOC_CLEAR_ES_CACHE:
 	{
-		if (!inode_owner_or_capable(mnt_userns, inode))
+		if (!inode_owner_or_capable(idmap, inode))
 			return -EACCES;
 		ext4_clear_inode_es(inode);
 		return 0;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index dd28453d6ea3..d10a508d95cd 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2792,7 +2792,7 @@ static int ext4_add_nondir(handle_t *handle,
  * If the create succeeds, we fill in the inode information
  * with d_instantiate().
  */
-static int ext4_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int ext4_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
 	handle_t *handle;
@@ -2806,7 +2806,7 @@ static int ext4_create(struct user_namespace *mnt_userns, struct inode *dir,
 	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
 		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
 retry:
-	inode = ext4_new_inode_start_handle(mnt_userns, dir, mode, &dentry->d_name,
+	inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name,
 					    0, NULL, EXT4_HT_DIR, credits);
 	handle = ext4_journal_current_handle();
 	err = PTR_ERR(inode);
@@ -2827,7 +2827,7 @@ retry:
 	return err;
 }
 
-static int ext4_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int ext4_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	handle_t *handle;
@@ -2841,7 +2841,7 @@ static int ext4_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
 		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
 retry:
-	inode = ext4_new_inode_start_handle(mnt_userns, dir, mode, &dentry->d_name,
+	inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name,
 					    0, NULL, EXT4_HT_DIR, credits);
 	handle = ext4_journal_current_handle();
 	err = PTR_ERR(inode);
@@ -2861,7 +2861,7 @@ retry:
 	return err;
 }
 
-static int ext4_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+static int ext4_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 			struct file *file, umode_t mode)
 {
 	handle_t *handle;
@@ -2873,7 +2873,7 @@ static int ext4_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 		return err;
 
 retry:
-	inode = ext4_new_inode_start_handle(mnt_userns, dir, mode,
+	inode = ext4_new_inode_start_handle(idmap, dir, mode,
 					    NULL, 0, NULL,
 					    EXT4_HT_DIR,
 			EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
@@ -2972,7 +2972,7 @@ out:
 	return err;
 }
 
-static int ext4_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int ext4_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
 	handle_t *handle;
@@ -2989,7 +2989,7 @@ static int ext4_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
 		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
 retry:
-	inode = ext4_new_inode_start_handle(mnt_userns, dir, S_IFDIR | mode,
+	inode = ext4_new_inode_start_handle(idmap, dir, S_IFDIR | mode,
 					    &dentry->d_name,
 					    0, NULL, EXT4_HT_DIR, credits);
 	handle = ext4_journal_current_handle();
@@ -3339,7 +3339,7 @@ out:
 	return err;
 }
 
-static int ext4_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int ext4_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, const char *symname)
 {
 	handle_t *handle;
@@ -3370,7 +3370,7 @@ static int ext4_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 	credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
 		  EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
 retry:
-	inode = ext4_new_inode_start_handle(mnt_userns, dir, S_IFLNK|S_IRWXUGO,
+	inode = ext4_new_inode_start_handle(idmap, dir, S_IFLNK|S_IRWXUGO,
 					    &dentry->d_name, 0, NULL,
 					    EXT4_HT_DIR, credits);
 	handle = ext4_journal_current_handle();
@@ -3720,7 +3720,7 @@ static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
 	}
 }
 
-static struct inode *ext4_whiteout_for_rename(struct user_namespace *mnt_userns,
+static struct inode *ext4_whiteout_for_rename(struct mnt_idmap *idmap,
 					      struct ext4_renament *ent,
 					      int credits, handle_t **h)
 {
@@ -3735,7 +3735,7 @@ static struct inode *ext4_whiteout_for_rename(struct user_namespace *mnt_userns,
 	credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
 		    EXT4_XATTR_TRANS_BLOCKS + 4);
 retry:
-	wh = ext4_new_inode_start_handle(mnt_userns, ent->dir,
+	wh = ext4_new_inode_start_handle(idmap, ent->dir,
 					 S_IFCHR | WHITEOUT_MODE,
 					 &ent->dentry->d_name, 0, NULL,
 					 EXT4_HT_DIR, credits);
@@ -3763,7 +3763,7 @@ retry:
  * while new_{dentry,inode) refers to the destination dentry/inode
  * This comes from rename(const char *oldpath, const char *newpath)
  */
-static int ext4_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		       struct dentry *old_dentry, struct inode *new_dir,
 		       struct dentry *new_dentry, unsigned int flags)
 {
@@ -3851,7 +3851,7 @@ static int ext4_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
 			goto release_bh;
 		}
 	} else {
-		whiteout = ext4_whiteout_for_rename(mnt_userns, &old, credits, &handle);
+		whiteout = ext4_whiteout_for_rename(idmap, &old, credits, &handle);
 		if (IS_ERR(whiteout)) {
 			retval = PTR_ERR(whiteout);
 			goto release_bh;
@@ -4158,7 +4158,7 @@ end_rename:
 	return retval;
 }
 
-static int ext4_rename2(struct user_namespace *mnt_userns,
+static int ext4_rename2(struct mnt_idmap *idmap,
 			struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
@@ -4181,7 +4181,7 @@ static int ext4_rename2(struct user_namespace *mnt_userns,
 					 new_dir, new_dentry);
 	}
 
-	return ext4_rename(mnt_userns, old_dir, old_dentry, new_dir, new_dentry, flags);
+	return ext4_rename(idmap, old_dir, old_dentry, new_dir, new_dentry, flags);
 }
 
 /*
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index 3d3ed3c38f56..75bf1f88843c 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -55,12 +55,12 @@ static const char *ext4_encrypted_get_link(struct dentry *dentry,
 	return paddr;
 }
 
-static int ext4_encrypted_symlink_getattr(struct user_namespace *mnt_userns,
+static int ext4_encrypted_symlink_getattr(struct mnt_idmap *idmap,
 					  const struct path *path,
 					  struct kstat *stat, u32 request_mask,
 					  unsigned int query_flags)
 {
-	ext4_getattr(mnt_userns, path, stat, request_mask, query_flags);
+	ext4_getattr(idmap, path, stat, request_mask, query_flags);
 
 	return fscrypt_symlink_getattr(path, stat);
 }
diff --git a/fs/ext4/xattr_hurd.c b/fs/ext4/xattr_hurd.c
index c78df5790377..8a5842e4cd95 100644
--- a/fs/ext4/xattr_hurd.c
+++ b/fs/ext4/xattr_hurd.c
@@ -32,7 +32,7 @@ ext4_xattr_hurd_get(const struct xattr_handler *handler,
 
 static int
 ext4_xattr_hurd_set(const struct xattr_handler *handler,
-		    struct user_namespace *mnt_userns,
+		    struct mnt_idmap *idmap,
 		    struct dentry *unused, struct inode *inode,
 		    const char *name, const void *value,
 		    size_t size, int flags)
diff --git a/fs/ext4/xattr_security.c b/fs/ext4/xattr_security.c
index 8213f66f7b2d..776cf11d24ca 100644
--- a/fs/ext4/xattr_security.c
+++ b/fs/ext4/xattr_security.c
@@ -23,7 +23,7 @@ ext4_xattr_security_get(const struct xattr_handler *handler,
 
 static int
 ext4_xattr_security_set(const struct xattr_handler *handler,
-			struct user_namespace *mnt_userns,
+			struct mnt_idmap *idmap,
 			struct dentry *unused, struct inode *inode,
 			const char *name, const void *value,
 			size_t size, int flags)
diff --git a/fs/ext4/xattr_trusted.c b/fs/ext4/xattr_trusted.c
index 7c21ffb26d25..9811eb0ab276 100644
--- a/fs/ext4/xattr_trusted.c
+++ b/fs/ext4/xattr_trusted.c
@@ -30,7 +30,7 @@ ext4_xattr_trusted_get(const struct xattr_handler *handler,
 
 static int
 ext4_xattr_trusted_set(const struct xattr_handler *handler,
-		       struct user_namespace *mnt_userns,
+		       struct mnt_idmap *idmap,
 		       struct dentry *unused, struct inode *inode,
 		       const char *name, const void *value,
 		       size_t size, int flags)
diff --git a/fs/ext4/xattr_user.c b/fs/ext4/xattr_user.c
index 2fe7ff0a479c..4b70bf4e7626 100644
--- a/fs/ext4/xattr_user.c
+++ b/fs/ext4/xattr_user.c
@@ -31,7 +31,7 @@ ext4_xattr_user_get(const struct xattr_handler *handler,
 
 static int
 ext4_xattr_user_set(const struct xattr_handler *handler,
-		    struct user_namespace *mnt_userns,
+		    struct mnt_idmap *idmap,
 		    struct dentry *unused, struct inode *inode,
 		    const char *name, const void *value,
 		    size_t size, int flags)
diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index c1c74aa658ae..ec2aeccb69a3 100644
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -204,7 +204,7 @@ struct posix_acl *f2fs_get_acl(struct inode *inode, int type, bool rcu)
 	return __f2fs_get_acl(inode, type, NULL);
 }
 
-static int f2fs_acl_update_mode(struct user_namespace *mnt_userns,
+static int f2fs_acl_update_mode(struct mnt_idmap *idmap,
 				struct inode *inode, umode_t *mode_p,
 				struct posix_acl **acl)
 {
@@ -219,14 +219,14 @@ static int f2fs_acl_update_mode(struct user_namespace *mnt_userns,
 		return error;
 	if (error == 0)
 		*acl = NULL;
-	if (!vfsgid_in_group_p(i_gid_into_vfsgid(mnt_userns, inode)) &&
-	    !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
+	if (!vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)) &&
+	    !capable_wrt_inode_uidgid(idmap, inode, CAP_FSETID))
 		mode &= ~S_ISGID;
 	*mode_p = mode;
 	return 0;
 }
 
-static int __f2fs_set_acl(struct user_namespace *mnt_userns,
+static int __f2fs_set_acl(struct mnt_idmap *idmap,
 			struct inode *inode, int type,
 			struct posix_acl *acl, struct page *ipage)
 {
@@ -240,7 +240,7 @@ static int __f2fs_set_acl(struct user_namespace *mnt_userns,
 	case ACL_TYPE_ACCESS:
 		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
 		if (acl && !ipage) {
-			error = f2fs_acl_update_mode(mnt_userns, inode,
+			error = f2fs_acl_update_mode(idmap, inode,
 								&mode, &acl);
 			if (error)
 				return error;
@@ -276,7 +276,7 @@ static int __f2fs_set_acl(struct user_namespace *mnt_userns,
 	return error;
 }
 
-int f2fs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int f2fs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type)
 {
 	struct inode *inode = d_inode(dentry);
@@ -284,7 +284,7 @@ int f2fs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
 		return -EIO;
 
-	return __f2fs_set_acl(mnt_userns, inode, type, acl, NULL);
+	return __f2fs_set_acl(idmap, inode, type, acl, NULL);
 }
 
 /*
diff --git a/fs/f2fs/acl.h b/fs/f2fs/acl.h
index ea2bbb3f264b..94ebfbfbdc6f 100644
--- a/fs/f2fs/acl.h
+++ b/fs/f2fs/acl.h
@@ -34,7 +34,7 @@ struct f2fs_acl_header {
 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 
 extern struct posix_acl *f2fs_get_acl(struct inode *, int, bool);
-extern int f2fs_set_acl(struct user_namespace *, struct dentry *,
+extern int f2fs_set_acl(struct mnt_idmap *, struct dentry *,
 			struct posix_acl *, int);
 extern int f2fs_init_acl(struct inode *, struct inode *, struct page *,
 							struct page *);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e8953c3dc81a..9a3ffa39ad30 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3469,15 +3469,15 @@ void f2fs_truncate_data_blocks(struct dnode_of_data *dn);
 int f2fs_do_truncate_blocks(struct inode *inode, u64 from, bool lock);
 int f2fs_truncate_blocks(struct inode *inode, u64 from, bool lock);
 int f2fs_truncate(struct inode *inode);
-int f2fs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int f2fs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, unsigned int flags);
-int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct iattr *attr);
 int f2fs_truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end);
 void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count);
 int f2fs_precache_extents(struct inode *inode);
 int f2fs_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-int f2fs_fileattr_set(struct user_namespace *mnt_userns,
+int f2fs_fileattr_set(struct mnt_idmap *idmap,
 		      struct dentry *dentry, struct fileattr *fa);
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
 long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
@@ -3505,7 +3505,7 @@ void f2fs_handle_failed_inode(struct inode *inode);
 int f2fs_update_extension_list(struct f2fs_sb_info *sbi, const char *name,
 							bool hot, bool set);
 struct dentry *f2fs_get_parent(struct dentry *child);
-int f2fs_get_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+int f2fs_get_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 		     struct inode **new_inode);
 
 /*
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ecbc8c135b49..b90617639743 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -837,7 +837,7 @@ static bool f2fs_force_buffered_io(struct inode *inode, int rw)
 	return false;
 }
 
-int f2fs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int f2fs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
@@ -892,7 +892,7 @@ int f2fs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 				  STATX_ATTR_NODUMP |
 				  STATX_ATTR_VERITY);
 
-	generic_fillattr(mnt_userns, inode, stat);
+	generic_fillattr(idmap, inode, stat);
 
 	/* we need to show initial sectors used for inline_data/dentries */
 	if ((S_ISREG(inode->i_mode) && f2fs_has_inline_data(inode)) ||
@@ -903,13 +903,13 @@ int f2fs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 }
 
 #ifdef CONFIG_F2FS_FS_POSIX_ACL
-static void __setattr_copy(struct user_namespace *mnt_userns,
+static void __setattr_copy(struct mnt_idmap *idmap,
 			   struct inode *inode, const struct iattr *attr)
 {
 	unsigned int ia_valid = attr->ia_valid;
 
-	i_uid_update(mnt_userns, attr, inode);
-	i_gid_update(mnt_userns, attr, inode);
+	i_uid_update(idmap, attr, inode);
+	i_gid_update(idmap, attr, inode);
 	if (ia_valid & ATTR_ATIME)
 		inode->i_atime = attr->ia_atime;
 	if (ia_valid & ATTR_MTIME)
@@ -918,10 +918,10 @@ static void __setattr_copy(struct user_namespace *mnt_userns,
 		inode->i_ctime = attr->ia_ctime;
 	if (ia_valid & ATTR_MODE) {
 		umode_t mode = attr->ia_mode;
-		vfsgid_t vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
+		vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
 
 		if (!vfsgid_in_group_p(vfsgid) &&
-		    !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
+		    !capable_wrt_inode_uidgid(idmap, inode, CAP_FSETID))
 			mode &= ~S_ISGID;
 		set_acl_inode(inode, mode);
 	}
@@ -930,7 +930,7 @@ static void __setattr_copy(struct user_namespace *mnt_userns,
 #define __setattr_copy setattr_copy
 #endif
 
-int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -951,7 +951,7 @@ int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		!f2fs_is_compress_backend_ready(inode))
 		return -EOPNOTSUPP;
 
-	err = setattr_prepare(mnt_userns, dentry, attr);
+	err = setattr_prepare(idmap, dentry, attr);
 	if (err)
 		return err;
 
@@ -963,15 +963,15 @@ int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (err)
 		return err;
 
-	if (is_quota_modification(mnt_userns, inode, attr)) {
+	if (is_quota_modification(idmap, inode, attr)) {
 		err = f2fs_dquot_initialize(inode);
 		if (err)
 			return err;
 	}
-	if (i_uid_needs_update(mnt_userns, attr, inode) ||
-	    i_gid_needs_update(mnt_userns, attr, inode)) {
+	if (i_uid_needs_update(idmap, attr, inode) ||
+	    i_gid_needs_update(idmap, attr, inode)) {
 		f2fs_lock_op(F2FS_I_SB(inode));
-		err = dquot_transfer(mnt_userns, inode, attr);
+		err = dquot_transfer(idmap, inode, attr);
 		if (err) {
 			set_sbi_flag(F2FS_I_SB(inode),
 					SBI_QUOTA_NEED_REPAIR);
@@ -982,8 +982,8 @@ int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		 * update uid/gid under lock_op(), so that dquot and inode can
 		 * be updated atomically.
 		 */
-		i_uid_update(mnt_userns, attr, inode);
-		i_gid_update(mnt_userns, attr, inode);
+		i_uid_update(idmap, attr, inode);
+		i_gid_update(idmap, attr, inode);
 		f2fs_mark_inode_dirty_sync(inode, true);
 		f2fs_unlock_op(F2FS_I_SB(inode));
 	}
@@ -1023,10 +1023,10 @@ int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		spin_unlock(&F2FS_I(inode)->i_size_lock);
 	}
 
-	__setattr_copy(mnt_userns, inode, attr);
+	__setattr_copy(idmap, inode, attr);
 
 	if (attr->ia_valid & ATTR_MODE) {
-		err = posix_acl_chmod(mnt_userns, dentry, f2fs_get_inode_mode(inode));
+		err = posix_acl_chmod(idmap, dentry, f2fs_get_inode_mode(inode));
 
 		if (is_inode_flag_set(inode, FI_ACL_MODE)) {
 			if (!err)
@@ -2038,14 +2038,14 @@ static int f2fs_ioc_getversion(struct file *filp, unsigned long arg)
 static int f2fs_ioc_start_atomic_write(struct file *filp, bool truncate)
 {
 	struct inode *inode = file_inode(filp);
-	struct user_namespace *mnt_userns = file_mnt_user_ns(filp);
+	struct mnt_idmap *idmap = file_mnt_idmap(filp);
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct inode *pinode;
 	loff_t isize;
 	int ret;
 
-	if (!inode_owner_or_capable(mnt_userns, inode))
+	if (!inode_owner_or_capable(idmap, inode))
 		return -EACCES;
 
 	if (!S_ISREG(inode->i_mode))
@@ -2095,7 +2095,7 @@ static int f2fs_ioc_start_atomic_write(struct file *filp, bool truncate)
 		goto out;
 	}
 
-	ret = f2fs_get_tmpfile(mnt_userns, pinode, &fi->cow_inode);
+	ret = f2fs_get_tmpfile(idmap, pinode, &fi->cow_inode);
 	iput(pinode);
 	if (ret) {
 		f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
@@ -2135,10 +2135,10 @@ out:
 static int f2fs_ioc_commit_atomic_write(struct file *filp)
 {
 	struct inode *inode = file_inode(filp);
-	struct user_namespace *mnt_userns = file_mnt_user_ns(filp);
+	struct mnt_idmap *idmap = file_mnt_idmap(filp);
 	int ret;
 
-	if (!inode_owner_or_capable(mnt_userns, inode))
+	if (!inode_owner_or_capable(idmap, inode))
 		return -EACCES;
 
 	ret = mnt_want_write_file(filp);
@@ -2167,10 +2167,10 @@ static int f2fs_ioc_commit_atomic_write(struct file *filp)
 static int f2fs_ioc_abort_atomic_write(struct file *filp)
 {
 	struct inode *inode = file_inode(filp);
-	struct user_namespace *mnt_userns = file_mnt_user_ns(filp);
+	struct mnt_idmap *idmap = file_mnt_idmap(filp);
 	int ret;
 
-	if (!inode_owner_or_capable(mnt_userns, inode))
+	if (!inode_owner_or_capable(idmap, inode))
 		return -EACCES;
 
 	ret = mnt_want_write_file(filp);
@@ -3090,7 +3090,7 @@ int f2fs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return 0;
 }
 
-int f2fs_fileattr_set(struct user_namespace *mnt_userns,
+int f2fs_fileattr_set(struct mnt_idmap *idmap,
 		      struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 6032589099ce..d8e01bbbf27f 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -202,7 +202,7 @@ static void set_file_temperature(struct f2fs_sb_info *sbi, struct inode *inode,
 		file_set_hot(inode);
 }
 
-static struct inode *f2fs_new_inode(struct user_namespace *mnt_userns,
+static struct inode *f2fs_new_inode(struct mnt_idmap *idmap,
 						struct inode *dir, umode_t mode,
 						const char *name)
 {
@@ -225,7 +225,7 @@ static struct inode *f2fs_new_inode(struct user_namespace *mnt_userns,
 
 	nid_free = true;
 
-	inode_init_owner(mnt_userns, inode, dir, mode);
+	inode_init_owner(idmap, inode, dir, mode);
 
 	inode->i_ino = ino;
 	inode->i_blocks = 0;
@@ -246,7 +246,7 @@ static struct inode *f2fs_new_inode(struct user_namespace *mnt_userns,
 		(F2FS_I(dir)->i_flags & F2FS_PROJINHERIT_FL))
 		F2FS_I(inode)->i_projid = F2FS_I(dir)->i_projid;
 	else
-		F2FS_I(inode)->i_projid = make_kprojid(mnt_userns,
+		F2FS_I(inode)->i_projid = make_kprojid(&init_user_ns,
 							F2FS_DEF_PROJID);
 
 	err = fscrypt_prepare_new_inode(dir, inode, &encrypt);
@@ -333,7 +333,7 @@ fail_drop:
 	return ERR_PTR(err);
 }
 
-static int f2fs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int f2fs_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
@@ -350,7 +350,7 @@ static int f2fs_create(struct user_namespace *mnt_userns, struct inode *dir,
 	if (err)
 		return err;
 
-	inode = f2fs_new_inode(mnt_userns, dir, mode, dentry->d_name.name);
+	inode = f2fs_new_inode(idmap, dir, mode, dentry->d_name.name);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
@@ -659,7 +659,7 @@ static const char *f2fs_get_link(struct dentry *dentry,
 	return link;
 }
 
-static int f2fs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int f2fs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, const char *symname)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
@@ -682,7 +682,7 @@ static int f2fs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 	if (err)
 		return err;
 
-	inode = f2fs_new_inode(mnt_userns, dir, S_IFLNK | S_IRWXUGO, NULL);
+	inode = f2fs_new_inode(idmap, dir, S_IFLNK | S_IRWXUGO, NULL);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
@@ -739,7 +739,7 @@ out_free_encrypted_link:
 	return err;
 }
 
-static int f2fs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int f2fs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
@@ -753,7 +753,7 @@ static int f2fs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 	if (err)
 		return err;
 
-	inode = f2fs_new_inode(mnt_userns, dir, S_IFDIR | mode, NULL);
+	inode = f2fs_new_inode(idmap, dir, S_IFDIR | mode, NULL);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
@@ -794,7 +794,7 @@ static int f2fs_rmdir(struct inode *dir, struct dentry *dentry)
 	return -ENOTEMPTY;
 }
 
-static int f2fs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int f2fs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
@@ -810,7 +810,7 @@ static int f2fs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	if (err)
 		return err;
 
-	inode = f2fs_new_inode(mnt_userns, dir, mode, NULL);
+	inode = f2fs_new_inode(idmap, dir, mode, NULL);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
@@ -837,7 +837,7 @@ out:
 	return err;
 }
 
-static int __f2fs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+static int __f2fs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 			  struct file *file, umode_t mode, bool is_whiteout,
 			  struct inode **new_inode)
 {
@@ -849,7 +849,7 @@ static int __f2fs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	if (err)
 		return err;
 
-	inode = f2fs_new_inode(mnt_userns, dir, mode, NULL);
+	inode = f2fs_new_inode(idmap, dir, mode, NULL);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
@@ -907,7 +907,7 @@ out:
 	return err;
 }
 
-static int f2fs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+static int f2fs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 			struct file *file, umode_t mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
@@ -918,28 +918,28 @@ static int f2fs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	if (!f2fs_is_checkpoint_ready(sbi))
 		return -ENOSPC;
 
-	err = __f2fs_tmpfile(mnt_userns, dir, file, mode, false, NULL);
+	err = __f2fs_tmpfile(idmap, dir, file, mode, false, NULL);
 
 	return finish_open_simple(file, err);
 }
 
-static int f2fs_create_whiteout(struct user_namespace *mnt_userns,
+static int f2fs_create_whiteout(struct mnt_idmap *idmap,
 				struct inode *dir, struct inode **whiteout)
 {
 	if (unlikely(f2fs_cp_error(F2FS_I_SB(dir))))
 		return -EIO;
 
-	return __f2fs_tmpfile(mnt_userns, dir, NULL,
+	return __f2fs_tmpfile(idmap, dir, NULL,
 				S_IFCHR | WHITEOUT_MODE, true, whiteout);
 }
 
-int f2fs_get_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+int f2fs_get_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 		     struct inode **new_inode)
 {
-	return __f2fs_tmpfile(mnt_userns, dir, NULL, S_IFREG, false, new_inode);
+	return __f2fs_tmpfile(idmap, dir, NULL, S_IFREG, false, new_inode);
 }
 
-static int f2fs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int f2fs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 			struct dentry *old_dentry, struct inode *new_dir,
 			struct dentry *new_dentry, unsigned int flags)
 {
@@ -979,7 +979,7 @@ static int f2fs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
 	}
 
 	if (flags & RENAME_WHITEOUT) {
-		err = f2fs_create_whiteout(mnt_userns, old_dir, &whiteout);
+		err = f2fs_create_whiteout(idmap, old_dir, &whiteout);
 		if (err)
 			return err;
 	}
@@ -1295,7 +1295,7 @@ out:
 	return err;
 }
 
-static int f2fs_rename2(struct user_namespace *mnt_userns,
+static int f2fs_rename2(struct mnt_idmap *idmap,
 			struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
@@ -1318,7 +1318,7 @@ static int f2fs_rename2(struct user_namespace *mnt_userns,
 	 * VFS has already handled the new dentry existence case,
 	 * here, we just deal with "RENAME_NOREPLACE" as regular rename.
 	 */
-	return f2fs_rename(mnt_userns, old_dir, old_dentry,
+	return f2fs_rename(idmap, old_dir, old_dentry,
 					new_dir, new_dentry, flags);
 }
 
@@ -1342,12 +1342,12 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
 	return target;
 }
 
-static int f2fs_encrypted_symlink_getattr(struct user_namespace *mnt_userns,
+static int f2fs_encrypted_symlink_getattr(struct mnt_idmap *idmap,
 					  const struct path *path,
 					  struct kstat *stat, u32 request_mask,
 					  unsigned int query_flags)
 {
-	f2fs_getattr(mnt_userns, path, stat, request_mask, query_flags);
+	f2fs_getattr(idmap, path, stat, request_mask, query_flags);
 
 	return fscrypt_symlink_getattr(path, stat);
 }
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index 77fd453949b1..dfd41908b12d 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -258,15 +258,15 @@ static int recover_quota_data(struct inode *inode, struct page *page)
 	attr.ia_vfsuid = VFSUIDT_INIT(make_kuid(inode->i_sb->s_user_ns, i_uid));
 	attr.ia_vfsgid = VFSGIDT_INIT(make_kgid(inode->i_sb->s_user_ns, i_gid));
 
-	if (!vfsuid_eq(attr.ia_vfsuid, i_uid_into_vfsuid(&init_user_ns, inode)))
+	if (!vfsuid_eq(attr.ia_vfsuid, i_uid_into_vfsuid(&nop_mnt_idmap, inode)))
 		attr.ia_valid |= ATTR_UID;
-	if (!vfsgid_eq(attr.ia_vfsgid, i_gid_into_vfsgid(&init_user_ns, inode)))
+	if (!vfsgid_eq(attr.ia_vfsgid, i_gid_into_vfsgid(&nop_mnt_idmap, inode)))
 		attr.ia_valid |= ATTR_GID;
 
 	if (!attr.ia_valid)
 		return 0;
 
-	err = dquot_transfer(&init_user_ns, inode, &attr);
+	err = dquot_transfer(&nop_mnt_idmap, inode, &attr);
 	if (err)
 		set_sbi_flag(F2FS_I_SB(inode), SBI_QUOTA_NEED_REPAIR);
 	return err;
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index dc2e8637189e..d92edbbdc30e 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -65,7 +65,7 @@ static int f2fs_xattr_generic_get(const struct xattr_handler *handler,
 }
 
 static int f2fs_xattr_generic_set(const struct xattr_handler *handler,
-		struct user_namespace *mnt_userns,
+		struct mnt_idmap *idmap,
 		struct dentry *unused, struct inode *inode,
 		const char *name, const void *value,
 		size_t size, int flags)
@@ -109,7 +109,7 @@ static int f2fs_xattr_advise_get(const struct xattr_handler *handler,
 }
 
 static int f2fs_xattr_advise_set(const struct xattr_handler *handler,
-		struct user_namespace *mnt_userns,
+		struct mnt_idmap *idmap,
 		struct dentry *unused, struct inode *inode,
 		const char *name, const void *value,
 		size_t size, int flags)
@@ -117,7 +117,7 @@ static int f2fs_xattr_advise_set(const struct xattr_handler *handler,
 	unsigned char old_advise = F2FS_I(inode)->i_advise;
 	unsigned char new_advise;
 
-	if (!inode_owner_or_capable(&init_user_ns, inode))
+	if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
 		return -EPERM;
 	if (value == NULL)
 		return -EINVAL;
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index a415c02ede39..e3b690b48e3e 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -398,10 +398,10 @@ extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
 			      unsigned long arg);
 extern const struct file_operations fat_file_operations;
 extern const struct inode_operations fat_file_inode_operations;
-extern int fat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+extern int fat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		       struct iattr *attr);
 extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
-extern int fat_getattr(struct user_namespace *mnt_userns,
+extern int fat_getattr(struct mnt_idmap *idmap,
 		       const struct path *path, struct kstat *stat,
 		       u32 request_mask, unsigned int flags);
 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 8a6b493b5b5f..795a4fad5c40 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -90,13 +90,13 @@ static int fat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
 	 * out the RO attribute for checking by the security
 	 * module, just because it maps to a file mode.
 	 */
-	err = security_inode_setattr(file_mnt_user_ns(file),
+	err = security_inode_setattr(file_mnt_idmap(file),
 				     file->f_path.dentry, &ia);
 	if (err)
 		goto out_unlock_inode;
 
 	/* This MUST be done before doing anything irreversible... */
-	err = fat_setattr(file_mnt_user_ns(file), file->f_path.dentry, &ia);
+	err = fat_setattr(file_mnt_idmap(file), file->f_path.dentry, &ia);
 	if (err)
 		goto out_unlock_inode;
 
@@ -395,13 +395,13 @@ void fat_truncate_blocks(struct inode *inode, loff_t offset)
 	fat_flush_inodes(inode->i_sb, inode, NULL);
 }
 
-int fat_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int fat_getattr(struct mnt_idmap *idmap, const struct path *path,
 		struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	struct inode *inode = d_inode(path->dentry);
 	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 
-	generic_fillattr(mnt_userns, inode, stat);
+	generic_fillattr(idmap, inode, stat);
 	stat->blksize = sbi->cluster_size;
 
 	if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) {
@@ -456,14 +456,14 @@ static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
 	return 0;
 }
 
-static int fat_allow_set_time(struct user_namespace *mnt_userns,
+static int fat_allow_set_time(struct mnt_idmap *idmap,
 			      struct msdos_sb_info *sbi, struct inode *inode)
 {
 	umode_t allow_utime = sbi->options.allow_utime;
 
-	if (!vfsuid_eq_kuid(i_uid_into_vfsuid(mnt_userns, inode),
+	if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode),
 			    current_fsuid())) {
-		if (vfsgid_in_group_p(i_gid_into_vfsgid(mnt_userns, inode)))
+		if (vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)))
 			allow_utime >>= 3;
 		if (allow_utime & MAY_WRITE)
 			return 1;
@@ -477,7 +477,7 @@ static int fat_allow_set_time(struct user_namespace *mnt_userns,
 /* valid file mode bits */
 #define FAT_VALID_MODE	(S_IFREG | S_IFDIR | S_IRWXUGO)
 
-int fat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int fat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct iattr *attr)
 {
 	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
@@ -488,11 +488,11 @@ int fat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	/* Check for setting the inode time. */
 	ia_valid = attr->ia_valid;
 	if (ia_valid & TIMES_SET_FLAGS) {
-		if (fat_allow_set_time(mnt_userns, sbi, inode))
+		if (fat_allow_set_time(idmap, sbi, inode))
 			attr->ia_valid &= ~TIMES_SET_FLAGS;
 	}
 
-	error = setattr_prepare(mnt_userns, dentry, attr);
+	error = setattr_prepare(idmap, dentry, attr);
 	attr->ia_valid = ia_valid;
 	if (error) {
 		if (sbi->options.quiet)
@@ -518,10 +518,10 @@ int fat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	}
 
 	if (((attr->ia_valid & ATTR_UID) &&
-	     (!uid_eq(from_vfsuid(mnt_userns, i_user_ns(inode), attr->ia_vfsuid),
+	     (!uid_eq(from_vfsuid(idmap, i_user_ns(inode), attr->ia_vfsuid),
 		      sbi->options.fs_uid))) ||
 	    ((attr->ia_valid & ATTR_GID) &&
-	     (!gid_eq(from_vfsgid(mnt_userns, i_user_ns(inode), attr->ia_vfsgid),
+	     (!gid_eq(from_vfsgid(idmap, i_user_ns(inode), attr->ia_vfsgid),
 		      sbi->options.fs_gid))) ||
 	    ((attr->ia_valid & ATTR_MODE) &&
 	     (attr->ia_mode & ~FAT_VALID_MODE)))
@@ -564,7 +564,7 @@ int fat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		fat_truncate_time(inode, &attr->ia_mtime, S_MTIME);
 	attr->ia_valid &= ~(ATTR_ATIME|ATTR_CTIME|ATTR_MTIME);
 
-	setattr_copy(mnt_userns, inode, attr);
+	setattr_copy(idmap, inode, attr);
 	mark_inode_dirty(inode);
 out:
 	return error;
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index efba301d68ae..2116c486843b 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -261,7 +261,7 @@ static int msdos_add_entry(struct inode *dir, const unsigned char *name,
 }
 
 /***** Create a file */
-static int msdos_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int msdos_create(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct super_block *sb = dir->i_sb;
@@ -339,7 +339,7 @@ out:
 }
 
 /***** Make a directory */
-static int msdos_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int msdos_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode)
 {
 	struct super_block *sb = dir->i_sb;
@@ -594,7 +594,7 @@ error_inode:
 }
 
 /***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
-static int msdos_rename(struct user_namespace *mnt_userns,
+static int msdos_rename(struct mnt_idmap *idmap,
 			struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 21620054e1c4..fceda1de4805 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -756,7 +756,7 @@ error:
 	return ERR_PTR(err);
 }
 
-static int vfat_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int vfat_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct super_block *sb = dir->i_sb;
@@ -844,7 +844,7 @@ out:
 	return err;
 }
 
-static int vfat_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int vfat_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
 	struct super_block *sb = dir->i_sb;
@@ -1158,7 +1158,7 @@ error_exchange:
 	goto out;
 }
 
-static int vfat_rename2(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int vfat_rename2(struct mnt_idmap *idmap, struct inode *old_dir,
 			struct dentry *old_dentry, struct inode *new_dir,
 			struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 7852e946fdf4..b622be119706 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -48,7 +48,7 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
 
 	/* O_NOATIME can only be set by the owner or superuser */
 	if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME))
-		if (!inode_owner_or_capable(file_mnt_user_ns(filp), inode))
+		if (!inode_owner_or_capable(file_mnt_idmap(filp), inode))
 			return -EPERM;
 
 	/* required for strict SunOS emulation */
diff --git a/fs/fuse/acl.c b/fs/fuse/acl.c
index ad670369955f..3d192b80a561 100644
--- a/fs/fuse/acl.c
+++ b/fs/fuse/acl.c
@@ -12,7 +12,7 @@
 #include <linux/posix_acl_xattr.h>
 
 static struct posix_acl *__fuse_get_acl(struct fuse_conn *fc,
-					struct user_namespace *mnt_userns,
+					struct mnt_idmap *idmap,
 					struct inode *inode, int type, bool rcu)
 {
 	int size;
@@ -65,7 +65,7 @@ static inline bool fuse_no_acl(const struct fuse_conn *fc,
 	return !fc->posix_acl && (i_user_ns(inode) != &init_user_ns);
 }
 
-struct posix_acl *fuse_get_acl(struct user_namespace *mnt_userns,
+struct posix_acl *fuse_get_acl(struct mnt_idmap *idmap,
 			       struct dentry *dentry, int type)
 {
 	struct inode *inode = d_inode(dentry);
@@ -74,7 +74,7 @@ struct posix_acl *fuse_get_acl(struct user_namespace *mnt_userns,
 	if (fuse_no_acl(fc, inode))
 		return ERR_PTR(-EOPNOTSUPP);
 
-	return __fuse_get_acl(fc, mnt_userns, inode, type, false);
+	return __fuse_get_acl(fc, idmap, inode, type, false);
 }
 
 struct posix_acl *fuse_get_inode_acl(struct inode *inode, int type, bool rcu)
@@ -91,10 +91,10 @@ struct posix_acl *fuse_get_inode_acl(struct inode *inode, int type, bool rcu)
 	if (!fc->posix_acl)
 		return NULL;
 
-	return __fuse_get_acl(fc, &init_user_ns, inode, type, rcu);
+	return __fuse_get_acl(fc, &nop_mnt_idmap, inode, type, rcu);
 }
 
-int fuse_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int fuse_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type)
 {
 	struct inode *inode = d_inode(dentry);
@@ -146,8 +146,8 @@ int fuse_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 		 * be stripped.
 		 */
 		if (fc->posix_acl &&
-		    !vfsgid_in_group_p(i_gid_into_vfsgid(&init_user_ns, inode)) &&
-		    !capable_wrt_inode_uidgid(&init_user_ns, inode, CAP_FSETID))
+		    !vfsgid_in_group_p(i_gid_into_vfsgid(&nop_mnt_idmap, inode)) &&
+		    !capable_wrt_inode_uidgid(&nop_mnt_idmap, inode, CAP_FSETID))
 			extra_flags |= FUSE_SETXATTR_ACL_KILL_SGID;
 
 		ret = fuse_setxattr(inode, name, value, size, 0, extra_flags);
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 2725fb54328e..cd1eae61e84c 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -645,7 +645,7 @@ out_err:
 	return err;
 }
 
-static int fuse_mknod(struct user_namespace *, struct inode *, struct dentry *,
+static int fuse_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
 		      umode_t, dev_t);
 static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
 			    struct file *file, unsigned flags,
@@ -686,7 +686,7 @@ out_dput:
 	return err;
 
 mknod:
-	err = fuse_mknod(&init_user_ns, dir, entry, mode, 0);
+	err = fuse_mknod(&nop_mnt_idmap, dir, entry, mode, 0);
 	if (err)
 		goto out_dput;
 no_open:
@@ -773,7 +773,7 @@ static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args,
 	return err;
 }
 
-static int fuse_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *entry, umode_t mode, dev_t rdev)
 {
 	struct fuse_mknod_in inarg;
@@ -796,13 +796,13 @@ static int fuse_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	return create_new_entry(fm, &args, dir, entry, mode);
 }
 
-static int fuse_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int fuse_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *entry, umode_t mode, bool excl)
 {
-	return fuse_mknod(&init_user_ns, dir, entry, mode, 0);
+	return fuse_mknod(&nop_mnt_idmap, dir, entry, mode, 0);
 }
 
-static int fuse_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+static int fuse_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 			struct file *file, umode_t mode)
 {
 	struct fuse_conn *fc = get_fuse_conn(dir);
@@ -819,7 +819,7 @@ static int fuse_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	return err;
 }
 
-static int fuse_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int fuse_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *entry, umode_t mode)
 {
 	struct fuse_mkdir_in inarg;
@@ -841,7 +841,7 @@ static int fuse_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 	return create_new_entry(fm, &args, dir, entry, S_IFDIR);
 }
 
-static int fuse_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int fuse_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *entry, const char *link)
 {
 	struct fuse_mount *fm = get_fuse_mount(dir);
@@ -998,7 +998,7 @@ static int fuse_rename_common(struct inode *olddir, struct dentry *oldent,
 	return err;
 }
 
-static int fuse_rename2(struct user_namespace *mnt_userns, struct inode *olddir,
+static int fuse_rename2(struct mnt_idmap *idmap, struct inode *olddir,
 			struct dentry *oldent, struct inode *newdir,
 			struct dentry *newent, unsigned int flags)
 {
@@ -1156,7 +1156,7 @@ static int fuse_update_get_attr(struct inode *inode, struct file *file,
 		forget_all_cached_acls(inode);
 		err = fuse_do_getattr(inode, stat, file);
 	} else if (stat) {
-		generic_fillattr(&init_user_ns, inode, stat);
+		generic_fillattr(&nop_mnt_idmap, inode, stat);
 		stat->mode = fi->orig_i_mode;
 		stat->ino = fi->orig_ino;
 	}
@@ -1326,7 +1326,7 @@ static int fuse_perm_getattr(struct inode *inode, int mask)
  * access request is sent.  Execute permission is still checked
  * locally based on file mode.
  */
-static int fuse_permission(struct user_namespace *mnt_userns,
+static int fuse_permission(struct mnt_idmap *idmap,
 			   struct inode *inode, int mask)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
@@ -1358,7 +1358,7 @@ static int fuse_permission(struct user_namespace *mnt_userns,
 	}
 
 	if (fc->default_permissions) {
-		err = generic_permission(&init_user_ns, inode, mask);
+		err = generic_permission(&nop_mnt_idmap, inode, mask);
 
 		/* If permission is denied, try to refresh file
 		   attributes.  This is also needed, because the root
@@ -1366,7 +1366,7 @@ static int fuse_permission(struct user_namespace *mnt_userns,
 		if (err == -EACCES && !refreshed) {
 			err = fuse_perm_getattr(inode, mask);
 			if (!err)
-				err = generic_permission(&init_user_ns,
+				err = generic_permission(&nop_mnt_idmap,
 							 inode, mask);
 		}
 
@@ -1690,7 +1690,7 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
 	if (!fc->default_permissions)
 		attr->ia_valid |= ATTR_FORCE;
 
-	err = setattr_prepare(&init_user_ns, dentry, attr);
+	err = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (err)
 		return err;
 
@@ -1837,7 +1837,7 @@ error:
 	return err;
 }
 
-static int fuse_setattr(struct user_namespace *mnt_userns, struct dentry *entry,
+static int fuse_setattr(struct mnt_idmap *idmap, struct dentry *entry,
 			struct iattr *attr)
 {
 	struct inode *inode = d_inode(entry);
@@ -1900,7 +1900,7 @@ static int fuse_setattr(struct user_namespace *mnt_userns, struct dentry *entry,
 	return ret;
 }
 
-static int fuse_getattr(struct user_namespace *mnt_userns,
+static int fuse_getattr(struct mnt_idmap *idmap,
 			const struct path *path, struct kstat *stat,
 			u32 request_mask, unsigned int flags)
 {
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 1458412f2492..82710d103556 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1314,7 +1314,8 @@ static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
 			return err;
 
 		if (fc->handle_killpriv_v2 &&
-		    setattr_should_drop_suidgid(&init_user_ns, file_inode(file))) {
+		    setattr_should_drop_suidgid(&nop_mnt_idmap,
+						file_inode(file))) {
 			goto writethrough;
 		}
 
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 46797a171a84..9b5058cf5bc3 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1267,9 +1267,9 @@ extern const struct xattr_handler *fuse_xattr_handlers[];
 
 struct posix_acl;
 struct posix_acl *fuse_get_inode_acl(struct inode *inode, int type, bool rcu);
-struct posix_acl *fuse_get_acl(struct user_namespace *mnt_userns,
+struct posix_acl *fuse_get_acl(struct mnt_idmap *idmap,
 			       struct dentry *dentry, int type);
-int fuse_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int fuse_set_acl(struct mnt_idmap *, struct dentry *dentry,
 		 struct posix_acl *acl, int type);
 
 /* readdir.c */
@@ -1309,7 +1309,7 @@ long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
 			    unsigned long arg);
 int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-int fuse_fileattr_set(struct user_namespace *mnt_userns,
+int fuse_fileattr_set(struct mnt_idmap *idmap,
 		      struct dentry *dentry, struct fileattr *fa);
 
 /* file.c */
diff --git a/fs/fuse/ioctl.c b/fs/fuse/ioctl.c
index fcce94ace2c2..e50a18ee6cc6 100644
--- a/fs/fuse/ioctl.c
+++ b/fs/fuse/ioctl.c
@@ -467,7 +467,7 @@ cleanup:
 	return err;
 }
 
-int fuse_fileattr_set(struct user_namespace *mnt_userns,
+int fuse_fileattr_set(struct mnt_idmap *idmap,
 		      struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
diff --git a/fs/fuse/xattr.c b/fs/fuse/xattr.c
index 9fe571ab569e..49c01559580f 100644
--- a/fs/fuse/xattr.c
+++ b/fs/fuse/xattr.c
@@ -189,7 +189,7 @@ static int fuse_xattr_get(const struct xattr_handler *handler,
 }
 
 static int fuse_xattr_set(const struct xattr_handler *handler,
-			  struct user_namespace *mnt_userns,
+			  struct mnt_idmap *idmap,
 			  struct dentry *dentry, struct inode *inode,
 			  const char *name, const void *value, size_t size,
 			  int flags)
diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c
index 3dcde4912413..a392aa0f041d 100644
--- a/fs/gfs2/acl.c
+++ b/fs/gfs2/acl.c
@@ -109,7 +109,7 @@ out:
 	return error;
 }
 
-int gfs2_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int gfs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type)
 {
 	struct inode *inode = d_inode(dentry);
@@ -135,7 +135,7 @@ int gfs2_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 	mode = inode->i_mode;
 	if (type == ACL_TYPE_ACCESS && acl) {
-		ret = posix_acl_update_mode(&init_user_ns, inode, &mode, &acl);
+		ret = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode, &acl);
 		if (ret)
 			goto unlock;
 	}
diff --git a/fs/gfs2/acl.h b/fs/gfs2/acl.h
index b8de8c148f5c..d4deb2b19959 100644
--- a/fs/gfs2/acl.h
+++ b/fs/gfs2/acl.h
@@ -13,7 +13,7 @@
 
 extern struct posix_acl *gfs2_get_acl(struct inode *inode, int type, bool rcu);
 extern int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type);
-extern int gfs2_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+extern int gfs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 			struct posix_acl *acl, int type);
 
 #endif /* __ACL_DOT_H__ */
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index e8e20a716004..300844f50dcd 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -236,7 +236,7 @@ static int do_gfs2_set_flags(struct inode *inode, u32 reqflags, u32 mask)
 		goto out;
 
 	if (!IS_IMMUTABLE(inode)) {
-		error = gfs2_permission(&init_user_ns, inode, MAY_WRITE);
+		error = gfs2_permission(&nop_mnt_idmap, inode, MAY_WRITE);
 		if (error)
 			goto out;
 	}
@@ -274,7 +274,7 @@ out:
 	return error;
 }
 
-int gfs2_fileattr_set(struct user_namespace *mnt_userns,
+int gfs2_fileattr_set(struct mnt_idmap *idmap,
 		      struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 614db3055c02..713efa3bb732 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -320,7 +320,7 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
 	}
 
 	if (!is_root) {
-		error = gfs2_permission(&init_user_ns, dir, MAY_EXEC);
+		error = gfs2_permission(&nop_mnt_idmap, dir, MAY_EXEC);
 		if (error)
 			goto out;
 	}
@@ -350,7 +350,7 @@ static int create_ok(struct gfs2_inode *dip, const struct qstr *name,
 {
 	int error;
 
-	error = gfs2_permission(&init_user_ns, &dip->i_inode,
+	error = gfs2_permission(&nop_mnt_idmap, &dip->i_inode,
 				MAY_WRITE | MAY_EXEC);
 	if (error)
 		return error;
@@ -843,7 +843,7 @@ fail:
 
 /**
  * gfs2_create - Create a file
- * @mnt_userns: User namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @dir: The directory in which to create the file
  * @dentry: The dentry of the new file
  * @mode: The mode of the new file
@@ -852,7 +852,7 @@ fail:
  * Returns: errno
  */
 
-static int gfs2_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int gfs2_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
 	return gfs2_create_inode(dir, dentry, NULL, S_IFREG | mode, 0, NULL, 0, excl);
@@ -960,7 +960,7 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
 	if (inode->i_nlink == 0)
 		goto out_gunlock;
 
-	error = gfs2_permission(&init_user_ns, dir, MAY_WRITE | MAY_EXEC);
+	error = gfs2_permission(&nop_mnt_idmap, dir, MAY_WRITE | MAY_EXEC);
 	if (error)
 		goto out_gunlock;
 
@@ -1078,7 +1078,7 @@ static int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
 	if (IS_APPEND(&dip->i_inode))
 		return -EPERM;
 
-	error = gfs2_permission(&init_user_ns, &dip->i_inode,
+	error = gfs2_permission(&nop_mnt_idmap, &dip->i_inode,
 				MAY_WRITE | MAY_EXEC);
 	if (error)
 		return error;
@@ -1207,7 +1207,7 @@ out_inodes:
 
 /**
  * gfs2_symlink - Create a symlink
- * @mnt_userns: User namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @dir: The directory to create the symlink in
  * @dentry: The dentry to put the symlink in
  * @symname: The thing which the link points to
@@ -1215,7 +1215,7 @@ out_inodes:
  * Returns: errno
  */
 
-static int gfs2_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int gfs2_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, const char *symname)
 {
 	unsigned int size;
@@ -1229,7 +1229,7 @@ static int gfs2_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 
 /**
  * gfs2_mkdir - Make a directory
- * @mnt_userns: User namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @dir: The parent directory of the new one
  * @dentry: The dentry of the new directory
  * @mode: The mode of the new directory
@@ -1237,7 +1237,7 @@ static int gfs2_symlink(struct user_namespace *mnt_userns, struct inode *dir,
  * Returns: errno
  */
 
-static int gfs2_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int gfs2_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
 	unsigned dsize = gfs2_max_stuffed_size(GFS2_I(dir));
@@ -1246,7 +1246,7 @@ static int gfs2_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 
 /**
  * gfs2_mknod - Make a special file
- * @mnt_userns: User namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @dir: The directory in which the special file will reside
  * @dentry: The dentry of the special file
  * @mode: The mode of the special file
@@ -1254,7 +1254,7 @@ static int gfs2_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
  *
  */
 
-static int gfs2_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int gfs2_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t dev)
 {
 	return gfs2_create_inode(dir, dentry, NULL, mode, dev, NULL, 0, 0);
@@ -1504,7 +1504,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
 			}
 		}
 	} else {
-		error = gfs2_permission(&init_user_ns, ndir,
+		error = gfs2_permission(&nop_mnt_idmap, ndir,
 					MAY_WRITE | MAY_EXEC);
 		if (error)
 			goto out_gunlock;
@@ -1541,7 +1541,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
 	/* Check out the dir to be renamed */
 
 	if (dir_rename) {
-		error = gfs2_permission(&init_user_ns, d_inode(odentry),
+		error = gfs2_permission(&nop_mnt_idmap, d_inode(odentry),
 					MAY_WRITE);
 		if (error)
 			goto out_gunlock;
@@ -1705,13 +1705,13 @@ static int gfs2_exchange(struct inode *odir, struct dentry *odentry,
 		goto out_gunlock;
 
 	if (S_ISDIR(old_mode)) {
-		error = gfs2_permission(&init_user_ns, odentry->d_inode,
+		error = gfs2_permission(&nop_mnt_idmap, odentry->d_inode,
 					MAY_WRITE);
 		if (error)
 			goto out_gunlock;
 	}
 	if (S_ISDIR(new_mode)) {
-		error = gfs2_permission(&init_user_ns, ndentry->d_inode,
+		error = gfs2_permission(&nop_mnt_idmap, ndentry->d_inode,
 					MAY_WRITE);
 		if (error)
 			goto out_gunlock;
@@ -1766,7 +1766,7 @@ out:
 	return error;
 }
 
-static int gfs2_rename2(struct user_namespace *mnt_userns, struct inode *odir,
+static int gfs2_rename2(struct mnt_idmap *idmap, struct inode *odir,
 			struct dentry *odentry, struct inode *ndir,
 			struct dentry *ndentry, unsigned int flags)
 {
@@ -1841,7 +1841,7 @@ out:
 
 /**
  * gfs2_permission
- * @mnt_userns: User namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @inode: The inode
  * @mask: The mask to be tested
  *
@@ -1852,7 +1852,7 @@ out:
  * Returns: errno
  */
 
-int gfs2_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int gfs2_permission(struct mnt_idmap *idmap, struct inode *inode,
 		    int mask)
 {
 	struct gfs2_inode *ip;
@@ -1872,7 +1872,7 @@ int gfs2_permission(struct user_namespace *mnt_userns, struct inode *inode,
 	if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode))
 		error = -EPERM;
 	else
-		error = generic_permission(&init_user_ns, inode, mask);
+		error = generic_permission(&nop_mnt_idmap, inode, mask);
 	if (gfs2_holder_initialized(&i_gh))
 		gfs2_glock_dq_uninit(&i_gh);
 
@@ -1881,7 +1881,7 @@ int gfs2_permission(struct user_namespace *mnt_userns, struct inode *inode,
 
 static int __gfs2_setattr_simple(struct inode *inode, struct iattr *attr)
 {
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
@@ -1966,7 +1966,7 @@ out:
 
 /**
  * gfs2_setattr - Change attributes on an inode
- * @mnt_userns: User namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @dentry: The dentry which is changing
  * @attr: The structure describing the change
  *
@@ -1976,7 +1976,7 @@ out:
  * Returns: errno
  */
 
-static int gfs2_setattr(struct user_namespace *mnt_userns,
+static int gfs2_setattr(struct mnt_idmap *idmap,
 			struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -1992,11 +1992,11 @@ static int gfs2_setattr(struct user_namespace *mnt_userns,
 	if (error)
 		goto out;
 
-	error = may_setattr(&init_user_ns, inode, attr->ia_valid);
+	error = may_setattr(&nop_mnt_idmap, inode, attr->ia_valid);
 	if (error)
 		goto error;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		goto error;
 
@@ -2007,7 +2007,7 @@ static int gfs2_setattr(struct user_namespace *mnt_userns,
 	else {
 		error = gfs2_setattr_simple(inode, attr);
 		if (!error && attr->ia_valid & ATTR_MODE)
-			error = posix_acl_chmod(&init_user_ns, dentry,
+			error = posix_acl_chmod(&nop_mnt_idmap, dentry,
 						inode->i_mode);
 	}
 
@@ -2022,7 +2022,7 @@ out:
 
 /**
  * gfs2_getattr - Read out an inode's attributes
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @path: Object to query
  * @stat: The inode's stats
  * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
@@ -2037,7 +2037,7 @@ out:
  * Returns: errno
  */
 
-static int gfs2_getattr(struct user_namespace *mnt_userns,
+static int gfs2_getattr(struct mnt_idmap *idmap,
 			const struct path *path, struct kstat *stat,
 			u32 request_mask, unsigned int flags)
 {
@@ -2066,7 +2066,7 @@ static int gfs2_getattr(struct user_namespace *mnt_userns,
 				  STATX_ATTR_IMMUTABLE |
 				  STATX_ATTR_NODUMP);
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 
 	if (gfs2_holder_initialized(&gh))
 		gfs2_glock_dq_uninit(&gh);
diff --git a/fs/gfs2/inode.h b/fs/gfs2/inode.h
index 0264d514dda7..c8c5814e7295 100644
--- a/fs/gfs2/inode.h
+++ b/fs/gfs2/inode.h
@@ -99,7 +99,7 @@ extern int gfs2_inode_refresh(struct gfs2_inode *ip);
 
 extern struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
 				  int is_root);
-extern int gfs2_permission(struct user_namespace *mnt_userns,
+extern int gfs2_permission(struct mnt_idmap *idmap,
 			   struct inode *inode, int mask);
 extern struct inode *gfs2_lookup_simple(struct inode *dip, const char *name);
 extern void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf);
@@ -111,7 +111,7 @@ extern const struct file_operations gfs2_file_fops_nolock;
 extern const struct file_operations gfs2_dir_fops_nolock;
 
 extern int gfs2_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-extern int gfs2_fileattr_set(struct user_namespace *mnt_userns,
+extern int gfs2_fileattr_set(struct mnt_idmap *idmap,
 			     struct dentry *dentry, struct fileattr *fa);
 extern void gfs2_set_inode_flags(struct inode *inode);
  
diff --git a/fs/gfs2/xattr.c b/fs/gfs2/xattr.c
index 518c0677e12a..adf6d17cf033 100644
--- a/fs/gfs2/xattr.c
+++ b/fs/gfs2/xattr.c
@@ -1225,7 +1225,7 @@ int __gfs2_xattr_set(struct inode *inode, const char *name,
 }
 
 static int gfs2_xattr_set(const struct xattr_handler *handler,
-			  struct user_namespace *mnt_userns,
+			  struct mnt_idmap *idmap,
 			  struct dentry *unused, struct inode *inode,
 			  const char *name, const void *value,
 			  size_t size, int flags)
diff --git a/fs/hfs/attr.c b/fs/hfs/attr.c
index 2bd54efaf416..6341bb248247 100644
--- a/fs/hfs/attr.c
+++ b/fs/hfs/attr.c
@@ -121,7 +121,7 @@ static int hfs_xattr_get(const struct xattr_handler *handler,
 }
 
 static int hfs_xattr_set(const struct xattr_handler *handler,
-			 struct user_namespace *mnt_userns,
+			 struct mnt_idmap *idmap,
 			 struct dentry *unused, struct inode *inode,
 			 const char *name, const void *value, size_t size,
 			 int flags)
diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c
index 527f6e46cbe8..3e1e3dcf0b48 100644
--- a/fs/hfs/dir.c
+++ b/fs/hfs/dir.c
@@ -189,7 +189,7 @@ static int hfs_dir_release(struct inode *inode, struct file *file)
  * a directory and return a corresponding inode, given the inode for
  * the directory and the name (and its length) of the new file.
  */
-static int hfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int hfs_create(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct inode *inode;
@@ -219,7 +219,7 @@ static int hfs_create(struct user_namespace *mnt_userns, struct inode *dir,
  * in a directory, given the inode for the parent directory and the
  * name (and its length) of the new directory.
  */
-static int hfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int hfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode;
@@ -280,7 +280,7 @@ static int hfs_remove(struct inode *dir, struct dentry *dentry)
  * new file/directory.
  * XXX: how do you handle must_be dir?
  */
-static int hfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int hfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		      struct dentry *old_dentry, struct inode *new_dir,
 		      struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/hfs/hfs_fs.h b/fs/hfs/hfs_fs.h
index 68d0305880f7..49d02524e667 100644
--- a/fs/hfs/hfs_fs.h
+++ b/fs/hfs/hfs_fs.h
@@ -206,7 +206,7 @@ int hfs_write_begin(struct file *file, struct address_space *mapping,
 extern struct inode *hfs_new_inode(struct inode *, const struct qstr *, umode_t);
 extern void hfs_inode_write_fork(struct inode *, struct hfs_extent *, __be32 *, __be32 *);
 extern int hfs_write_inode(struct inode *, struct writeback_control *);
-extern int hfs_inode_setattr(struct user_namespace *, struct dentry *,
+extern int hfs_inode_setattr(struct mnt_idmap *, struct dentry *,
 			     struct iattr *);
 extern void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
 			__be32 log_size, __be32 phys_size, u32 clump_size);
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 3a155c1d810e..1f7bd068acf0 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -611,14 +611,14 @@ static int hfs_file_release(struct inode *inode, struct file *file)
  *     correspond to the same HFS file.
  */
 
-int hfs_inode_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int hfs_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		      struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
 	int error;
 
-	error = setattr_prepare(&init_user_ns, dentry,
+	error = setattr_prepare(&nop_mnt_idmap, dentry,
 				attr); /* basic permission checks */
 	if (error)
 		return error;
@@ -658,7 +658,7 @@ int hfs_inode_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 						  current_time(inode);
 	}
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
index 84714bbccc12..56fb5f1312e7 100644
--- a/fs/hfsplus/dir.c
+++ b/fs/hfsplus/dir.c
@@ -434,7 +434,7 @@ out:
 	return res;
 }
 
-static int hfsplus_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int hfsplus_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			   struct dentry *dentry, const char *symname)
 {
 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
@@ -476,7 +476,7 @@ out:
 	return res;
 }
 
-static int hfsplus_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int hfsplus_mknod(struct mnt_idmap *idmap, struct inode *dir,
 			 struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
@@ -517,19 +517,19 @@ out:
 	return res;
 }
 
-static int hfsplus_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int hfsplus_create(struct mnt_idmap *idmap, struct inode *dir,
 			  struct dentry *dentry, umode_t mode, bool excl)
 {
-	return hfsplus_mknod(&init_user_ns, dir, dentry, mode, 0);
+	return hfsplus_mknod(&nop_mnt_idmap, dir, dentry, mode, 0);
 }
 
-static int hfsplus_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int hfsplus_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			 struct dentry *dentry, umode_t mode)
 {
-	return hfsplus_mknod(&init_user_ns, dir, dentry, mode | S_IFDIR, 0);
+	return hfsplus_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFDIR, 0);
 }
 
-static int hfsplus_rename(struct user_namespace *mnt_userns,
+static int hfsplus_rename(struct mnt_idmap *idmap,
 			  struct inode *old_dir, struct dentry *old_dentry,
 			  struct inode *new_dir, struct dentry *new_dentry,
 			  unsigned int flags)
diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index 6aa919e59483..7ededcb720c1 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -481,13 +481,13 @@ void hfsplus_inode_write_fork(struct inode *inode,
 			      struct hfsplus_fork_raw *fork);
 int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd);
 int hfsplus_cat_write_inode(struct inode *inode);
-int hfsplus_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int hfsplus_getattr(struct mnt_idmap *idmap, const struct path *path,
 		    struct kstat *stat, u32 request_mask,
 		    unsigned int query_flags);
 int hfsplus_file_fsync(struct file *file, loff_t start, loff_t end,
 		       int datasync);
 int hfsplus_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-int hfsplus_fileattr_set(struct user_namespace *mnt_userns,
+int hfsplus_fileattr_set(struct mnt_idmap *idmap,
 			 struct dentry *dentry, struct fileattr *fa);
 
 /* ioctl.c */
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index 840577a0c1e7..abb91f5fae92 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -246,13 +246,13 @@ static int hfsplus_file_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-static int hfsplus_setattr(struct user_namespace *mnt_userns,
+static int hfsplus_setattr(struct mnt_idmap *idmap,
 			   struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	int error;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
@@ -270,13 +270,13 @@ static int hfsplus_setattr(struct user_namespace *mnt_userns,
 		inode->i_mtime = inode->i_ctime = current_time(inode);
 	}
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 
 	return 0;
 }
 
-int hfsplus_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int hfsplus_getattr(struct mnt_idmap *idmap, const struct path *path,
 		    struct kstat *stat, u32 request_mask,
 		    unsigned int query_flags)
 {
@@ -298,7 +298,7 @@ int hfsplus_getattr(struct user_namespace *mnt_userns, const struct path *path,
 	stat->attributes_mask |= STATX_ATTR_APPEND | STATX_ATTR_IMMUTABLE |
 				 STATX_ATTR_NODUMP;
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	return 0;
 }
 
@@ -390,7 +390,7 @@ struct inode *hfsplus_new_inode(struct super_block *sb, struct inode *dir,
 		return NULL;
 
 	inode->i_ino = sbi->next_cnid++;
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 	set_nlink(inode, 1);
 	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 
@@ -655,7 +655,7 @@ int hfsplus_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return 0;
 }
 
-int hfsplus_fileattr_set(struct user_namespace *mnt_userns,
+int hfsplus_fileattr_set(struct mnt_idmap *idmap,
 			 struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
index 49891b12c415..5b476f57eb17 100644
--- a/fs/hfsplus/xattr.c
+++ b/fs/hfsplus/xattr.c
@@ -857,7 +857,7 @@ static int hfsplus_osx_getxattr(const struct xattr_handler *handler,
 }
 
 static int hfsplus_osx_setxattr(const struct xattr_handler *handler,
-				struct user_namespace *mnt_userns,
+				struct mnt_idmap *idmap,
 				struct dentry *unused, struct inode *inode,
 				const char *name, const void *buffer,
 				size_t size, int flags)
diff --git a/fs/hfsplus/xattr_security.c b/fs/hfsplus/xattr_security.c
index c1c7a16cbf21..90f68ec119cd 100644
--- a/fs/hfsplus/xattr_security.c
+++ b/fs/hfsplus/xattr_security.c
@@ -23,7 +23,7 @@ static int hfsplus_security_getxattr(const struct xattr_handler *handler,
 }
 
 static int hfsplus_security_setxattr(const struct xattr_handler *handler,
-				     struct user_namespace *mnt_userns,
+				     struct mnt_idmap *idmap,
 				     struct dentry *unused, struct inode *inode,
 				     const char *name, const void *buffer,
 				     size_t size, int flags)
diff --git a/fs/hfsplus/xattr_trusted.c b/fs/hfsplus/xattr_trusted.c
index e150372ec564..fdbaebc1c49a 100644
--- a/fs/hfsplus/xattr_trusted.c
+++ b/fs/hfsplus/xattr_trusted.c
@@ -22,7 +22,7 @@ static int hfsplus_trusted_getxattr(const struct xattr_handler *handler,
 }
 
 static int hfsplus_trusted_setxattr(const struct xattr_handler *handler,
-				    struct user_namespace *mnt_userns,
+				    struct mnt_idmap *idmap,
 				    struct dentry *unused, struct inode *inode,
 				    const char *name, const void *buffer,
 				    size_t size, int flags)
diff --git a/fs/hfsplus/xattr_user.c b/fs/hfsplus/xattr_user.c
index a6b60b153916..6464b6c3d58d 100644
--- a/fs/hfsplus/xattr_user.c
+++ b/fs/hfsplus/xattr_user.c
@@ -22,7 +22,7 @@ static int hfsplus_user_getxattr(const struct xattr_handler *handler,
 }
 
 static int hfsplus_user_setxattr(const struct xattr_handler *handler,
-				 struct user_namespace *mnt_userns,
+				 struct mnt_idmap *idmap,
 				 struct dentry *unused, struct inode *inode,
 				 const char *name, const void *buffer,
 				 size_t size, int flags)
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 277468783fee..c18bb50c31b6 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -559,7 +559,7 @@ static int read_name(struct inode *ino, char *name)
 	return 0;
 }
 
-static int hostfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int hostfs_create(struct mnt_idmap *idmap, struct inode *dir,
 			 struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct inode *inode;
@@ -658,7 +658,7 @@ static int hostfs_unlink(struct inode *ino, struct dentry *dentry)
 	return err;
 }
 
-static int hostfs_symlink(struct user_namespace *mnt_userns, struct inode *ino,
+static int hostfs_symlink(struct mnt_idmap *idmap, struct inode *ino,
 			  struct dentry *dentry, const char *to)
 {
 	char *file;
@@ -671,7 +671,7 @@ static int hostfs_symlink(struct user_namespace *mnt_userns, struct inode *ino,
 	return err;
 }
 
-static int hostfs_mkdir(struct user_namespace *mnt_userns, struct inode *ino,
+static int hostfs_mkdir(struct mnt_idmap *idmap, struct inode *ino,
 			struct dentry *dentry, umode_t mode)
 {
 	char *file;
@@ -696,7 +696,7 @@ static int hostfs_rmdir(struct inode *ino, struct dentry *dentry)
 	return err;
 }
 
-static int hostfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int hostfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, umode_t mode, dev_t dev)
 {
 	struct inode *inode;
@@ -734,7 +734,7 @@ static int hostfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	return err;
 }
 
-static int hostfs_rename2(struct user_namespace *mnt_userns,
+static int hostfs_rename2(struct mnt_idmap *idmap,
 			  struct inode *old_dir, struct dentry *old_dentry,
 			  struct inode *new_dir, struct dentry *new_dentry,
 			  unsigned int flags)
@@ -763,7 +763,7 @@ static int hostfs_rename2(struct user_namespace *mnt_userns,
 	return err;
 }
 
-static int hostfs_permission(struct user_namespace *mnt_userns,
+static int hostfs_permission(struct mnt_idmap *idmap,
 			     struct inode *ino, int desired)
 {
 	char *name;
@@ -786,11 +786,11 @@ static int hostfs_permission(struct user_namespace *mnt_userns,
 		err = access_file(name, r, w, x);
 	__putname(name);
 	if (!err)
-		err = generic_permission(&init_user_ns, ino, desired);
+		err = generic_permission(&nop_mnt_idmap, ino, desired);
 	return err;
 }
 
-static int hostfs_setattr(struct user_namespace *mnt_userns,
+static int hostfs_setattr(struct mnt_idmap *idmap,
 			  struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -800,7 +800,7 @@ static int hostfs_setattr(struct user_namespace *mnt_userns,
 
 	int fd = HOSTFS_I(inode)->fd;
 
-	err = setattr_prepare(&init_user_ns, dentry, attr);
+	err = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (err)
 		return err;
 
@@ -857,7 +857,7 @@ static int hostfs_setattr(struct user_namespace *mnt_userns,
 	    attr->ia_size != i_size_read(inode))
 		truncate_setsize(inode, attr->ia_size);
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
diff --git a/fs/hpfs/hpfs_fn.h b/fs/hpfs/hpfs_fn.h
index 167ec6884642..f5a2476c47bf 100644
--- a/fs/hpfs/hpfs_fn.h
+++ b/fs/hpfs/hpfs_fn.h
@@ -280,7 +280,7 @@ void hpfs_init_inode(struct inode *);
 void hpfs_read_inode(struct inode *);
 void hpfs_write_inode(struct inode *);
 void hpfs_write_inode_nolock(struct inode *);
-int hpfs_setattr(struct user_namespace *, struct dentry *, struct iattr *);
+int hpfs_setattr(struct mnt_idmap *, struct dentry *, struct iattr *);
 void hpfs_write_if_changed(struct inode *);
 void hpfs_evict_inode(struct inode *);
 
diff --git a/fs/hpfs/inode.c b/fs/hpfs/inode.c
index 82208cc28ebd..e50e92a42432 100644
--- a/fs/hpfs/inode.c
+++ b/fs/hpfs/inode.c
@@ -257,7 +257,7 @@ void hpfs_write_inode_nolock(struct inode *i)
 	brelse(bh);
 }
 
-int hpfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int hpfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -275,7 +275,7 @@ int hpfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size > inode->i_size)
 		goto out_unlock;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		goto out_unlock;
 
@@ -289,7 +289,7 @@ int hpfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		hpfs_truncate(inode);
 	}
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 
 	hpfs_write_inode(inode);
 
diff --git a/fs/hpfs/namei.c b/fs/hpfs/namei.c
index 15fc63276caa..69fb40b2c99a 100644
--- a/fs/hpfs/namei.c
+++ b/fs/hpfs/namei.c
@@ -20,7 +20,7 @@ static void hpfs_update_directory_times(struct inode *dir)
 	hpfs_write_inode_nolock(dir);
 }
 
-static int hpfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int hpfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
 	const unsigned char *name = dentry->d_name.name;
@@ -129,7 +129,7 @@ bail:
 	return err;
 }
 
-static int hpfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int hpfs_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
 	const unsigned char *name = dentry->d_name.name;
@@ -217,7 +217,7 @@ bail:
 	return err;
 }
 
-static int hpfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int hpfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	const unsigned char *name = dentry->d_name.name;
@@ -292,7 +292,7 @@ bail:
 	return err;
 }
 
-static int hpfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int hpfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, const char *symlink)
 {
 	const unsigned char *name = dentry->d_name.name;
@@ -512,7 +512,7 @@ const struct address_space_operations hpfs_symlink_aops = {
 	.read_folio	= hpfs_symlink_read_folio
 };
 
-static int hpfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int hpfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		       struct dentry *old_dentry, struct inode *new_dir,
 		       struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 790d2727141a..0ce1cc4c2add 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -898,7 +898,7 @@ out:
 	return error;
 }
 
-static int hugetlbfs_setattr(struct user_namespace *mnt_userns,
+static int hugetlbfs_setattr(struct mnt_idmap *idmap,
 			     struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -907,7 +907,7 @@ static int hugetlbfs_setattr(struct user_namespace *mnt_userns,
 	unsigned int ia_valid = attr->ia_valid;
 	struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
@@ -924,7 +924,7 @@ static int hugetlbfs_setattr(struct user_namespace *mnt_userns,
 		hugetlb_vmtruncate(inode, newsize);
 	}
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
@@ -980,7 +980,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
 		struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
 
 		inode->i_ino = get_next_ino();
-		inode_init_owner(&init_user_ns, inode, dir, mode);
+		inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 		lockdep_set_class(&inode->i_mapping->i_mmap_rwsem,
 				&hugetlbfs_i_mmap_rwsem_key);
 		inode->i_mapping->a_ops = &hugetlbfs_aops;
@@ -1019,7 +1019,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
 /*
  * File creation. Allocate an inode, and we're done..
  */
-static int hugetlbfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int hugetlbfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 			   struct dentry *dentry, umode_t mode, dev_t dev)
 {
 	struct inode *inode;
@@ -1033,24 +1033,24 @@ static int hugetlbfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	return 0;
 }
 
-static int hugetlbfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int hugetlbfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			   struct dentry *dentry, umode_t mode)
 {
-	int retval = hugetlbfs_mknod(&init_user_ns, dir, dentry,
+	int retval = hugetlbfs_mknod(&nop_mnt_idmap, dir, dentry,
 				     mode | S_IFDIR, 0);
 	if (!retval)
 		inc_nlink(dir);
 	return retval;
 }
 
-static int hugetlbfs_create(struct user_namespace *mnt_userns,
+static int hugetlbfs_create(struct mnt_idmap *idmap,
 			    struct inode *dir, struct dentry *dentry,
 			    umode_t mode, bool excl)
 {
-	return hugetlbfs_mknod(&init_user_ns, dir, dentry, mode | S_IFREG, 0);
+	return hugetlbfs_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFREG, 0);
 }
 
-static int hugetlbfs_tmpfile(struct user_namespace *mnt_userns,
+static int hugetlbfs_tmpfile(struct mnt_idmap *idmap,
 			     struct inode *dir, struct file *file,
 			     umode_t mode)
 {
@@ -1064,7 +1064,7 @@ static int hugetlbfs_tmpfile(struct user_namespace *mnt_userns,
 	return finish_open_simple(file, 0);
 }
 
-static int hugetlbfs_symlink(struct user_namespace *mnt_userns,
+static int hugetlbfs_symlink(struct mnt_idmap *idmap,
 			     struct inode *dir, struct dentry *dentry,
 			     const char *symname)
 {
diff --git a/fs/init.c b/fs/init.c
index 5c36adaa9b44..9684406a8416 100644
--- a/fs/init.c
+++ b/fs/init.c
@@ -157,7 +157,7 @@ int __init init_mknod(const char *filename, umode_t mode, unsigned int dev)
 		mode &= ~current_umask();
 	error = security_path_mknod(&path, dentry, mode, dev);
 	if (!error)
-		error = vfs_mknod(mnt_user_ns(path.mnt), path.dentry->d_inode,
+		error = vfs_mknod(mnt_idmap(path.mnt), path.dentry->d_inode,
 				  dentry, mode, new_decode_dev(dev));
 	done_path_create(&path, dentry);
 	return error;
@@ -167,7 +167,7 @@ int __init init_link(const char *oldname, const char *newname)
 {
 	struct dentry *new_dentry;
 	struct path old_path, new_path;
-	struct user_namespace *mnt_userns;
+	struct mnt_idmap *idmap;
 	int error;
 
 	error = kern_path(oldname, 0, &old_path);
@@ -182,14 +182,14 @@ int __init init_link(const char *oldname, const char *newname)
 	error = -EXDEV;
 	if (old_path.mnt != new_path.mnt)
 		goto out_dput;
-	mnt_userns = mnt_user_ns(new_path.mnt);
-	error = may_linkat(mnt_userns, &old_path);
+	idmap = mnt_idmap(new_path.mnt);
+	error = may_linkat(idmap, &old_path);
 	if (unlikely(error))
 		goto out_dput;
 	error = security_path_link(old_path.dentry, &new_path, new_dentry);
 	if (error)
 		goto out_dput;
-	error = vfs_link(old_path.dentry, mnt_userns, new_path.dentry->d_inode,
+	error = vfs_link(old_path.dentry, idmap, new_path.dentry->d_inode,
 			 new_dentry, NULL);
 out_dput:
 	done_path_create(&new_path, new_dentry);
@@ -209,7 +209,7 @@ int __init init_symlink(const char *oldname, const char *newname)
 		return PTR_ERR(dentry);
 	error = security_path_symlink(&path, dentry, oldname);
 	if (!error)
-		error = vfs_symlink(mnt_user_ns(path.mnt), path.dentry->d_inode,
+		error = vfs_symlink(mnt_idmap(path.mnt), path.dentry->d_inode,
 				    dentry, oldname);
 	done_path_create(&path, dentry);
 	return error;
@@ -233,7 +233,7 @@ int __init init_mkdir(const char *pathname, umode_t mode)
 		mode &= ~current_umask();
 	error = security_path_mkdir(&path, dentry, mode);
 	if (!error)
-		error = vfs_mkdir(mnt_user_ns(path.mnt), path.dentry->d_inode,
+		error = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
 				  dentry, mode);
 	done_path_create(&path, dentry);
 	return error;
diff --git a/fs/inode.c b/fs/inode.c
index d02dd8f1e967..4558dc2f1355 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1894,7 +1894,7 @@ bool atime_needs_update(const struct path *path, struct inode *inode)
 	/* Atime updates will likely cause i_uid and i_gid to be written
 	 * back improprely if their true value is unknown to the vfs.
 	 */
-	if (HAS_UNMAPPED_ID(mnt_user_ns(mnt), inode))
+	if (HAS_UNMAPPED_ID(mnt_idmap(mnt), inode))
 		return false;
 
 	if (IS_NOATIME(inode))
@@ -1954,7 +1954,7 @@ EXPORT_SYMBOL(touch_atime);
  * response to write or truncate. Return 0 if nothing has to be changed.
  * Negative value on error (change should be denied).
  */
-int dentry_needs_remove_privs(struct user_namespace *mnt_userns,
+int dentry_needs_remove_privs(struct mnt_idmap *idmap,
 			      struct dentry *dentry)
 {
 	struct inode *inode = d_inode(dentry);
@@ -1964,7 +1964,7 @@ int dentry_needs_remove_privs(struct user_namespace *mnt_userns,
 	if (IS_NOSEC(inode))
 		return 0;
 
-	mask = setattr_should_drop_suidgid(mnt_userns, inode);
+	mask = setattr_should_drop_suidgid(idmap, inode);
 	ret = security_inode_need_killpriv(dentry);
 	if (ret < 0)
 		return ret;
@@ -1973,7 +1973,7 @@ int dentry_needs_remove_privs(struct user_namespace *mnt_userns,
 	return mask;
 }
 
-static int __remove_privs(struct user_namespace *mnt_userns,
+static int __remove_privs(struct mnt_idmap *idmap,
 			  struct dentry *dentry, int kill)
 {
 	struct iattr newattrs;
@@ -1983,7 +1983,7 @@ static int __remove_privs(struct user_namespace *mnt_userns,
 	 * Note we call this on write, so notify_change will not
 	 * encounter any conflicting delegations:
 	 */
-	return notify_change(mnt_userns, dentry, &newattrs, NULL);
+	return notify_change(idmap, dentry, &newattrs, NULL);
 }
 
 static int __file_remove_privs(struct file *file, unsigned int flags)
@@ -1996,7 +1996,7 @@ static int __file_remove_privs(struct file *file, unsigned int flags)
 	if (IS_NOSEC(inode) || !S_ISREG(inode->i_mode))
 		return 0;
 
-	kill = dentry_needs_remove_privs(file_mnt_user_ns(file), dentry);
+	kill = dentry_needs_remove_privs(file_mnt_idmap(file), dentry);
 	if (kill < 0)
 		return kill;
 
@@ -2004,7 +2004,7 @@ static int __file_remove_privs(struct file *file, unsigned int flags)
 		if (flags & IOCB_NOWAIT)
 			return -EAGAIN;
 
-		error = __remove_privs(file_mnt_user_ns(file), dentry, kill);
+		error = __remove_privs(file_mnt_idmap(file), dentry, kill);
 	}
 
 	if (!error)
@@ -2280,21 +2280,21 @@ EXPORT_SYMBOL(init_special_inode);
 
 /**
  * inode_init_owner - Init uid,gid,mode for new inode according to posix standards
- * @mnt_userns:	User namespace of the mount the inode was created from
+ * @idmap: idmap of the mount the inode was created from
  * @inode: New inode
  * @dir: Directory inode
  * @mode: mode of the new inode
  *
- * If the inode has been created through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions
+ * If the inode has been created through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions
  * and initializing i_uid and i_gid. On non-idmapped mounts or if permission
- * checking is to be performed on the raw inode simply passs init_user_ns.
+ * checking is to be performed on the raw inode simply pass @nop_mnt_idmap.
  */
-void inode_init_owner(struct user_namespace *mnt_userns, struct inode *inode,
+void inode_init_owner(struct mnt_idmap *idmap, struct inode *inode,
 		      const struct inode *dir, umode_t mode)
 {
-	inode_fsuid_set(inode, mnt_userns);
+	inode_fsuid_set(inode, idmap);
 	if (dir && dir->i_mode & S_ISGID) {
 		inode->i_gid = dir->i_gid;
 
@@ -2302,32 +2302,32 @@ void inode_init_owner(struct user_namespace *mnt_userns, struct inode *inode,
 		if (S_ISDIR(mode))
 			mode |= S_ISGID;
 	} else
-		inode_fsgid_set(inode, mnt_userns);
+		inode_fsgid_set(inode, idmap);
 	inode->i_mode = mode;
 }
 EXPORT_SYMBOL(inode_init_owner);
 
 /**
  * inode_owner_or_capable - check current task permissions to inode
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @inode: inode being checked
  *
  * Return true if current either has CAP_FOWNER in a namespace with the
  * inode owner uid mapped, or owns the file.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-bool inode_owner_or_capable(struct user_namespace *mnt_userns,
+bool inode_owner_or_capable(struct mnt_idmap *idmap,
 			    const struct inode *inode)
 {
 	vfsuid_t vfsuid;
 	struct user_namespace *ns;
 
-	vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
+	vfsuid = i_uid_into_vfsuid(idmap, inode);
 	if (vfsuid_eq_kuid(vfsuid, current_fsuid()))
 		return true;
 
@@ -2459,7 +2459,7 @@ EXPORT_SYMBOL(current_time);
 
 /**
  * in_group_or_capable - check whether caller is CAP_FSETID privileged
- * @mnt_userns: user namespace of the mount @inode was found from
+ * @idmap:	idmap of the mount @inode was found from
  * @inode:	inode to check
  * @vfsgid:	the new/current vfsgid of @inode
  *
@@ -2469,19 +2469,19 @@ EXPORT_SYMBOL(current_time);
  *
  * Return: true if the caller is sufficiently privileged, false if not.
  */
-bool in_group_or_capable(struct user_namespace *mnt_userns,
+bool in_group_or_capable(struct mnt_idmap *idmap,
 			 const struct inode *inode, vfsgid_t vfsgid)
 {
 	if (vfsgid_in_group_p(vfsgid))
 		return true;
-	if (capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
+	if (capable_wrt_inode_uidgid(idmap, inode, CAP_FSETID))
 		return true;
 	return false;
 }
 
 /**
  * mode_strip_sgid - handle the sgid bit for non-directories
- * @mnt_userns: User namespace of the mount the inode was created from
+ * @idmap: idmap of the mount the inode was created from
  * @dir: parent directory inode
  * @mode: mode of the file to be created in @dir
  *
@@ -2493,15 +2493,14 @@ bool in_group_or_capable(struct user_namespace *mnt_userns,
  *
  * Return: the new mode to use for the file
  */
-umode_t mode_strip_sgid(struct user_namespace *mnt_userns,
+umode_t mode_strip_sgid(struct mnt_idmap *idmap,
 			const struct inode *dir, umode_t mode)
 {
 	if ((mode & (S_ISGID | S_IXGRP)) != (S_ISGID | S_IXGRP))
 		return mode;
 	if (S_ISDIR(mode) || !dir || !(dir->i_mode & S_ISGID))
 		return mode;
-	if (in_group_or_capable(mnt_userns, dir,
-				i_gid_into_vfsgid(mnt_userns, dir)))
+	if (in_group_or_capable(idmap, dir, i_gid_into_vfsgid(idmap, dir)))
 		return mode;
 	return mode & ~S_ISGID;
 }
diff --git a/fs/internal.h b/fs/internal.h
index a803cc3cf716..766e8a554b2c 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -14,9 +14,9 @@ struct path;
 struct mount;
 struct shrink_control;
 struct fs_context;
-struct user_namespace;
 struct pipe_inode_info;
 struct iov_iter;
+struct mnt_idmap;
 
 /*
  * block/bdev.c
@@ -63,7 +63,7 @@ extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
 			   const char *, unsigned int, struct path *);
 int do_rmdir(int dfd, struct filename *name);
 int do_unlinkat(int dfd, struct filename *name);
-int may_linkat(struct user_namespace *mnt_userns, const struct path *link);
+int may_linkat(struct mnt_idmap *idmap, const struct path *link);
 int do_renameat2(int olddfd, struct filename *oldname, int newdfd,
 		 struct filename *newname, unsigned int flags);
 int do_mkdirat(int dfd, struct filename *name, umode_t mode);
@@ -150,8 +150,8 @@ extern int vfs_open(const struct path *, struct file *);
  * inode.c
  */
 extern long prune_icache_sb(struct super_block *sb, struct shrink_control *sc);
-int dentry_needs_remove_privs(struct user_namespace *, struct dentry *dentry);
-bool in_group_or_capable(struct user_namespace *mnt_userns,
+int dentry_needs_remove_privs(struct mnt_idmap *, struct dentry *dentry);
+bool in_group_or_capable(struct mnt_idmap *idmap,
 			 const struct inode *inode, vfsgid_t vfsgid);
 
 /*
@@ -234,7 +234,7 @@ ssize_t do_getxattr(struct mnt_idmap *idmap,
 int setxattr_copy(const char __user *name, struct xattr_ctx *ctx);
 int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct xattr_ctx *ctx);
-int may_write_xattr(struct user_namespace *mnt_userns, struct inode *inode);
+int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode);
 
 #ifdef CONFIG_FS_POSIX_ACL
 int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
@@ -261,5 +261,8 @@ ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *po
 /*
  * fs/attr.c
  */
-int setattr_should_drop_sgid(struct user_namespace *mnt_userns,
+int setattr_should_drop_sgid(struct mnt_idmap *idmap,
 			     const struct inode *inode);
+struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns);
+struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap);
+void mnt_idmap_put(struct mnt_idmap *idmap);
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 80ac36aea913..5b2481cd4750 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -651,7 +651,7 @@ static int fileattr_set_prepare(struct inode *inode,
 
 /**
  * vfs_fileattr_set - change miscellaneous file attributes
- * @mnt_userns:	user namespace of the mount
+ * @idmap:	idmap of the mount
  * @dentry:	the object to change
  * @fa:		fileattr pointer
  *
@@ -665,7 +665,7 @@ static int fileattr_set_prepare(struct inode *inode,
  *
  * Return: 0 on success, or a negative error on failure.
  */
-int vfs_fileattr_set(struct user_namespace *mnt_userns, struct dentry *dentry,
+int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
@@ -675,7 +675,7 @@ int vfs_fileattr_set(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (!inode->i_op->fileattr_set)
 		return -ENOIOCTLCMD;
 
-	if (!inode_owner_or_capable(mnt_userns, inode))
+	if (!inode_owner_or_capable(idmap, inode))
 		return -EPERM;
 
 	inode_lock(inode);
@@ -693,7 +693,7 @@ int vfs_fileattr_set(struct user_namespace *mnt_userns, struct dentry *dentry,
 		}
 		err = fileattr_set_prepare(inode, &old_ma, fa);
 		if (!err)
-			err = inode->i_op->fileattr_set(mnt_userns, dentry, fa);
+			err = inode->i_op->fileattr_set(idmap, dentry, fa);
 	}
 	inode_unlock(inode);
 
@@ -714,7 +714,7 @@ static int ioctl_getflags(struct file *file, unsigned int __user *argp)
 
 static int ioctl_setflags(struct file *file, unsigned int __user *argp)
 {
-	struct user_namespace *mnt_userns = file_mnt_user_ns(file);
+	struct mnt_idmap *idmap = file_mnt_idmap(file);
 	struct dentry *dentry = file->f_path.dentry;
 	struct fileattr fa;
 	unsigned int flags;
@@ -725,7 +725,7 @@ static int ioctl_setflags(struct file *file, unsigned int __user *argp)
 		err = mnt_want_write_file(file);
 		if (!err) {
 			fileattr_fill_flags(&fa, flags);
-			err = vfs_fileattr_set(mnt_userns, dentry, &fa);
+			err = vfs_fileattr_set(idmap, dentry, &fa);
 			mnt_drop_write_file(file);
 		}
 	}
@@ -746,7 +746,7 @@ static int ioctl_fsgetxattr(struct file *file, void __user *argp)
 
 static int ioctl_fssetxattr(struct file *file, void __user *argp)
 {
-	struct user_namespace *mnt_userns = file_mnt_user_ns(file);
+	struct mnt_idmap *idmap = file_mnt_idmap(file);
 	struct dentry *dentry = file->f_path.dentry;
 	struct fileattr fa;
 	int err;
@@ -755,7 +755,7 @@ static int ioctl_fssetxattr(struct file *file, void __user *argp)
 	if (!err) {
 		err = mnt_want_write_file(file);
 		if (!err) {
-			err = vfs_fileattr_set(mnt_userns, dentry, &fa);
+			err = vfs_fileattr_set(idmap, dentry, &fa);
 			mnt_drop_write_file(file);
 		}
 	}
diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
index 8bb58ce5c06c..888a7ceb6479 100644
--- a/fs/jffs2/acl.c
+++ b/fs/jffs2/acl.c
@@ -229,7 +229,7 @@ static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *a
 	return rc;
 }
 
-int jffs2_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int jffs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct posix_acl *acl, int type)
 {
 	int rc, xprefix;
@@ -241,7 +241,7 @@ int jffs2_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 		if (acl) {
 			umode_t mode;
 
-			rc = posix_acl_update_mode(&init_user_ns, inode, &mode,
+			rc = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode,
 						   &acl);
 			if (rc)
 				return rc;
diff --git a/fs/jffs2/acl.h b/fs/jffs2/acl.h
index ca36a6eca594..e976b8cb82cf 100644
--- a/fs/jffs2/acl.h
+++ b/fs/jffs2/acl.h
@@ -28,7 +28,7 @@ struct jffs2_acl_header {
 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 
 struct posix_acl *jffs2_get_acl(struct inode *inode, int type, bool rcu);
-int jffs2_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int jffs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct posix_acl *acl, int type);
 extern int jffs2_init_acl_pre(struct inode *, struct inode *, umode_t *);
 extern int jffs2_init_acl_post(struct inode *);
diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
index f399b390b5f6..5075a0a6d594 100644
--- a/fs/jffs2/dir.c
+++ b/fs/jffs2/dir.c
@@ -24,20 +24,20 @@
 
 static int jffs2_readdir (struct file *, struct dir_context *);
 
-static int jffs2_create (struct user_namespace *, struct inode *,
+static int jffs2_create (struct mnt_idmap *, struct inode *,
 		         struct dentry *, umode_t, bool);
 static struct dentry *jffs2_lookup (struct inode *,struct dentry *,
 				    unsigned int);
 static int jffs2_link (struct dentry *,struct inode *,struct dentry *);
 static int jffs2_unlink (struct inode *,struct dentry *);
-static int jffs2_symlink (struct user_namespace *, struct inode *,
+static int jffs2_symlink (struct mnt_idmap *, struct inode *,
 			  struct dentry *, const char *);
-static int jffs2_mkdir (struct user_namespace *, struct inode *,struct dentry *,
+static int jffs2_mkdir (struct mnt_idmap *, struct inode *,struct dentry *,
 			umode_t);
 static int jffs2_rmdir (struct inode *,struct dentry *);
-static int jffs2_mknod (struct user_namespace *, struct inode *,struct dentry *,
+static int jffs2_mknod (struct mnt_idmap *, struct inode *,struct dentry *,
 			umode_t,dev_t);
-static int jffs2_rename (struct user_namespace *, struct inode *,
+static int jffs2_rename (struct mnt_idmap *, struct inode *,
 			 struct dentry *, struct inode *, struct dentry *,
 			 unsigned int);
 
@@ -160,7 +160,7 @@ static int jffs2_readdir(struct file *file, struct dir_context *ctx)
 /***********************************************************************/
 
 
-static int jffs2_create(struct user_namespace *mnt_userns, struct inode *dir_i,
+static int jffs2_create(struct mnt_idmap *idmap, struct inode *dir_i,
 			struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct jffs2_raw_inode *ri;
@@ -279,7 +279,7 @@ static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct de
 
 /***********************************************************************/
 
-static int jffs2_symlink (struct user_namespace *mnt_userns, struct inode *dir_i,
+static int jffs2_symlink (struct mnt_idmap *idmap, struct inode *dir_i,
 			  struct dentry *dentry, const char *target)
 {
 	struct jffs2_inode_info *f, *dir_f;
@@ -442,7 +442,7 @@ static int jffs2_symlink (struct user_namespace *mnt_userns, struct inode *dir_i
 }
 
 
-static int jffs2_mkdir (struct user_namespace *mnt_userns, struct inode *dir_i,
+static int jffs2_mkdir (struct mnt_idmap *idmap, struct inode *dir_i,
 		        struct dentry *dentry, umode_t mode)
 {
 	struct jffs2_inode_info *f, *dir_f;
@@ -614,7 +614,7 @@ static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
 	return ret;
 }
 
-static int jffs2_mknod (struct user_namespace *mnt_userns, struct inode *dir_i,
+static int jffs2_mknod (struct mnt_idmap *idmap, struct inode *dir_i,
 		        struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct jffs2_inode_info *f, *dir_f;
@@ -762,7 +762,7 @@ static int jffs2_mknod (struct user_namespace *mnt_userns, struct inode *dir_i,
 	return ret;
 }
 
-static int jffs2_rename (struct user_namespace *mnt_userns,
+static int jffs2_rename (struct mnt_idmap *idmap,
 			 struct inode *old_dir_i, struct dentry *old_dentry,
 			 struct inode *new_dir_i, struct dentry *new_dentry,
 			 unsigned int flags)
diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c
index 66af51c41619..09174898efd0 100644
--- a/fs/jffs2/fs.c
+++ b/fs/jffs2/fs.c
@@ -190,19 +190,19 @@ int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
 	return 0;
 }
 
-int jffs2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int jffs2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *iattr)
 {
 	struct inode *inode = d_inode(dentry);
 	int rc;
 
-	rc = setattr_prepare(&init_user_ns, dentry, iattr);
+	rc = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (rc)
 		return rc;
 
 	rc = jffs2_do_setattr(inode, iattr);
 	if (!rc && (iattr->ia_valid & ATTR_MODE))
-		rc = posix_acl_chmod(&init_user_ns, dentry, inode->i_mode);
+		rc = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
 
 	return rc;
 }
diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h
index 921d782583d6..8da19766c101 100644
--- a/fs/jffs2/os-linux.h
+++ b/fs/jffs2/os-linux.h
@@ -164,7 +164,7 @@ long jffs2_ioctl(struct file *, unsigned int, unsigned long);
 extern const struct inode_operations jffs2_symlink_inode_operations;
 
 /* fs.c */
-int jffs2_setattr (struct user_namespace *, struct dentry *, struct iattr *);
+int jffs2_setattr (struct mnt_idmap *, struct dentry *, struct iattr *);
 int jffs2_do_setattr (struct inode *, struct iattr *);
 struct inode *jffs2_iget(struct super_block *, unsigned long);
 void jffs2_evict_inode (struct inode *);
diff --git a/fs/jffs2/security.c b/fs/jffs2/security.c
index aef5522551db..437f3a2c1b54 100644
--- a/fs/jffs2/security.c
+++ b/fs/jffs2/security.c
@@ -57,7 +57,7 @@ static int jffs2_security_getxattr(const struct xattr_handler *handler,
 }
 
 static int jffs2_security_setxattr(const struct xattr_handler *handler,
-				   struct user_namespace *mnt_userns,
+				   struct mnt_idmap *idmap,
 				   struct dentry *unused, struct inode *inode,
 				   const char *name, const void *buffer,
 				   size_t size, int flags)
diff --git a/fs/jffs2/xattr_trusted.c b/fs/jffs2/xattr_trusted.c
index cc3f24883e7d..b7c5da2d89bd 100644
--- a/fs/jffs2/xattr_trusted.c
+++ b/fs/jffs2/xattr_trusted.c
@@ -25,7 +25,7 @@ static int jffs2_trusted_getxattr(const struct xattr_handler *handler,
 }
 
 static int jffs2_trusted_setxattr(const struct xattr_handler *handler,
-				  struct user_namespace *mnt_userns,
+				  struct mnt_idmap *idmap,
 				  struct dentry *unused, struct inode *inode,
 				  const char *name, const void *buffer,
 				  size_t size, int flags)
diff --git a/fs/jffs2/xattr_user.c b/fs/jffs2/xattr_user.c
index fb945977c013..f64edce4927b 100644
--- a/fs/jffs2/xattr_user.c
+++ b/fs/jffs2/xattr_user.c
@@ -25,7 +25,7 @@ static int jffs2_user_getxattr(const struct xattr_handler *handler,
 }
 
 static int jffs2_user_setxattr(const struct xattr_handler *handler,
-			       struct user_namespace *mnt_userns,
+			       struct mnt_idmap *idmap,
 			       struct dentry *unused, struct inode *inode,
 			       const char *name, const void *buffer,
 			       size_t size, int flags)
diff --git a/fs/jfs/acl.c b/fs/jfs/acl.c
index 3b667eccc73b..fb96f872d207 100644
--- a/fs/jfs/acl.c
+++ b/fs/jfs/acl.c
@@ -94,7 +94,7 @@ out:
 	return rc;
 }
 
-int jfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int jfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct posix_acl *acl, int type)
 {
 	int rc;
@@ -106,7 +106,7 @@ int jfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 	tid = txBegin(inode->i_sb, 0);
 	mutex_lock(&JFS_IP(inode)->commit_mutex);
 	if (type == ACL_TYPE_ACCESS && acl) {
-		rc = posix_acl_update_mode(&init_user_ns, inode, &mode, &acl);
+		rc = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode, &acl);
 		if (rc)
 			goto end_tx;
 		if (mode != inode->i_mode)
diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index 88663465aecd..2ee35be49de1 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -85,24 +85,24 @@ static int jfs_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-int jfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int jfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct iattr *iattr)
 {
 	struct inode *inode = d_inode(dentry);
 	int rc;
 
-	rc = setattr_prepare(&init_user_ns, dentry, iattr);
+	rc = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (rc)
 		return rc;
 
-	if (is_quota_modification(mnt_userns, inode, iattr)) {
+	if (is_quota_modification(&nop_mnt_idmap, inode, iattr)) {
 		rc = dquot_initialize(inode);
 		if (rc)
 			return rc;
 	}
 	if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) ||
 	    (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) {
-		rc = dquot_transfer(mnt_userns, inode, iattr);
+		rc = dquot_transfer(&nop_mnt_idmap, inode, iattr);
 		if (rc)
 			return rc;
 	}
@@ -119,11 +119,11 @@ int jfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		jfs_truncate(inode);
 	}
 
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 	mark_inode_dirty(inode);
 
 	if (iattr->ia_valid & ATTR_MODE)
-		rc = posix_acl_chmod(&init_user_ns, dentry, inode->i_mode);
+		rc = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
 	return rc;
 }
 
diff --git a/fs/jfs/ioctl.c b/fs/jfs/ioctl.c
index 1e7b177ece60..ed7989bc2db1 100644
--- a/fs/jfs/ioctl.c
+++ b/fs/jfs/ioctl.c
@@ -70,7 +70,7 @@ int jfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return 0;
 }
 
-int jfs_fileattr_set(struct user_namespace *mnt_userns,
+int jfs_fileattr_set(struct mnt_idmap *idmap,
 		     struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
diff --git a/fs/jfs/jfs_acl.h b/fs/jfs/jfs_acl.h
index f0704a25835f..f892e54d0fcd 100644
--- a/fs/jfs/jfs_acl.h
+++ b/fs/jfs/jfs_acl.h
@@ -8,7 +8,7 @@
 #ifdef CONFIG_JFS_POSIX_ACL
 
 struct posix_acl *jfs_get_acl(struct inode *inode, int type, bool rcu);
-int jfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int jfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct posix_acl *acl, int type);
 int jfs_init_acl(tid_t, struct inode *, struct inode *);
 
diff --git a/fs/jfs/jfs_inode.c b/fs/jfs/jfs_inode.c
index 59379089e939..9e1f02767201 100644
--- a/fs/jfs/jfs_inode.c
+++ b/fs/jfs/jfs_inode.c
@@ -64,7 +64,7 @@ struct inode *ialloc(struct inode *parent, umode_t mode)
 		goto fail_put;
 	}
 
-	inode_init_owner(&init_user_ns, inode, parent, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, parent, mode);
 	/*
 	 * New inodes need to save sane values on disk when
 	 * uid & gid mount options are used
diff --git a/fs/jfs/jfs_inode.h b/fs/jfs/jfs_inode.h
index 7de961a81862..ea80661597ac 100644
--- a/fs/jfs/jfs_inode.h
+++ b/fs/jfs/jfs_inode.h
@@ -10,7 +10,7 @@ struct fid;
 extern struct inode *ialloc(struct inode *, umode_t);
 extern int jfs_fsync(struct file *, loff_t, loff_t, int);
 extern int jfs_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-extern int jfs_fileattr_set(struct user_namespace *mnt_userns,
+extern int jfs_fileattr_set(struct mnt_idmap *idmap,
 			    struct dentry *dentry, struct fileattr *fa);
 extern long jfs_ioctl(struct file *, unsigned int, unsigned long);
 extern struct inode *jfs_iget(struct super_block *, unsigned long);
@@ -28,7 +28,7 @@ extern struct dentry *jfs_fh_to_parent(struct super_block *sb, struct fid *fid,
 	int fh_len, int fh_type);
 extern void jfs_set_inode_flags(struct inode *);
 extern int jfs_get_block(struct inode *, sector_t, struct buffer_head *, int);
-extern int jfs_setattr(struct user_namespace *, struct dentry *, struct iattr *);
+extern int jfs_setattr(struct mnt_idmap *, struct dentry *, struct iattr *);
 
 extern const struct address_space_operations jfs_aops;
 extern const struct inode_operations jfs_dir_inode_operations;
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index a38d14eed047..b29d68b5eec5 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -59,7 +59,7 @@ static inline void free_ea_wmap(struct inode *inode)
  * RETURN:	Errors from subroutines
  *
  */
-static int jfs_create(struct user_namespace *mnt_userns, struct inode *dip,
+static int jfs_create(struct mnt_idmap *idmap, struct inode *dip,
 		      struct dentry *dentry, umode_t mode, bool excl)
 {
 	int rc = 0;
@@ -192,7 +192,7 @@ static int jfs_create(struct user_namespace *mnt_userns, struct inode *dip,
  * note:
  * EACCES: user needs search+write permission on the parent directory
  */
-static int jfs_mkdir(struct user_namespace *mnt_userns, struct inode *dip,
+static int jfs_mkdir(struct mnt_idmap *idmap, struct inode *dip,
 		     struct dentry *dentry, umode_t mode)
 {
 	int rc = 0;
@@ -869,7 +869,7 @@ static int jfs_link(struct dentry *old_dentry,
  * an intermediate result whose length exceeds PATH_MAX [XPG4.2]
 */
 
-static int jfs_symlink(struct user_namespace *mnt_userns, struct inode *dip,
+static int jfs_symlink(struct mnt_idmap *idmap, struct inode *dip,
 		       struct dentry *dentry, const char *name)
 {
 	int rc;
@@ -1059,7 +1059,7 @@ static int jfs_symlink(struct user_namespace *mnt_userns, struct inode *dip,
  *
  * FUNCTION:	rename a file or directory
  */
-static int jfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int jfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		      struct dentry *old_dentry, struct inode *new_dir,
 		      struct dentry *new_dentry, unsigned int flags)
 {
@@ -1345,7 +1345,7 @@ static int jfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
  *
  * FUNCTION:	Create a special file (device)
  */
-static int jfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int jfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct jfs_inode_info *jfs_ip;
diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c
index f9273f6901c8..f817798fa1eb 100644
--- a/fs/jfs/xattr.c
+++ b/fs/jfs/xattr.c
@@ -932,7 +932,7 @@ static int jfs_xattr_get(const struct xattr_handler *handler,
 }
 
 static int jfs_xattr_set(const struct xattr_handler *handler,
-			 struct user_namespace *mnt_userns,
+			 struct mnt_idmap *idmap,
 			 struct dentry *unused, struct inode *inode,
 			 const char *name, const void *value,
 			 size_t size, int flags)
@@ -951,7 +951,7 @@ static int jfs_xattr_get_os2(const struct xattr_handler *handler,
 }
 
 static int jfs_xattr_set_os2(const struct xattr_handler *handler,
-			     struct user_namespace *mnt_userns,
+			     struct mnt_idmap *idmap,
 			     struct dentry *unused, struct inode *inode,
 			     const char *name, const void *value,
 			     size_t size, int flags)
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 935ef8cb02b2..e3181c3e1988 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -1200,7 +1200,7 @@ static struct dentry *kernfs_iop_lookup(struct inode *dir,
 	return d_splice_alias(inode, dentry);
 }
 
-static int kernfs_iop_mkdir(struct user_namespace *mnt_userns,
+static int kernfs_iop_mkdir(struct mnt_idmap *idmap,
 			    struct inode *dir, struct dentry *dentry,
 			    umode_t mode)
 {
@@ -1238,7 +1238,7 @@ static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry)
 	return ret;
 }
 
-static int kernfs_iop_rename(struct user_namespace *mnt_userns,
+static int kernfs_iop_rename(struct mnt_idmap *idmap,
 			     struct inode *old_dir, struct dentry *old_dentry,
 			     struct inode *new_dir, struct dentry *new_dentry,
 			     unsigned int flags)
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index eac0f210299a..30494dcb0df3 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -107,7 +107,7 @@ int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)
 	return ret;
 }
 
-int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int kernfs_iop_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		       struct iattr *iattr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -120,7 +120,7 @@ int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 	root = kernfs_root(kn);
 	down_write(&root->kernfs_rwsem);
-	error = setattr_prepare(&init_user_ns, dentry, iattr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (error)
 		goto out;
 
@@ -129,7 +129,7 @@ int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		goto out;
 
 	/* this ignores size changes */
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 
 out:
 	up_write(&root->kernfs_rwsem);
@@ -181,7 +181,7 @@ static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode)
 		set_nlink(inode, kn->dir.subdirs + 2);
 }
 
-int kernfs_iop_getattr(struct user_namespace *mnt_userns,
+int kernfs_iop_getattr(struct mnt_idmap *idmap,
 		       const struct path *path, struct kstat *stat,
 		       u32 request_mask, unsigned int query_flags)
 {
@@ -191,7 +191,7 @@ int kernfs_iop_getattr(struct user_namespace *mnt_userns,
 
 	down_read(&root->kernfs_rwsem);
 	kernfs_refresh_inode(kn, inode);
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	up_read(&root->kernfs_rwsem);
 
 	return 0;
@@ -272,7 +272,7 @@ void kernfs_evict_inode(struct inode *inode)
 	kernfs_put(kn);
 }
 
-int kernfs_iop_permission(struct user_namespace *mnt_userns,
+int kernfs_iop_permission(struct mnt_idmap *idmap,
 			  struct inode *inode, int mask)
 {
 	struct kernfs_node *kn;
@@ -287,7 +287,7 @@ int kernfs_iop_permission(struct user_namespace *mnt_userns,
 
 	down_read(&root->kernfs_rwsem);
 	kernfs_refresh_inode(kn, inode);
-	ret = generic_permission(&init_user_ns, inode, mask);
+	ret = generic_permission(&nop_mnt_idmap, inode, mask);
 	up_read(&root->kernfs_rwsem);
 
 	return ret;
@@ -324,7 +324,7 @@ static int kernfs_vfs_xattr_get(const struct xattr_handler *handler,
 }
 
 static int kernfs_vfs_xattr_set(const struct xattr_handler *handler,
-				struct user_namespace *mnt_userns,
+				struct mnt_idmap *idmap,
 				struct dentry *unused, struct inode *inode,
 				const char *suffix, const void *value,
 				size_t size, int flags)
@@ -391,7 +391,7 @@ static int kernfs_vfs_user_xattr_rm(struct kernfs_node *kn,
 }
 
 static int kernfs_vfs_user_xattr_set(const struct xattr_handler *handler,
-				     struct user_namespace *mnt_userns,
+				     struct mnt_idmap *idmap,
 				     struct dentry *unused, struct inode *inode,
 				     const char *suffix, const void *value,
 				     size_t size, int flags)
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 9046d9f39e63..236c3a6113f1 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -127,11 +127,11 @@ extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
  */
 extern const struct xattr_handler *kernfs_xattr_handlers[];
 void kernfs_evict_inode(struct inode *inode);
-int kernfs_iop_permission(struct user_namespace *mnt_userns,
+int kernfs_iop_permission(struct mnt_idmap *idmap,
 			  struct inode *inode, int mask);
-int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int kernfs_iop_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		       struct iattr *iattr);
-int kernfs_iop_getattr(struct user_namespace *mnt_userns,
+int kernfs_iop_getattr(struct mnt_idmap *idmap,
 		       const struct path *path, struct kstat *stat,
 		       u32 request_mask, unsigned int query_flags);
 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
diff --git a/fs/ksmbd/ndr.c b/fs/ksmbd/ndr.c
index 4d9e0b54e3db..3507d8f89074 100644
--- a/fs/ksmbd/ndr.c
+++ b/fs/ksmbd/ndr.c
@@ -338,7 +338,7 @@ static int ndr_encode_posix_acl_entry(struct ndr *n, struct xattr_smb_acl *acl)
 }
 
 int ndr_encode_posix_acl(struct ndr *n,
-			 struct user_namespace *user_ns,
+			 struct mnt_idmap *idmap,
 			 struct inode *inode,
 			 struct xattr_smb_acl *acl,
 			 struct xattr_smb_acl *def_acl)
@@ -374,11 +374,11 @@ int ndr_encode_posix_acl(struct ndr *n,
 	if (ret)
 		return ret;
 
-	vfsuid = i_uid_into_vfsuid(user_ns, inode);
+	vfsuid = i_uid_into_vfsuid(idmap, inode);
 	ret = ndr_write_int64(n, from_kuid(&init_user_ns, vfsuid_into_kuid(vfsuid)));
 	if (ret)
 		return ret;
-	vfsgid = i_gid_into_vfsgid(user_ns, inode);
+	vfsgid = i_gid_into_vfsgid(idmap, inode);
 	ret = ndr_write_int64(n, from_kgid(&init_user_ns, vfsgid_into_kgid(vfsgid)));
 	if (ret)
 		return ret;
diff --git a/fs/ksmbd/ndr.h b/fs/ksmbd/ndr.h
index 60ca265d1bb0..f3c108c8cf4d 100644
--- a/fs/ksmbd/ndr.h
+++ b/fs/ksmbd/ndr.h
@@ -14,7 +14,7 @@ struct ndr {
 
 int ndr_encode_dos_attr(struct ndr *n, struct xattr_dos_attrib *da);
 int ndr_decode_dos_attr(struct ndr *n, struct xattr_dos_attrib *da);
-int ndr_encode_posix_acl(struct ndr *n, struct user_namespace *user_ns,
+int ndr_encode_posix_acl(struct ndr *n, struct mnt_idmap *idmap,
 			 struct inode *inode, struct xattr_smb_acl *acl,
 			 struct xattr_smb_acl *def_acl);
 int ndr_encode_v4_ntacl(struct ndr *n, struct xattr_ntacl *acl);
diff --git a/fs/ksmbd/oplock.c b/fs/ksmbd/oplock.c
index d7d47b82451d..2e54ded4d92c 100644
--- a/fs/ksmbd/oplock.c
+++ b/fs/ksmbd/oplock.c
@@ -1608,9 +1608,9 @@ void create_posix_rsp_buf(char *cc, struct ksmbd_file *fp)
 {
 	struct create_posix_rsp *buf;
 	struct inode *inode = file_inode(fp->filp);
-	struct user_namespace *user_ns = file_mnt_user_ns(fp->filp);
-	vfsuid_t vfsuid = i_uid_into_vfsuid(user_ns, inode);
-	vfsgid_t vfsgid = i_gid_into_vfsgid(user_ns, inode);
+	struct mnt_idmap *idmap = file_mnt_idmap(fp->filp);
+	vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
+	vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
 
 	buf = (struct create_posix_rsp *)cc;
 	memset(buf, 0, sizeof(struct create_posix_rsp));
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 90eb05ca4a3c..4ef6e1e59a40 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -2193,7 +2193,7 @@ out:
 static int smb2_set_ea(struct smb2_ea_info *eabuf, unsigned int buf_len,
 		       const struct path *path)
 {
-	struct user_namespace *user_ns = mnt_user_ns(path->mnt);
+	struct mnt_idmap *idmap = mnt_idmap(path->mnt);
 	char *attr_name = NULL, *value;
 	int rc = 0;
 	unsigned int next = 0;
@@ -2229,7 +2229,7 @@ static int smb2_set_ea(struct smb2_ea_info *eabuf, unsigned int buf_len,
 		value = (char *)&eabuf->name + eabuf->EaNameLength + 1;
 
 		if (!eabuf->EaValueLength) {
-			rc = ksmbd_vfs_casexattr_len(user_ns,
+			rc = ksmbd_vfs_casexattr_len(idmap,
 						     path->dentry,
 						     attr_name,
 						     XATTR_USER_PREFIX_LEN +
@@ -2237,7 +2237,7 @@ static int smb2_set_ea(struct smb2_ea_info *eabuf, unsigned int buf_len,
 
 			/* delete the EA only when it exits */
 			if (rc > 0) {
-				rc = ksmbd_vfs_remove_xattr(user_ns,
+				rc = ksmbd_vfs_remove_xattr(idmap,
 							    path->dentry,
 							    attr_name);
 
@@ -2252,7 +2252,7 @@ static int smb2_set_ea(struct smb2_ea_info *eabuf, unsigned int buf_len,
 			/* if the EA doesn't exist, just do nothing. */
 			rc = 0;
 		} else {
-			rc = ksmbd_vfs_setxattr(user_ns,
+			rc = ksmbd_vfs_setxattr(idmap,
 						path->dentry, attr_name, value,
 						le16_to_cpu(eabuf->EaValueLength), 0);
 			if (rc < 0) {
@@ -2282,7 +2282,7 @@ static noinline int smb2_set_stream_name_xattr(const struct path *path,
 					       struct ksmbd_file *fp,
 					       char *stream_name, int s_type)
 {
-	struct user_namespace *user_ns = mnt_user_ns(path->mnt);
+	struct mnt_idmap *idmap = mnt_idmap(path->mnt);
 	size_t xattr_stream_size;
 	char *xattr_stream_name;
 	int rc;
@@ -2298,7 +2298,7 @@ static noinline int smb2_set_stream_name_xattr(const struct path *path,
 	fp->stream.size = xattr_stream_size;
 
 	/* Check if there is stream prefix in xattr space */
-	rc = ksmbd_vfs_casexattr_len(user_ns,
+	rc = ksmbd_vfs_casexattr_len(idmap,
 				     path->dentry,
 				     xattr_stream_name,
 				     xattr_stream_size);
@@ -2310,7 +2310,7 @@ static noinline int smb2_set_stream_name_xattr(const struct path *path,
 		return -EBADF;
 	}
 
-	rc = ksmbd_vfs_setxattr(user_ns, path->dentry,
+	rc = ksmbd_vfs_setxattr(idmap, path->dentry,
 				xattr_stream_name, NULL, 0, 0);
 	if (rc < 0)
 		pr_err("Failed to store XATTR stream name :%d\n", rc);
@@ -2319,7 +2319,7 @@ static noinline int smb2_set_stream_name_xattr(const struct path *path,
 
 static int smb2_remove_smb_xattrs(const struct path *path)
 {
-	struct user_namespace *user_ns = mnt_user_ns(path->mnt);
+	struct mnt_idmap *idmap = mnt_idmap(path->mnt);
 	char *name, *xattr_list = NULL;
 	ssize_t xattr_list_len;
 	int err = 0;
@@ -2339,7 +2339,7 @@ static int smb2_remove_smb_xattrs(const struct path *path)
 		if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
 		    !strncmp(&name[XATTR_USER_PREFIX_LEN], STREAM_PREFIX,
 			     STREAM_PREFIX_LEN)) {
-			err = ksmbd_vfs_remove_xattr(user_ns, path->dentry,
+			err = ksmbd_vfs_remove_xattr(idmap, path->dentry,
 						     name);
 			if (err)
 				ksmbd_debug(SMB, "remove xattr failed : %s\n",
@@ -2386,7 +2386,7 @@ static void smb2_new_xattrs(struct ksmbd_tree_connect *tcon, const struct path *
 	da.flags = XATTR_DOSINFO_ATTRIB | XATTR_DOSINFO_CREATE_TIME |
 		XATTR_DOSINFO_ITIME;
 
-	rc = ksmbd_vfs_set_dos_attrib_xattr(mnt_user_ns(path->mnt),
+	rc = ksmbd_vfs_set_dos_attrib_xattr(mnt_idmap(path->mnt),
 					    path->dentry, &da);
 	if (rc)
 		ksmbd_debug(SMB, "failed to store file attribute into xattr\n");
@@ -2405,7 +2405,7 @@ static void smb2_update_xattrs(struct ksmbd_tree_connect *tcon,
 				    KSMBD_SHARE_FLAG_STORE_DOS_ATTRS))
 		return;
 
-	rc = ksmbd_vfs_get_dos_attrib_xattr(mnt_user_ns(path->mnt),
+	rc = ksmbd_vfs_get_dos_attrib_xattr(mnt_idmap(path->mnt),
 					    path->dentry, &da);
 	if (rc > 0) {
 		fp->f_ci->m_fattr = cpu_to_le32(da.attr);
@@ -2480,11 +2480,11 @@ static int smb2_create_sd_buffer(struct ksmbd_work *work,
 }
 
 static void ksmbd_acls_fattr(struct smb_fattr *fattr,
-			     struct user_namespace *mnt_userns,
+			     struct mnt_idmap *idmap,
 			     struct inode *inode)
 {
-	vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
-	vfsgid_t vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
+	vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
+	vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
 
 	fattr->cf_uid = vfsuid_into_kuid(vfsuid);
 	fattr->cf_gid = vfsgid_into_kgid(vfsgid);
@@ -2516,7 +2516,7 @@ int smb2_open(struct ksmbd_work *work)
 	struct ksmbd_share_config *share = tcon->share_conf;
 	struct ksmbd_file *fp = NULL;
 	struct file *filp = NULL;
-	struct user_namespace *user_ns = NULL;
+	struct mnt_idmap *idmap = NULL;
 	struct kstat stat;
 	struct create_context *context;
 	struct lease_ctx_info *lc = NULL;
@@ -2769,7 +2769,7 @@ int smb2_open(struct ksmbd_work *work)
 		rc = 0;
 	} else {
 		file_present = true;
-		user_ns = mnt_user_ns(path.mnt);
+		idmap = mnt_idmap(path.mnt);
 	}
 	if (stream_name) {
 		if (req->CreateOptions & FILE_DIRECTORY_FILE_LE) {
@@ -2832,7 +2832,7 @@ int smb2_open(struct ksmbd_work *work)
 		if (!file_present) {
 			daccess = cpu_to_le32(GENERIC_ALL_FLAGS);
 		} else {
-			rc = ksmbd_vfs_query_maximal_access(user_ns,
+			rc = ksmbd_vfs_query_maximal_access(idmap,
 							    path.dentry,
 							    &daccess);
 			if (rc)
@@ -2868,7 +2868,7 @@ int smb2_open(struct ksmbd_work *work)
 		}
 
 		created = true;
-		user_ns = mnt_user_ns(path.mnt);
+		idmap = mnt_idmap(path.mnt);
 		if (ea_buf) {
 			if (le32_to_cpu(ea_buf->ccontext.DataLength) <
 			    sizeof(struct smb2_ea_info)) {
@@ -2890,7 +2890,7 @@ int smb2_open(struct ksmbd_work *work)
 		 * is already granted.
 		 */
 		if (daccess & ~(FILE_READ_ATTRIBUTES_LE | FILE_READ_CONTROL_LE)) {
-			rc = inode_permission(user_ns,
+			rc = inode_permission(idmap,
 					      d_inode(path.dentry),
 					      may_flags);
 			if (rc)
@@ -2898,7 +2898,7 @@ int smb2_open(struct ksmbd_work *work)
 
 			if ((daccess & FILE_DELETE_LE) ||
 			    (req->CreateOptions & FILE_DELETE_ON_CLOSE_LE)) {
-				rc = ksmbd_vfs_may_delete(user_ns,
+				rc = ksmbd_vfs_may_delete(idmap,
 							  path.dentry);
 				if (rc)
 					goto err_out;
@@ -2961,7 +2961,7 @@ int smb2_open(struct ksmbd_work *work)
 		int posix_acl_rc;
 		struct inode *inode = d_inode(path.dentry);
 
-		posix_acl_rc = ksmbd_vfs_inherit_posix_acl(user_ns,
+		posix_acl_rc = ksmbd_vfs_inherit_posix_acl(idmap,
 							   path.dentry,
 							   d_inode(path.dentry->d_parent));
 		if (posix_acl_rc)
@@ -2977,7 +2977,7 @@ int smb2_open(struct ksmbd_work *work)
 			rc = smb2_create_sd_buffer(work, req, &path);
 			if (rc) {
 				if (posix_acl_rc)
-					ksmbd_vfs_set_init_posix_acl(user_ns,
+					ksmbd_vfs_set_init_posix_acl(idmap,
 								     path.dentry);
 
 				if (test_share_config_flag(work->tcon->share_conf,
@@ -2986,7 +2986,7 @@ int smb2_open(struct ksmbd_work *work)
 					struct smb_ntsd *pntsd;
 					int pntsd_size, ace_num = 0;
 
-					ksmbd_acls_fattr(&fattr, user_ns, inode);
+					ksmbd_acls_fattr(&fattr, idmap, inode);
 					if (fattr.cf_acls)
 						ace_num = fattr.cf_acls->a_count;
 					if (fattr.cf_dacls)
@@ -3000,7 +3000,7 @@ int smb2_open(struct ksmbd_work *work)
 					if (!pntsd)
 						goto err_out;
 
-					rc = build_sec_desc(user_ns,
+					rc = build_sec_desc(idmap,
 							    pntsd, NULL, 0,
 							    OWNER_SECINFO |
 							    GROUP_SECINFO |
@@ -3014,7 +3014,7 @@ int smb2_open(struct ksmbd_work *work)
 					}
 
 					rc = ksmbd_vfs_set_sd_xattr(conn,
-								    user_ns,
+								    idmap,
 								    path.dentry,
 								    pntsd,
 								    pntsd_size);
@@ -3210,7 +3210,7 @@ int smb2_open(struct ksmbd_work *work)
 		struct create_context *mxac_ccontext;
 
 		if (maximal_access == 0)
-			ksmbd_vfs_query_maximal_access(user_ns,
+			ksmbd_vfs_query_maximal_access(idmap,
 						       path.dentry,
 						       &maximal_access);
 		mxac_ccontext = (struct create_context *)(rsp->Buffer +
@@ -3635,7 +3635,7 @@ static void unlock_dir(struct ksmbd_file *dir_fp)
 
 static int process_query_dir_entries(struct smb2_query_dir_private *priv)
 {
-	struct user_namespace	*user_ns = file_mnt_user_ns(priv->dir_fp->filp);
+	struct mnt_idmap	*idmap = file_mnt_idmap(priv->dir_fp->filp);
 	struct kstat		kstat;
 	struct ksmbd_kstat	ksmbd_kstat;
 	int			rc;
@@ -3648,7 +3648,7 @@ static int process_query_dir_entries(struct smb2_query_dir_private *priv)
 			return -EINVAL;
 
 		lock_dir(priv->dir_fp);
-		dent = lookup_one(user_ns, priv->d_info->name,
+		dent = lookup_one(idmap, priv->d_info->name,
 				  priv->dir_fp->filp->f_path.dentry,
 				  priv->d_info->name_len);
 		unlock_dir(priv->dir_fp);
@@ -3669,7 +3669,7 @@ static int process_query_dir_entries(struct smb2_query_dir_private *priv)
 		ksmbd_kstat.kstat = &kstat;
 		if (priv->info_level != FILE_NAMES_INFORMATION)
 			ksmbd_vfs_fill_dentry_attrs(priv->work,
-						    user_ns,
+						    idmap,
 						    dent,
 						    &ksmbd_kstat);
 
@@ -3899,7 +3899,7 @@ int smb2_query_dir(struct ksmbd_work *work)
 	}
 
 	if (!(dir_fp->daccess & FILE_LIST_DIRECTORY_LE) ||
-	    inode_permission(file_mnt_user_ns(dir_fp->filp),
+	    inode_permission(file_mnt_idmap(dir_fp->filp),
 			     file_inode(dir_fp->filp),
 			     MAY_READ | MAY_EXEC)) {
 		pr_err("no right to enumerate directory (%pD)\n", dir_fp->filp);
@@ -4165,7 +4165,7 @@ static int smb2_get_ea(struct ksmbd_work *work, struct ksmbd_file *fp,
 	ssize_t buf_free_len, alignment_bytes, next_offset, rsp_data_cnt = 0;
 	struct smb2_ea_info_req *ea_req = NULL;
 	const struct path *path;
-	struct user_namespace *user_ns = file_mnt_user_ns(fp->filp);
+	struct mnt_idmap *idmap = file_mnt_idmap(fp->filp);
 
 	if (!(fp->daccess & FILE_READ_EA_LE)) {
 		pr_err("Not permitted to read ext attr : 0x%x\n",
@@ -4245,7 +4245,7 @@ static int smb2_get_ea(struct ksmbd_work *work, struct ksmbd_file *fp,
 		buf_free_len -= (offsetof(struct smb2_ea_info, name) +
 				name_len + 1);
 		/* bailout if xattr can't fit in buf_free_len */
-		value_len = ksmbd_vfs_getxattr(user_ns, path->dentry,
+		value_len = ksmbd_vfs_getxattr(idmap, path->dentry,
 					       name, &buf);
 		if (value_len <= 0) {
 			rc = -ENOENT;
@@ -4335,7 +4335,7 @@ static int get_file_basic_info(struct smb2_query_info_rsp *rsp,
 	}
 
 	basic_info = (struct smb2_file_basic_info *)rsp->Buffer;
-	generic_fillattr(file_mnt_user_ns(fp->filp), file_inode(fp->filp),
+	generic_fillattr(file_mnt_idmap(fp->filp), file_inode(fp->filp),
 			 &stat);
 	basic_info->CreationTime = cpu_to_le64(fp->create_time);
 	time = ksmbd_UnixTimeToNT(stat.atime);
@@ -4376,7 +4376,7 @@ static void get_file_standard_info(struct smb2_query_info_rsp *rsp,
 	struct kstat stat;
 
 	inode = file_inode(fp->filp);
-	generic_fillattr(file_mnt_user_ns(fp->filp), inode, &stat);
+	generic_fillattr(file_mnt_idmap(fp->filp), inode, &stat);
 
 	sinfo = (struct smb2_file_standard_info *)rsp->Buffer;
 	delete_pending = ksmbd_inode_pending_delete(fp);
@@ -4430,7 +4430,7 @@ static int get_file_all_info(struct ksmbd_work *work,
 		return PTR_ERR(filename);
 
 	inode = file_inode(fp->filp);
-	generic_fillattr(file_mnt_user_ns(fp->filp), inode, &stat);
+	generic_fillattr(file_mnt_idmap(fp->filp), inode, &stat);
 
 	ksmbd_debug(SMB, "filename = %s\n", filename);
 	delete_pending = ksmbd_inode_pending_delete(fp);
@@ -4507,7 +4507,7 @@ static void get_file_stream_info(struct ksmbd_work *work,
 	int buf_free_len;
 	struct smb2_query_info_req *req = ksmbd_req_buf_next(work);
 
-	generic_fillattr(file_mnt_user_ns(fp->filp), file_inode(fp->filp),
+	generic_fillattr(file_mnt_idmap(fp->filp), file_inode(fp->filp),
 			 &stat);
 	file_info = (struct smb2_file_stream_info *)rsp->Buffer;
 
@@ -4598,7 +4598,7 @@ static void get_file_internal_info(struct smb2_query_info_rsp *rsp,
 	struct smb2_file_internal_info *file_info;
 	struct kstat stat;
 
-	generic_fillattr(file_mnt_user_ns(fp->filp), file_inode(fp->filp),
+	generic_fillattr(file_mnt_idmap(fp->filp), file_inode(fp->filp),
 			 &stat);
 	file_info = (struct smb2_file_internal_info *)rsp->Buffer;
 	file_info->IndexNumber = cpu_to_le64(stat.ino);
@@ -4624,7 +4624,7 @@ static int get_file_network_open_info(struct smb2_query_info_rsp *rsp,
 	file_info = (struct smb2_file_ntwrk_info *)rsp->Buffer;
 
 	inode = file_inode(fp->filp);
-	generic_fillattr(file_mnt_user_ns(fp->filp), inode, &stat);
+	generic_fillattr(file_mnt_idmap(fp->filp), inode, &stat);
 
 	file_info->CreationTime = cpu_to_le64(fp->create_time);
 	time = ksmbd_UnixTimeToNT(stat.atime);
@@ -4685,7 +4685,7 @@ static void get_file_compression_info(struct smb2_query_info_rsp *rsp,
 	struct smb2_file_comp_info *file_info;
 	struct kstat stat;
 
-	generic_fillattr(file_mnt_user_ns(fp->filp), file_inode(fp->filp),
+	generic_fillattr(file_mnt_idmap(fp->filp), file_inode(fp->filp),
 			 &stat);
 
 	file_info = (struct smb2_file_comp_info *)rsp->Buffer;
@@ -4726,9 +4726,9 @@ static int find_file_posix_info(struct smb2_query_info_rsp *rsp,
 {
 	struct smb311_posix_qinfo *file_info;
 	struct inode *inode = file_inode(fp->filp);
-	struct user_namespace *user_ns = file_mnt_user_ns(fp->filp);
-	vfsuid_t vfsuid = i_uid_into_vfsuid(user_ns, inode);
-	vfsgid_t vfsgid = i_gid_into_vfsgid(user_ns, inode);
+	struct mnt_idmap *idmap = file_mnt_idmap(fp->filp);
+	vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
+	vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
 	u64 time;
 	int out_buf_len = sizeof(struct smb311_posix_qinfo) + 32;
 
@@ -5128,7 +5128,7 @@ static int smb2_get_info_sec(struct ksmbd_work *work,
 			     struct smb2_query_info_rsp *rsp)
 {
 	struct ksmbd_file *fp;
-	struct user_namespace *user_ns;
+	struct mnt_idmap *idmap;
 	struct smb_ntsd *pntsd = (struct smb_ntsd *)rsp->Buffer, *ppntsd = NULL;
 	struct smb_fattr fattr = {{0}};
 	struct inode *inode;
@@ -5175,19 +5175,19 @@ static int smb2_get_info_sec(struct ksmbd_work *work,
 	if (!fp)
 		return -ENOENT;
 
-	user_ns = file_mnt_user_ns(fp->filp);
+	idmap = file_mnt_idmap(fp->filp);
 	inode = file_inode(fp->filp);
-	ksmbd_acls_fattr(&fattr, user_ns, inode);
+	ksmbd_acls_fattr(&fattr, idmap, inode);
 
 	if (test_share_config_flag(work->tcon->share_conf,
 				   KSMBD_SHARE_FLAG_ACL_XATTR))
-		ppntsd_size = ksmbd_vfs_get_sd_xattr(work->conn, user_ns,
+		ppntsd_size = ksmbd_vfs_get_sd_xattr(work->conn, idmap,
 						     fp->filp->f_path.dentry,
 						     &ppntsd);
 
 	/* Check if sd buffer size exceeds response buffer size */
 	if (smb2_resp_buf_len(work, 8) > ppntsd_size)
-		rc = build_sec_desc(user_ns, pntsd, ppntsd, ppntsd_size,
+		rc = build_sec_desc(idmap, pntsd, ppntsd, ppntsd_size,
 				    addition_info, &secdesclen, &fattr);
 	posix_acl_release(fattr.cf_acls);
 	posix_acl_release(fattr.cf_dacls);
@@ -5417,7 +5417,7 @@ int smb2_echo(struct ksmbd_work *work)
 
 static int smb2_rename(struct ksmbd_work *work,
 		       struct ksmbd_file *fp,
-		       struct user_namespace *user_ns,
+		       struct mnt_idmap *idmap,
 		       struct smb2_file_rename_info *file_info,
 		       struct nls_table *local_nls)
 {
@@ -5480,7 +5480,7 @@ static int smb2_rename(struct ksmbd_work *work,
 		if (rc)
 			goto out;
 
-		rc = ksmbd_vfs_setxattr(user_ns,
+		rc = ksmbd_vfs_setxattr(idmap,
 					fp->filp->f_path.dentry,
 					xattr_stream_name,
 					NULL, 0, 0);
@@ -5619,7 +5619,7 @@ static int set_file_basic_info(struct ksmbd_file *fp,
 	struct iattr attrs;
 	struct file *filp;
 	struct inode *inode;
-	struct user_namespace *user_ns;
+	struct mnt_idmap *idmap;
 	int rc = 0;
 
 	if (!(fp->daccess & FILE_WRITE_ATTRIBUTES_LE))
@@ -5628,7 +5628,7 @@ static int set_file_basic_info(struct ksmbd_file *fp,
 	attrs.ia_valid = 0;
 	filp = fp->filp;
 	inode = file_inode(filp);
-	user_ns = file_mnt_user_ns(filp);
+	idmap = file_mnt_idmap(filp);
 
 	if (file_info->CreationTime)
 		fp->create_time = le64_to_cpu(file_info->CreationTime);
@@ -5672,7 +5672,7 @@ static int set_file_basic_info(struct ksmbd_file *fp,
 		da.flags = XATTR_DOSINFO_ATTRIB | XATTR_DOSINFO_CREATE_TIME |
 			XATTR_DOSINFO_ITIME;
 
-		rc = ksmbd_vfs_set_dos_attrib_xattr(user_ns,
+		rc = ksmbd_vfs_set_dos_attrib_xattr(idmap,
 						    filp->f_path.dentry, &da);
 		if (rc)
 			ksmbd_debug(SMB,
@@ -5690,7 +5690,7 @@ static int set_file_basic_info(struct ksmbd_file *fp,
 		inode_lock(inode);
 		inode->i_ctime = attrs.ia_ctime;
 		attrs.ia_valid &= ~ATTR_CTIME;
-		rc = notify_change(user_ns, dentry, &attrs, NULL);
+		rc = notify_change(idmap, dentry, &attrs, NULL);
 		inode_unlock(inode);
 	}
 	return rc;
@@ -5783,7 +5783,7 @@ static int set_rename_info(struct ksmbd_work *work, struct ksmbd_file *fp,
 			   struct smb2_file_rename_info *rename_info,
 			   unsigned int buf_len)
 {
-	struct user_namespace *user_ns;
+	struct mnt_idmap *idmap;
 	struct ksmbd_file *parent_fp;
 	struct dentry *parent;
 	struct dentry *dentry = fp->filp->f_path.dentry;
@@ -5798,12 +5798,12 @@ static int set_rename_info(struct ksmbd_work *work, struct ksmbd_file *fp,
 			le32_to_cpu(rename_info->FileNameLength))
 		return -EINVAL;
 
-	user_ns = file_mnt_user_ns(fp->filp);
+	idmap = file_mnt_idmap(fp->filp);
 	if (ksmbd_stream_fd(fp))
 		goto next;
 
 	parent = dget_parent(dentry);
-	ret = ksmbd_vfs_lock_parent(user_ns, parent, dentry);
+	ret = ksmbd_vfs_lock_parent(idmap, parent, dentry);
 	if (ret) {
 		dput(parent);
 		return ret;
@@ -5822,7 +5822,7 @@ static int set_rename_info(struct ksmbd_work *work, struct ksmbd_file *fp,
 		ksmbd_fd_put(work, parent_fp);
 	}
 next:
-	return smb2_rename(work, fp, user_ns, rename_info,
+	return smb2_rename(work, fp, idmap, rename_info,
 			   work->conn->local_nls);
 }
 
@@ -7531,14 +7531,14 @@ static inline int fsctl_set_sparse(struct ksmbd_work *work, u64 id,
 				   struct file_sparse *sparse)
 {
 	struct ksmbd_file *fp;
-	struct user_namespace *user_ns;
+	struct mnt_idmap *idmap;
 	int ret = 0;
 	__le32 old_fattr;
 
 	fp = ksmbd_lookup_fd_fast(work, id);
 	if (!fp)
 		return -ENOENT;
-	user_ns = file_mnt_user_ns(fp->filp);
+	idmap = file_mnt_idmap(fp->filp);
 
 	old_fattr = fp->f_ci->m_fattr;
 	if (sparse->SetSparse)
@@ -7551,13 +7551,13 @@ static inline int fsctl_set_sparse(struct ksmbd_work *work, u64 id,
 				   KSMBD_SHARE_FLAG_STORE_DOS_ATTRS)) {
 		struct xattr_dos_attrib da;
 
-		ret = ksmbd_vfs_get_dos_attrib_xattr(user_ns,
+		ret = ksmbd_vfs_get_dos_attrib_xattr(idmap,
 						     fp->filp->f_path.dentry, &da);
 		if (ret <= 0)
 			goto out;
 
 		da.attr = le32_to_cpu(fp->f_ci->m_fattr);
-		ret = ksmbd_vfs_set_dos_attrib_xattr(user_ns,
+		ret = ksmbd_vfs_set_dos_attrib_xattr(idmap,
 						     fp->filp->f_path.dentry, &da);
 		if (ret)
 			fp->f_ci->m_fattr = old_fattr;
diff --git a/fs/ksmbd/smb_common.c b/fs/ksmbd/smb_common.c
index 2a4fbbd55b91..fa2b54df6ee6 100644
--- a/fs/ksmbd/smb_common.c
+++ b/fs/ksmbd/smb_common.c
@@ -307,7 +307,7 @@ int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
 {
 	int i, rc = 0;
 	struct ksmbd_conn *conn = work->conn;
-	struct user_namespace *user_ns = file_mnt_user_ns(dir->filp);
+	struct mnt_idmap *idmap = file_mnt_idmap(dir->filp);
 
 	for (i = 0; i < 2; i++) {
 		struct kstat kstat;
@@ -333,7 +333,7 @@ int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
 
 			ksmbd_kstat.kstat = &kstat;
 			ksmbd_vfs_fill_dentry_attrs(work,
-						    user_ns,
+						    idmap,
 						    dentry,
 						    &ksmbd_kstat);
 			rc = fn(conn, info_level, d_info, &ksmbd_kstat);
diff --git a/fs/ksmbd/smbacl.c b/fs/ksmbd/smbacl.c
index ab5c68cc0e13..6d6cfb6957a9 100644
--- a/fs/ksmbd/smbacl.c
+++ b/fs/ksmbd/smbacl.c
@@ -254,7 +254,7 @@ void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid)
 	ssid->num_subauth++;
 }
 
-static int sid_to_id(struct user_namespace *user_ns,
+static int sid_to_id(struct mnt_idmap *idmap,
 		     struct smb_sid *psid, uint sidtype,
 		     struct smb_fattr *fattr)
 {
@@ -276,7 +276,7 @@ static int sid_to_id(struct user_namespace *user_ns,
 
 		id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]);
 		uid = KUIDT_INIT(id);
-		uid = from_vfsuid(user_ns, &init_user_ns, VFSUIDT_INIT(uid));
+		uid = from_vfsuid(idmap, &init_user_ns, VFSUIDT_INIT(uid));
 		if (uid_valid(uid)) {
 			fattr->cf_uid = uid;
 			rc = 0;
@@ -287,7 +287,7 @@ static int sid_to_id(struct user_namespace *user_ns,
 
 		id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]);
 		gid = KGIDT_INIT(id);
-		gid = from_vfsgid(user_ns, &init_user_ns, VFSGIDT_INIT(gid));
+		gid = from_vfsgid(idmap, &init_user_ns, VFSGIDT_INIT(gid));
 		if (gid_valid(gid)) {
 			fattr->cf_gid = gid;
 			rc = 0;
@@ -362,7 +362,7 @@ void free_acl_state(struct posix_acl_state *state)
 	kfree(state->groups);
 }
 
-static void parse_dacl(struct user_namespace *user_ns,
+static void parse_dacl(struct mnt_idmap *idmap,
 		       struct smb_acl *pdacl, char *end_of_acl,
 		       struct smb_sid *pownersid, struct smb_sid *pgrpsid,
 		       struct smb_fattr *fattr)
@@ -489,7 +489,7 @@ static void parse_dacl(struct user_namespace *user_ns,
 			acl_mode = access_flags_to_mode(fattr, ppace[i]->access_req,
 							ppace[i]->type);
 			temp_fattr.cf_uid = INVALID_UID;
-			ret = sid_to_id(user_ns, &ppace[i]->sid, SIDOWNER, &temp_fattr);
+			ret = sid_to_id(idmap, &ppace[i]->sid, SIDOWNER, &temp_fattr);
 			if (ret || uid_eq(temp_fattr.cf_uid, INVALID_UID)) {
 				pr_err("%s: Error %d mapping Owner SID to uid\n",
 				       __func__, ret);
@@ -575,7 +575,7 @@ static void parse_dacl(struct user_namespace *user_ns,
 	free_acl_state(&default_acl_state);
 }
 
-static void set_posix_acl_entries_dacl(struct user_namespace *user_ns,
+static void set_posix_acl_entries_dacl(struct mnt_idmap *idmap,
 				       struct smb_ace *pndace,
 				       struct smb_fattr *fattr, u32 *num_aces,
 				       u16 *size, u32 nt_aces_num)
@@ -600,14 +600,14 @@ static void set_posix_acl_entries_dacl(struct user_namespace *user_ns,
 			uid_t uid;
 			unsigned int sid_type = SIDOWNER;
 
-			uid = posix_acl_uid_translate(user_ns, pace);
+			uid = posix_acl_uid_translate(idmap, pace);
 			if (!uid)
 				sid_type = SIDUNIX_USER;
 			id_to_sid(uid, sid_type, sid);
 		} else if (pace->e_tag == ACL_GROUP) {
 			gid_t gid;
 
-			gid = posix_acl_gid_translate(user_ns, pace);
+			gid = posix_acl_gid_translate(idmap, pace);
 			id_to_sid(gid, SIDUNIX_GROUP, sid);
 		} else if (pace->e_tag == ACL_OTHER && !nt_aces_num) {
 			smb_copy_sid(sid, &sid_everyone);
@@ -666,12 +666,12 @@ posix_default_acl:
 		if (pace->e_tag == ACL_USER) {
 			uid_t uid;
 
-			uid = posix_acl_uid_translate(user_ns, pace);
+			uid = posix_acl_uid_translate(idmap, pace);
 			id_to_sid(uid, SIDCREATOR_OWNER, sid);
 		} else if (pace->e_tag == ACL_GROUP) {
 			gid_t gid;
 
-			gid = posix_acl_gid_translate(user_ns, pace);
+			gid = posix_acl_gid_translate(idmap, pace);
 			id_to_sid(gid, SIDCREATOR_GROUP, sid);
 		} else {
 			kfree(sid);
@@ -689,7 +689,7 @@ posix_default_acl:
 	}
 }
 
-static void set_ntacl_dacl(struct user_namespace *user_ns,
+static void set_ntacl_dacl(struct mnt_idmap *idmap,
 			   struct smb_acl *pndacl,
 			   struct smb_acl *nt_dacl,
 			   unsigned int aces_size,
@@ -723,13 +723,13 @@ static void set_ntacl_dacl(struct user_namespace *user_ns,
 		}
 	}
 
-	set_posix_acl_entries_dacl(user_ns, pndace, fattr,
+	set_posix_acl_entries_dacl(idmap, pndace, fattr,
 				   &num_aces, &size, nt_num_aces);
 	pndacl->num_aces = cpu_to_le32(num_aces);
 	pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size);
 }
 
-static void set_mode_dacl(struct user_namespace *user_ns,
+static void set_mode_dacl(struct mnt_idmap *idmap,
 			  struct smb_acl *pndacl, struct smb_fattr *fattr)
 {
 	struct smb_ace *pace, *pndace;
@@ -741,7 +741,7 @@ static void set_mode_dacl(struct user_namespace *user_ns,
 	pace = pndace = (struct smb_ace *)((char *)pndacl + sizeof(struct smb_acl));
 
 	if (fattr->cf_acls) {
-		set_posix_acl_entries_dacl(user_ns, pndace, fattr,
+		set_posix_acl_entries_dacl(idmap, pndace, fattr,
 					   &num_aces, &size, num_aces);
 		goto out;
 	}
@@ -808,7 +808,7 @@ static int parse_sid(struct smb_sid *psid, char *end_of_acl)
 }
 
 /* Convert CIFS ACL to POSIX form */
-int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
+int parse_sec_desc(struct mnt_idmap *idmap, struct smb_ntsd *pntsd,
 		   int acl_len, struct smb_fattr *fattr)
 {
 	int rc = 0;
@@ -851,7 +851,7 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
 			return rc;
 		}
 
-		rc = sid_to_id(user_ns, owner_sid_ptr, SIDOWNER, fattr);
+		rc = sid_to_id(idmap, owner_sid_ptr, SIDOWNER, fattr);
 		if (rc) {
 			pr_err("%s: Error %d mapping Owner SID to uid\n",
 			       __func__, rc);
@@ -866,7 +866,7 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
 			       __func__, rc);
 			return rc;
 		}
-		rc = sid_to_id(user_ns, group_sid_ptr, SIDUNIX_GROUP, fattr);
+		rc = sid_to_id(idmap, group_sid_ptr, SIDUNIX_GROUP, fattr);
 		if (rc) {
 			pr_err("%s: Error %d mapping Group SID to gid\n",
 			       __func__, rc);
@@ -881,7 +881,7 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
 		pntsd->type |= cpu_to_le16(DACL_PROTECTED);
 
 	if (dacloffset) {
-		parse_dacl(user_ns, dacl_ptr, end_of_acl,
+		parse_dacl(idmap, dacl_ptr, end_of_acl,
 			   owner_sid_ptr, group_sid_ptr, fattr);
 	}
 
@@ -889,7 +889,7 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
 }
 
 /* Convert permission bits from mode to equivalent CIFS ACL */
-int build_sec_desc(struct user_namespace *user_ns,
+int build_sec_desc(struct mnt_idmap *idmap,
 		   struct smb_ntsd *pntsd, struct smb_ntsd *ppntsd,
 		   int ppntsd_size, int addition_info, __u32 *secdesclen,
 		   struct smb_fattr *fattr)
@@ -950,7 +950,7 @@ int build_sec_desc(struct user_namespace *user_ns,
 		dacl_ptr->num_aces = 0;
 
 		if (!ppntsd) {
-			set_mode_dacl(user_ns, dacl_ptr, fattr);
+			set_mode_dacl(idmap, dacl_ptr, fattr);
 		} else {
 			struct smb_acl *ppdacl_ptr;
 			unsigned int dacl_offset = le32_to_cpu(ppntsd->dacloffset);
@@ -966,7 +966,7 @@ int build_sec_desc(struct user_namespace *user_ns,
 			    ppdacl_size < sizeof(struct smb_acl))
 				goto out;
 
-			set_ntacl_dacl(user_ns, dacl_ptr, ppdacl_ptr,
+			set_ntacl_dacl(idmap, dacl_ptr, ppdacl_ptr,
 				       ntacl_size - sizeof(struct smb_acl),
 				       nowner_sid_ptr, ngroup_sid_ptr,
 				       fattr);
@@ -1002,13 +1002,13 @@ int smb_inherit_dacl(struct ksmbd_conn *conn,
 	struct smb_ntsd *parent_pntsd = NULL;
 	struct smb_sid owner_sid, group_sid;
 	struct dentry *parent = path->dentry->d_parent;
-	struct user_namespace *user_ns = mnt_user_ns(path->mnt);
+	struct mnt_idmap *idmap = mnt_idmap(path->mnt);
 	int inherited_flags = 0, flags = 0, i, ace_cnt = 0, nt_size = 0, pdacl_size;
 	int rc = 0, num_aces, dacloffset, pntsd_type, pntsd_size, acl_len, aces_size;
 	char *aces_base;
 	bool is_dir = S_ISDIR(d_inode(path->dentry)->i_mode);
 
-	pntsd_size = ksmbd_vfs_get_sd_xattr(conn, user_ns,
+	pntsd_size = ksmbd_vfs_get_sd_xattr(conn, idmap,
 					    parent, &parent_pntsd);
 	if (pntsd_size <= 0)
 		return -ENOENT;
@@ -1162,7 +1162,7 @@ pass:
 			pntsd_size += sizeof(struct smb_acl) + nt_size;
 		}
 
-		ksmbd_vfs_set_sd_xattr(conn, user_ns,
+		ksmbd_vfs_set_sd_xattr(conn, idmap,
 				       path->dentry, pntsd, pntsd_size);
 		kfree(pntsd);
 	}
@@ -1190,7 +1190,7 @@ bool smb_inherit_flags(int flags, bool is_dir)
 int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path,
 			__le32 *pdaccess, int uid)
 {
-	struct user_namespace *user_ns = mnt_user_ns(path->mnt);
+	struct mnt_idmap *idmap = mnt_idmap(path->mnt);
 	struct smb_ntsd *pntsd = NULL;
 	struct smb_acl *pdacl;
 	struct posix_acl *posix_acls;
@@ -1206,7 +1206,7 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path,
 	unsigned short ace_size;
 
 	ksmbd_debug(SMB, "check permission using windows acl\n");
-	pntsd_size = ksmbd_vfs_get_sd_xattr(conn, user_ns,
+	pntsd_size = ksmbd_vfs_get_sd_xattr(conn, idmap,
 					    path->dentry, &pntsd);
 	if (pntsd_size <= 0 || !pntsd)
 		goto err_out;
@@ -1296,9 +1296,9 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path,
 			pa_entry = posix_acls->a_entries;
 			for (i = 0; i < posix_acls->a_count; i++, pa_entry++) {
 				if (pa_entry->e_tag == ACL_USER)
-					id = posix_acl_uid_translate(user_ns, pa_entry);
+					id = posix_acl_uid_translate(idmap, pa_entry);
 				else if (pa_entry->e_tag == ACL_GROUP)
-					id = posix_acl_gid_translate(user_ns, pa_entry);
+					id = posix_acl_gid_translate(idmap, pa_entry);
 				else
 					continue;
 
@@ -1360,14 +1360,14 @@ int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
 	int rc;
 	struct smb_fattr fattr = {{0}};
 	struct inode *inode = d_inode(path->dentry);
-	struct user_namespace *user_ns = mnt_user_ns(path->mnt);
+	struct mnt_idmap *idmap = mnt_idmap(path->mnt);
 	struct iattr newattrs;
 
 	fattr.cf_uid = INVALID_UID;
 	fattr.cf_gid = INVALID_GID;
 	fattr.cf_mode = inode->i_mode;
 
-	rc = parse_sec_desc(user_ns, pntsd, ntsd_len, &fattr);
+	rc = parse_sec_desc(idmap, pntsd, ntsd_len, &fattr);
 	if (rc)
 		goto out;
 
@@ -1383,17 +1383,17 @@ int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
 	newattrs.ia_valid |= ATTR_MODE;
 	newattrs.ia_mode = (inode->i_mode & ~0777) | (fattr.cf_mode & 0777);
 
-	ksmbd_vfs_remove_acl_xattrs(user_ns, path->dentry);
+	ksmbd_vfs_remove_acl_xattrs(idmap, path->dentry);
 	/* Update posix acls */
 	if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && fattr.cf_dacls) {
-		rc = set_posix_acl(user_ns, path->dentry,
+		rc = set_posix_acl(idmap, path->dentry,
 				   ACL_TYPE_ACCESS, fattr.cf_acls);
 		if (rc < 0)
 			ksmbd_debug(SMB,
 				    "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
 				    rc);
 		if (S_ISDIR(inode->i_mode) && fattr.cf_dacls) {
-			rc = set_posix_acl(user_ns, path->dentry,
+			rc = set_posix_acl(idmap, path->dentry,
 					   ACL_TYPE_DEFAULT, fattr.cf_dacls);
 			if (rc)
 				ksmbd_debug(SMB,
@@ -1403,7 +1403,7 @@ int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
 	}
 
 	inode_lock(inode);
-	rc = notify_change(user_ns, path->dentry, &newattrs, NULL);
+	rc = notify_change(idmap, path->dentry, &newattrs, NULL);
 	inode_unlock(inode);
 	if (rc)
 		goto out;
@@ -1414,8 +1414,8 @@ int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
 
 	if (test_share_config_flag(tcon->share_conf, KSMBD_SHARE_FLAG_ACL_XATTR)) {
 		/* Update WinACL in xattr */
-		ksmbd_vfs_remove_sd_xattrs(user_ns, path->dentry);
-		ksmbd_vfs_set_sd_xattr(conn, user_ns,
+		ksmbd_vfs_remove_sd_xattrs(idmap, path->dentry);
+		ksmbd_vfs_set_sd_xattr(conn, idmap,
 				       path->dentry, pntsd, ntsd_len);
 	}
 
diff --git a/fs/ksmbd/smbacl.h b/fs/ksmbd/smbacl.h
index 618f2e0236b3..49a8c292bd2e 100644
--- a/fs/ksmbd/smbacl.h
+++ b/fs/ksmbd/smbacl.h
@@ -190,9 +190,9 @@ struct posix_acl_state {
 	struct posix_ace_state_array *groups;
 };
 
-int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
+int parse_sec_desc(struct mnt_idmap *idmap, struct smb_ntsd *pntsd,
 		   int acl_len, struct smb_fattr *fattr);
-int build_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
+int build_sec_desc(struct mnt_idmap *idmap, struct smb_ntsd *pntsd,
 		   struct smb_ntsd *ppntsd, int ppntsd_size, int addition_info,
 		   __u32 *secdesclen, struct smb_fattr *fattr);
 int init_acl_state(struct posix_acl_state *state, int cnt);
@@ -211,25 +211,25 @@ int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
 void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid);
 void ksmbd_init_domain(u32 *sub_auth);
 
-static inline uid_t posix_acl_uid_translate(struct user_namespace *mnt_userns,
+static inline uid_t posix_acl_uid_translate(struct mnt_idmap *idmap,
 					    struct posix_acl_entry *pace)
 {
 	vfsuid_t vfsuid;
 
 	/* If this is an idmapped mount, apply the idmapping. */
-	vfsuid = make_vfsuid(mnt_userns, &init_user_ns, pace->e_uid);
+	vfsuid = make_vfsuid(idmap, &init_user_ns, pace->e_uid);
 
 	/* Translate the kuid into a userspace id ksmbd would see. */
 	return from_kuid(&init_user_ns, vfsuid_into_kuid(vfsuid));
 }
 
-static inline gid_t posix_acl_gid_translate(struct user_namespace *mnt_userns,
+static inline gid_t posix_acl_gid_translate(struct mnt_idmap *idmap,
 					    struct posix_acl_entry *pace)
 {
 	vfsgid_t vfsgid;
 
 	/* If this is an idmapped mount, apply the idmapping. */
-	vfsgid = make_vfsgid(mnt_userns, &init_user_ns, pace->e_gid);
+	vfsgid = make_vfsgid(idmap, &init_user_ns, pace->e_gid);
 
 	/* Translate the kgid into a userspace id ksmbd would see. */
 	return from_kgid(&init_user_ns, vfsgid_into_kgid(vfsgid));
diff --git a/fs/ksmbd/vfs.c b/fs/ksmbd/vfs.c
index 5851934dc85b..aa1300b7bfc2 100644
--- a/fs/ksmbd/vfs.c
+++ b/fs/ksmbd/vfs.c
@@ -70,14 +70,14 @@ static void ksmbd_vfs_inherit_owner(struct ksmbd_work *work,
  *
  * the reference count of @parent isn't incremented.
  */
-int ksmbd_vfs_lock_parent(struct user_namespace *user_ns, struct dentry *parent,
+int ksmbd_vfs_lock_parent(struct mnt_idmap *idmap, struct dentry *parent,
 			  struct dentry *child)
 {
 	struct dentry *dentry;
 	int ret = 0;
 
 	inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
-	dentry = lookup_one(user_ns, child->d_name.name, parent,
+	dentry = lookup_one(idmap, child->d_name.name, parent,
 			    child->d_name.len);
 	if (IS_ERR(dentry)) {
 		ret = PTR_ERR(dentry);
@@ -97,20 +97,20 @@ out_err:
 	return ret;
 }
 
-int ksmbd_vfs_may_delete(struct user_namespace *user_ns,
+int ksmbd_vfs_may_delete(struct mnt_idmap *idmap,
 			 struct dentry *dentry)
 {
 	struct dentry *parent;
 	int ret;
 
 	parent = dget_parent(dentry);
-	ret = ksmbd_vfs_lock_parent(user_ns, parent, dentry);
+	ret = ksmbd_vfs_lock_parent(idmap, parent, dentry);
 	if (ret) {
 		dput(parent);
 		return ret;
 	}
 
-	ret = inode_permission(user_ns, d_inode(parent),
+	ret = inode_permission(idmap, d_inode(parent),
 			       MAY_EXEC | MAY_WRITE);
 
 	inode_unlock(d_inode(parent));
@@ -118,7 +118,7 @@ int ksmbd_vfs_may_delete(struct user_namespace *user_ns,
 	return ret;
 }
 
-int ksmbd_vfs_query_maximal_access(struct user_namespace *user_ns,
+int ksmbd_vfs_query_maximal_access(struct mnt_idmap *idmap,
 				   struct dentry *dentry, __le32 *daccess)
 {
 	struct dentry *parent;
@@ -126,26 +126,26 @@ int ksmbd_vfs_query_maximal_access(struct user_namespace *user_ns,
 
 	*daccess = cpu_to_le32(FILE_READ_ATTRIBUTES | READ_CONTROL);
 
-	if (!inode_permission(user_ns, d_inode(dentry), MAY_OPEN | MAY_WRITE))
+	if (!inode_permission(idmap, d_inode(dentry), MAY_OPEN | MAY_WRITE))
 		*daccess |= cpu_to_le32(WRITE_DAC | WRITE_OWNER | SYNCHRONIZE |
 				FILE_WRITE_DATA | FILE_APPEND_DATA |
 				FILE_WRITE_EA | FILE_WRITE_ATTRIBUTES |
 				FILE_DELETE_CHILD);
 
-	if (!inode_permission(user_ns, d_inode(dentry), MAY_OPEN | MAY_READ))
+	if (!inode_permission(idmap, d_inode(dentry), MAY_OPEN | MAY_READ))
 		*daccess |= FILE_READ_DATA_LE | FILE_READ_EA_LE;
 
-	if (!inode_permission(user_ns, d_inode(dentry), MAY_OPEN | MAY_EXEC))
+	if (!inode_permission(idmap, d_inode(dentry), MAY_OPEN | MAY_EXEC))
 		*daccess |= FILE_EXECUTE_LE;
 
 	parent = dget_parent(dentry);
-	ret = ksmbd_vfs_lock_parent(user_ns, parent, dentry);
+	ret = ksmbd_vfs_lock_parent(idmap, parent, dentry);
 	if (ret) {
 		dput(parent);
 		return ret;
 	}
 
-	if (!inode_permission(user_ns, d_inode(parent), MAY_EXEC | MAY_WRITE))
+	if (!inode_permission(idmap, d_inode(parent), MAY_EXEC | MAY_WRITE))
 		*daccess |= FILE_DELETE_LE;
 
 	inode_unlock(d_inode(parent));
@@ -178,7 +178,7 @@ int ksmbd_vfs_create(struct ksmbd_work *work, const char *name, umode_t mode)
 	}
 
 	mode |= S_IFREG;
-	err = vfs_create(mnt_user_ns(path.mnt), d_inode(path.dentry),
+	err = vfs_create(mnt_idmap(path.mnt), d_inode(path.dentry),
 			 dentry, mode, true);
 	if (!err) {
 		ksmbd_vfs_inherit_owner(work, d_inode(path.dentry),
@@ -200,7 +200,7 @@ int ksmbd_vfs_create(struct ksmbd_work *work, const char *name, umode_t mode)
  */
 int ksmbd_vfs_mkdir(struct ksmbd_work *work, const char *name, umode_t mode)
 {
-	struct user_namespace *user_ns;
+	struct mnt_idmap *idmap;
 	struct path path;
 	struct dentry *dentry;
 	int err;
@@ -216,15 +216,15 @@ int ksmbd_vfs_mkdir(struct ksmbd_work *work, const char *name, umode_t mode)
 		return err;
 	}
 
-	user_ns = mnt_user_ns(path.mnt);
+	idmap = mnt_idmap(path.mnt);
 	mode |= S_IFDIR;
-	err = vfs_mkdir(user_ns, d_inode(path.dentry), dentry, mode);
+	err = vfs_mkdir(idmap, d_inode(path.dentry), dentry, mode);
 	if (err) {
 		goto out;
 	} else if (d_unhashed(dentry)) {
 		struct dentry *d;
 
-		d = lookup_one(user_ns, dentry->d_name.name, dentry->d_parent,
+		d = lookup_one(idmap, dentry->d_name.name, dentry->d_parent,
 			       dentry->d_name.len);
 		if (IS_ERR(d)) {
 			err = PTR_ERR(d);
@@ -246,7 +246,7 @@ out:
 	return err;
 }
 
-static ssize_t ksmbd_vfs_getcasexattr(struct user_namespace *user_ns,
+static ssize_t ksmbd_vfs_getcasexattr(struct mnt_idmap *idmap,
 				      struct dentry *dentry, char *attr_name,
 				      int attr_name_len, char **attr_value)
 {
@@ -263,7 +263,7 @@ static ssize_t ksmbd_vfs_getcasexattr(struct user_namespace *user_ns,
 		if (strncasecmp(attr_name, name, attr_name_len))
 			continue;
 
-		value_len = ksmbd_vfs_getxattr(user_ns,
+		value_len = ksmbd_vfs_getxattr(idmap,
 					       dentry,
 					       name,
 					       attr_value);
@@ -286,7 +286,7 @@ static int ksmbd_vfs_stream_read(struct ksmbd_file *fp, char *buf, loff_t *pos,
 	ksmbd_debug(VFS, "read stream data pos : %llu, count : %zd\n",
 		    *pos, count);
 
-	v_len = ksmbd_vfs_getcasexattr(file_mnt_user_ns(fp->filp),
+	v_len = ksmbd_vfs_getcasexattr(file_mnt_idmap(fp->filp),
 				       fp->filp->f_path.dentry,
 				       fp->stream.name,
 				       fp->stream.size,
@@ -410,7 +410,7 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos,
 				  size_t count)
 {
 	char *stream_buf = NULL, *wbuf;
-	struct user_namespace *user_ns = file_mnt_user_ns(fp->filp);
+	struct mnt_idmap *idmap = file_mnt_idmap(fp->filp);
 	size_t size, v_len;
 	int err = 0;
 
@@ -423,7 +423,7 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos,
 		count = (*pos + count) - XATTR_SIZE_MAX;
 	}
 
-	v_len = ksmbd_vfs_getcasexattr(user_ns,
+	v_len = ksmbd_vfs_getcasexattr(idmap,
 				       fp->filp->f_path.dentry,
 				       fp->stream.name,
 				       fp->stream.size,
@@ -449,7 +449,7 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos,
 
 	memcpy(&stream_buf[*pos], buf, count);
 
-	err = ksmbd_vfs_setxattr(user_ns,
+	err = ksmbd_vfs_setxattr(idmap,
 				 fp->filp->f_path.dentry,
 				 fp->stream.name,
 				 (void *)stream_buf,
@@ -584,7 +584,7 @@ int ksmbd_vfs_fsync(struct ksmbd_work *work, u64 fid, u64 p_id)
  */
 int ksmbd_vfs_remove_file(struct ksmbd_work *work, char *name)
 {
-	struct user_namespace *user_ns;
+	struct mnt_idmap *idmap;
 	struct path path;
 	struct dentry *parent;
 	int err;
@@ -599,9 +599,9 @@ int ksmbd_vfs_remove_file(struct ksmbd_work *work, char *name)
 		return err;
 	}
 
-	user_ns = mnt_user_ns(path.mnt);
+	idmap = mnt_idmap(path.mnt);
 	parent = dget_parent(path.dentry);
-	err = ksmbd_vfs_lock_parent(user_ns, parent, path.dentry);
+	err = ksmbd_vfs_lock_parent(idmap, parent, path.dentry);
 	if (err) {
 		dput(parent);
 		path_put(&path);
@@ -615,12 +615,12 @@ int ksmbd_vfs_remove_file(struct ksmbd_work *work, char *name)
 	}
 
 	if (S_ISDIR(d_inode(path.dentry)->i_mode)) {
-		err = vfs_rmdir(user_ns, d_inode(parent), path.dentry);
+		err = vfs_rmdir(idmap, d_inode(parent), path.dentry);
 		if (err && err != -ENOTEMPTY)
 			ksmbd_debug(VFS, "%s: rmdir failed, err %d\n", name,
 				    err);
 	} else {
-		err = vfs_unlink(user_ns, d_inode(parent), path.dentry, NULL);
+		err = vfs_unlink(idmap, d_inode(parent), path.dentry, NULL);
 		if (err)
 			ksmbd_debug(VFS, "%s: unlink failed, err %d\n", name,
 				    err);
@@ -673,7 +673,7 @@ int ksmbd_vfs_link(struct ksmbd_work *work, const char *oldname,
 		goto out3;
 	}
 
-	err = vfs_link(oldpath.dentry, mnt_user_ns(newpath.mnt),
+	err = vfs_link(oldpath.dentry, mnt_idmap(newpath.mnt),
 		       d_inode(newpath.dentry),
 		       dentry, NULL);
 	if (err)
@@ -712,10 +712,10 @@ static int ksmbd_validate_entry_in_use(struct dentry *src_dent)
 }
 
 static int __ksmbd_vfs_rename(struct ksmbd_work *work,
-			      struct user_namespace *src_user_ns,
+			      struct mnt_idmap *src_idmap,
 			      struct dentry *src_dent_parent,
 			      struct dentry *src_dent,
-			      struct user_namespace *dst_user_ns,
+			      struct mnt_idmap *dst_idmap,
 			      struct dentry *dst_dent_parent,
 			      struct dentry *trap_dent,
 			      char *dst_name)
@@ -741,8 +741,8 @@ static int __ksmbd_vfs_rename(struct ksmbd_work *work,
 	if (ksmbd_override_fsids(work))
 		return -ENOMEM;
 
-	dst_dent = lookup_one(dst_user_ns, dst_name, dst_dent_parent,
-			      strlen(dst_name));
+	dst_dent = lookup_one(dst_idmap, dst_name,
+			      dst_dent_parent, strlen(dst_name));
 	err = PTR_ERR(dst_dent);
 	if (IS_ERR(dst_dent)) {
 		pr_err("lookup failed %s [%d]\n", dst_name, err);
@@ -752,10 +752,10 @@ static int __ksmbd_vfs_rename(struct ksmbd_work *work,
 	err = -ENOTEMPTY;
 	if (dst_dent != trap_dent && !d_really_is_positive(dst_dent)) {
 		struct renamedata rd = {
-			.old_mnt_userns	= src_user_ns,
+			.old_mnt_idmap	= src_idmap,
 			.old_dir	= d_inode(src_dent_parent),
 			.old_dentry	= src_dent,
-			.new_mnt_userns	= dst_user_ns,
+			.new_mnt_idmap	= dst_idmap,
 			.new_dir	= d_inode(dst_dent_parent),
 			.new_dentry	= dst_dent,
 		};
@@ -773,7 +773,7 @@ out:
 int ksmbd_vfs_fp_rename(struct ksmbd_work *work, struct ksmbd_file *fp,
 			char *newname)
 {
-	struct user_namespace *user_ns;
+	struct mnt_idmap *idmap;
 	struct path dst_path;
 	struct dentry *src_dent_parent, *dst_dent_parent;
 	struct dentry *src_dent, *trap_dent, *src_child;
@@ -801,8 +801,8 @@ int ksmbd_vfs_fp_rename(struct ksmbd_work *work, struct ksmbd_file *fp,
 	trap_dent = lock_rename(src_dent_parent, dst_dent_parent);
 	dget(src_dent);
 	dget(dst_dent_parent);
-	user_ns = file_mnt_user_ns(fp->filp);
-	src_child = lookup_one(user_ns, src_dent->d_name.name, src_dent_parent,
+	idmap = file_mnt_idmap(fp->filp);
+	src_child = lookup_one(idmap, src_dent->d_name.name, src_dent_parent,
 			       src_dent->d_name.len);
 	if (IS_ERR(src_child)) {
 		err = PTR_ERR(src_child);
@@ -817,10 +817,10 @@ int ksmbd_vfs_fp_rename(struct ksmbd_work *work, struct ksmbd_file *fp,
 	dput(src_child);
 
 	err = __ksmbd_vfs_rename(work,
-				 user_ns,
+				 idmap,
 				 src_dent_parent,
 				 src_dent,
-				 mnt_user_ns(dst_path.mnt),
+				 mnt_idmap(dst_path.mnt),
 				 dst_dent_parent,
 				 trap_dent,
 				 dst_name);
@@ -908,22 +908,22 @@ ssize_t ksmbd_vfs_listxattr(struct dentry *dentry, char **list)
 	return size;
 }
 
-static ssize_t ksmbd_vfs_xattr_len(struct user_namespace *user_ns,
+static ssize_t ksmbd_vfs_xattr_len(struct mnt_idmap *idmap,
 				   struct dentry *dentry, char *xattr_name)
 {
-	return vfs_getxattr(user_ns, dentry, xattr_name, NULL, 0);
+	return vfs_getxattr(idmap, dentry, xattr_name, NULL, 0);
 }
 
 /**
  * ksmbd_vfs_getxattr() - vfs helper for smb get extended attributes value
- * @user_ns:	user namespace
+ * @idmap:	idmap
  * @dentry:	dentry of file for getting xattrs
  * @xattr_name:	name of xattr name to query
  * @xattr_buf:	destination buffer xattr value
  *
  * Return:	read xattr value length on success, otherwise error
  */
-ssize_t ksmbd_vfs_getxattr(struct user_namespace *user_ns,
+ssize_t ksmbd_vfs_getxattr(struct mnt_idmap *idmap,
 			   struct dentry *dentry,
 			   char *xattr_name, char **xattr_buf)
 {
@@ -931,7 +931,7 @@ ssize_t ksmbd_vfs_getxattr(struct user_namespace *user_ns,
 	char *buf;
 
 	*xattr_buf = NULL;
-	xattr_len = ksmbd_vfs_xattr_len(user_ns, dentry, xattr_name);
+	xattr_len = ksmbd_vfs_xattr_len(idmap, dentry, xattr_name);
 	if (xattr_len < 0)
 		return xattr_len;
 
@@ -939,7 +939,7 @@ ssize_t ksmbd_vfs_getxattr(struct user_namespace *user_ns,
 	if (!buf)
 		return -ENOMEM;
 
-	xattr_len = vfs_getxattr(user_ns, dentry, xattr_name,
+	xattr_len = vfs_getxattr(idmap, dentry, xattr_name,
 				 (void *)buf, xattr_len);
 	if (xattr_len > 0)
 		*xattr_buf = buf;
@@ -950,7 +950,7 @@ ssize_t ksmbd_vfs_getxattr(struct user_namespace *user_ns,
 
 /**
  * ksmbd_vfs_setxattr() - vfs helper for smb set extended attributes value
- * @user_ns:	user namespace
+ * @idmap:	idmap of the relevant mount
  * @dentry:	dentry to set XATTR at
  * @name:	xattr name for setxattr
  * @value:	xattr value to set
@@ -959,13 +959,13 @@ ssize_t ksmbd_vfs_getxattr(struct user_namespace *user_ns,
  *
  * Return:	0 on success, otherwise error
  */
-int ksmbd_vfs_setxattr(struct user_namespace *user_ns,
+int ksmbd_vfs_setxattr(struct mnt_idmap *idmap,
 		       struct dentry *dentry, const char *attr_name,
 		       void *attr_value, size_t attr_size, int flags)
 {
 	int err;
 
-	err = vfs_setxattr(user_ns,
+	err = vfs_setxattr(idmap,
 			   dentry,
 			   attr_name,
 			   attr_value,
@@ -1075,26 +1075,26 @@ int ksmbd_vfs_fqar_lseek(struct ksmbd_file *fp, loff_t start, loff_t length,
 	return ret;
 }
 
-int ksmbd_vfs_remove_xattr(struct user_namespace *user_ns,
+int ksmbd_vfs_remove_xattr(struct mnt_idmap *idmap,
 			   struct dentry *dentry, char *attr_name)
 {
-	return vfs_removexattr(user_ns, dentry, attr_name);
+	return vfs_removexattr(idmap, dentry, attr_name);
 }
 
-int ksmbd_vfs_unlink(struct user_namespace *user_ns,
+int ksmbd_vfs_unlink(struct mnt_idmap *idmap,
 		     struct dentry *dir, struct dentry *dentry)
 {
 	int err = 0;
 
-	err = ksmbd_vfs_lock_parent(user_ns, dir, dentry);
+	err = ksmbd_vfs_lock_parent(idmap, dir, dentry);
 	if (err)
 		return err;
 	dget(dentry);
 
 	if (S_ISDIR(d_inode(dentry)->i_mode))
-		err = vfs_rmdir(user_ns, d_inode(dir), dentry);
+		err = vfs_rmdir(idmap, d_inode(dir), dentry);
 	else
-		err = vfs_unlink(user_ns, d_inode(dir), dentry, NULL);
+		err = vfs_unlink(idmap, d_inode(dir), dentry, NULL);
 
 	dput(dentry);
 	inode_unlock(d_inode(dir));
@@ -1299,7 +1299,7 @@ struct dentry *ksmbd_vfs_kern_path_create(struct ksmbd_work *work,
 	return dent;
 }
 
-int ksmbd_vfs_remove_acl_xattrs(struct user_namespace *user_ns,
+int ksmbd_vfs_remove_acl_xattrs(struct mnt_idmap *idmap,
 				struct dentry *dentry)
 {
 	char *name, *xattr_list = NULL;
@@ -1322,7 +1322,7 @@ int ksmbd_vfs_remove_acl_xattrs(struct user_namespace *user_ns,
 			     sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1) ||
 		    !strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT,
 			     sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1)) {
-			err = vfs_remove_acl(user_ns, dentry, name);
+			err = vfs_remove_acl(idmap, dentry, name);
 			if (err)
 				ksmbd_debug(SMB,
 					    "remove acl xattr failed : %s\n", name);
@@ -1333,7 +1333,7 @@ out:
 	return err;
 }
 
-int ksmbd_vfs_remove_sd_xattrs(struct user_namespace *user_ns,
+int ksmbd_vfs_remove_sd_xattrs(struct mnt_idmap *idmap,
 			       struct dentry *dentry)
 {
 	char *name, *xattr_list = NULL;
@@ -1353,7 +1353,7 @@ int ksmbd_vfs_remove_sd_xattrs(struct user_namespace *user_ns,
 		ksmbd_debug(SMB, "%s, len %zd\n", name, strlen(name));
 
 		if (!strncmp(name, XATTR_NAME_SD, XATTR_NAME_SD_LEN)) {
-			err = ksmbd_vfs_remove_xattr(user_ns, dentry, name);
+			err = ksmbd_vfs_remove_xattr(idmap, dentry, name);
 			if (err)
 				ksmbd_debug(SMB, "remove xattr failed : %s\n", name);
 		}
@@ -1363,7 +1363,7 @@ out:
 	return err;
 }
 
-static struct xattr_smb_acl *ksmbd_vfs_make_xattr_posix_acl(struct user_namespace *user_ns,
+static struct xattr_smb_acl *ksmbd_vfs_make_xattr_posix_acl(struct mnt_idmap *idmap,
 							    struct inode *inode,
 							    int acl_type)
 {
@@ -1393,14 +1393,14 @@ static struct xattr_smb_acl *ksmbd_vfs_make_xattr_posix_acl(struct user_namespac
 		switch (pa_entry->e_tag) {
 		case ACL_USER:
 			xa_entry->type = SMB_ACL_USER;
-			xa_entry->uid = posix_acl_uid_translate(user_ns, pa_entry);
+			xa_entry->uid = posix_acl_uid_translate(idmap, pa_entry);
 			break;
 		case ACL_USER_OBJ:
 			xa_entry->type = SMB_ACL_USER_OBJ;
 			break;
 		case ACL_GROUP:
 			xa_entry->type = SMB_ACL_GROUP;
-			xa_entry->gid = posix_acl_gid_translate(user_ns, pa_entry);
+			xa_entry->gid = posix_acl_gid_translate(idmap, pa_entry);
 			break;
 		case ACL_GROUP_OBJ:
 			xa_entry->type = SMB_ACL_GROUP_OBJ;
@@ -1429,7 +1429,7 @@ out:
 }
 
 int ksmbd_vfs_set_sd_xattr(struct ksmbd_conn *conn,
-			   struct user_namespace *user_ns,
+			   struct mnt_idmap *idmap,
 			   struct dentry *dentry,
 			   struct smb_ntsd *pntsd, int len)
 {
@@ -1462,13 +1462,13 @@ int ksmbd_vfs_set_sd_xattr(struct ksmbd_conn *conn,
 		return rc;
 	}
 
-	smb_acl = ksmbd_vfs_make_xattr_posix_acl(user_ns, inode,
+	smb_acl = ksmbd_vfs_make_xattr_posix_acl(idmap, inode,
 						 ACL_TYPE_ACCESS);
 	if (S_ISDIR(inode->i_mode))
-		def_smb_acl = ksmbd_vfs_make_xattr_posix_acl(user_ns, inode,
+		def_smb_acl = ksmbd_vfs_make_xattr_posix_acl(idmap, inode,
 							     ACL_TYPE_DEFAULT);
 
-	rc = ndr_encode_posix_acl(&acl_ndr, user_ns, inode,
+	rc = ndr_encode_posix_acl(&acl_ndr, idmap, inode,
 				  smb_acl, def_smb_acl);
 	if (rc) {
 		pr_err("failed to encode ndr to posix acl\n");
@@ -1488,7 +1488,7 @@ int ksmbd_vfs_set_sd_xattr(struct ksmbd_conn *conn,
 		goto out;
 	}
 
-	rc = ksmbd_vfs_setxattr(user_ns, dentry,
+	rc = ksmbd_vfs_setxattr(idmap, dentry,
 				XATTR_NAME_SD, sd_ndr.data,
 				sd_ndr.offset, 0);
 	if (rc < 0)
@@ -1503,7 +1503,7 @@ out:
 }
 
 int ksmbd_vfs_get_sd_xattr(struct ksmbd_conn *conn,
-			   struct user_namespace *user_ns,
+			   struct mnt_idmap *idmap,
 			   struct dentry *dentry,
 			   struct smb_ntsd **pntsd)
 {
@@ -1515,7 +1515,7 @@ int ksmbd_vfs_get_sd_xattr(struct ksmbd_conn *conn,
 	struct xattr_smb_acl *smb_acl = NULL, *def_smb_acl = NULL;
 	__u8 cmp_hash[XATTR_SD_HASH_SIZE] = {0};
 
-	rc = ksmbd_vfs_getxattr(user_ns, dentry, XATTR_NAME_SD, &n.data);
+	rc = ksmbd_vfs_getxattr(idmap, dentry, XATTR_NAME_SD, &n.data);
 	if (rc <= 0)
 		return rc;
 
@@ -1524,13 +1524,13 @@ int ksmbd_vfs_get_sd_xattr(struct ksmbd_conn *conn,
 	if (rc)
 		goto free_n_data;
 
-	smb_acl = ksmbd_vfs_make_xattr_posix_acl(user_ns, inode,
+	smb_acl = ksmbd_vfs_make_xattr_posix_acl(idmap, inode,
 						 ACL_TYPE_ACCESS);
 	if (S_ISDIR(inode->i_mode))
-		def_smb_acl = ksmbd_vfs_make_xattr_posix_acl(user_ns, inode,
+		def_smb_acl = ksmbd_vfs_make_xattr_posix_acl(idmap, inode,
 							     ACL_TYPE_DEFAULT);
 
-	rc = ndr_encode_posix_acl(&acl_ndr, user_ns, inode, smb_acl,
+	rc = ndr_encode_posix_acl(&acl_ndr, idmap, inode, smb_acl,
 				  def_smb_acl);
 	if (rc) {
 		pr_err("failed to encode ndr to posix acl\n");
@@ -1577,7 +1577,7 @@ free_n_data:
 	return rc;
 }
 
-int ksmbd_vfs_set_dos_attrib_xattr(struct user_namespace *user_ns,
+int ksmbd_vfs_set_dos_attrib_xattr(struct mnt_idmap *idmap,
 				   struct dentry *dentry,
 				   struct xattr_dos_attrib *da)
 {
@@ -1588,7 +1588,7 @@ int ksmbd_vfs_set_dos_attrib_xattr(struct user_namespace *user_ns,
 	if (err)
 		return err;
 
-	err = ksmbd_vfs_setxattr(user_ns, dentry, XATTR_NAME_DOS_ATTRIBUTE,
+	err = ksmbd_vfs_setxattr(idmap, dentry, XATTR_NAME_DOS_ATTRIBUTE,
 				 (void *)n.data, n.offset, 0);
 	if (err)
 		ksmbd_debug(SMB, "failed to store dos attribute in xattr\n");
@@ -1597,14 +1597,14 @@ int ksmbd_vfs_set_dos_attrib_xattr(struct user_namespace *user_ns,
 	return err;
 }
 
-int ksmbd_vfs_get_dos_attrib_xattr(struct user_namespace *user_ns,
+int ksmbd_vfs_get_dos_attrib_xattr(struct mnt_idmap *idmap,
 				   struct dentry *dentry,
 				   struct xattr_dos_attrib *da)
 {
 	struct ndr n;
 	int err;
 
-	err = ksmbd_vfs_getxattr(user_ns, dentry, XATTR_NAME_DOS_ATTRIBUTE,
+	err = ksmbd_vfs_getxattr(idmap, dentry, XATTR_NAME_DOS_ATTRIBUTE,
 				 (char **)&n.data);
 	if (err > 0) {
 		n.length = err;
@@ -1651,14 +1651,14 @@ void *ksmbd_vfs_init_kstat(char **p, struct ksmbd_kstat *ksmbd_kstat)
 }
 
 int ksmbd_vfs_fill_dentry_attrs(struct ksmbd_work *work,
-				struct user_namespace *user_ns,
+				struct mnt_idmap *idmap,
 				struct dentry *dentry,
 				struct ksmbd_kstat *ksmbd_kstat)
 {
 	u64 time;
 	int rc;
 
-	generic_fillattr(user_ns, d_inode(dentry), ksmbd_kstat->kstat);
+	generic_fillattr(idmap, d_inode(dentry), ksmbd_kstat->kstat);
 
 	time = ksmbd_UnixTimeToNT(ksmbd_kstat->kstat->ctime);
 	ksmbd_kstat->create_time = time;
@@ -1676,7 +1676,7 @@ int ksmbd_vfs_fill_dentry_attrs(struct ksmbd_work *work,
 				   KSMBD_SHARE_FLAG_STORE_DOS_ATTRS)) {
 		struct xattr_dos_attrib da;
 
-		rc = ksmbd_vfs_get_dos_attrib_xattr(user_ns, dentry, &da);
+		rc = ksmbd_vfs_get_dos_attrib_xattr(idmap, dentry, &da);
 		if (rc > 0) {
 			ksmbd_kstat->file_attributes = cpu_to_le32(da.attr);
 			ksmbd_kstat->create_time = da.create_time;
@@ -1688,7 +1688,7 @@ int ksmbd_vfs_fill_dentry_attrs(struct ksmbd_work *work,
 	return 0;
 }
 
-ssize_t ksmbd_vfs_casexattr_len(struct user_namespace *user_ns,
+ssize_t ksmbd_vfs_casexattr_len(struct mnt_idmap *idmap,
 				struct dentry *dentry, char *attr_name,
 				int attr_name_len)
 {
@@ -1705,7 +1705,7 @@ ssize_t ksmbd_vfs_casexattr_len(struct user_namespace *user_ns,
 		if (strncasecmp(attr_name, name, attr_name_len))
 			continue;
 
-		value_len = ksmbd_vfs_xattr_len(user_ns, dentry, name);
+		value_len = ksmbd_vfs_xattr_len(idmap, dentry, name);
 		break;
 	}
 
@@ -1824,7 +1824,7 @@ void ksmbd_vfs_posix_lock_unblock(struct file_lock *flock)
 	locks_delete_block(flock);
 }
 
-int ksmbd_vfs_set_init_posix_acl(struct user_namespace *user_ns,
+int ksmbd_vfs_set_init_posix_acl(struct mnt_idmap *idmap,
 				 struct dentry *dentry)
 {
 	struct posix_acl_state acl_state;
@@ -1858,13 +1858,13 @@ int ksmbd_vfs_set_init_posix_acl(struct user_namespace *user_ns,
 		return -ENOMEM;
 	}
 	posix_state_to_acl(&acl_state, acls->a_entries);
-	rc = set_posix_acl(user_ns, dentry, ACL_TYPE_ACCESS, acls);
+	rc = set_posix_acl(idmap, dentry, ACL_TYPE_ACCESS, acls);
 	if (rc < 0)
 		ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
 			    rc);
 	else if (S_ISDIR(inode->i_mode)) {
 		posix_state_to_acl(&acl_state, acls->a_entries);
-		rc = set_posix_acl(user_ns, dentry, ACL_TYPE_DEFAULT, acls);
+		rc = set_posix_acl(idmap, dentry, ACL_TYPE_DEFAULT, acls);
 		if (rc < 0)
 			ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
 				    rc);
@@ -1874,7 +1874,7 @@ int ksmbd_vfs_set_init_posix_acl(struct user_namespace *user_ns,
 	return rc;
 }
 
-int ksmbd_vfs_inherit_posix_acl(struct user_namespace *user_ns,
+int ksmbd_vfs_inherit_posix_acl(struct mnt_idmap *idmap,
 				struct dentry *dentry, struct inode *parent_inode)
 {
 	struct posix_acl *acls;
@@ -1897,12 +1897,12 @@ int ksmbd_vfs_inherit_posix_acl(struct user_namespace *user_ns,
 		}
 	}
 
-	rc = set_posix_acl(user_ns, dentry, ACL_TYPE_ACCESS, acls);
+	rc = set_posix_acl(idmap, dentry, ACL_TYPE_ACCESS, acls);
 	if (rc < 0)
 		ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
 			    rc);
 	if (S_ISDIR(inode->i_mode)) {
-		rc = set_posix_acl(user_ns, dentry, ACL_TYPE_DEFAULT,
+		rc = set_posix_acl(idmap, dentry, ACL_TYPE_DEFAULT,
 				   acls);
 		if (rc < 0)
 			ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
diff --git a/fs/ksmbd/vfs.h b/fs/ksmbd/vfs.h
index 0d73d735cc39..9d676ab0cd25 100644
--- a/fs/ksmbd/vfs.h
+++ b/fs/ksmbd/vfs.h
@@ -71,10 +71,10 @@ struct ksmbd_kstat {
 	__le32			file_attributes;
 };
 
-int ksmbd_vfs_lock_parent(struct user_namespace *user_ns, struct dentry *parent,
+int ksmbd_vfs_lock_parent(struct mnt_idmap *idmap, struct dentry *parent,
 			  struct dentry *child);
-int ksmbd_vfs_may_delete(struct user_namespace *user_ns, struct dentry *dentry);
-int ksmbd_vfs_query_maximal_access(struct user_namespace *user_ns,
+int ksmbd_vfs_may_delete(struct mnt_idmap *idmap, struct dentry *dentry);
+int ksmbd_vfs_query_maximal_access(struct mnt_idmap *idmap,
 				   struct dentry *dentry, __le32 *daccess);
 int ksmbd_vfs_create(struct ksmbd_work *work, const char *name, umode_t mode);
 int ksmbd_vfs_mkdir(struct ksmbd_work *work, const char *name, umode_t mode);
@@ -102,19 +102,19 @@ int ksmbd_vfs_copy_file_ranges(struct ksmbd_work *work,
 			       unsigned int *chunk_size_written,
 			       loff_t  *total_size_written);
 ssize_t ksmbd_vfs_listxattr(struct dentry *dentry, char **list);
-ssize_t ksmbd_vfs_getxattr(struct user_namespace *user_ns,
+ssize_t ksmbd_vfs_getxattr(struct mnt_idmap *idmap,
 			   struct dentry *dentry,
 			   char *xattr_name,
 			   char **xattr_buf);
-ssize_t ksmbd_vfs_casexattr_len(struct user_namespace *user_ns,
+ssize_t ksmbd_vfs_casexattr_len(struct mnt_idmap *idmap,
 				struct dentry *dentry, char *attr_name,
 				int attr_name_len);
-int ksmbd_vfs_setxattr(struct user_namespace *user_ns,
+int ksmbd_vfs_setxattr(struct mnt_idmap *idmap,
 		       struct dentry *dentry, const char *attr_name,
 		       void *attr_value, size_t attr_size, int flags);
 int ksmbd_vfs_xattr_stream_name(char *stream_name, char **xattr_stream_name,
 				size_t *xattr_stream_name_size, int s_type);
-int ksmbd_vfs_remove_xattr(struct user_namespace *user_ns,
+int ksmbd_vfs_remove_xattr(struct mnt_idmap *idmap,
 			   struct dentry *dentry, char *attr_name);
 int ksmbd_vfs_kern_path(struct ksmbd_work *work,
 			char *name, unsigned int flags, struct path *path,
@@ -131,37 +131,37 @@ struct file_allocated_range_buffer;
 int ksmbd_vfs_fqar_lseek(struct ksmbd_file *fp, loff_t start, loff_t length,
 			 struct file_allocated_range_buffer *ranges,
 			 unsigned int in_count, unsigned int *out_count);
-int ksmbd_vfs_unlink(struct user_namespace *user_ns,
-		     struct dentry *dir, struct dentry *dentry);
+int ksmbd_vfs_unlink(struct mnt_idmap *idmap, struct dentry *dir,
+		     struct dentry *dentry);
 void *ksmbd_vfs_init_kstat(char **p, struct ksmbd_kstat *ksmbd_kstat);
 int ksmbd_vfs_fill_dentry_attrs(struct ksmbd_work *work,
-				struct user_namespace *user_ns,
+				struct mnt_idmap *idmap,
 				struct dentry *dentry,
 				struct ksmbd_kstat *ksmbd_kstat);
 void ksmbd_vfs_posix_lock_wait(struct file_lock *flock);
 int ksmbd_vfs_posix_lock_wait_timeout(struct file_lock *flock, long timeout);
 void ksmbd_vfs_posix_lock_unblock(struct file_lock *flock);
-int ksmbd_vfs_remove_acl_xattrs(struct user_namespace *user_ns,
+int ksmbd_vfs_remove_acl_xattrs(struct mnt_idmap *idmap,
 				struct dentry *dentry);
-int ksmbd_vfs_remove_sd_xattrs(struct user_namespace *user_ns,
+int ksmbd_vfs_remove_sd_xattrs(struct mnt_idmap *idmap,
 			       struct dentry *dentry);
 int ksmbd_vfs_set_sd_xattr(struct ksmbd_conn *conn,
-			   struct user_namespace *user_ns,
+			   struct mnt_idmap *idmap,
 			   struct dentry *dentry,
 			   struct smb_ntsd *pntsd, int len);
 int ksmbd_vfs_get_sd_xattr(struct ksmbd_conn *conn,
-			   struct user_namespace *user_ns,
+			   struct mnt_idmap *idmap,
 			   struct dentry *dentry,
 			   struct smb_ntsd **pntsd);
-int ksmbd_vfs_set_dos_attrib_xattr(struct user_namespace *user_ns,
+int ksmbd_vfs_set_dos_attrib_xattr(struct mnt_idmap *idmap,
 				   struct dentry *dentry,
 				   struct xattr_dos_attrib *da);
-int ksmbd_vfs_get_dos_attrib_xattr(struct user_namespace *user_ns,
+int ksmbd_vfs_get_dos_attrib_xattr(struct mnt_idmap *idmap,
 				   struct dentry *dentry,
 				   struct xattr_dos_attrib *da);
-int ksmbd_vfs_set_init_posix_acl(struct user_namespace *user_ns,
+int ksmbd_vfs_set_init_posix_acl(struct mnt_idmap *idmap,
 				 struct dentry *dentry);
-int ksmbd_vfs_inherit_posix_acl(struct user_namespace *user_ns,
+int ksmbd_vfs_inherit_posix_acl(struct mnt_idmap *idmap,
 				struct dentry *dentry,
 				struct inode *parent_inode);
 #endif /* __KSMBD_VFS_H__ */
diff --git a/fs/ksmbd/vfs_cache.c b/fs/ksmbd/vfs_cache.c
index 552c3882a8f4..1d8126443a7f 100644
--- a/fs/ksmbd/vfs_cache.c
+++ b/fs/ksmbd/vfs_cache.c
@@ -252,7 +252,7 @@ static void __ksmbd_inode_close(struct ksmbd_file *fp)
 	filp = fp->filp;
 	if (ksmbd_stream_fd(fp) && (ci->m_flags & S_DEL_ON_CLS_STREAM)) {
 		ci->m_flags &= ~S_DEL_ON_CLS_STREAM;
-		err = ksmbd_vfs_remove_xattr(file_mnt_user_ns(filp),
+		err = ksmbd_vfs_remove_xattr(file_mnt_idmap(filp),
 					     filp->f_path.dentry,
 					     fp->stream.name);
 		if (err)
@@ -267,7 +267,7 @@ static void __ksmbd_inode_close(struct ksmbd_file *fp)
 			dir = dentry->d_parent;
 			ci->m_flags &= ~(S_DEL_ON_CLS | S_DEL_PENDING);
 			write_unlock(&ci->m_lock);
-			ksmbd_vfs_unlink(file_mnt_user_ns(filp), dir, dentry);
+			ksmbd_vfs_unlink(file_mnt_idmap(filp), dir, dentry);
 			write_lock(&ci->m_lock);
 		}
 		write_unlock(&ci->m_lock);
diff --git a/fs/libfs.c b/fs/libfs.c
index 17ecc47696e1..4eda519c3002 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -28,12 +28,12 @@
 
 #include "internal.h"
 
-int simple_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int simple_getattr(struct mnt_idmap *idmap, const struct path *path,
 		   struct kstat *stat, u32 request_mask,
 		   unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	stat->blocks = inode->i_mapping->nrpages << (PAGE_SHIFT - 9);
 	return 0;
 }
@@ -473,7 +473,7 @@ int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry,
 }
 EXPORT_SYMBOL_GPL(simple_rename_exchange);
 
-int simple_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+int simple_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		  struct dentry *old_dentry, struct inode *new_dir,
 		  struct dentry *new_dentry, unsigned int flags)
 {
@@ -509,7 +509,7 @@ EXPORT_SYMBOL(simple_rename);
 
 /**
  * simple_setattr - setattr for simple filesystem
- * @mnt_userns: user namespace of the target mount
+ * @idmap: idmap of the target mount
  * @dentry: dentry
  * @iattr: iattr structure
  *
@@ -522,19 +522,19 @@ EXPORT_SYMBOL(simple_rename);
  * on simple regular filesystems.  Anything that needs to change on-disk
  * or wire state on size changes needs its own setattr method.
  */
-int simple_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int simple_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		   struct iattr *iattr)
 {
 	struct inode *inode = d_inode(dentry);
 	int error;
 
-	error = setattr_prepare(mnt_userns, dentry, iattr);
+	error = setattr_prepare(idmap, dentry, iattr);
 	if (error)
 		return error;
 
 	if (iattr->ia_valid & ATTR_SIZE)
 		truncate_setsize(inode, iattr->ia_size);
-	setattr_copy(mnt_userns, inode, iattr);
+	setattr_copy(idmap, inode, iattr);
 	mark_inode_dirty(inode);
 	return 0;
 }
@@ -1315,16 +1315,16 @@ static struct dentry *empty_dir_lookup(struct inode *dir, struct dentry *dentry,
 	return ERR_PTR(-ENOENT);
 }
 
-static int empty_dir_getattr(struct user_namespace *mnt_userns,
+static int empty_dir_getattr(struct mnt_idmap *idmap,
 			     const struct path *path, struct kstat *stat,
 			     u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	return 0;
 }
 
-static int empty_dir_setattr(struct user_namespace *mnt_userns,
+static int empty_dir_setattr(struct mnt_idmap *idmap,
 			     struct dentry *dentry, struct iattr *attr)
 {
 	return -EPERM;
diff --git a/fs/minix/bitmap.c b/fs/minix/bitmap.c
index 9115948c624e..724d8191a310 100644
--- a/fs/minix/bitmap.c
+++ b/fs/minix/bitmap.c
@@ -252,7 +252,7 @@ struct inode *minix_new_inode(const struct inode *dir, umode_t mode, int *error)
 		iput(inode);
 		return NULL;
 	}
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 	inode->i_ino = j;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 	inode->i_blocks = 0;
diff --git a/fs/minix/file.c b/fs/minix/file.c
index 6a7bd2d9eec0..0dd05d47724a 100644
--- a/fs/minix/file.c
+++ b/fs/minix/file.c
@@ -22,13 +22,13 @@ const struct file_operations minix_file_operations = {
 	.splice_read	= generic_file_splice_read,
 };
 
-static int minix_setattr(struct user_namespace *mnt_userns,
+static int minix_setattr(struct mnt_idmap *idmap,
 			 struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	int error;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
@@ -42,7 +42,7 @@ static int minix_setattr(struct user_namespace *mnt_userns,
 		minix_truncate(inode);
 	}
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index da8bdd1712a7..e9fbb5303a22 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -654,13 +654,13 @@ static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
 	return err;
 }
 
-int minix_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int minix_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	struct super_block *sb = path->dentry->d_sb;
 	struct inode *inode = d_inode(path->dentry);
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	if (INODE_VERSION(inode) == MINIX_V1)
 		stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
 	else
diff --git a/fs/minix/minix.h b/fs/minix/minix.h
index 202173368025..e0b76defa85c 100644
--- a/fs/minix/minix.h
+++ b/fs/minix/minix.h
@@ -51,7 +51,7 @@ extern unsigned long minix_count_free_inodes(struct super_block *sb);
 extern int minix_new_block(struct inode * inode);
 extern void minix_free_block(struct inode *inode, unsigned long block);
 extern unsigned long minix_count_free_blocks(struct super_block *sb);
-extern int minix_getattr(struct user_namespace *, const struct path *,
+extern int minix_getattr(struct mnt_idmap *, const struct path *,
 			 struct kstat *, u32, unsigned int);
 extern int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len);
 
diff --git a/fs/minix/namei.c b/fs/minix/namei.c
index 8afdc408ca4f..39ebe10d6a8b 100644
--- a/fs/minix/namei.c
+++ b/fs/minix/namei.c
@@ -33,7 +33,7 @@ static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, un
 	return d_splice_alias(inode, dentry);
 }
 
-static int minix_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int minix_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	int error;
@@ -52,7 +52,7 @@ static int minix_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	return error;
 }
 
-static int minix_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+static int minix_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 			 struct file *file, umode_t mode)
 {
 	int error;
@@ -65,13 +65,13 @@ static int minix_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	return finish_open_simple(file, error);
 }
 
-static int minix_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int minix_create(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, umode_t mode, bool excl)
 {
-	return minix_mknod(mnt_userns, dir, dentry, mode, 0);
+	return minix_mknod(&nop_mnt_idmap, dir, dentry, mode, 0);
 }
 
-static int minix_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int minix_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			 struct dentry *dentry, const char *symname)
 {
 	int err = -ENAMETOOLONG;
@@ -111,7 +111,7 @@ static int minix_link(struct dentry * old_dentry, struct inode * dir,
 	return add_nondir(dentry, inode);
 }
 
-static int minix_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int minix_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode)
 {
 	struct inode * inode;
@@ -184,7 +184,7 @@ static int minix_rmdir(struct inode * dir, struct dentry *dentry)
 	return err;
 }
 
-static int minix_rename(struct user_namespace *mnt_userns,
+static int minix_rename(struct mnt_idmap *idmap,
 			struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
diff --git a/fs/mnt_idmapping.c b/fs/mnt_idmapping.c
new file mode 100644
index 000000000000..4905665c47d0
--- /dev/null
+++ b/fs/mnt_idmapping.c
@@ -0,0 +1,273 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Christian Brauner <brauner@kernel.org> */
+
+#include <linux/cred.h>
+#include <linux/fs.h>
+#include <linux/mnt_idmapping.h>
+#include <linux/slab.h>
+#include <linux/user_namespace.h>
+
+#include "internal.h"
+
+struct mnt_idmap {
+	struct user_namespace *owner;
+	refcount_t count;
+};
+
+/*
+ * Carries the initial idmapping of 0:0:4294967295 which is an identity
+ * mapping. This means that {g,u}id 0 is mapped to {g,u}id 0, {g,u}id 1 is
+ * mapped to {g,u}id 1, [...], {g,u}id 1000 to {g,u}id 1000, [...].
+ */
+struct mnt_idmap nop_mnt_idmap = {
+	.owner	= &init_user_ns,
+	.count	= REFCOUNT_INIT(1),
+};
+EXPORT_SYMBOL_GPL(nop_mnt_idmap);
+
+/**
+ * check_fsmapping - check whether an mount idmapping is allowed
+ * @idmap: idmap of the relevent mount
+ * @sb:    super block of the filesystem
+ *
+ * Return: true if @idmap is allowed, false if not.
+ */
+bool check_fsmapping(const struct mnt_idmap *idmap,
+		     const struct super_block *sb)
+{
+	return idmap->owner != sb->s_user_ns;
+}
+
+/**
+ * initial_idmapping - check whether this is the initial mapping
+ * @ns: idmapping to check
+ *
+ * Check whether this is the initial mapping, mapping 0 to 0, 1 to 1,
+ * [...], 1000 to 1000 [...].
+ *
+ * Return: true if this is the initial mapping, false if not.
+ */
+static inline bool initial_idmapping(const struct user_namespace *ns)
+{
+	return ns == &init_user_ns;
+}
+
+/**
+ * no_idmapping - check whether we can skip remapping a kuid/gid
+ * @mnt_userns: the mount's idmapping
+ * @fs_userns: the filesystem's idmapping
+ *
+ * This function can be used to check whether a remapping between two
+ * idmappings is required.
+ * An idmapped mount is a mount that has an idmapping attached to it that
+ * is different from the filsystem's idmapping and the initial idmapping.
+ * If the initial mapping is used or the idmapping of the mount and the
+ * filesystem are identical no remapping is required.
+ *
+ * Return: true if remapping can be skipped, false if not.
+ */
+static inline bool no_idmapping(const struct user_namespace *mnt_userns,
+				const struct user_namespace *fs_userns)
+{
+	return initial_idmapping(mnt_userns) || mnt_userns == fs_userns;
+}
+
+/**
+ * make_vfsuid - map a filesystem kuid according to an idmapping
+ * @idmap: the mount's idmapping
+ * @fs_userns: the filesystem's idmapping
+ * @kuid : kuid to be mapped
+ *
+ * Take a @kuid and remap it from @fs_userns into @idmap. Use this
+ * function when preparing a @kuid to be reported to userspace.
+ *
+ * If no_idmapping() determines that this is not an idmapped mount we can
+ * simply return @kuid unchanged.
+ * If initial_idmapping() tells us that the filesystem is not mounted with an
+ * idmapping we know the value of @kuid won't change when calling
+ * from_kuid() so we can simply retrieve the value via __kuid_val()
+ * directly.
+ *
+ * Return: @kuid mapped according to @idmap.
+ * If @kuid has no mapping in either @idmap or @fs_userns INVALID_UID is
+ * returned.
+ */
+
+vfsuid_t make_vfsuid(struct mnt_idmap *idmap,
+				   struct user_namespace *fs_userns,
+				   kuid_t kuid)
+{
+	uid_t uid;
+	struct user_namespace *mnt_userns = idmap->owner;
+
+	if (no_idmapping(mnt_userns, fs_userns))
+		return VFSUIDT_INIT(kuid);
+	if (initial_idmapping(fs_userns))
+		uid = __kuid_val(kuid);
+	else
+		uid = from_kuid(fs_userns, kuid);
+	if (uid == (uid_t)-1)
+		return INVALID_VFSUID;
+	return VFSUIDT_INIT(make_kuid(mnt_userns, uid));
+}
+EXPORT_SYMBOL_GPL(make_vfsuid);
+
+/**
+ * make_vfsgid - map a filesystem kgid according to an idmapping
+ * @idmap: the mount's idmapping
+ * @fs_userns: the filesystem's idmapping
+ * @kgid : kgid to be mapped
+ *
+ * Take a @kgid and remap it from @fs_userns into @idmap. Use this
+ * function when preparing a @kgid to be reported to userspace.
+ *
+ * If no_idmapping() determines that this is not an idmapped mount we can
+ * simply return @kgid unchanged.
+ * If initial_idmapping() tells us that the filesystem is not mounted with an
+ * idmapping we know the value of @kgid won't change when calling
+ * from_kgid() so we can simply retrieve the value via __kgid_val()
+ * directly.
+ *
+ * Return: @kgid mapped according to @idmap.
+ * If @kgid has no mapping in either @idmap or @fs_userns INVALID_GID is
+ * returned.
+ */
+vfsgid_t make_vfsgid(struct mnt_idmap *idmap,
+		     struct user_namespace *fs_userns, kgid_t kgid)
+{
+	gid_t gid;
+	struct user_namespace *mnt_userns = idmap->owner;
+
+	if (no_idmapping(mnt_userns, fs_userns))
+		return VFSGIDT_INIT(kgid);
+	if (initial_idmapping(fs_userns))
+		gid = __kgid_val(kgid);
+	else
+		gid = from_kgid(fs_userns, kgid);
+	if (gid == (gid_t)-1)
+		return INVALID_VFSGID;
+	return VFSGIDT_INIT(make_kgid(mnt_userns, gid));
+}
+EXPORT_SYMBOL_GPL(make_vfsgid);
+
+/**
+ * from_vfsuid - map a vfsuid into the filesystem idmapping
+ * @idmap: the mount's idmapping
+ * @fs_userns: the filesystem's idmapping
+ * @vfsuid : vfsuid to be mapped
+ *
+ * Map @vfsuid into the filesystem idmapping. This function has to be used in
+ * order to e.g. write @vfsuid to inode->i_uid.
+ *
+ * Return: @vfsuid mapped into the filesystem idmapping
+ */
+kuid_t from_vfsuid(struct mnt_idmap *idmap,
+		   struct user_namespace *fs_userns, vfsuid_t vfsuid)
+{
+	uid_t uid;
+	struct user_namespace *mnt_userns = idmap->owner;
+
+	if (no_idmapping(mnt_userns, fs_userns))
+		return AS_KUIDT(vfsuid);
+	uid = from_kuid(mnt_userns, AS_KUIDT(vfsuid));
+	if (uid == (uid_t)-1)
+		return INVALID_UID;
+	if (initial_idmapping(fs_userns))
+		return KUIDT_INIT(uid);
+	return make_kuid(fs_userns, uid);
+}
+EXPORT_SYMBOL_GPL(from_vfsuid);
+
+/**
+ * from_vfsgid - map a vfsgid into the filesystem idmapping
+ * @idmap: the mount's idmapping
+ * @fs_userns: the filesystem's idmapping
+ * @vfsgid : vfsgid to be mapped
+ *
+ * Map @vfsgid into the filesystem idmapping. This function has to be used in
+ * order to e.g. write @vfsgid to inode->i_gid.
+ *
+ * Return: @vfsgid mapped into the filesystem idmapping
+ */
+kgid_t from_vfsgid(struct mnt_idmap *idmap,
+		   struct user_namespace *fs_userns, vfsgid_t vfsgid)
+{
+	gid_t gid;
+	struct user_namespace *mnt_userns = idmap->owner;
+
+	if (no_idmapping(mnt_userns, fs_userns))
+		return AS_KGIDT(vfsgid);
+	gid = from_kgid(mnt_userns, AS_KGIDT(vfsgid));
+	if (gid == (gid_t)-1)
+		return INVALID_GID;
+	if (initial_idmapping(fs_userns))
+		return KGIDT_INIT(gid);
+	return make_kgid(fs_userns, gid);
+}
+EXPORT_SYMBOL_GPL(from_vfsgid);
+
+#ifdef CONFIG_MULTIUSER
+/**
+ * vfsgid_in_group_p() - check whether a vfsuid matches the caller's groups
+ * @vfsgid: the mnt gid to match
+ *
+ * This function can be used to determine whether @vfsuid matches any of the
+ * caller's groups.
+ *
+ * Return: 1 if vfsuid matches caller's groups, 0 if not.
+ */
+int vfsgid_in_group_p(vfsgid_t vfsgid)
+{
+	return in_group_p(AS_KGIDT(vfsgid));
+}
+#else
+int vfsgid_in_group_p(vfsgid_t vfsgid)
+{
+	return 1;
+}
+#endif
+EXPORT_SYMBOL_GPL(vfsgid_in_group_p);
+
+struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns)
+{
+	struct mnt_idmap *idmap;
+
+	idmap = kzalloc(sizeof(struct mnt_idmap), GFP_KERNEL_ACCOUNT);
+	if (!idmap)
+		return ERR_PTR(-ENOMEM);
+
+	idmap->owner = get_user_ns(mnt_userns);
+	refcount_set(&idmap->count, 1);
+	return idmap;
+}
+
+/**
+ * mnt_idmap_get - get a reference to an idmapping
+ * @idmap: the idmap to bump the reference on
+ *
+ * If @idmap is not the @nop_mnt_idmap bump the reference count.
+ *
+ * Return: @idmap with reference count bumped if @not_mnt_idmap isn't passed.
+ */
+struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap)
+{
+	if (idmap != &nop_mnt_idmap)
+		refcount_inc(&idmap->count);
+
+	return idmap;
+}
+
+/**
+ * mnt_idmap_put - put a reference to an idmapping
+ * @idmap: the idmap to put the reference on
+ *
+ * If this is a non-initial idmapping, put the reference count when a mount is
+ * released and free it if we're the last user.
+ */
+void mnt_idmap_put(struct mnt_idmap *idmap)
+{
+	if (idmap != &nop_mnt_idmap && refcount_dec_and_test(&idmap->count)) {
+		put_user_ns(idmap->owner);
+		kfree(idmap);
+	}
+}
diff --git a/fs/namei.c b/fs/namei.c
index 60a9d3ac941f..5855dc6edbd5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -274,7 +274,7 @@ void putname(struct filename *name)
 
 /**
  * check_acl - perform ACL permission checking
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @inode:	inode to check permissions on
  * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC ...)
  *
@@ -282,13 +282,13 @@ void putname(struct filename *name)
  * retrieve POSIX acls it needs to know whether it is called from a blocking or
  * non-blocking context and thus cares about the MAY_NOT_BLOCK bit.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-static int check_acl(struct user_namespace *mnt_userns,
+static int check_acl(struct mnt_idmap *idmap,
 		     struct inode *inode, int mask)
 {
 #ifdef CONFIG_FS_POSIX_ACL
@@ -301,14 +301,14 @@ static int check_acl(struct user_namespace *mnt_userns,
 		/* no ->get_inode_acl() calls in RCU mode... */
 		if (is_uncached_acl(acl))
 			return -ECHILD;
-	        return posix_acl_permission(mnt_userns, inode, acl, mask);
+	        return posix_acl_permission(idmap, inode, acl, mask);
 	}
 
 	acl = get_inode_acl(inode, ACL_TYPE_ACCESS);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
 	if (acl) {
-	        int error = posix_acl_permission(mnt_userns, inode, acl, mask);
+	        int error = posix_acl_permission(idmap, inode, acl, mask);
 	        posix_acl_release(acl);
 	        return error;
 	}
@@ -319,7 +319,7 @@ static int check_acl(struct user_namespace *mnt_userns,
 
 /**
  * acl_permission_check - perform basic UNIX permission checking
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @inode:	inode to check permissions on
  * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC ...)
  *
@@ -327,20 +327,20 @@ static int check_acl(struct user_namespace *mnt_userns,
  * function may retrieve POSIX acls it needs to know whether it is called from a
  * blocking or non-blocking context and thus cares about the MAY_NOT_BLOCK bit.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-static int acl_permission_check(struct user_namespace *mnt_userns,
+static int acl_permission_check(struct mnt_idmap *idmap,
 				struct inode *inode, int mask)
 {
 	unsigned int mode = inode->i_mode;
 	vfsuid_t vfsuid;
 
 	/* Are we the owner? If so, ACL's don't matter */
-	vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
+	vfsuid = i_uid_into_vfsuid(idmap, inode);
 	if (likely(vfsuid_eq_kuid(vfsuid, current_fsuid()))) {
 		mask &= 7;
 		mode >>= 6;
@@ -349,7 +349,7 @@ static int acl_permission_check(struct user_namespace *mnt_userns,
 
 	/* Do we have ACL's? */
 	if (IS_POSIXACL(inode) && (mode & S_IRWXG)) {
-		int error = check_acl(mnt_userns, inode, mask);
+		int error = check_acl(idmap, inode, mask);
 		if (error != -EAGAIN)
 			return error;
 	}
@@ -363,7 +363,7 @@ static int acl_permission_check(struct user_namespace *mnt_userns,
 	 * about? Need to check group ownership if so.
 	 */
 	if (mask & (mode ^ (mode >> 3))) {
-		vfsgid_t vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
+		vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
 		if (vfsgid_in_group_p(vfsgid))
 			mode >>= 3;
 	}
@@ -374,7 +374,7 @@ static int acl_permission_check(struct user_namespace *mnt_userns,
 
 /**
  * generic_permission -  check for access rights on a Posix-like filesystem
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @inode:	inode to check access rights for
  * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC,
  *		%MAY_NOT_BLOCK ...)
@@ -388,13 +388,13 @@ static int acl_permission_check(struct user_namespace *mnt_userns,
  * request cannot be satisfied (eg. requires blocking or too much complexity).
  * It would then be called again in ref-walk mode.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-int generic_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int generic_permission(struct mnt_idmap *idmap, struct inode *inode,
 		       int mask)
 {
 	int ret;
@@ -402,17 +402,17 @@ int generic_permission(struct user_namespace *mnt_userns, struct inode *inode,
 	/*
 	 * Do the basic permission checks.
 	 */
-	ret = acl_permission_check(mnt_userns, inode, mask);
+	ret = acl_permission_check(idmap, inode, mask);
 	if (ret != -EACCES)
 		return ret;
 
 	if (S_ISDIR(inode->i_mode)) {
 		/* DACs are overridable for directories */
 		if (!(mask & MAY_WRITE))
-			if (capable_wrt_inode_uidgid(mnt_userns, inode,
+			if (capable_wrt_inode_uidgid(idmap, inode,
 						     CAP_DAC_READ_SEARCH))
 				return 0;
-		if (capable_wrt_inode_uidgid(mnt_userns, inode,
+		if (capable_wrt_inode_uidgid(idmap, inode,
 					     CAP_DAC_OVERRIDE))
 			return 0;
 		return -EACCES;
@@ -423,7 +423,7 @@ int generic_permission(struct user_namespace *mnt_userns, struct inode *inode,
 	 */
 	mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
 	if (mask == MAY_READ)
-		if (capable_wrt_inode_uidgid(mnt_userns, inode,
+		if (capable_wrt_inode_uidgid(idmap, inode,
 					     CAP_DAC_READ_SEARCH))
 			return 0;
 	/*
@@ -432,7 +432,7 @@ int generic_permission(struct user_namespace *mnt_userns, struct inode *inode,
 	 * at least one exec bit set.
 	 */
 	if (!(mask & MAY_EXEC) || (inode->i_mode & S_IXUGO))
-		if (capable_wrt_inode_uidgid(mnt_userns, inode,
+		if (capable_wrt_inode_uidgid(idmap, inode,
 					     CAP_DAC_OVERRIDE))
 			return 0;
 
@@ -442,7 +442,7 @@ EXPORT_SYMBOL(generic_permission);
 
 /**
  * do_inode_permission - UNIX permission checking
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @inode:	inode to check permissions on
  * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC ...)
  *
@@ -451,19 +451,19 @@ EXPORT_SYMBOL(generic_permission);
  * flag in inode->i_opflags, that says "this has not special
  * permission function, use the fast case".
  */
-static inline int do_inode_permission(struct user_namespace *mnt_userns,
+static inline int do_inode_permission(struct mnt_idmap *idmap,
 				      struct inode *inode, int mask)
 {
 	if (unlikely(!(inode->i_opflags & IOP_FASTPERM))) {
 		if (likely(inode->i_op->permission))
-			return inode->i_op->permission(mnt_userns, inode, mask);
+			return inode->i_op->permission(idmap, inode, mask);
 
 		/* This gets set once for the inode lifetime */
 		spin_lock(&inode->i_lock);
 		inode->i_opflags |= IOP_FASTPERM;
 		spin_unlock(&inode->i_lock);
 	}
-	return generic_permission(mnt_userns, inode, mask);
+	return generic_permission(idmap, inode, mask);
 }
 
 /**
@@ -488,7 +488,7 @@ static int sb_permission(struct super_block *sb, struct inode *inode, int mask)
 
 /**
  * inode_permission - Check for access rights to a given inode
- * @mnt_userns:	User namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @inode:	Inode to check permission on
  * @mask:	Right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
  *
@@ -498,7 +498,7 @@ static int sb_permission(struct super_block *sb, struct inode *inode, int mask)
  *
  * When checking for MAY_APPEND, MAY_WRITE must also be set in @mask.
  */
-int inode_permission(struct user_namespace *mnt_userns,
+int inode_permission(struct mnt_idmap *idmap,
 		     struct inode *inode, int mask)
 {
 	int retval;
@@ -519,11 +519,11 @@ int inode_permission(struct user_namespace *mnt_userns,
 		 * written back improperly if their true value is unknown
 		 * to the vfs.
 		 */
-		if (HAS_UNMAPPED_ID(mnt_userns, inode))
+		if (HAS_UNMAPPED_ID(idmap, inode))
 			return -EACCES;
 	}
 
-	retval = do_inode_permission(mnt_userns, inode, mask);
+	retval = do_inode_permission(idmap, inode, mask);
 	if (retval)
 		return retval;
 
@@ -1095,14 +1095,14 @@ fs_initcall(init_fs_namei_sysctls);
  */
 static inline int may_follow_link(struct nameidata *nd, const struct inode *inode)
 {
-	struct user_namespace *mnt_userns;
+	struct mnt_idmap *idmap;
 	vfsuid_t vfsuid;
 
 	if (!sysctl_protected_symlinks)
 		return 0;
 
-	mnt_userns = mnt_user_ns(nd->path.mnt);
-	vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
+	idmap = mnt_idmap(nd->path.mnt);
+	vfsuid = i_uid_into_vfsuid(idmap, inode);
 	/* Allowed if owner and follower match. */
 	if (vfsuid_eq_kuid(vfsuid, current_fsuid()))
 		return 0;
@@ -1125,7 +1125,7 @@ static inline int may_follow_link(struct nameidata *nd, const struct inode *inod
 
 /**
  * safe_hardlink_source - Check for safe hardlink conditions
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @inode: the source inode to hardlink from
  *
  * Return false if at least one of the following conditions:
@@ -1136,7 +1136,7 @@ static inline int may_follow_link(struct nameidata *nd, const struct inode *inod
  *
  * Otherwise returns true.
  */
-static bool safe_hardlink_source(struct user_namespace *mnt_userns,
+static bool safe_hardlink_source(struct mnt_idmap *idmap,
 				 struct inode *inode)
 {
 	umode_t mode = inode->i_mode;
@@ -1154,7 +1154,7 @@ static bool safe_hardlink_source(struct user_namespace *mnt_userns,
 		return false;
 
 	/* Hardlinking to unreadable or unwritable sources is dangerous. */
-	if (inode_permission(mnt_userns, inode, MAY_READ | MAY_WRITE))
+	if (inode_permission(idmap, inode, MAY_READ | MAY_WRITE))
 		return false;
 
 	return true;
@@ -1162,8 +1162,8 @@ static bool safe_hardlink_source(struct user_namespace *mnt_userns,
 
 /**
  * may_linkat - Check permissions for creating a hardlink
- * @mnt_userns:	user namespace of the mount the inode was found from
- * @link: the source to hardlink from
+ * @idmap: idmap of the mount the inode was found from
+ * @link:  the source to hardlink from
  *
  * Block hardlink when all of:
  *  - sysctl_protected_hardlinks enabled
@@ -1171,21 +1171,21 @@ static bool safe_hardlink_source(struct user_namespace *mnt_userns,
  *  - hardlink source is unsafe (see safe_hardlink_source() above)
  *  - not CAP_FOWNER in a namespace with the inode owner uid mapped
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply pass @nop_mnt_idmap.
  *
  * Returns 0 if successful, -ve on error.
  */
-int may_linkat(struct user_namespace *mnt_userns, const struct path *link)
+int may_linkat(struct mnt_idmap *idmap, const struct path *link)
 {
 	struct inode *inode = link->dentry->d_inode;
 
 	/* Inode writeback is not safe when the uid or gid are invalid. */
-	if (!vfsuid_valid(i_uid_into_vfsuid(mnt_userns, inode)) ||
-	    !vfsgid_valid(i_gid_into_vfsgid(mnt_userns, inode)))
+	if (!vfsuid_valid(i_uid_into_vfsuid(idmap, inode)) ||
+	    !vfsgid_valid(i_gid_into_vfsgid(idmap, inode)))
 		return -EOVERFLOW;
 
 	if (!sysctl_protected_hardlinks)
@@ -1194,8 +1194,8 @@ int may_linkat(struct user_namespace *mnt_userns, const struct path *link)
 	/* Source inode owner (or CAP_FOWNER) can hardlink all they like,
 	 * otherwise, it must be a safe source.
 	 */
-	if (safe_hardlink_source(mnt_userns, inode) ||
-	    inode_owner_or_capable(mnt_userns, inode))
+	if (safe_hardlink_source(idmap, inode) ||
+	    inode_owner_or_capable(idmap, inode))
 		return 0;
 
 	audit_log_path_denied(AUDIT_ANOM_LINK, "linkat");
@@ -1206,7 +1206,7 @@ int may_linkat(struct user_namespace *mnt_userns, const struct path *link)
  * may_create_in_sticky - Check whether an O_CREAT open in a sticky directory
  *			  should be allowed, or not, on files that already
  *			  exist.
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @nd: nameidata pathwalk data
  * @inode: the inode of the file to open
  *
@@ -1221,15 +1221,15 @@ int may_linkat(struct user_namespace *mnt_userns, const struct path *link)
  * the directory doesn't have to be world writable: being group writable will
  * be enough.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply pass @nop_mnt_idmap.
  *
  * Returns 0 if the open is allowed, -ve on error.
  */
-static int may_create_in_sticky(struct user_namespace *mnt_userns,
+static int may_create_in_sticky(struct mnt_idmap *idmap,
 				struct nameidata *nd, struct inode *const inode)
 {
 	umode_t dir_mode = nd->dir_mode;
@@ -1238,8 +1238,8 @@ static int may_create_in_sticky(struct user_namespace *mnt_userns,
 	if ((!sysctl_protected_fifos && S_ISFIFO(inode->i_mode)) ||
 	    (!sysctl_protected_regular && S_ISREG(inode->i_mode)) ||
 	    likely(!(dir_mode & S_ISVTX)) ||
-	    vfsuid_eq(i_uid_into_vfsuid(mnt_userns, inode), dir_vfsuid) ||
-	    vfsuid_eq_kuid(i_uid_into_vfsuid(mnt_userns, inode), current_fsuid()))
+	    vfsuid_eq(i_uid_into_vfsuid(idmap, inode), dir_vfsuid) ||
+	    vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode), current_fsuid()))
 		return 0;
 
 	if (likely(dir_mode & 0002) ||
@@ -1705,15 +1705,15 @@ static struct dentry *lookup_slow(const struct qstr *name,
 	return res;
 }
 
-static inline int may_lookup(struct user_namespace *mnt_userns,
+static inline int may_lookup(struct mnt_idmap *idmap,
 			     struct nameidata *nd)
 {
 	if (nd->flags & LOOKUP_RCU) {
-		int err = inode_permission(mnt_userns, nd->inode, MAY_EXEC|MAY_NOT_BLOCK);
+		int err = inode_permission(idmap, nd->inode, MAY_EXEC|MAY_NOT_BLOCK);
 		if (err != -ECHILD || !try_to_unlazy(nd))
 			return err;
 	}
-	return inode_permission(mnt_userns, nd->inode, MAY_EXEC);
+	return inode_permission(idmap, nd->inode, MAY_EXEC);
 }
 
 static int reserve_stack(struct nameidata *nd, struct path *link)
@@ -2254,13 +2254,13 @@ static int link_path_walk(const char *name, struct nameidata *nd)
 
 	/* At this point we know we have a real path component. */
 	for(;;) {
-		struct user_namespace *mnt_userns;
+		struct mnt_idmap *idmap;
 		const char *link;
 		u64 hash_len;
 		int type;
 
-		mnt_userns = mnt_user_ns(nd->path.mnt);
-		err = may_lookup(mnt_userns, nd);
+		idmap = mnt_idmap(nd->path.mnt);
+		err = may_lookup(idmap, nd);
 		if (err)
 			return err;
 
@@ -2308,7 +2308,7 @@ static int link_path_walk(const char *name, struct nameidata *nd)
 OK:
 			/* pathname or trailing symlink, done */
 			if (!depth) {
-				nd->dir_vfsuid = i_uid_into_vfsuid(mnt_userns, nd->inode);
+				nd->dir_vfsuid = i_uid_into_vfsuid(idmap, nd->inode);
 				nd->dir_mode = nd->inode->i_mode;
 				nd->flags &= ~LOOKUP_PARENT;
 				return 0;
@@ -2623,7 +2623,7 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
 }
 EXPORT_SYMBOL(vfs_path_lookup);
 
-static int lookup_one_common(struct user_namespace *mnt_userns,
+static int lookup_one_common(struct mnt_idmap *idmap,
 			     const char *name, struct dentry *base, int len,
 			     struct qstr *this)
 {
@@ -2653,7 +2653,7 @@ static int lookup_one_common(struct user_namespace *mnt_userns,
 			return err;
 	}
 
-	return inode_permission(mnt_userns, base->d_inode, MAY_EXEC);
+	return inode_permission(idmap, base->d_inode, MAY_EXEC);
 }
 
 /**
@@ -2677,7 +2677,7 @@ struct dentry *try_lookup_one_len(const char *name, struct dentry *base, int len
 
 	WARN_ON_ONCE(!inode_is_locked(base->d_inode));
 
-	err = lookup_one_common(&init_user_ns, name, base, len, &this);
+	err = lookup_one_common(&nop_mnt_idmap, name, base, len, &this);
 	if (err)
 		return ERR_PTR(err);
 
@@ -2704,7 +2704,7 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
 
 	WARN_ON_ONCE(!inode_is_locked(base->d_inode));
 
-	err = lookup_one_common(&init_user_ns, name, base, len, &this);
+	err = lookup_one_common(&nop_mnt_idmap, name, base, len, &this);
 	if (err)
 		return ERR_PTR(err);
 
@@ -2715,7 +2715,7 @@ EXPORT_SYMBOL(lookup_one_len);
 
 /**
  * lookup_one - filesystem helper to lookup single pathname component
- * @mnt_userns:	user namespace of the mount the lookup is performed from
+ * @idmap:	idmap of the mount the lookup is performed from
  * @name:	pathname component to lookup
  * @base:	base directory to lookup from
  * @len:	maximum length @len should be interpreted to
@@ -2725,7 +2725,7 @@ EXPORT_SYMBOL(lookup_one_len);
  *
  * The caller must hold base->i_mutex.
  */
-struct dentry *lookup_one(struct user_namespace *mnt_userns, const char *name,
+struct dentry *lookup_one(struct mnt_idmap *idmap, const char *name,
 			  struct dentry *base, int len)
 {
 	struct dentry *dentry;
@@ -2734,7 +2734,7 @@ struct dentry *lookup_one(struct user_namespace *mnt_userns, const char *name,
 
 	WARN_ON_ONCE(!inode_is_locked(base->d_inode));
 
-	err = lookup_one_common(mnt_userns, name, base, len, &this);
+	err = lookup_one_common(idmap, name, base, len, &this);
 	if (err)
 		return ERR_PTR(err);
 
@@ -2745,7 +2745,7 @@ EXPORT_SYMBOL(lookup_one);
 
 /**
  * lookup_one_unlocked - filesystem helper to lookup single pathname component
- * @mnt_userns:	idmapping of the mount the lookup is performed from
+ * @idmap:	idmap of the mount the lookup is performed from
  * @name:	pathname component to lookup
  * @base:	base directory to lookup from
  * @len:	maximum length @len should be interpreted to
@@ -2756,7 +2756,7 @@ EXPORT_SYMBOL(lookup_one);
  * Unlike lookup_one_len, it should be called without the parent
  * i_mutex held, and will take the i_mutex itself if necessary.
  */
-struct dentry *lookup_one_unlocked(struct user_namespace *mnt_userns,
+struct dentry *lookup_one_unlocked(struct mnt_idmap *idmap,
 				   const char *name, struct dentry *base,
 				   int len)
 {
@@ -2764,7 +2764,7 @@ struct dentry *lookup_one_unlocked(struct user_namespace *mnt_userns,
 	int err;
 	struct dentry *ret;
 
-	err = lookup_one_common(mnt_userns, name, base, len, &this);
+	err = lookup_one_common(idmap, name, base, len, &this);
 	if (err)
 		return ERR_PTR(err);
 
@@ -2778,7 +2778,7 @@ EXPORT_SYMBOL(lookup_one_unlocked);
 /**
  * lookup_one_positive_unlocked - filesystem helper to lookup single
  *				  pathname component
- * @mnt_userns:	idmapping of the mount the lookup is performed from
+ * @idmap:	idmap of the mount the lookup is performed from
  * @name:	pathname component to lookup
  * @base:	base directory to lookup from
  * @len:	maximum length @len should be interpreted to
@@ -2795,11 +2795,11 @@ EXPORT_SYMBOL(lookup_one_unlocked);
  *
  * The helper should be called without i_mutex held.
  */
-struct dentry *lookup_one_positive_unlocked(struct user_namespace *mnt_userns,
+struct dentry *lookup_one_positive_unlocked(struct mnt_idmap *idmap,
 					    const char *name,
 					    struct dentry *base, int len)
 {
-	struct dentry *ret = lookup_one_unlocked(mnt_userns, name, base, len);
+	struct dentry *ret = lookup_one_unlocked(idmap, name, base, len);
 
 	if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) {
 		dput(ret);
@@ -2824,7 +2824,7 @@ EXPORT_SYMBOL(lookup_one_positive_unlocked);
 struct dentry *lookup_one_len_unlocked(const char *name,
 				       struct dentry *base, int len)
 {
-	return lookup_one_unlocked(&init_user_ns, name, base, len);
+	return lookup_one_unlocked(&nop_mnt_idmap, name, base, len);
 }
 EXPORT_SYMBOL(lookup_one_len_unlocked);
 
@@ -2839,7 +2839,7 @@ EXPORT_SYMBOL(lookup_one_len_unlocked);
 struct dentry *lookup_positive_unlocked(const char *name,
 				       struct dentry *base, int len)
 {
-	return lookup_one_positive_unlocked(&init_user_ns, name, base, len);
+	return lookup_one_positive_unlocked(&nop_mnt_idmap, name, base, len);
 }
 EXPORT_SYMBOL(lookup_positive_unlocked);
 
@@ -2881,16 +2881,16 @@ int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
 }
 EXPORT_SYMBOL(user_path_at_empty);
 
-int __check_sticky(struct user_namespace *mnt_userns, struct inode *dir,
+int __check_sticky(struct mnt_idmap *idmap, struct inode *dir,
 		   struct inode *inode)
 {
 	kuid_t fsuid = current_fsuid();
 
-	if (vfsuid_eq_kuid(i_uid_into_vfsuid(mnt_userns, inode), fsuid))
+	if (vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode), fsuid))
 		return 0;
-	if (vfsuid_eq_kuid(i_uid_into_vfsuid(mnt_userns, dir), fsuid))
+	if (vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, dir), fsuid))
 		return 0;
-	return !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FOWNER);
+	return !capable_wrt_inode_uidgid(idmap, inode, CAP_FOWNER);
 }
 EXPORT_SYMBOL(__check_sticky);
 
@@ -2914,7 +2914,7 @@ EXPORT_SYMBOL(__check_sticky);
  * 11. We don't allow removal of NFS sillyrenamed files; it's handled by
  *     nfs_async_unlink().
  */
-static int may_delete(struct user_namespace *mnt_userns, struct inode *dir,
+static int may_delete(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *victim, bool isdir)
 {
 	struct inode *inode = d_backing_inode(victim);
@@ -2927,21 +2927,21 @@ static int may_delete(struct user_namespace *mnt_userns, struct inode *dir,
 	BUG_ON(victim->d_parent->d_inode != dir);
 
 	/* Inode writeback is not safe when the uid or gid are invalid. */
-	if (!vfsuid_valid(i_uid_into_vfsuid(mnt_userns, inode)) ||
-	    !vfsgid_valid(i_gid_into_vfsgid(mnt_userns, inode)))
+	if (!vfsuid_valid(i_uid_into_vfsuid(idmap, inode)) ||
+	    !vfsgid_valid(i_gid_into_vfsgid(idmap, inode)))
 		return -EOVERFLOW;
 
 	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 
-	error = inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
+	error = inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
 	if (error)
 		return error;
 	if (IS_APPEND(dir))
 		return -EPERM;
 
-	if (check_sticky(mnt_userns, dir, inode) || IS_APPEND(inode) ||
+	if (check_sticky(idmap, dir, inode) || IS_APPEND(inode) ||
 	    IS_IMMUTABLE(inode) || IS_SWAPFILE(inode) ||
-	    HAS_UNMAPPED_ID(mnt_userns, inode))
+	    HAS_UNMAPPED_ID(idmap, inode))
 		return -EPERM;
 	if (isdir) {
 		if (!d_is_dir(victim))
@@ -2966,7 +2966,7 @@ static int may_delete(struct user_namespace *mnt_userns, struct inode *dir,
  *  4. We should have write and exec permissions on dir
  *  5. We can't do it if dir is immutable (done in permission())
  */
-static inline int may_create(struct user_namespace *mnt_userns,
+static inline int may_create(struct mnt_idmap *idmap,
 			     struct inode *dir, struct dentry *child)
 {
 	audit_inode_child(dir, child, AUDIT_TYPE_CHILD_CREATE);
@@ -2974,10 +2974,10 @@ static inline int may_create(struct user_namespace *mnt_userns,
 		return -EEXIST;
 	if (IS_DEADDIR(dir))
 		return -ENOENT;
-	if (!fsuidgid_has_mapping(dir->i_sb, mnt_userns))
+	if (!fsuidgid_has_mapping(dir->i_sb, idmap))
 		return -EOVERFLOW;
 
-	return inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
+	return inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
 }
 
 /*
@@ -3045,7 +3045,7 @@ static inline umode_t mode_strip_umask(const struct inode *dir, umode_t mode)
 
 /**
  * vfs_prepare_mode - prepare the mode to be used for a new inode
- * @mnt_userns:		user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dir:	parent directory of the new inode
  * @mode:	mode of the new inode
  * @mask_perms:	allowed permission by the vfs
@@ -3066,11 +3066,11 @@ static inline umode_t mode_strip_umask(const struct inode *dir, umode_t mode)
  *
  * Returns: mode to be passed to the filesystem
  */
-static inline umode_t vfs_prepare_mode(struct user_namespace *mnt_userns,
+static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
 				       const struct inode *dir, umode_t mode,
 				       umode_t mask_perms, umode_t type)
 {
-	mode = mode_strip_sgid(mnt_userns, dir, mode);
+	mode = mode_strip_sgid(idmap, dir, mode);
 	mode = mode_strip_umask(dir, mode);
 
 	/*
@@ -3085,7 +3085,7 @@ static inline umode_t vfs_prepare_mode(struct user_namespace *mnt_userns,
 
 /**
  * vfs_create - create new file
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dir:	inode of @dentry
  * @dentry:	pointer to dentry of the base directory
  * @mode:	mode of the new file
@@ -3093,27 +3093,29 @@ static inline umode_t vfs_prepare_mode(struct user_namespace *mnt_userns,
  *
  * Create a new file.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-int vfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+int vfs_create(struct mnt_idmap *idmap, struct inode *dir,
 	       struct dentry *dentry, umode_t mode, bool want_excl)
 {
-	int error = may_create(mnt_userns, dir, dentry);
+	int error;
+
+	error = may_create(idmap, dir, dentry);
 	if (error)
 		return error;
 
 	if (!dir->i_op->create)
 		return -EACCES;	/* shouldn't it be ENOSYS? */
 
-	mode = vfs_prepare_mode(mnt_userns, dir, mode, S_IALLUGO, S_IFREG);
+	mode = vfs_prepare_mode(idmap, dir, mode, S_IALLUGO, S_IFREG);
 	error = security_inode_create(dir, dentry, mode);
 	if (error)
 		return error;
-	error = dir->i_op->create(mnt_userns, dir, dentry, mode, want_excl);
+	error = dir->i_op->create(idmap, dir, dentry, mode, want_excl);
 	if (!error)
 		fsnotify_create(dir, dentry);
 	return error;
@@ -3125,7 +3127,7 @@ int vfs_mkobj(struct dentry *dentry, umode_t mode,
 		void *arg)
 {
 	struct inode *dir = dentry->d_parent->d_inode;
-	int error = may_create(&init_user_ns, dir, dentry);
+	int error = may_create(&nop_mnt_idmap, dir, dentry);
 	if (error)
 		return error;
 
@@ -3147,7 +3149,7 @@ bool may_open_dev(const struct path *path)
 		!(path->mnt->mnt_sb->s_iflags & SB_I_NODEV);
 }
 
-static int may_open(struct user_namespace *mnt_userns, const struct path *path,
+static int may_open(struct mnt_idmap *idmap, const struct path *path,
 		    int acc_mode, int flag)
 {
 	struct dentry *dentry = path->dentry;
@@ -3183,7 +3185,7 @@ static int may_open(struct user_namespace *mnt_userns, const struct path *path,
 		break;
 	}
 
-	error = inode_permission(mnt_userns, inode, MAY_OPEN | acc_mode);
+	error = inode_permission(idmap, inode, MAY_OPEN | acc_mode);
 	if (error)
 		return error;
 
@@ -3198,13 +3200,13 @@ static int may_open(struct user_namespace *mnt_userns, const struct path *path,
 	}
 
 	/* O_NOATIME can only be set by the owner or superuser */
-	if (flag & O_NOATIME && !inode_owner_or_capable(mnt_userns, inode))
+	if (flag & O_NOATIME && !inode_owner_or_capable(idmap, inode))
 		return -EPERM;
 
 	return 0;
 }
 
-static int handle_truncate(struct user_namespace *mnt_userns, struct file *filp)
+static int handle_truncate(struct mnt_idmap *idmap, struct file *filp)
 {
 	const struct path *path = &filp->f_path;
 	struct inode *inode = path->dentry->d_inode;
@@ -3214,7 +3216,7 @@ static int handle_truncate(struct user_namespace *mnt_userns, struct file *filp)
 
 	error = security_file_truncate(filp);
 	if (!error) {
-		error = do_truncate(mnt_userns, path->dentry, 0,
+		error = do_truncate(idmap, path->dentry, 0,
 				    ATTR_MTIME|ATTR_CTIME|ATTR_OPEN,
 				    filp);
 	}
@@ -3229,7 +3231,7 @@ static inline int open_to_namei_flags(int flag)
 	return flag;
 }
 
-static int may_o_create(struct user_namespace *mnt_userns,
+static int may_o_create(struct mnt_idmap *idmap,
 			const struct path *dir, struct dentry *dentry,
 			umode_t mode)
 {
@@ -3237,10 +3239,10 @@ static int may_o_create(struct user_namespace *mnt_userns,
 	if (error)
 		return error;
 
-	if (!fsuidgid_has_mapping(dir->dentry->d_sb, mnt_userns))
+	if (!fsuidgid_has_mapping(dir->dentry->d_sb, idmap))
 		return -EOVERFLOW;
 
-	error = inode_permission(mnt_userns, dir->dentry->d_inode,
+	error = inode_permission(idmap, dir->dentry->d_inode,
 				 MAY_WRITE | MAY_EXEC);
 	if (error)
 		return error;
@@ -3320,7 +3322,7 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 				  const struct open_flags *op,
 				  bool got_write)
 {
-	struct user_namespace *mnt_userns;
+	struct mnt_idmap *idmap;
 	struct dentry *dir = nd->path.dentry;
 	struct inode *dir_inode = dir->d_inode;
 	int open_flag = op->open_flag;
@@ -3368,13 +3370,13 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 	 */
 	if (unlikely(!got_write))
 		open_flag &= ~O_TRUNC;
-	mnt_userns = mnt_user_ns(nd->path.mnt);
+	idmap = mnt_idmap(nd->path.mnt);
 	if (open_flag & O_CREAT) {
 		if (open_flag & O_EXCL)
 			open_flag &= ~O_TRUNC;
-		mode = vfs_prepare_mode(mnt_userns, dir->d_inode, mode, mode, mode);
+		mode = vfs_prepare_mode(idmap, dir->d_inode, mode, mode, mode);
 		if (likely(got_write))
-			create_error = may_o_create(mnt_userns, &nd->path,
+			create_error = may_o_create(idmap, &nd->path,
 						    dentry, mode);
 		else
 			create_error = -EROFS;
@@ -3411,7 +3413,7 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 			goto out_dput;
 		}
 
-		error = dir_inode->i_op->create(mnt_userns, dir_inode, dentry,
+		error = dir_inode->i_op->create(idmap, dir_inode, dentry,
 						mode, open_flag & O_EXCL);
 		if (error)
 			goto out_dput;
@@ -3514,7 +3516,7 @@ finish_lookup:
 static int do_open(struct nameidata *nd,
 		   struct file *file, const struct open_flags *op)
 {
-	struct user_namespace *mnt_userns;
+	struct mnt_idmap *idmap;
 	int open_flag = op->open_flag;
 	bool do_truncate;
 	int acc_mode;
@@ -3527,13 +3529,13 @@ static int do_open(struct nameidata *nd,
 	}
 	if (!(file->f_mode & FMODE_CREATED))
 		audit_inode(nd->name, nd->path.dentry, 0);
-	mnt_userns = mnt_user_ns(nd->path.mnt);
+	idmap = mnt_idmap(nd->path.mnt);
 	if (open_flag & O_CREAT) {
 		if ((open_flag & O_EXCL) && !(file->f_mode & FMODE_CREATED))
 			return -EEXIST;
 		if (d_is_dir(nd->path.dentry))
 			return -EISDIR;
-		error = may_create_in_sticky(mnt_userns, nd,
+		error = may_create_in_sticky(idmap, nd,
 					     d_backing_inode(nd->path.dentry));
 		if (unlikely(error))
 			return error;
@@ -3553,13 +3555,13 @@ static int do_open(struct nameidata *nd,
 			return error;
 		do_truncate = true;
 	}
-	error = may_open(mnt_userns, &nd->path, acc_mode, open_flag);
+	error = may_open(idmap, &nd->path, acc_mode, open_flag);
 	if (!error && !(file->f_mode & FMODE_OPENED))
 		error = vfs_open(&nd->path, file);
 	if (!error)
 		error = ima_file_check(file, op->acc_mode);
 	if (!error && do_truncate)
-		error = handle_truncate(mnt_userns, file);
+		error = handle_truncate(idmap, file);
 	if (unlikely(error > 0)) {
 		WARN_ON(1);
 		error = -EINVAL;
@@ -3571,20 +3573,20 @@ static int do_open(struct nameidata *nd,
 
 /**
  * vfs_tmpfile - create tmpfile
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dentry:	pointer to dentry of the base directory
  * @mode:	mode of the new tmpfile
  * @open_flag:	flags
  *
  * Create a temporary file.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-static int vfs_tmpfile(struct user_namespace *mnt_userns,
+static int vfs_tmpfile(struct mnt_idmap *idmap,
 		       const struct path *parentpath,
 		       struct file *file, umode_t mode)
 {
@@ -3595,7 +3597,7 @@ static int vfs_tmpfile(struct user_namespace *mnt_userns,
 	int open_flag = file->f_flags;
 
 	/* we want directory to be writable */
-	error = inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
+	error = inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
 	if (error)
 		return error;
 	if (!dir->i_op->tmpfile)
@@ -3605,13 +3607,13 @@ static int vfs_tmpfile(struct user_namespace *mnt_userns,
 		return -ENOMEM;
 	file->f_path.mnt = parentpath->mnt;
 	file->f_path.dentry = child;
-	mode = vfs_prepare_mode(mnt_userns, dir, mode, mode, mode);
-	error = dir->i_op->tmpfile(mnt_userns, dir, file, mode);
+	mode = vfs_prepare_mode(idmap, dir, mode, mode, mode);
+	error = dir->i_op->tmpfile(idmap, dir, file, mode);
 	dput(child);
 	if (error)
 		return error;
 	/* Don't check for other permissions, the inode was just created */
-	error = may_open(mnt_userns, &file->f_path, 0, file->f_flags);
+	error = may_open(idmap, &file->f_path, 0, file->f_flags);
 	if (error)
 		return error;
 	inode = file_inode(file);
@@ -3620,13 +3622,13 @@ static int vfs_tmpfile(struct user_namespace *mnt_userns,
 		inode->i_state |= I_LINKABLE;
 		spin_unlock(&inode->i_lock);
 	}
-	ima_post_create_tmpfile(mnt_userns, inode);
+	ima_post_create_tmpfile(idmap, inode);
 	return 0;
 }
 
 /**
  * vfs_tmpfile_open - open a tmpfile for kernel internal use
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @parentpath:	path of the base directory
  * @mode:	mode of the new tmpfile
  * @open_flag:	flags
@@ -3636,7 +3638,7 @@ static int vfs_tmpfile(struct user_namespace *mnt_userns,
  * hence this is only for kernel internal use, and must not be installed into
  * file tables or such.
  */
-struct file *vfs_tmpfile_open(struct user_namespace *mnt_userns,
+struct file *vfs_tmpfile_open(struct mnt_idmap *idmap,
 			  const struct path *parentpath,
 			  umode_t mode, int open_flag, const struct cred *cred)
 {
@@ -3645,7 +3647,7 @@ struct file *vfs_tmpfile_open(struct user_namespace *mnt_userns,
 
 	file = alloc_empty_file_noaccount(open_flag, cred);
 	if (!IS_ERR(file)) {
-		error = vfs_tmpfile(mnt_userns, parentpath, file, mode);
+		error = vfs_tmpfile(idmap, parentpath, file, mode);
 		if (error) {
 			fput(file);
 			file = ERR_PTR(error);
@@ -3659,7 +3661,6 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags,
 		const struct open_flags *op,
 		struct file *file)
 {
-	struct user_namespace *mnt_userns;
 	struct path path;
 	int error = path_lookupat(nd, flags | LOOKUP_DIRECTORY, &path);
 
@@ -3668,8 +3669,7 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags,
 	error = mnt_want_write(path.mnt);
 	if (unlikely(error))
 		goto out;
-	mnt_userns = mnt_user_ns(path.mnt);
-	error = vfs_tmpfile(mnt_userns, &path, file, op->mode);
+	error = vfs_tmpfile(mnt_idmap(path.mnt), &path, file, op->mode);
 	if (error)
 		goto out2;
 	audit_inode(nd->name, file->f_path.dentry, 0);
@@ -3874,7 +3874,7 @@ EXPORT_SYMBOL(user_path_create);
 
 /**
  * vfs_mknod - create device node or file
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dir:	inode of @dentry
  * @dentry:	pointer to dentry of the base directory
  * @mode:	mode of the new device node or file
@@ -3882,17 +3882,17 @@ EXPORT_SYMBOL(user_path_create);
  *
  * Create a device node or file.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-int vfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+int vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	      struct dentry *dentry, umode_t mode, dev_t dev)
 {
 	bool is_whiteout = S_ISCHR(mode) && dev == WHITEOUT_DEV;
-	int error = may_create(mnt_userns, dir, dentry);
+	int error = may_create(idmap, dir, dentry);
 
 	if (error)
 		return error;
@@ -3904,7 +3904,7 @@ int vfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	if (!dir->i_op->mknod)
 		return -EPERM;
 
-	mode = vfs_prepare_mode(mnt_userns, dir, mode, mode, mode);
+	mode = vfs_prepare_mode(idmap, dir, mode, mode, mode);
 	error = devcgroup_inode_mknod(mode, dev);
 	if (error)
 		return error;
@@ -3913,7 +3913,7 @@ int vfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	if (error)
 		return error;
 
-	error = dir->i_op->mknod(mnt_userns, dir, dentry, mode, dev);
+	error = dir->i_op->mknod(idmap, dir, dentry, mode, dev);
 	if (!error)
 		fsnotify_create(dir, dentry);
 	return error;
@@ -3940,7 +3940,7 @@ static int may_mknod(umode_t mode)
 static int do_mknodat(int dfd, struct filename *name, umode_t mode,
 		unsigned int dev)
 {
-	struct user_namespace *mnt_userns;
+	struct mnt_idmap *idmap;
 	struct dentry *dentry;
 	struct path path;
 	int error;
@@ -3960,20 +3960,20 @@ retry:
 	if (error)
 		goto out2;
 
-	mnt_userns = mnt_user_ns(path.mnt);
+	idmap = mnt_idmap(path.mnt);
 	switch (mode & S_IFMT) {
 		case 0: case S_IFREG:
-			error = vfs_create(mnt_userns, path.dentry->d_inode,
+			error = vfs_create(idmap, path.dentry->d_inode,
 					   dentry, mode, true);
 			if (!error)
-				ima_post_path_mknod(mnt_userns, dentry);
+				ima_post_path_mknod(idmap, dentry);
 			break;
 		case S_IFCHR: case S_IFBLK:
-			error = vfs_mknod(mnt_userns, path.dentry->d_inode,
+			error = vfs_mknod(idmap, path.dentry->d_inode,
 					  dentry, mode, new_decode_dev(dev));
 			break;
 		case S_IFIFO: case S_IFSOCK:
-			error = vfs_mknod(mnt_userns, path.dentry->d_inode,
+			error = vfs_mknod(idmap, path.dentry->d_inode,
 					  dentry, mode, 0);
 			break;
 	}
@@ -4001,32 +4001,33 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d
 
 /**
  * vfs_mkdir - create directory
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dir:	inode of @dentry
  * @dentry:	pointer to dentry of the base directory
  * @mode:	mode of the new directory
  *
  * Create a directory.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-int vfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+int vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	      struct dentry *dentry, umode_t mode)
 {
-	int error = may_create(mnt_userns, dir, dentry);
+	int error;
 	unsigned max_links = dir->i_sb->s_max_links;
 
+	error = may_create(idmap, dir, dentry);
 	if (error)
 		return error;
 
 	if (!dir->i_op->mkdir)
 		return -EPERM;
 
-	mode = vfs_prepare_mode(mnt_userns, dir, mode, S_IRWXUGO | S_ISVTX, 0);
+	mode = vfs_prepare_mode(idmap, dir, mode, S_IRWXUGO | S_ISVTX, 0);
 	error = security_inode_mkdir(dir, dentry, mode);
 	if (error)
 		return error;
@@ -4034,7 +4035,7 @@ int vfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 	if (max_links && dir->i_nlink >= max_links)
 		return -EMLINK;
 
-	error = dir->i_op->mkdir(mnt_userns, dir, dentry, mode);
+	error = dir->i_op->mkdir(idmap, dir, dentry, mode);
 	if (!error)
 		fsnotify_mkdir(dir, dentry);
 	return error;
@@ -4057,10 +4058,8 @@ retry:
 	error = security_path_mkdir(&path, dentry,
 			mode_strip_umask(path.dentry->d_inode, mode));
 	if (!error) {
-		struct user_namespace *mnt_userns;
-		mnt_userns = mnt_user_ns(path.mnt);
-		error = vfs_mkdir(mnt_userns, path.dentry->d_inode, dentry,
-				  mode);
+		error = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
+				  dentry, mode);
 	}
 	done_path_create(&path, dentry);
 	if (retry_estale(error, lookup_flags)) {
@@ -4084,22 +4083,22 @@ SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode)
 
 /**
  * vfs_rmdir - remove directory
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dir:	inode of @dentry
  * @dentry:	pointer to dentry of the base directory
  *
  * Remove a directory.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-int vfs_rmdir(struct user_namespace *mnt_userns, struct inode *dir,
+int vfs_rmdir(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry)
 {
-	int error = may_delete(mnt_userns, dir, dentry, 1);
+	int error = may_delete(idmap, dir, dentry, 1);
 
 	if (error)
 		return error;
@@ -4139,7 +4138,6 @@ EXPORT_SYMBOL(vfs_rmdir);
 
 int do_rmdir(int dfd, struct filename *name)
 {
-	struct user_namespace *mnt_userns;
 	int error;
 	struct dentry *dentry;
 	struct path path;
@@ -4179,8 +4177,7 @@ retry:
 	error = security_path_rmdir(&path, dentry);
 	if (error)
 		goto exit4;
-	mnt_userns = mnt_user_ns(path.mnt);
-	error = vfs_rmdir(mnt_userns, path.dentry->d_inode, dentry);
+	error = vfs_rmdir(mnt_idmap(path.mnt), path.dentry->d_inode, dentry);
 exit4:
 	dput(dentry);
 exit3:
@@ -4204,7 +4201,7 @@ SYSCALL_DEFINE1(rmdir, const char __user *, pathname)
 
 /**
  * vfs_unlink - unlink a filesystem object
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dir:	parent directory
  * @dentry:	victim
  * @delegated_inode: returns victim inode, if the inode is delegated.
@@ -4221,17 +4218,17 @@ SYSCALL_DEFINE1(rmdir, const char __user *, pathname)
  * be appropriate for callers that expect the underlying filesystem not
  * to be NFS exported.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-int vfs_unlink(struct user_namespace *mnt_userns, struct inode *dir,
+int vfs_unlink(struct mnt_idmap *idmap, struct inode *dir,
 	       struct dentry *dentry, struct inode **delegated_inode)
 {
 	struct inode *target = dentry->d_inode;
-	int error = may_delete(mnt_userns, dir, dentry, 0);
+	int error = may_delete(idmap, dir, dentry, 0);
 
 	if (error)
 		return error;
@@ -4305,7 +4302,6 @@ retry_deleg:
 	dentry = __lookup_hash(&last, path.dentry, lookup_flags);
 	error = PTR_ERR(dentry);
 	if (!IS_ERR(dentry)) {
-		struct user_namespace *mnt_userns;
 
 		/* Why not before? Because we want correct error value */
 		if (last.name[last.len])
@@ -4317,9 +4313,8 @@ retry_deleg:
 		error = security_path_unlink(&path, dentry);
 		if (error)
 			goto exit3;
-		mnt_userns = mnt_user_ns(path.mnt);
-		error = vfs_unlink(mnt_userns, path.dentry->d_inode, dentry,
-				   &delegated_inode);
+		error = vfs_unlink(mnt_idmap(path.mnt), path.dentry->d_inode,
+				   dentry, &delegated_inode);
 exit3:
 		dput(dentry);
 	}
@@ -4371,24 +4366,25 @@ SYSCALL_DEFINE1(unlink, const char __user *, pathname)
 
 /**
  * vfs_symlink - create symlink
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dir:	inode of @dentry
  * @dentry:	pointer to dentry of the base directory
  * @oldname:	name of the file to link to
  *
  * Create a symlink.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-int vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+int vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 		struct dentry *dentry, const char *oldname)
 {
-	int error = may_create(mnt_userns, dir, dentry);
+	int error;
 
+	error = may_create(idmap, dir, dentry);
 	if (error)
 		return error;
 
@@ -4399,7 +4395,7 @@ int vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 	if (error)
 		return error;
 
-	error = dir->i_op->symlink(mnt_userns, dir, dentry, oldname);
+	error = dir->i_op->symlink(idmap, dir, dentry, oldname);
 	if (!error)
 		fsnotify_create(dir, dentry);
 	return error;
@@ -4424,13 +4420,9 @@ retry:
 		goto out_putnames;
 
 	error = security_path_symlink(&path, dentry, from->name);
-	if (!error) {
-		struct user_namespace *mnt_userns;
-
-		mnt_userns = mnt_user_ns(path.mnt);
-		error = vfs_symlink(mnt_userns, path.dentry->d_inode, dentry,
-				    from->name);
-	}
+	if (!error)
+		error = vfs_symlink(mnt_idmap(path.mnt), path.dentry->d_inode,
+				    dentry, from->name);
 	done_path_create(&path, dentry);
 	if (retry_estale(error, lookup_flags)) {
 		lookup_flags |= LOOKUP_REVAL;
@@ -4456,7 +4448,7 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn
 /**
  * vfs_link - create a new link
  * @old_dentry:	object to be linked
- * @mnt_userns:	the user namespace of the mount
+ * @idmap:	idmap of the mount
  * @dir:	new parent
  * @new_dentry:	where to create the new link
  * @delegated_inode: returns inode needing a delegation break
@@ -4473,13 +4465,13 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn
  * be appropriate for callers that expect the underlying filesystem not
  * to be NFS exported.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-int vfs_link(struct dentry *old_dentry, struct user_namespace *mnt_userns,
+int vfs_link(struct dentry *old_dentry, struct mnt_idmap *idmap,
 	     struct inode *dir, struct dentry *new_dentry,
 	     struct inode **delegated_inode)
 {
@@ -4490,7 +4482,7 @@ int vfs_link(struct dentry *old_dentry, struct user_namespace *mnt_userns,
 	if (!inode)
 		return -ENOENT;
 
-	error = may_create(mnt_userns, dir, new_dentry);
+	error = may_create(idmap, dir, new_dentry);
 	if (error)
 		return error;
 
@@ -4507,7 +4499,7 @@ int vfs_link(struct dentry *old_dentry, struct user_namespace *mnt_userns,
 	 * be writen back improperly if their true value is unknown to
 	 * the vfs.
 	 */
-	if (HAS_UNMAPPED_ID(mnt_userns, inode))
+	if (HAS_UNMAPPED_ID(idmap, inode))
 		return -EPERM;
 	if (!dir->i_op->link)
 		return -EPERM;
@@ -4554,7 +4546,7 @@ EXPORT_SYMBOL(vfs_link);
 int do_linkat(int olddfd, struct filename *old, int newdfd,
 	      struct filename *new, int flags)
 {
-	struct user_namespace *mnt_userns;
+	struct mnt_idmap *idmap;
 	struct dentry *new_dentry;
 	struct path old_path, new_path;
 	struct inode *delegated_inode = NULL;
@@ -4591,14 +4583,14 @@ retry:
 	error = -EXDEV;
 	if (old_path.mnt != new_path.mnt)
 		goto out_dput;
-	mnt_userns = mnt_user_ns(new_path.mnt);
-	error = may_linkat(mnt_userns, &old_path);
+	idmap = mnt_idmap(new_path.mnt);
+	error = may_linkat(idmap, &old_path);
 	if (unlikely(error))
 		goto out_dput;
 	error = security_path_link(old_path.dentry, &new_path, new_dentry);
 	if (error)
 		goto out_dput;
-	error = vfs_link(old_path.dentry, mnt_userns, new_path.dentry->d_inode,
+	error = vfs_link(old_path.dentry, idmap, new_path.dentry->d_inode,
 			 new_dentry, &delegated_inode);
 out_dput:
 	done_path_create(&new_path, new_dentry);
@@ -4698,20 +4690,20 @@ int vfs_rename(struct renamedata *rd)
 	if (source == target)
 		return 0;
 
-	error = may_delete(rd->old_mnt_userns, old_dir, old_dentry, is_dir);
+	error = may_delete(rd->old_mnt_idmap, old_dir, old_dentry, is_dir);
 	if (error)
 		return error;
 
 	if (!target) {
-		error = may_create(rd->new_mnt_userns, new_dir, new_dentry);
+		error = may_create(rd->new_mnt_idmap, new_dir, new_dentry);
 	} else {
 		new_is_dir = d_is_dir(new_dentry);
 
 		if (!(flags & RENAME_EXCHANGE))
-			error = may_delete(rd->new_mnt_userns, new_dir,
+			error = may_delete(rd->new_mnt_idmap, new_dir,
 					   new_dentry, is_dir);
 		else
-			error = may_delete(rd->new_mnt_userns, new_dir,
+			error = may_delete(rd->new_mnt_idmap, new_dir,
 					   new_dentry, new_is_dir);
 	}
 	if (error)
@@ -4726,13 +4718,13 @@ int vfs_rename(struct renamedata *rd)
 	 */
 	if (new_dir != old_dir) {
 		if (is_dir) {
-			error = inode_permission(rd->old_mnt_userns, source,
+			error = inode_permission(rd->old_mnt_idmap, source,
 						 MAY_WRITE);
 			if (error)
 				return error;
 		}
 		if ((flags & RENAME_EXCHANGE) && new_is_dir) {
-			error = inode_permission(rd->new_mnt_userns, target,
+			error = inode_permission(rd->new_mnt_idmap, target,
 						 MAY_WRITE);
 			if (error)
 				return error;
@@ -4777,7 +4769,7 @@ int vfs_rename(struct renamedata *rd)
 		if (error)
 			goto out;
 	}
-	error = old_dir->i_op->rename(rd->new_mnt_userns, old_dir, old_dentry,
+	error = old_dir->i_op->rename(rd->new_mnt_idmap, old_dir, old_dentry,
 				      new_dir, new_dentry, flags);
 	if (error)
 		goto out;
@@ -4922,10 +4914,10 @@ retry_deleg:
 
 	rd.old_dir	   = old_path.dentry->d_inode;
 	rd.old_dentry	   = old_dentry;
-	rd.old_mnt_userns  = mnt_user_ns(old_path.mnt);
+	rd.old_mnt_idmap   = mnt_idmap(old_path.mnt);
 	rd.new_dir	   = new_path.dentry->d_inode;
 	rd.new_dentry	   = new_dentry;
-	rd.new_mnt_userns  = mnt_user_ns(new_path.mnt);
+	rd.new_mnt_idmap   = mnt_idmap(new_path.mnt);
 	rd.delegated_inode = &delegated_inode;
 	rd.flags	   = flags;
 	error = vfs_rename(&rd);
diff --git a/fs/namespace.c b/fs/namespace.c
index ab467ee58341..5927d90e24a0 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -75,22 +75,6 @@ static DECLARE_RWSEM(namespace_sem);
 static HLIST_HEAD(unmounted);	/* protected by namespace_sem */
 static LIST_HEAD(ex_mountpoints); /* protected by namespace_sem */
 
-struct mnt_idmap {
-	struct user_namespace *owner;
-	refcount_t count;
-};
-
-/*
- * Carries the initial idmapping of 0:0:4294967295 which is an identity
- * mapping. This means that {g,u}id 0 is mapped to {g,u}id 0, {g,u}id 1 is
- * mapped to {g,u}id 1, [...], {g,u}id 1000 to {g,u}id 1000, [...].
- */
-struct mnt_idmap nop_mnt_idmap = {
-	.owner	= &init_user_ns,
-	.count	= REFCOUNT_INIT(1),
-};
-EXPORT_SYMBOL_GPL(nop_mnt_idmap);
-
 struct mount_kattr {
 	unsigned int attr_set;
 	unsigned int attr_clr;
@@ -210,104 +194,6 @@ int mnt_get_count(struct mount *mnt)
 #endif
 }
 
-/**
- * mnt_idmap_owner - retrieve owner of the mount's idmapping
- * @idmap: mount idmapping
- *
- * This helper will go away once the conversion to use struct mnt_idmap
- * everywhere has finished at which point the helper will be unexported.
- *
- * Only code that needs to perform permission checks based on the owner of the
- * idmapping will get access to it. All other code will solely rely on
- * idmappings. This will get us type safety so it's impossible to conflate
- * filesystems idmappings with mount idmappings.
- *
- * Return: The owner of the idmapping.
- */
-struct user_namespace *mnt_idmap_owner(const struct mnt_idmap *idmap)
-{
-	return idmap->owner;
-}
-EXPORT_SYMBOL_GPL(mnt_idmap_owner);
-
-/**
- * mnt_user_ns - retrieve owner of an idmapped mount
- * @mnt: the relevant vfsmount
- *
- * This helper will go away once the conversion to use struct mnt_idmap
- * everywhere has finished at which point the helper will be unexported.
- *
- * Only code that needs to perform permission checks based on the owner of the
- * idmapping will get access to it. All other code will solely rely on
- * idmappings. This will get us type safety so it's impossible to conflate
- * filesystems idmappings with mount idmappings.
- *
- * Return: The owner of the idmapped.
- */
-struct user_namespace *mnt_user_ns(const struct vfsmount *mnt)
-{
-	struct mnt_idmap *idmap = mnt_idmap(mnt);
-
-	/* Return the actual owner of the filesystem instead of the nop. */
-	if (idmap == &nop_mnt_idmap &&
-	    !initial_idmapping(mnt->mnt_sb->s_user_ns))
-		return mnt->mnt_sb->s_user_ns;
-	return mnt_idmap_owner(idmap);
-}
-EXPORT_SYMBOL_GPL(mnt_user_ns);
-
-/**
- * alloc_mnt_idmap - allocate a new idmapping for the mount
- * @mnt_userns: owning userns of the idmapping
- *
- * Allocate a new struct mnt_idmap which carries the idmapping of the mount.
- *
- * Return: On success a new idmap, on error an error pointer is returned.
- */
-static struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns)
-{
-	struct mnt_idmap *idmap;
-
-	idmap = kzalloc(sizeof(struct mnt_idmap), GFP_KERNEL_ACCOUNT);
-	if (!idmap)
-		return ERR_PTR(-ENOMEM);
-
-	idmap->owner = get_user_ns(mnt_userns);
-	refcount_set(&idmap->count, 1);
-	return idmap;
-}
-
-/**
- * mnt_idmap_get - get a reference to an idmapping
- * @idmap: the idmap to bump the reference on
- *
- * If @idmap is not the @nop_mnt_idmap bump the reference count.
- *
- * Return: @idmap with reference count bumped if @not_mnt_idmap isn't passed.
- */
-static inline struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap)
-{
-	if (idmap != &nop_mnt_idmap)
-		refcount_inc(&idmap->count);
-
-	return idmap;
-}
-
-/**
- * mnt_idmap_put - put a reference to an idmapping
- * @idmap: the idmap to put the reference on
- *
- * If this is a non-initial idmapping, put the reference count when a mount is
- * released and free it if we're the last user.
- */
-static inline void mnt_idmap_put(struct mnt_idmap *idmap)
-{
-	if (idmap != &nop_mnt_idmap && refcount_dec_and_test(&idmap->count)) {
-		put_user_ns(idmap->owner);
-		kfree(idmap);
-	}
-}
-
 static struct mount *alloc_vfsmnt(const char *name)
 {
 	struct mount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
@@ -4094,7 +3980,7 @@ static int can_idmap_mount(const struct mount_kattr *kattr, struct mount *mnt)
 	 * Creating an idmapped mount with the filesystem wide idmapping
 	 * doesn't make sense so block that. We don't allow mushy semantics.
 	 */
-	if (mnt_idmap_owner(kattr->mnt_idmap) == fs_userns)
+	if (!check_fsmapping(kattr->mnt_idmap, m->mnt_sb))
 		return -EINVAL;
 
 	/*
@@ -4340,7 +4226,7 @@ static int build_mount_idmapped(const struct mount_attr *attr, size_t usize,
 	 * result.
 	 */
 	mnt_userns = container_of(ns, struct user_namespace, ns);
-	if (initial_idmapping(mnt_userns)) {
+	if (mnt_userns == &init_user_ns) {
 		err = -EPERM;
 		goto out_fput;
 	}
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index f7e4a88d5d92..f8e420464b77 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2296,7 +2296,7 @@ EXPORT_SYMBOL_GPL(nfs_instantiate);
  * that the operation succeeded on the server, but an error in the
  * reply path made it appear to have failed.
  */
-int nfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+int nfs_create(struct mnt_idmap *idmap, struct inode *dir,
 	       struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct iattr attr;
@@ -2325,7 +2325,7 @@ EXPORT_SYMBOL_GPL(nfs_create);
  * See comments for nfs_proc_create regarding failed operations.
  */
 int
-nfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+nfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	  struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct iattr attr;
@@ -2352,7 +2352,7 @@ EXPORT_SYMBOL_GPL(nfs_mknod);
 /*
  * See comments for nfs_proc_create regarding failed operations.
  */
-int nfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+int nfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	      struct dentry *dentry, umode_t mode)
 {
 	struct iattr attr;
@@ -2524,7 +2524,7 @@ EXPORT_SYMBOL_GPL(nfs_unlink);
  * now have a new file handle and can instantiate an in-core NFS inode
  * and move the raw page into its mapping.
  */
-int nfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+int nfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 		struct dentry *dentry, const char *symname)
 {
 	struct page *page;
@@ -2642,7 +2642,7 @@ nfs_unblock_rename(struct rpc_task *task, struct nfs_renamedata *data)
  * If these conditions are met, we can drop the dentries before doing
  * the rename.
  */
-int nfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+int nfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 	       struct dentry *old_dentry, struct inode *new_dir,
 	       struct dentry *new_dentry, unsigned int flags)
 {
@@ -3262,7 +3262,7 @@ static int nfs_execute_ok(struct inode *inode, int mask)
 	return ret;
 }
 
-int nfs_permission(struct user_namespace *mnt_userns,
+int nfs_permission(struct mnt_idmap *idmap,
 		   struct inode *inode,
 		   int mask)
 {
@@ -3313,7 +3313,7 @@ out_notsup:
 	res = nfs_revalidate_inode(inode, NFS_INO_INVALID_MODE |
 						  NFS_INO_INVALID_OTHER);
 	if (res == 0)
-		res = generic_permission(&init_user_ns, inode, mask);
+		res = generic_permission(&nop_mnt_idmap, inode, mask);
 	goto out;
 }
 EXPORT_SYMBOL_GPL(nfs_permission);
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 756ad4fa6f2a..222a28320e1c 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -606,7 +606,7 @@ EXPORT_SYMBOL_GPL(nfs_fhget);
 #define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET|ATTR_FILE|ATTR_OPEN)
 
 int
-nfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+nfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	    struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -830,7 +830,7 @@ static u32 nfs_get_valid_attrmask(struct inode *inode)
 	return reply_mask;
 }
 
-int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int nfs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
@@ -912,7 +912,7 @@ out_no_revalidate:
 	/* Only return attributes that were revalidated. */
 	stat->result_mask = nfs_get_valid_attrmask(inode) | request_mask;
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
 	stat->change_cookie = inode_peek_iversion_raw(inode);
 	stat->attributes_mask |= STATX_ATTR_CHANGE_MONOTONIC;
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index ae7d4a8c728c..41468c21291d 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -384,18 +384,18 @@ extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
 					   struct shrink_control *sc);
 struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
 void nfs_d_prune_case_insensitive_aliases(struct inode *inode);
-int nfs_create(struct user_namespace *, struct inode *, struct dentry *,
+int nfs_create(struct mnt_idmap *, struct inode *, struct dentry *,
 	       umode_t, bool);
-int nfs_mkdir(struct user_namespace *, struct inode *, struct dentry *,
+int nfs_mkdir(struct mnt_idmap *, struct inode *, struct dentry *,
 	      umode_t);
 int nfs_rmdir(struct inode *, struct dentry *);
 int nfs_unlink(struct inode *, struct dentry *);
-int nfs_symlink(struct user_namespace *, struct inode *, struct dentry *,
+int nfs_symlink(struct mnt_idmap *, struct inode *, struct dentry *,
 		const char *);
 int nfs_link(struct dentry *, struct inode *, struct dentry *);
-int nfs_mknod(struct user_namespace *, struct inode *, struct dentry *, umode_t,
+int nfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *, umode_t,
 	      dev_t);
-int nfs_rename(struct user_namespace *, struct inode *, struct dentry *,
+int nfs_rename(struct mnt_idmap *, struct inode *, struct dentry *,
 	       struct inode *, struct dentry *, unsigned int);
 
 #ifdef CONFIG_NFS_V4_2
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index b0ef7e7ddb30..19d51ebf842c 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -208,23 +208,23 @@ out_fc:
 }
 
 static int
-nfs_namespace_getattr(struct user_namespace *mnt_userns,
+nfs_namespace_getattr(struct mnt_idmap *idmap,
 		      const struct path *path, struct kstat *stat,
 		      u32 request_mask, unsigned int query_flags)
 {
 	if (NFS_FH(d_inode(path->dentry))->size != 0)
-		return nfs_getattr(mnt_userns, path, stat, request_mask,
+		return nfs_getattr(idmap, path, stat, request_mask,
 				   query_flags);
-	generic_fillattr(&init_user_ns, d_inode(path->dentry), stat);
+	generic_fillattr(&nop_mnt_idmap, d_inode(path->dentry), stat);
 	return 0;
 }
 
 static int
-nfs_namespace_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+nfs_namespace_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		      struct iattr *attr)
 {
 	if (NFS_FH(d_inode(dentry))->size != 0)
-		return nfs_setattr(mnt_userns, dentry, attr);
+		return nfs_setattr(idmap, dentry, attr);
 	return -EACCES;
 }
 
diff --git a/fs/nfs/nfs3_fs.h b/fs/nfs/nfs3_fs.h
index df9ca56db347..4fa37dc038b5 100644
--- a/fs/nfs/nfs3_fs.h
+++ b/fs/nfs/nfs3_fs.h
@@ -12,7 +12,7 @@
  */
 #ifdef CONFIG_NFS_V3_ACL
 extern struct posix_acl *nfs3_get_acl(struct inode *inode, int type, bool rcu);
-extern int nfs3_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+extern int nfs3_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 			struct posix_acl *acl, int type);
 extern int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 		struct posix_acl *dfacl);
diff --git a/fs/nfs/nfs3acl.c b/fs/nfs/nfs3acl.c
index 74d11e3c4205..1247f544a440 100644
--- a/fs/nfs/nfs3acl.c
+++ b/fs/nfs/nfs3acl.c
@@ -255,7 +255,7 @@ int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 
 }
 
-int nfs3_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int nfs3_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type)
 {
 	struct posix_acl *orig = acl, *dfacl = NULL, *alloc;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 40d749f29ed3..d9c332019d06 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7692,7 +7692,7 @@ nfs4_release_lockowner(struct nfs_server *server, struct nfs4_lock_state *lsp)
 #define XATTR_NAME_NFSV4_ACL "system.nfs4_acl"
 
 static int nfs4_xattr_set_nfs4_acl(const struct xattr_handler *handler,
-				   struct user_namespace *mnt_userns,
+				   struct mnt_idmap *idmap,
 				   struct dentry *unused, struct inode *inode,
 				   const char *key, const void *buf,
 				   size_t buflen, int flags)
@@ -7716,7 +7716,7 @@ static bool nfs4_xattr_list_nfs4_acl(struct dentry *dentry)
 #define XATTR_NAME_NFSV4_DACL "system.nfs4_dacl"
 
 static int nfs4_xattr_set_nfs4_dacl(const struct xattr_handler *handler,
-				    struct user_namespace *mnt_userns,
+				    struct mnt_idmap *idmap,
 				    struct dentry *unused, struct inode *inode,
 				    const char *key, const void *buf,
 				    size_t buflen, int flags)
@@ -7739,7 +7739,7 @@ static bool nfs4_xattr_list_nfs4_dacl(struct dentry *dentry)
 #define XATTR_NAME_NFSV4_SACL "system.nfs4_sacl"
 
 static int nfs4_xattr_set_nfs4_sacl(const struct xattr_handler *handler,
-				    struct user_namespace *mnt_userns,
+				    struct mnt_idmap *idmap,
 				    struct dentry *unused, struct inode *inode,
 				    const char *key, const void *buf,
 				    size_t buflen, int flags)
@@ -7764,7 +7764,7 @@ static bool nfs4_xattr_list_nfs4_sacl(struct dentry *dentry)
 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
 
 static int nfs4_xattr_set_nfs4_label(const struct xattr_handler *handler,
-				     struct user_namespace *mnt_userns,
+				     struct mnt_idmap *idmap,
 				     struct dentry *unused, struct inode *inode,
 				     const char *key, const void *buf,
 				     size_t buflen, int flags)
@@ -7815,7 +7815,7 @@ nfs4_listxattr_nfs4_label(struct inode *inode, char *list, size_t list_len)
 
 #ifdef CONFIG_NFS_V4_2
 static int nfs4_xattr_set_nfs4_user(const struct xattr_handler *handler,
-				    struct user_namespace *mnt_userns,
+				    struct mnt_idmap *idmap,
 				    struct dentry *unused, struct inode *inode,
 				    const char *key, const void *buf,
 				    size_t buflen, int flags)
diff --git a/fs/nfsd/nfs2acl.c b/fs/nfsd/nfs2acl.c
index 1457f59f447a..995cb2c90b1a 100644
--- a/fs/nfsd/nfs2acl.c
+++ b/fs/nfsd/nfs2acl.c
@@ -113,11 +113,11 @@ static __be32 nfsacld_proc_setacl(struct svc_rqst *rqstp)
 
 	inode_lock(inode);
 
-	error = set_posix_acl(&init_user_ns, fh->fh_dentry, ACL_TYPE_ACCESS,
+	error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry, ACL_TYPE_ACCESS,
 			      argp->acl_access);
 	if (error)
 		goto out_drop_lock;
-	error = set_posix_acl(&init_user_ns, fh->fh_dentry, ACL_TYPE_DEFAULT,
+	error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry, ACL_TYPE_DEFAULT,
 			      argp->acl_default);
 	if (error)
 		goto out_drop_lock;
diff --git a/fs/nfsd/nfs3acl.c b/fs/nfsd/nfs3acl.c
index 647108138e8a..887803735e2a 100644
--- a/fs/nfsd/nfs3acl.c
+++ b/fs/nfsd/nfs3acl.c
@@ -103,11 +103,11 @@ static __be32 nfsd3_proc_setacl(struct svc_rqst *rqstp)
 
 	inode_lock(inode);
 
-	error = set_posix_acl(&init_user_ns, fh->fh_dentry, ACL_TYPE_ACCESS,
+	error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry, ACL_TYPE_ACCESS,
 			      argp->acl_access);
 	if (error)
 		goto out_drop_lock;
-	error = set_posix_acl(&init_user_ns, fh->fh_dentry, ACL_TYPE_DEFAULT,
+	error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry, ACL_TYPE_DEFAULT,
 			      argp->acl_default);
 
 out_drop_lock:
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index d01b29aba662..f41992ecd0d7 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -320,7 +320,7 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		iap->ia_mode &= ~current_umask();
 
 	fh_fill_pre_attrs(fhp);
-	host_err = vfs_create(&init_user_ns, inode, child, iap->ia_mode, true);
+	host_err = vfs_create(&nop_mnt_idmap, inode, child, iap->ia_mode, true);
 	if (host_err < 0) {
 		status = nfserrno(host_err);
 		goto out;
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 78b8cd9651d5..3509e73abe1f 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -233,7 +233,7 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
 		 * as well be forgiving and just succeed silently.
 		 */
 		goto out_put;
-	status = vfs_mkdir(&init_user_ns, d_inode(dir), dentry, S_IRWXU);
+	status = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, S_IRWXU);
 out_put:
 	dput(dentry);
 out_unlock:
@@ -353,7 +353,7 @@ nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
 	status = -ENOENT;
 	if (d_really_is_negative(dentry))
 		goto out;
-	status = vfs_rmdir(&init_user_ns, d_inode(dir), dentry);
+	status = vfs_rmdir(&nop_mnt_idmap, d_inode(dir), dentry);
 out:
 	dput(dentry);
 out_unlock:
@@ -443,7 +443,7 @@ purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
 	if (nfs4_has_reclaimed_state(name, nn))
 		goto out_free;
 
-	status = vfs_rmdir(&init_user_ns, d_inode(parent), child);
+	status = vfs_rmdir(&nop_mnt_idmap, d_inode(parent), child);
 	if (status)
 		printk("failed to remove client recovery directory %pd\n",
 				child);
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 76ea268dc420..ccd8485fee04 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -40,7 +40,7 @@ static int nfsd_acceptable(void *expv, struct dentry *dentry)
 		/* make sure parents give x permission to user */
 		int err;
 		parent = dget_parent(tdentry);
-		err = inode_permission(&init_user_ns,
+		err = inode_permission(&nop_mnt_idmap,
 				       d_inode(parent), MAY_EXEC);
 		if (err < 0) {
 			dput(parent);
diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index 9744443c3965..a82d91afdc9c 100644
--- a/fs/nfsd/nfsproc.c
+++ b/fs/nfsd/nfsproc.c
@@ -93,7 +93,7 @@ nfsd_proc_setattr(struct svc_rqst *rqstp)
 		if (delta < 0)
 			delta = -delta;
 		if (delta < MAX_TOUCH_TIME_ERROR &&
-		    setattr_prepare(&init_user_ns, fhp->fh_dentry, iap) != 0) {
+		    setattr_prepare(&nop_mnt_idmap, fhp->fh_dentry, iap) != 0) {
 			/*
 			 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
 			 * This will cause notify_change to set these times
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 4c3a0d84043c..ab4ee3509ce3 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -426,7 +426,7 @@ static int __nfsd_setattr(struct dentry *dentry, struct iattr *iap)
 		if (iap->ia_size < 0)
 			return -EFBIG;
 
-		host_err = notify_change(&init_user_ns, dentry, &size_attr, NULL);
+		host_err = notify_change(&nop_mnt_idmap, dentry, &size_attr, NULL);
 		if (host_err)
 			return host_err;
 		iap->ia_valid &= ~ATTR_SIZE;
@@ -444,7 +444,7 @@ static int __nfsd_setattr(struct dentry *dentry, struct iattr *iap)
 		return 0;
 
 	iap->ia_valid |= ATTR_CTIME;
-	return notify_change(&init_user_ns, dentry, iap, NULL);
+	return notify_change(&nop_mnt_idmap, dentry, iap, NULL);
 }
 
 /**
@@ -542,12 +542,12 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		attr->na_labelerr = security_inode_setsecctx(dentry,
 			attr->na_seclabel->data, attr->na_seclabel->len);
 	if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && attr->na_pacl)
-		attr->na_aclerr = set_posix_acl(&init_user_ns,
+		attr->na_aclerr = set_posix_acl(&nop_mnt_idmap,
 						dentry, ACL_TYPE_ACCESS,
 						attr->na_pacl);
 	if (IS_ENABLED(CONFIG_FS_POSIX_ACL) &&
 	    !attr->na_aclerr && attr->na_dpacl && S_ISDIR(inode->i_mode))
-		attr->na_aclerr = set_posix_acl(&init_user_ns,
+		attr->na_aclerr = set_posix_acl(&nop_mnt_idmap,
 						dentry, ACL_TYPE_DEFAULT,
 						attr->na_dpacl);
 	inode_unlock(inode);
@@ -583,7 +583,7 @@ int nfsd4_is_junction(struct dentry *dentry)
 		return 0;
 	if (!(inode->i_mode & S_ISVTX))
 		return 0;
-	if (vfs_getxattr(&init_user_ns, dentry, NFSD_JUNCTION_XATTR_NAME,
+	if (vfs_getxattr(&nop_mnt_idmap, dentry, NFSD_JUNCTION_XATTR_NAME,
 			 NULL, 0) <= 0)
 		return 0;
 	return 1;
@@ -1363,12 +1363,13 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	err = 0;
 	switch (type) {
 	case S_IFREG:
-		host_err = vfs_create(&init_user_ns, dirp, dchild, iap->ia_mode, true);
+		host_err = vfs_create(&nop_mnt_idmap, dirp, dchild,
+				      iap->ia_mode, true);
 		if (!host_err)
 			nfsd_check_ignore_resizing(iap);
 		break;
 	case S_IFDIR:
-		host_err = vfs_mkdir(&init_user_ns, dirp, dchild, iap->ia_mode);
+		host_err = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode);
 		if (!host_err && unlikely(d_unhashed(dchild))) {
 			struct dentry *d;
 			d = lookup_one_len(dchild->d_name.name,
@@ -1396,7 +1397,7 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	case S_IFBLK:
 	case S_IFIFO:
 	case S_IFSOCK:
-		host_err = vfs_mknod(&init_user_ns, dirp, dchild,
+		host_err = vfs_mknod(&nop_mnt_idmap, dirp, dchild,
 				     iap->ia_mode, rdev);
 		break;
 	default:
@@ -1557,7 +1558,7 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		goto out_drop_write;
 	}
 	fh_fill_pre_attrs(fhp);
-	host_err = vfs_symlink(&init_user_ns, d_inode(dentry), dnew, path);
+	host_err = vfs_symlink(&nop_mnt_idmap, d_inode(dentry), dnew, path);
 	err = nfserrno(host_err);
 	cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
 	if (!err)
@@ -1625,7 +1626,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
 	if (d_really_is_negative(dold))
 		goto out_dput;
 	fh_fill_pre_attrs(ffhp);
-	host_err = vfs_link(dold, &init_user_ns, dirp, dnew, NULL);
+	host_err = vfs_link(dold, &nop_mnt_idmap, dirp, dnew, NULL);
 	fh_fill_post_attrs(ffhp);
 	inode_unlock(dirp);
 	if (!host_err) {
@@ -1745,10 +1746,10 @@ retry:
 		goto out_dput_old;
 	} else {
 		struct renamedata rd = {
-			.old_mnt_userns	= &init_user_ns,
+			.old_mnt_idmap	= &nop_mnt_idmap,
 			.old_dir	= fdir,
 			.old_dentry	= odentry,
-			.new_mnt_userns	= &init_user_ns,
+			.new_mnt_idmap	= &nop_mnt_idmap,
 			.new_dir	= tdir,
 			.new_dentry	= ndentry,
 		};
@@ -1850,14 +1851,14 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 			nfsd_close_cached_files(rdentry);
 
 		for (retries = 1;;) {
-			host_err = vfs_unlink(&init_user_ns, dirp, rdentry, NULL);
+			host_err = vfs_unlink(&nop_mnt_idmap, dirp, rdentry, NULL);
 			if (host_err != -EAGAIN || !retries--)
 				break;
 			if (!nfsd_wait_for_delegreturn(rqstp, rinode))
 				break;
 		}
 	} else {
-		host_err = vfs_rmdir(&init_user_ns, dirp, rdentry);
+		host_err = vfs_rmdir(&nop_mnt_idmap, dirp, rdentry);
 	}
 	fh_fill_post_attrs(fhp);
 
@@ -2129,7 +2130,7 @@ nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
 
 	inode_lock_shared(inode);
 
-	len = vfs_getxattr(&init_user_ns, dentry, name, NULL, 0);
+	len = vfs_getxattr(&nop_mnt_idmap, dentry, name, NULL, 0);
 
 	/*
 	 * Zero-length attribute, just return.
@@ -2156,7 +2157,7 @@ nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
 		goto out;
 	}
 
-	len = vfs_getxattr(&init_user_ns, dentry, name, buf, len);
+	len = vfs_getxattr(&nop_mnt_idmap, dentry, name, buf, len);
 	if (len <= 0) {
 		kvfree(buf);
 		buf = NULL;
@@ -2267,7 +2268,7 @@ nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name)
 	inode_lock(fhp->fh_dentry->d_inode);
 	fh_fill_pre_attrs(fhp);
 
-	ret = __vfs_removexattr_locked(&init_user_ns, fhp->fh_dentry,
+	ret = __vfs_removexattr_locked(&nop_mnt_idmap, fhp->fh_dentry,
 				       name, NULL);
 
 	fh_fill_post_attrs(fhp);
@@ -2294,7 +2295,7 @@ nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
 	inode_lock(fhp->fh_dentry->d_inode);
 	fh_fill_pre_attrs(fhp);
 
-	ret = __vfs_setxattr_locked(&init_user_ns, fhp->fh_dentry, name, buf,
+	ret = __vfs_setxattr_locked(&nop_mnt_idmap, fhp->fh_dentry, name, buf,
 				    len, flags, NULL);
 	fh_fill_post_attrs(fhp);
 	inode_unlock(fhp->fh_dentry->d_inode);
@@ -2378,14 +2379,14 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
 		return 0;
 
 	/* This assumes  NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
-	err = inode_permission(&init_user_ns, inode,
+	err = inode_permission(&nop_mnt_idmap, inode,
 			       acc & (MAY_READ | MAY_WRITE | MAY_EXEC));
 
 	/* Allow read access to binaries even when mode 111 */
 	if (err == -EACCES && S_ISREG(inode->i_mode) &&
 	     (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
 	      acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
-		err = inode_permission(&init_user_ns, inode, MAY_EXEC);
+		err = inode_permission(&nop_mnt_idmap, inode, MAY_EXEC);
 
 	return err? nfserrno(err) : 0;
 }
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 232dd7b6cca1..1310d2d5feb3 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -364,7 +364,7 @@ struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 	ii->i_bh = bh;
 
 	atomic64_inc(&root->inodes_count);
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 	inode->i_ino = ino;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 
@@ -949,7 +949,7 @@ void nilfs_evict_inode(struct inode *inode)
 	 */
 }
 
-int nilfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int nilfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *iattr)
 {
 	struct nilfs_transaction_info ti;
@@ -957,7 +957,7 @@ int nilfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	struct super_block *sb = inode->i_sb;
 	int err;
 
-	err = setattr_prepare(&init_user_ns, dentry, iattr);
+	err = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (err)
 		return err;
 
@@ -972,7 +972,7 @@ int nilfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		nilfs_truncate(inode);
 	}
 
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 	mark_inode_dirty(inode);
 
 	if (iattr->ia_valid & ATTR_MODE) {
@@ -988,7 +988,7 @@ out_err:
 	return err;
 }
 
-int nilfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int nilfs_permission(struct mnt_idmap *idmap, struct inode *inode,
 		     int mask)
 {
 	struct nilfs_root *root = NILFS_I(inode)->i_root;
@@ -997,7 +997,7 @@ int nilfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
 	    root->cno != NILFS_CPTREE_CURRENT_CNO)
 		return -EROFS; /* snapshot is not writable */
 
-	return generic_permission(&init_user_ns, inode, mask);
+	return generic_permission(&nop_mnt_idmap, inode, mask);
 }
 
 int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index b4041d0566a9..5ccc638ae92f 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -128,7 +128,7 @@ int nilfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 /**
  * nilfs_fileattr_set - ioctl to support chattr
  */
-int nilfs_fileattr_set(struct user_namespace *mnt_userns,
+int nilfs_fileattr_set(struct mnt_idmap *idmap,
 		       struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index 23899e0ae850..c7024da8f1e2 100644
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -72,7 +72,7 @@ nilfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
  * If the create succeeds, we fill in the inode information
  * with d_instantiate().
  */
-static int nilfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int nilfs_create(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct inode *inode;
@@ -100,7 +100,7 @@ static int nilfs_create(struct user_namespace *mnt_userns, struct inode *dir,
 }
 
 static int
-nilfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+nilfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	    struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct inode *inode;
@@ -125,7 +125,7 @@ nilfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	return err;
 }
 
-static int nilfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int nilfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			 struct dentry *dentry, const char *symname)
 {
 	struct nilfs_transaction_info ti;
@@ -202,7 +202,7 @@ static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
 	return err;
 }
 
-static int nilfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int nilfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode;
@@ -340,7 +340,7 @@ static int nilfs_rmdir(struct inode *dir, struct dentry *dentry)
 	return err;
 }
 
-static int nilfs_rename(struct user_namespace *mnt_userns,
+static int nilfs_rename(struct mnt_idmap *idmap,
 			struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index aecda4fc95f5..8046490cd7fe 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -242,7 +242,7 @@ extern int nilfs_sync_file(struct file *, loff_t, loff_t, int);
 
 /* ioctl.c */
 int nilfs_fileattr_get(struct dentry *dentry, struct fileattr *m);
-int nilfs_fileattr_set(struct user_namespace *mnt_userns,
+int nilfs_fileattr_set(struct mnt_idmap *idmap,
 		       struct dentry *dentry, struct fileattr *fa);
 long nilfs_ioctl(struct file *, unsigned int, unsigned long);
 long nilfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
@@ -271,10 +271,10 @@ struct inode *nilfs_iget_for_shadow(struct inode *inode);
 extern void nilfs_update_inode(struct inode *, struct buffer_head *, int);
 extern void nilfs_truncate(struct inode *);
 extern void nilfs_evict_inode(struct inode *);
-extern int nilfs_setattr(struct user_namespace *, struct dentry *,
+extern int nilfs_setattr(struct mnt_idmap *, struct dentry *,
 			 struct iattr *);
 extern void nilfs_write_failed(struct address_space *mapping, loff_t to);
-int nilfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int nilfs_permission(struct mnt_idmap *idmap, struct inode *inode,
 		     int mask);
 int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh);
 extern int nilfs_inode_dirty(struct inode *);
diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index 08c659332e26..e6fc5f7cb1d7 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -2865,7 +2865,7 @@ void ntfs_truncate_vfs(struct inode *vi) {
 
 /**
  * ntfs_setattr - called from notify_change() when an attribute is being changed
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dentry:	dentry whose attributes to change
  * @attr:	structure describing the attributes and the changes
  *
@@ -2878,14 +2878,14 @@ void ntfs_truncate_vfs(struct inode *vi) {
  *
  * Called with ->i_mutex held.
  */
-int ntfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ntfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct iattr *attr)
 {
 	struct inode *vi = d_inode(dentry);
 	int err;
 	unsigned int ia_valid = attr->ia_valid;
 
-	err = setattr_prepare(&init_user_ns, dentry, attr);
+	err = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (err)
 		goto out;
 	/* We do not support NTFS ACLs yet. */
diff --git a/fs/ntfs/inode.h b/fs/ntfs/inode.h
index 6f78ee00f57f..147ef4ddb691 100644
--- a/fs/ntfs/inode.h
+++ b/fs/ntfs/inode.h
@@ -289,7 +289,7 @@ extern int ntfs_show_options(struct seq_file *sf, struct dentry *root);
 extern int ntfs_truncate(struct inode *vi);
 extern void ntfs_truncate_vfs(struct inode *vi);
 
-extern int ntfs_setattr(struct user_namespace *mnt_userns,
+extern int ntfs_setattr(struct mnt_idmap *idmap,
 			struct dentry *dentry, struct iattr *attr);
 
 extern int __ntfs_write_inode(struct inode *vi, int sync);
diff --git a/fs/ntfs3/file.c b/fs/ntfs3/file.c
index d294cd975688..e9bdc1ff08c9 100644
--- a/fs/ntfs3/file.c
+++ b/fs/ntfs3/file.c
@@ -70,7 +70,7 @@ static long ntfs_compat_ioctl(struct file *filp, u32 cmd, unsigned long arg)
 /*
  * ntfs_getattr - inode_operations::getattr
  */
-int ntfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ntfs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, u32 flags)
 {
 	struct inode *inode = d_inode(path->dentry);
@@ -84,7 +84,7 @@ int ntfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 
 	stat->attributes_mask |= STATX_ATTR_COMPRESSED | STATX_ATTR_ENCRYPTED;
 
-	generic_fillattr(mnt_userns, inode, stat);
+	generic_fillattr(idmap, inode, stat);
 
 	stat->result_mask |= STATX_BTIME;
 	stat->btime = ni->i_crtime;
@@ -657,7 +657,7 @@ out:
 /*
  * ntfs3_setattr - inode_operations::setattr
  */
-int ntfs3_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ntfs3_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr)
 {
 	struct super_block *sb = dentry->d_sb;
@@ -676,7 +676,7 @@ int ntfs3_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		ia_valid = attr->ia_valid;
 	}
 
-	err = setattr_prepare(mnt_userns, dentry, attr);
+	err = setattr_prepare(idmap, dentry, attr);
 	if (err)
 		goto out;
 
@@ -704,10 +704,10 @@ int ntfs3_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		inode->i_size = newsize;
 	}
 
-	setattr_copy(mnt_userns, inode, attr);
+	setattr_copy(idmap, inode, attr);
 
 	if (mode != inode->i_mode) {
-		err = ntfs_acl_chmod(mnt_userns, dentry);
+		err = ntfs_acl_chmod(idmap, dentry);
 		if (err)
 			goto out;
 
diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index 20b953871574..8ce2616b087f 100644
--- a/fs/ntfs3/inode.c
+++ b/fs/ntfs3/inode.c
@@ -1185,7 +1185,7 @@ out:
  * 
  * NOTE: if fnd != NULL (ntfs_atomic_open) then @dir is locked
  */
-struct inode *ntfs_create_inode(struct user_namespace *mnt_userns,
+struct inode *ntfs_create_inode(struct mnt_idmap *idmap,
 				struct inode *dir, struct dentry *dentry,
 				const struct cpu_str *uni, umode_t mode,
 				dev_t dev, const char *symname, u32 size,
@@ -1307,7 +1307,7 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns,
 		goto out3;
 	}
 	inode = &ni->vfs_inode;
-	inode_init_owner(mnt_userns, inode, dir, mode);
+	inode_init_owner(idmap, inode, dir, mode);
 	mode = inode->i_mode;
 
 	inode->i_atime = inode->i_mtime = inode->i_ctime = ni->i_crtime =
@@ -1614,7 +1614,7 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns,
 
 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
 	if (!S_ISLNK(mode) && (sb->s_flags & SB_POSIXACL)) {
-		err = ntfs_init_acl(mnt_userns, inode, dir);
+		err = ntfs_init_acl(idmap, inode, dir);
 		if (err)
 			goto out7;
 	} else
diff --git a/fs/ntfs3/namei.c b/fs/ntfs3/namei.c
index c8db35e2ae17..407fe92394e2 100644
--- a/fs/ntfs3/namei.c
+++ b/fs/ntfs3/namei.c
@@ -94,12 +94,12 @@ static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
 /*
  * ntfs_create - inode_operations::create
  */
-static int ntfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int ntfs_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct inode *inode;
 
-	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFREG | mode,
+	inode = ntfs_create_inode(idmap, dir, dentry, NULL, S_IFREG | mode,
 				  0, NULL, 0, NULL);
 
 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
@@ -110,12 +110,12 @@ static int ntfs_create(struct user_namespace *mnt_userns, struct inode *dir,
  *
  * inode_operations::mknod
  */
-static int ntfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int ntfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct inode *inode;
 
-	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, mode, rdev,
+	inode = ntfs_create_inode(idmap, dir, dentry, NULL, mode, rdev,
 				  NULL, 0, NULL);
 
 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
@@ -183,13 +183,13 @@ static int ntfs_unlink(struct inode *dir, struct dentry *dentry)
 /*
  * ntfs_symlink - inode_operations::symlink
  */
-static int ntfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int ntfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, const char *symname)
 {
 	u32 size = strlen(symname);
 	struct inode *inode;
 
-	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFLNK | 0777,
+	inode = ntfs_create_inode(idmap, dir, dentry, NULL, S_IFLNK | 0777,
 				  0, symname, size, NULL);
 
 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
@@ -198,12 +198,12 @@ static int ntfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 /*
  * ntfs_mkdir- inode_operations::mkdir
  */
-static int ntfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int ntfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode;
 
-	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFDIR | mode,
+	inode = ntfs_create_inode(idmap, dir, dentry, NULL, S_IFDIR | mode,
 				  0, NULL, 0, NULL);
 
 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
@@ -229,7 +229,7 @@ static int ntfs_rmdir(struct inode *dir, struct dentry *dentry)
 /*
  * ntfs_rename - inode_operations::rename
  */
-static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *dir,
+static int ntfs_rename(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, struct inode *new_dir,
 		       struct dentry *new_dentry, u32 flags)
 {
@@ -415,13 +415,13 @@ static int ntfs_atomic_open(struct inode *dir, struct dentry *dentry,
 
 	/*
 	 * Unfortunately I don't know how to get here correct 'struct nameidata *nd'
-	 * or 'struct user_namespace *mnt_userns'.
+	 * or 'struct mnt_idmap *idmap'.
 	 * See atomic_open in fs/namei.c.
 	 * This is why xfstest/633 failed.
-	 * Looks like ntfs_atomic_open must accept 'struct user_namespace *mnt_userns' as argument.
+	 * Looks like ntfs_atomic_open must accept 'struct mnt_idmap *idmap' as argument.
 	 */
 
-	inode = ntfs_create_inode(&init_user_ns, dir, dentry, uni, mode, 0,
+	inode = ntfs_create_inode(&nop_mnt_idmap, dir, dentry, uni, mode, 0,
 				  NULL, 0, fnd);
 	err = IS_ERR(inode) ? PTR_ERR(inode)
 			    : finish_open(file, dentry, ntfs_file_open);
diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index 0e051c5595a2..80072e5f96f7 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -492,10 +492,12 @@ bool dir_is_empty(struct inode *dir);
 extern const struct file_operations ntfs_dir_operations;
 
 /* Globals from file.c */
-int ntfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ntfs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, u32 flags);
-int ntfs3_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ntfs3_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr);
+void ntfs_sparse_cluster(struct inode *inode, struct page *page0, CLST vcn,
+			 CLST len);
 int ntfs_file_open(struct inode *inode, struct file *file);
 int ntfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		__u64 start, __u64 len);
@@ -706,7 +708,7 @@ int ntfs_sync_inode(struct inode *inode);
 int ntfs_flush_inodes(struct super_block *sb, struct inode *i1,
 		      struct inode *i2);
 int inode_write_data(struct inode *inode, const void *data, size_t bytes);
-struct inode *ntfs_create_inode(struct user_namespace *mnt_userns,
+struct inode *ntfs_create_inode(struct mnt_idmap *idmap,
 				struct inode *dir, struct dentry *dentry,
 				const struct cpu_str *uni, umode_t mode,
 				dev_t dev, const char *symname, u32 size,
@@ -857,17 +859,17 @@ unsigned long ntfs_names_hash(const u16 *name, size_t len, const u16 *upcase,
 /* globals from xattr.c */
 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
 struct posix_acl *ntfs_get_acl(struct inode *inode, int type, bool rcu);
-int ntfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type);
-int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
+int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
 		  struct inode *dir);
 #else
 #define ntfs_get_acl NULL
 #define ntfs_set_acl NULL
 #endif
 
-int ntfs_acl_chmod(struct user_namespace *mnt_userns, struct dentry *dentry);
-int ntfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int ntfs_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry);
+int ntfs_permission(struct mnt_idmap *idmap, struct inode *inode,
 		    int mask);
 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
 extern const struct xattr_handler *ntfs_xattr_handlers[];
diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c
index 616df209feea..ff64302e87e5 100644
--- a/fs/ntfs3/xattr.c
+++ b/fs/ntfs3/xattr.c
@@ -578,7 +578,7 @@ struct posix_acl *ntfs_get_acl(struct inode *inode, int type, bool rcu)
 	return ntfs_get_acl_ex(inode, type, 0);
 }
 
-static noinline int ntfs_set_acl_ex(struct user_namespace *mnt_userns,
+static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
 				    struct inode *inode, struct posix_acl *acl,
 				    int type, bool init_acl)
 {
@@ -597,7 +597,7 @@ static noinline int ntfs_set_acl_ex(struct user_namespace *mnt_userns,
 	case ACL_TYPE_ACCESS:
 		/* Do not change i_mode if we are in init_acl */
 		if (acl && !init_acl) {
-			err = posix_acl_update_mode(mnt_userns, inode, &mode,
+			err = posix_acl_update_mode(idmap, inode, &mode,
 						    &acl);
 			if (err)
 				return err;
@@ -652,10 +652,10 @@ out:
 /*
  * ntfs_set_acl - inode_operations::set_acl
  */
-int ntfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type)
 {
-	return ntfs_set_acl_ex(mnt_userns, d_inode(dentry), acl, type, false);
+	return ntfs_set_acl_ex(idmap, d_inode(dentry), acl, type, false);
 }
 
 /*
@@ -663,7 +663,7 @@ int ntfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
  *
  * Called from ntfs_create_inode().
  */
-int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
+int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
 		  struct inode *dir)
 {
 	struct posix_acl *default_acl, *acl;
@@ -674,7 +674,7 @@ int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
 		return err;
 
 	if (default_acl) {
-		err = ntfs_set_acl_ex(mnt_userns, inode, default_acl,
+		err = ntfs_set_acl_ex(idmap, inode, default_acl,
 				      ACL_TYPE_DEFAULT, true);
 		posix_acl_release(default_acl);
 	} else {
@@ -683,7 +683,7 @@ int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
 
 	if (acl) {
 		if (!err)
-			err = ntfs_set_acl_ex(mnt_userns, inode, acl,
+			err = ntfs_set_acl_ex(idmap, inode, acl,
 					      ACL_TYPE_ACCESS, true);
 		posix_acl_release(acl);
 	} else {
@@ -697,7 +697,7 @@ int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
 /*
  * ntfs_acl_chmod - Helper for ntfs3_setattr().
  */
-int ntfs_acl_chmod(struct user_namespace *mnt_userns, struct dentry *dentry)
+int ntfs_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry)
 {
 	struct inode *inode = d_inode(dentry);
 	struct super_block *sb = inode->i_sb;
@@ -708,13 +708,13 @@ int ntfs_acl_chmod(struct user_namespace *mnt_userns, struct dentry *dentry)
 	if (S_ISLNK(inode->i_mode))
 		return -EOPNOTSUPP;
 
-	return posix_acl_chmod(mnt_userns, dentry, inode->i_mode);
+	return posix_acl_chmod(idmap, dentry, inode->i_mode);
 }
 
 /*
  * ntfs_permission - inode_operations::permission
  */
-int ntfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int ntfs_permission(struct mnt_idmap *idmap, struct inode *inode,
 		    int mask)
 {
 	if (ntfs_sb(inode->i_sb)->options->noacsrules) {
@@ -722,7 +722,7 @@ int ntfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
 		return 0;
 	}
 
-	return generic_permission(mnt_userns, inode, mask);
+	return generic_permission(idmap, inode, mask);
 }
 
 /*
@@ -835,7 +835,7 @@ out:
  * ntfs_setxattr - inode_operations::setxattr
  */
 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
-				  struct user_namespace *mnt_userns,
+				  struct mnt_idmap *idmap,
 				  struct dentry *de, struct inode *inode,
 				  const char *name, const void *value,
 				  size_t size, int flags)
diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
index 9f19cf9a5a9f..9fd03eaf15f8 100644
--- a/fs/ocfs2/acl.c
+++ b/fs/ocfs2/acl.c
@@ -260,7 +260,7 @@ static int ocfs2_set_acl(handle_t *handle,
 	return ret;
 }
 
-int ocfs2_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ocfs2_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		      struct posix_acl *acl, int type)
 {
 	struct buffer_head *bh = NULL;
@@ -274,7 +274,7 @@ int ocfs2_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (type == ACL_TYPE_ACCESS && acl) {
 		umode_t mode;
 
-		status = posix_acl_update_mode(&init_user_ns, inode, &mode,
+		status = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode,
 					       &acl);
 		if (status)
 			goto unlock;
diff --git a/fs/ocfs2/acl.h b/fs/ocfs2/acl.h
index a897c4e41b26..667c6f03fa60 100644
--- a/fs/ocfs2/acl.h
+++ b/fs/ocfs2/acl.h
@@ -17,7 +17,7 @@ struct ocfs2_acl_entry {
 };
 
 struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type, bool rcu);
-int ocfs2_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ocfs2_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		      struct posix_acl *acl, int type);
 extern int ocfs2_acl_chmod(struct inode *, struct buffer_head *);
 extern int ocfs2_init_acl(handle_t *, struct inode *, struct inode *,
diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
index 8b2020f92b5f..ba26c5567cff 100644
--- a/fs/ocfs2/dlmfs/dlmfs.c
+++ b/fs/ocfs2/dlmfs/dlmfs.c
@@ -188,18 +188,18 @@ static int dlmfs_file_release(struct inode *inode,
  * We do ->setattr() just to override size changes.  Our size is the size
  * of the LVB and nothing else.
  */
-static int dlmfs_file_setattr(struct user_namespace *mnt_userns,
+static int dlmfs_file_setattr(struct mnt_idmap *idmap,
 			      struct dentry *dentry, struct iattr *attr)
 {
 	int error;
 	struct inode *inode = d_inode(dentry);
 
 	attr->ia_valid &= ~ATTR_SIZE;
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
@@ -336,7 +336,7 @@ static struct inode *dlmfs_get_root_inode(struct super_block *sb)
 
 	if (inode) {
 		inode->i_ino = get_next_ino();
-		inode_init_owner(&init_user_ns, inode, NULL, mode);
+		inode_init_owner(&nop_mnt_idmap, inode, NULL, mode);
 		inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 		inc_nlink(inode);
 
@@ -359,7 +359,7 @@ static struct inode *dlmfs_get_inode(struct inode *parent,
 		return NULL;
 
 	inode->i_ino = get_next_ino();
-	inode_init_owner(&init_user_ns, inode, parent, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, parent, mode);
 	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 
 	ip = DLMFS_I(inode);
@@ -402,7 +402,7 @@ static struct inode *dlmfs_get_inode(struct inode *parent,
  * File creation. Allocate an inode, and we're done..
  */
 /* SMP-safe */
-static int dlmfs_mkdir(struct user_namespace * mnt_userns,
+static int dlmfs_mkdir(struct mnt_idmap * idmap,
 		       struct inode * dir,
 		       struct dentry * dentry,
 		       umode_t mode)
@@ -451,7 +451,7 @@ bail:
 	return status;
 }
 
-static int dlmfs_create(struct user_namespace *mnt_userns,
+static int dlmfs_create(struct mnt_idmap *idmap,
 			struct inode *dir,
 			struct dentry *dentry,
 			umode_t mode,
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 5c60b6bc85bf..efb09de4343d 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1111,7 +1111,7 @@ out:
 	return ret;
 }
 
-int ocfs2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ocfs2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr)
 {
 	int status = 0, size_change;
@@ -1142,11 +1142,11 @@ int ocfs2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (!(attr->ia_valid & OCFS2_VALID_ATTRS))
 		return 0;
 
-	status = setattr_prepare(&init_user_ns, dentry, attr);
+	status = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (status)
 		return status;
 
-	if (is_quota_modification(mnt_userns, inode, attr)) {
+	if (is_quota_modification(&nop_mnt_idmap, inode, attr)) {
 		status = dquot_initialize(inode);
 		if (status)
 			return status;
@@ -1265,7 +1265,7 @@ int ocfs2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		}
 	}
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 
 	status = ocfs2_mark_inode_dirty(handle, inode, bh);
@@ -1302,7 +1302,7 @@ bail:
 	return status;
 }
 
-int ocfs2_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ocfs2_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	struct inode *inode = d_inode(path->dentry);
@@ -1317,7 +1317,7 @@ int ocfs2_getattr(struct user_namespace *mnt_userns, const struct path *path,
 		goto bail;
 	}
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	/*
 	 * If there is inline data in the inode, the inode will normally not
 	 * have data blocks allocated (it may have an external xattr block).
@@ -1334,7 +1334,7 @@ bail:
 	return err;
 }
 
-int ocfs2_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int ocfs2_permission(struct mnt_idmap *idmap, struct inode *inode,
 		     int mask)
 {
 	int ret, had_lock;
@@ -1360,7 +1360,7 @@ int ocfs2_permission(struct user_namespace *mnt_userns, struct inode *inode,
 		dump_stack();
 	}
 
-	ret = generic_permission(&init_user_ns, inode, mask);
+	ret = generic_permission(&nop_mnt_idmap, inode, mask);
 
 	ocfs2_inode_unlock_tracker(inode, 0, &oh, had_lock);
 out:
@@ -1991,7 +1991,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
 		}
 	}
 
-	if (file && setattr_should_drop_suidgid(&init_user_ns, file_inode(file))) {
+	if (file && setattr_should_drop_suidgid(&nop_mnt_idmap, file_inode(file))) {
 		ret = __ocfs2_write_remove_suid(inode, di_bh);
 		if (ret) {
 			mlog_errno(ret);
@@ -2279,7 +2279,7 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
 		 * inode. There's also the dinode i_size state which
 		 * can be lost via setattr during extending writes (we
 		 * set inode->i_size at the end of a write. */
-		if (setattr_should_drop_suidgid(&init_user_ns, inode)) {
+		if (setattr_should_drop_suidgid(&nop_mnt_idmap, inode)) {
 			if (meta_level == 0) {
 				ocfs2_inode_unlock_for_extent_tree(inode,
 								   &di_bh,
diff --git a/fs/ocfs2/file.h b/fs/ocfs2/file.h
index 71db8f3aa027..8e53e4ac1120 100644
--- a/fs/ocfs2/file.h
+++ b/fs/ocfs2/file.h
@@ -49,11 +49,11 @@ int ocfs2_extend_no_holes(struct inode *inode, struct buffer_head *di_bh,
 			  u64 new_i_size, u64 zero_to);
 int ocfs2_zero_extend(struct inode *inode, struct buffer_head *di_bh,
 		      loff_t zero_to);
-int ocfs2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ocfs2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr);
-int ocfs2_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ocfs2_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, u32 request_mask, unsigned int flags);
-int ocfs2_permission(struct user_namespace *mnt_userns,
+int ocfs2_permission(struct mnt_idmap *idmap,
 		     struct inode *inode,
 		     int mask);
 
diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index afd54ec66103..811a6ea374bb 100644
--- a/fs/ocfs2/ioctl.c
+++ b/fs/ocfs2/ioctl.c
@@ -82,7 +82,7 @@ int ocfs2_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return status;
 }
 
-int ocfs2_fileattr_set(struct user_namespace *mnt_userns,
+int ocfs2_fileattr_set(struct mnt_idmap *idmap,
 		       struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
diff --git a/fs/ocfs2/ioctl.h b/fs/ocfs2/ioctl.h
index 0297c8846945..48a5fdfe87a1 100644
--- a/fs/ocfs2/ioctl.h
+++ b/fs/ocfs2/ioctl.h
@@ -12,7 +12,7 @@
 #define OCFS2_IOCTL_PROTO_H
 
 int ocfs2_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-int ocfs2_fileattr_set(struct user_namespace *mnt_userns,
+int ocfs2_fileattr_set(struct mnt_idmap *idmap,
 		       struct dentry *dentry, struct fileattr *fa);
 long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
 long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg);
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index a8fd51afb794..9175dbc47201 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -197,8 +197,8 @@ static struct inode *ocfs2_get_init_inode(struct inode *dir, umode_t mode)
 	 * callers. */
 	if (S_ISDIR(mode))
 		set_nlink(inode, 2);
-	mode = mode_strip_sgid(&init_user_ns, dir, mode);
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	mode = mode_strip_sgid(&nop_mnt_idmap, dir, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 	status = dquot_initialize(inode);
 	if (status)
 		return ERR_PTR(status);
@@ -221,7 +221,7 @@ static void ocfs2_cleanup_add_entry_failure(struct ocfs2_super *osb,
 	iput(inode);
 }
 
-static int ocfs2_mknod(struct user_namespace *mnt_userns,
+static int ocfs2_mknod(struct mnt_idmap *idmap,
 		       struct inode *dir,
 		       struct dentry *dentry,
 		       umode_t mode,
@@ -642,7 +642,7 @@ static int ocfs2_mknod_locked(struct ocfs2_super *osb,
 				    fe_blkno, suballoc_loc, suballoc_bit);
 }
 
-static int ocfs2_mkdir(struct user_namespace *mnt_userns,
+static int ocfs2_mkdir(struct mnt_idmap *idmap,
 		       struct inode *dir,
 		       struct dentry *dentry,
 		       umode_t mode)
@@ -651,14 +651,14 @@ static int ocfs2_mkdir(struct user_namespace *mnt_userns,
 
 	trace_ocfs2_mkdir(dir, dentry, dentry->d_name.len, dentry->d_name.name,
 			  OCFS2_I(dir)->ip_blkno, mode);
-	ret = ocfs2_mknod(&init_user_ns, dir, dentry, mode | S_IFDIR, 0);
+	ret = ocfs2_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFDIR, 0);
 	if (ret)
 		mlog_errno(ret);
 
 	return ret;
 }
 
-static int ocfs2_create(struct user_namespace *mnt_userns,
+static int ocfs2_create(struct mnt_idmap *idmap,
 			struct inode *dir,
 			struct dentry *dentry,
 			umode_t mode,
@@ -668,7 +668,7 @@ static int ocfs2_create(struct user_namespace *mnt_userns,
 
 	trace_ocfs2_create(dir, dentry, dentry->d_name.len, dentry->d_name.name,
 			   (unsigned long long)OCFS2_I(dir)->ip_blkno, mode);
-	ret = ocfs2_mknod(&init_user_ns, dir, dentry, mode | S_IFREG, 0);
+	ret = ocfs2_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFREG, 0);
 	if (ret)
 		mlog_errno(ret);
 
@@ -1194,7 +1194,7 @@ static void ocfs2_double_unlock(struct inode *inode1, struct inode *inode2)
 		ocfs2_inode_unlock(inode2, 1);
 }
 
-static int ocfs2_rename(struct user_namespace *mnt_userns,
+static int ocfs2_rename(struct mnt_idmap *idmap,
 			struct inode *old_dir,
 			struct dentry *old_dentry,
 			struct inode *new_dir,
@@ -1784,7 +1784,7 @@ bail:
 	return status;
 }
 
-static int ocfs2_symlink(struct user_namespace *mnt_userns,
+static int ocfs2_symlink(struct mnt_idmap *idmap,
 			 struct inode *dir,
 			 struct dentry *dentry,
 			 const char *symname)
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 623db358b1ef..5a656dc683f1 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -4316,7 +4316,7 @@ static inline int ocfs2_may_create(struct inode *dir, struct dentry *child)
 		return -EEXIST;
 	if (IS_DEADDIR(dir))
 		return -ENOENT;
-	return inode_permission(&init_user_ns, dir, MAY_WRITE | MAY_EXEC);
+	return inode_permission(&nop_mnt_idmap, dir, MAY_WRITE | MAY_EXEC);
 }
 
 /**
@@ -4370,7 +4370,7 @@ static int ocfs2_vfs_reflink(struct dentry *old_dentry, struct inode *dir,
 	 * file.
 	 */
 	if (!preserve) {
-		error = inode_permission(&init_user_ns, inode, MAY_READ);
+		error = inode_permission(&nop_mnt_idmap, inode, MAY_READ);
 		if (error)
 			return error;
 	}
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 95d0611c5fc7..389308efe854 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -7247,7 +7247,7 @@ static int ocfs2_xattr_security_get(const struct xattr_handler *handler,
 }
 
 static int ocfs2_xattr_security_set(const struct xattr_handler *handler,
-				    struct user_namespace *mnt_userns,
+				    struct mnt_idmap *idmap,
 				    struct dentry *unused, struct inode *inode,
 				    const char *name, const void *value,
 				    size_t size, int flags)
@@ -7320,7 +7320,7 @@ static int ocfs2_xattr_trusted_get(const struct xattr_handler *handler,
 }
 
 static int ocfs2_xattr_trusted_set(const struct xattr_handler *handler,
-				   struct user_namespace *mnt_userns,
+				   struct mnt_idmap *idmap,
 				   struct dentry *unused, struct inode *inode,
 				   const char *name, const void *value,
 				   size_t size, int flags)
@@ -7351,7 +7351,7 @@ static int ocfs2_xattr_user_get(const struct xattr_handler *handler,
 }
 
 static int ocfs2_xattr_user_set(const struct xattr_handler *handler,
-				struct user_namespace *mnt_userns,
+				struct mnt_idmap *idmap,
 				struct dentry *unused, struct inode *inode,
 				const char *name, const void *value,
 				size_t size, int flags)
diff --git a/fs/omfs/dir.c b/fs/omfs/dir.c
index c219f91f44e9..82cf7e9a665f 100644
--- a/fs/omfs/dir.c
+++ b/fs/omfs/dir.c
@@ -279,13 +279,13 @@ out_free_inode:
 	return err;
 }
 
-static int omfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int omfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
 	return omfs_add_node(dir, dentry, mode | S_IFDIR);
 }
 
-static int omfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int omfs_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
 	return omfs_add_node(dir, dentry, mode | S_IFREG);
@@ -370,7 +370,7 @@ static bool omfs_fill_chain(struct inode *dir, struct dir_context *ctx,
 	return true;
 }
 
-static int omfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int omfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		       struct dentry *old_dentry, struct inode *new_dir,
 		       struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/omfs/file.c b/fs/omfs/file.c
index 3a5b4b88a583..0101f1f87b56 100644
--- a/fs/omfs/file.c
+++ b/fs/omfs/file.c
@@ -337,13 +337,13 @@ const struct file_operations omfs_file_operations = {
 	.splice_read = generic_file_splice_read,
 };
 
-static int omfs_setattr(struct user_namespace *mnt_userns,
+static int omfs_setattr(struct mnt_idmap *idmap,
 			struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	int error;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
@@ -356,7 +356,7 @@ static int omfs_setattr(struct user_namespace *mnt_userns,
 		omfs_truncate(inode);
 	}
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
diff --git a/fs/omfs/inode.c b/fs/omfs/inode.c
index 2a0e83236c01..c4c79e07efc7 100644
--- a/fs/omfs/inode.c
+++ b/fs/omfs/inode.c
@@ -48,7 +48,7 @@ struct inode *omfs_new_inode(struct inode *dir, umode_t mode)
 		goto fail;
 
 	inode->i_ino = new_block;
-	inode_init_owner(&init_user_ns, inode, NULL, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, NULL, mode);
 	inode->i_mapping->a_ops = &omfs_aops;
 
 	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
diff --git a/fs/open.c b/fs/open.c
index 117ad27922a1..68051c1c0579 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -37,7 +37,7 @@
 
 #include "internal.h"
 
-int do_truncate(struct user_namespace *mnt_userns, struct dentry *dentry,
+int do_truncate(struct mnt_idmap *idmap, struct dentry *dentry,
 		loff_t length, unsigned int time_attrs, struct file *filp)
 {
 	int ret;
@@ -55,7 +55,7 @@ int do_truncate(struct user_namespace *mnt_userns, struct dentry *dentry,
 	}
 
 	/* Remove suid, sgid, and file capabilities on truncate too */
-	ret = dentry_needs_remove_privs(mnt_userns, dentry);
+	ret = dentry_needs_remove_privs(idmap, dentry);
 	if (ret < 0)
 		return ret;
 	if (ret)
@@ -63,14 +63,14 @@ int do_truncate(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 	inode_lock(dentry->d_inode);
 	/* Note any delegations or leases have already been broken: */
-	ret = notify_change(mnt_userns, dentry, &newattrs, NULL);
+	ret = notify_change(idmap, dentry, &newattrs, NULL);
 	inode_unlock(dentry->d_inode);
 	return ret;
 }
 
 long vfs_truncate(const struct path *path, loff_t length)
 {
-	struct user_namespace *mnt_userns;
+	struct mnt_idmap *idmap;
 	struct inode *inode;
 	long error;
 
@@ -86,8 +86,8 @@ long vfs_truncate(const struct path *path, loff_t length)
 	if (error)
 		goto out;
 
-	mnt_userns = mnt_user_ns(path->mnt);
-	error = inode_permission(mnt_userns, inode, MAY_WRITE);
+	idmap = mnt_idmap(path->mnt);
+	error = inode_permission(idmap, inode, MAY_WRITE);
 	if (error)
 		goto mnt_drop_write_and_out;
 
@@ -109,7 +109,7 @@ long vfs_truncate(const struct path *path, loff_t length)
 
 	error = security_path_truncate(path);
 	if (!error)
-		error = do_truncate(mnt_userns, path->dentry, length, 0, NULL);
+		error = do_truncate(idmap, path->dentry, length, 0, NULL);
 
 put_write_and_out:
 	put_write_access(inode);
@@ -191,7 +191,7 @@ long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
 	sb_start_write(inode->i_sb);
 	error = security_file_truncate(f.file);
 	if (!error)
-		error = do_truncate(file_mnt_user_ns(f.file), dentry, length,
+		error = do_truncate(file_mnt_idmap(f.file), dentry, length,
 				    ATTR_MTIME | ATTR_CTIME, f.file);
 	sb_end_write(inode->i_sb);
 out_putf:
@@ -460,7 +460,7 @@ retry:
 			goto out_path_release;
 	}
 
-	res = inode_permission(mnt_user_ns(path.mnt), inode, mode | MAY_ACCESS);
+	res = inode_permission(mnt_idmap(path.mnt), inode, mode | MAY_ACCESS);
 	/* SuS v2 requires we report a read only fs too */
 	if (res || !(mode & S_IWOTH) || special_file(inode->i_mode))
 		goto out_path_release;
@@ -604,7 +604,7 @@ retry_deleg:
 		goto out_unlock;
 	newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
 	newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
-	error = notify_change(mnt_user_ns(path->mnt), path->dentry,
+	error = notify_change(mnt_idmap(path->mnt), path->dentry,
 			      &newattrs, &delegated_inode);
 out_unlock:
 	inode_unlock(inode);
@@ -702,7 +702,8 @@ static inline bool setattr_vfsgid(struct iattr *attr, kgid_t kgid)
 
 int chown_common(const struct path *path, uid_t user, gid_t group)
 {
-	struct user_namespace *mnt_userns, *fs_userns;
+	struct mnt_idmap *idmap;
+	struct user_namespace *fs_userns;
 	struct inode *inode = path->dentry->d_inode;
 	struct inode *delegated_inode = NULL;
 	int error;
@@ -713,7 +714,7 @@ int chown_common(const struct path *path, uid_t user, gid_t group)
 	uid = make_kuid(current_user_ns(), user);
 	gid = make_kgid(current_user_ns(), group);
 
-	mnt_userns = mnt_user_ns(path->mnt);
+	idmap = mnt_idmap(path->mnt);
 	fs_userns = i_user_ns(inode);
 
 retry_deleg:
@@ -727,14 +728,14 @@ retry_deleg:
 	inode_lock(inode);
 	if (!S_ISDIR(inode->i_mode))
 		newattrs.ia_valid |= ATTR_KILL_SUID | ATTR_KILL_PRIV |
-				     setattr_should_drop_sgid(mnt_userns, inode);
+				     setattr_should_drop_sgid(idmap, inode);
 	/* Continue to send actual fs values, not the mount values. */
 	error = security_path_chown(
 		path,
-		from_vfsuid(mnt_userns, fs_userns, newattrs.ia_vfsuid),
-		from_vfsgid(mnt_userns, fs_userns, newattrs.ia_vfsgid));
+		from_vfsuid(idmap, fs_userns, newattrs.ia_vfsuid),
+		from_vfsgid(idmap, fs_userns, newattrs.ia_vfsgid));
 	if (!error)
-		error = notify_change(mnt_userns, path->dentry, &newattrs,
+		error = notify_change(idmap, path->dentry, &newattrs,
 				      &delegated_inode);
 	inode_unlock(inode);
 	if (delegated_inode) {
@@ -1065,7 +1066,7 @@ struct file *dentry_create(const struct path *path, int flags, umode_t mode,
 	if (IS_ERR(f))
 		return f;
 
-	error = vfs_create(mnt_user_ns(path->mnt),
+	error = vfs_create(mnt_idmap(path->mnt),
 			   d_inode(path->dentry->d_parent),
 			   path->dentry, mode, true);
 	if (!error)
diff --git a/fs/orangefs/acl.c b/fs/orangefs/acl.c
index c5da2091cefb..5aefb705bcc8 100644
--- a/fs/orangefs/acl.c
+++ b/fs/orangefs/acl.c
@@ -118,7 +118,7 @@ out:
 	return error;
 }
 
-int orangefs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int orangefs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct posix_acl *acl, int type)
 {
 	int error;
@@ -136,7 +136,7 @@ int orangefs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 		 * and "mode" to the new desired value. It is up to
 		 * us to propagate the new mode back to the server...
 		 */
-		error = posix_acl_update_mode(&init_user_ns, inode,
+		error = posix_acl_update_mode(&nop_mnt_idmap, inode,
 					      &iattr.ia_mode, &acl);
 		if (error) {
 			gossip_err("%s: posix_acl_update_mode err: %d\n",
diff --git a/fs/orangefs/inode.c b/fs/orangefs/inode.c
index 4df560894386..11e21a0e65ce 100644
--- a/fs/orangefs/inode.c
+++ b/fs/orangefs/inode.c
@@ -822,7 +822,7 @@ again:
 		ORANGEFS_I(inode)->attr_uid = current_fsuid();
 		ORANGEFS_I(inode)->attr_gid = current_fsgid();
 	}
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 	spin_unlock(&inode->i_lock);
 	mark_inode_dirty(inode);
 
@@ -839,20 +839,20 @@ int __orangefs_setattr_mode(struct dentry *dentry, struct iattr *iattr)
 	ret = __orangefs_setattr(inode, iattr);
 	/* change mode on a file that has ACLs */
 	if (!ret && (iattr->ia_valid & ATTR_MODE))
-		ret = posix_acl_chmod(&init_user_ns, dentry, inode->i_mode);
+		ret = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
 	return ret;
 }
 
 /*
  * Change attributes of an object referenced by dentry.
  */
-int orangefs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int orangefs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct iattr *iattr)
 {
 	int ret;
 	gossip_debug(GOSSIP_INODE_DEBUG, "__orangefs_setattr: called on %pd\n",
 	    dentry);
-	ret = setattr_prepare(&init_user_ns, dentry, iattr);
+	ret = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (ret)
 	        goto out;
 	ret = __orangefs_setattr_mode(dentry, iattr);
@@ -866,7 +866,7 @@ out:
 /*
  * Obtain attributes of an object given a dentry
  */
-int orangefs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int orangefs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		     struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	int ret;
@@ -879,7 +879,7 @@ int orangefs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 	ret = orangefs_inode_getattr(inode,
 	    request_mask & STATX_SIZE ? ORANGEFS_GETATTR_SIZE : 0);
 	if (ret == 0) {
-		generic_fillattr(&init_user_ns, inode, stat);
+		generic_fillattr(&nop_mnt_idmap, inode, stat);
 
 		/* override block size reported to stat */
 		if (!(request_mask & STATX_SIZE))
@@ -890,7 +890,7 @@ int orangefs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 	return ret;
 }
 
-int orangefs_permission(struct user_namespace *mnt_userns,
+int orangefs_permission(struct mnt_idmap *idmap,
 			struct inode *inode, int mask)
 {
 	int ret;
@@ -905,7 +905,7 @@ int orangefs_permission(struct user_namespace *mnt_userns,
 	if (ret < 0)
 		return ret;
 
-	return generic_permission(&init_user_ns, inode, mask);
+	return generic_permission(&nop_mnt_idmap, inode, mask);
 }
 
 int orangefs_update_time(struct inode *inode, struct timespec64 *time, int flags)
@@ -944,7 +944,7 @@ static int orangefs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return 0;
 }
 
-static int orangefs_fileattr_set(struct user_namespace *mnt_userns,
+static int orangefs_fileattr_set(struct mnt_idmap *idmap,
 				 struct dentry *dentry, struct fileattr *fa)
 {
 	u64 val = 0;
diff --git a/fs/orangefs/namei.c b/fs/orangefs/namei.c
index 75c1a3dcf68c..77518e248cf7 100644
--- a/fs/orangefs/namei.c
+++ b/fs/orangefs/namei.c
@@ -15,7 +15,7 @@
 /*
  * Get a newly allocated inode to go with a negative dentry.
  */
-static int orangefs_create(struct user_namespace *mnt_userns,
+static int orangefs_create(struct mnt_idmap *idmap,
 			struct inode *dir,
 			struct dentry *dentry,
 			umode_t mode,
@@ -216,7 +216,7 @@ static int orangefs_unlink(struct inode *dir, struct dentry *dentry)
 	return ret;
 }
 
-static int orangefs_symlink(struct user_namespace *mnt_userns,
+static int orangefs_symlink(struct mnt_idmap *idmap,
 		         struct inode *dir,
 			 struct dentry *dentry,
 			 const char *symname)
@@ -305,7 +305,7 @@ out:
 	return ret;
 }
 
-static int orangefs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int orangefs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			  struct dentry *dentry, umode_t mode)
 {
 	struct orangefs_inode_s *parent = ORANGEFS_I(dir);
@@ -375,7 +375,7 @@ out:
 	return ret;
 }
 
-static int orangefs_rename(struct user_namespace *mnt_userns,
+static int orangefs_rename(struct mnt_idmap *idmap,
 			struct inode *old_dir,
 			struct dentry *old_dentry,
 			struct inode *new_dir,
diff --git a/fs/orangefs/orangefs-kernel.h b/fs/orangefs/orangefs-kernel.h
index 6e0cc01b3a14..ce20d3443869 100644
--- a/fs/orangefs/orangefs-kernel.h
+++ b/fs/orangefs/orangefs-kernel.h
@@ -106,7 +106,7 @@ enum orangefs_vfs_op_states {
 extern const struct xattr_handler *orangefs_xattr_handlers[];
 
 extern struct posix_acl *orangefs_get_acl(struct inode *inode, int type, bool rcu);
-extern int orangefs_set_acl(struct user_namespace *mnt_userns,
+extern int orangefs_set_acl(struct mnt_idmap *idmap,
 			    struct dentry *dentry, struct posix_acl *acl,
 			    int type);
 int __orangefs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
@@ -362,12 +362,12 @@ struct inode *orangefs_new_inode(struct super_block *sb,
 
 int __orangefs_setattr(struct inode *, struct iattr *);
 int __orangefs_setattr_mode(struct dentry *dentry, struct iattr *iattr);
-int orangefs_setattr(struct user_namespace *, struct dentry *, struct iattr *);
+int orangefs_setattr(struct mnt_idmap *, struct dentry *, struct iattr *);
 
-int orangefs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int orangefs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		     struct kstat *stat, u32 request_mask, unsigned int flags);
 
-int orangefs_permission(struct user_namespace *mnt_userns,
+int orangefs_permission(struct mnt_idmap *idmap,
 			struct inode *inode, int mask);
 
 int orangefs_update_time(struct inode *, struct timespec64 *, int);
diff --git a/fs/orangefs/xattr.c b/fs/orangefs/xattr.c
index 9a5b757fbd2f..6ecad4f94ae6 100644
--- a/fs/orangefs/xattr.c
+++ b/fs/orangefs/xattr.c
@@ -526,7 +526,7 @@ out_unlock:
 }
 
 static int orangefs_xattr_set_default(const struct xattr_handler *handler,
-				      struct user_namespace *mnt_userns,
+				      struct mnt_idmap *idmap,
 				      struct dentry *unused,
 				      struct inode *inode,
 				      const char *name,
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index f61e37f4c8ff..fc25fb95d5fc 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -641,7 +641,7 @@ static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev,
 	inode->i_state |= I_CREATING;
 	spin_unlock(&inode->i_lock);
 
-	inode_init_owner(&init_user_ns, inode, dentry->d_parent->d_inode, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dentry->d_parent->d_inode, mode);
 	attr.mode = inode->i_mode;
 
 	err = ovl_create_or_link(dentry, inode, &attr, false);
@@ -655,19 +655,19 @@ out:
 	return err;
 }
 
-static int ovl_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int ovl_create(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, bool excl)
 {
 	return ovl_create_object(dentry, (mode & 07777) | S_IFREG, 0, NULL);
 }
 
-static int ovl_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int ovl_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry, umode_t mode)
 {
 	return ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL);
 }
 
-static int ovl_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int ovl_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	/* Don't allow creation of "whiteout" on overlay */
@@ -677,7 +677,7 @@ static int ovl_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	return ovl_create_object(dentry, mode, rdev, NULL);
 }
 
-static int ovl_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int ovl_symlink(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, const char *link)
 {
 	return ovl_create_object(dentry, S_IFLNK, 0, link);
@@ -1075,7 +1075,7 @@ static int ovl_set_redirect(struct dentry *dentry, bool samedir)
 	return err;
 }
 
-static int ovl_rename(struct user_namespace *mnt_userns, struct inode *olddir,
+static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir,
 		      struct dentry *old, struct inode *newdir,
 		      struct dentry *new, unsigned int flags)
 {
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index a25bb3453dde..defd4e231ad2 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -392,8 +392,8 @@ static struct dentry *ovl_lookup_real_one(struct dentry *connected,
 	 */
 	take_dentry_name_snapshot(&name, real);
 	/*
-	 * No mnt_userns handling here: it's an internal lookup.  Could skip
-	 * permission checking altogether, but for now just use non-mnt_userns
+	 * No idmap handling here: it's an internal lookup.  Could skip
+	 * permission checking altogether, but for now just use non-idmap
 	 * transformed ids.
 	 */
 	this = lookup_one_len(name.name.name, connected, name.name.len);
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index c9d0c362c7ef..7c04f033aadd 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -42,7 +42,7 @@ static struct file *ovl_open_realfile(const struct file *file,
 {
 	struct inode *realinode = d_inode(realpath->dentry);
 	struct inode *inode = file_inode(file);
-	struct user_namespace *real_mnt_userns;
+	struct mnt_idmap *real_idmap;
 	struct file *realfile;
 	const struct cred *old_cred;
 	int flags = file->f_flags | OVL_OPEN_FLAGS;
@@ -53,12 +53,12 @@ static struct file *ovl_open_realfile(const struct file *file,
 		acc_mode |= MAY_APPEND;
 
 	old_cred = ovl_override_creds(inode->i_sb);
-	real_mnt_userns = mnt_user_ns(realpath->mnt);
-	err = inode_permission(real_mnt_userns, realinode, MAY_OPEN | acc_mode);
+	real_idmap = mnt_idmap(realpath->mnt);
+	err = inode_permission(real_idmap, realinode, MAY_OPEN | acc_mode);
 	if (err) {
 		realfile = ERR_PTR(err);
 	} else {
-		if (!inode_owner_or_capable(real_mnt_userns, realinode))
+		if (!inode_owner_or_capable(real_idmap, realinode))
 			flags &= ~O_NOATIME;
 
 		realfile = open_with_fake_path(&file->f_path, flags, realinode,
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index ee6dfa577c93..541cf3717fc2 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -19,7 +19,7 @@
 #include "overlayfs.h"
 
 
-int ovl_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct iattr *attr)
 {
 	int err;
@@ -28,7 +28,7 @@ int ovl_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	struct dentry *upperdentry;
 	const struct cred *old_cred;
 
-	err = setattr_prepare(&init_user_ns, dentry, attr);
+	err = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (err)
 		return err;
 
@@ -153,7 +153,7 @@ static void ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat, int fsid)
 	}
 }
 
-int ovl_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ovl_getattr(struct mnt_idmap *idmap, const struct path *path,
 		struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	struct dentry *dentry = path->dentry;
@@ -278,7 +278,7 @@ out:
 	return err;
 }
 
-int ovl_permission(struct user_namespace *mnt_userns,
+int ovl_permission(struct mnt_idmap *idmap,
 		   struct inode *inode, int mask)
 {
 	struct inode *upperinode = ovl_inode_upper(inode);
@@ -298,7 +298,7 @@ int ovl_permission(struct user_namespace *mnt_userns,
 	 * Check overlay inode with the creds of task and underlying inode
 	 * with creds of mounter
 	 */
-	err = generic_permission(&init_user_ns, inode, mask);
+	err = generic_permission(&nop_mnt_idmap, inode, mask);
 	if (err)
 		return err;
 
@@ -310,7 +310,7 @@ int ovl_permission(struct user_namespace *mnt_userns,
 		/* Make sure mounter can read file for copy up later */
 		mask |= MAY_READ;
 	}
-	err = inode_permission(mnt_user_ns(realpath.mnt), realinode, mask);
+	err = inode_permission(mnt_idmap(realpath.mnt), realinode, mask);
 	revert_creds(old_cred);
 
 	return err;
@@ -361,7 +361,7 @@ int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
 	if (!value && !upperdentry) {
 		ovl_path_lower(dentry, &realpath);
 		old_cred = ovl_override_creds(dentry->d_sb);
-		err = vfs_getxattr(mnt_user_ns(realpath.mnt), realdentry, name, NULL, 0);
+		err = vfs_getxattr(mnt_idmap(realpath.mnt), realdentry, name, NULL, 0);
 		revert_creds(old_cred);
 		if (err < 0)
 			goto out_drop_write;
@@ -403,7 +403,7 @@ int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
 
 	ovl_i_path_real(inode, &realpath);
 	old_cred = ovl_override_creds(dentry->d_sb);
-	res = vfs_getxattr(mnt_user_ns(realpath.mnt), realpath.dentry, name, value, size);
+	res = vfs_getxattr(mnt_idmap(realpath.mnt), realpath.dentry, name, value, size);
 	revert_creds(old_cred);
 	return res;
 }
@@ -463,7 +463,7 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
  * alter the POSIX ACLs for the underlying filesystem.
  */
 static void ovl_idmap_posix_acl(const struct inode *realinode,
-				struct user_namespace *mnt_userns,
+				struct mnt_idmap *idmap,
 				struct posix_acl *acl)
 {
 	struct user_namespace *fs_userns = i_user_ns(realinode);
@@ -475,11 +475,11 @@ static void ovl_idmap_posix_acl(const struct inode *realinode,
 		struct posix_acl_entry *e = &acl->a_entries[i];
 		switch (e->e_tag) {
 		case ACL_USER:
-			vfsuid = make_vfsuid(mnt_userns, fs_userns, e->e_uid);
+			vfsuid = make_vfsuid(idmap, fs_userns, e->e_uid);
 			e->e_uid = vfsuid_into_kuid(vfsuid);
 			break;
 		case ACL_GROUP:
-			vfsgid = make_vfsgid(mnt_userns, fs_userns, e->e_gid);
+			vfsgid = make_vfsgid(idmap, fs_userns, e->e_gid);
 			e->e_gid = vfsgid_into_kgid(vfsgid);
 			break;
 		}
@@ -514,15 +514,15 @@ struct posix_acl *ovl_get_acl_path(const struct path *path,
 				   const char *acl_name, bool noperm)
 {
 	struct posix_acl *real_acl, *clone;
-	struct user_namespace *mnt_userns;
+	struct mnt_idmap *idmap;
 	struct inode *realinode = d_inode(path->dentry);
 
-	mnt_userns = mnt_user_ns(path->mnt);
+	idmap = mnt_idmap(path->mnt);
 
 	if (noperm)
 		real_acl = get_inode_acl(realinode, posix_acl_type(acl_name));
 	else
-		real_acl = vfs_get_acl(mnt_userns, path->dentry, acl_name);
+		real_acl = vfs_get_acl(idmap, path->dentry, acl_name);
 	if (IS_ERR_OR_NULL(real_acl))
 		return real_acl;
 
@@ -540,7 +540,7 @@ struct posix_acl *ovl_get_acl_path(const struct path *path,
 	if (!clone)
 		return ERR_PTR(-ENOMEM);
 
-	ovl_idmap_posix_acl(realinode, mnt_userns, clone);
+	ovl_idmap_posix_acl(realinode, idmap, clone);
 	return clone;
 }
 
@@ -555,7 +555,7 @@ struct posix_acl *ovl_get_acl_path(const struct path *path,
  *
  * This is obviously only relevant when idmapped layers are used.
  */
-struct posix_acl *do_ovl_get_acl(struct user_namespace *mnt_userns,
+struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap,
 				 struct inode *inode, int type,
 				 bool rcu, bool noperm)
 {
@@ -618,7 +618,7 @@ static int ovl_set_or_remove_acl(struct dentry *dentry, struct inode *inode,
 
 		ovl_path_lower(dentry, &realpath);
 		old_cred = ovl_override_creds(dentry->d_sb);
-		real_acl = vfs_get_acl(mnt_user_ns(realpath.mnt), realdentry,
+		real_acl = vfs_get_acl(mnt_idmap(realpath.mnt), realdentry,
 				       acl_name);
 		revert_creds(old_cred);
 		if (IS_ERR(real_acl)) {
@@ -651,7 +651,7 @@ out_drop_write:
 	return err;
 }
 
-int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct posix_acl *acl, int type)
 {
 	int err;
@@ -665,7 +665,7 @@ int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 		return -EOPNOTSUPP;
 	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
 		return acl ? -EACCES : 0;
-	if (!inode_owner_or_capable(&init_user_ns, inode))
+	if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
 		return -EPERM;
 
 	/*
@@ -674,10 +674,10 @@ int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 	 */
 	if (unlikely(inode->i_mode & S_ISGID) && type == ACL_TYPE_ACCESS &&
 	    !in_group_p(inode->i_gid) &&
-	    !capable_wrt_inode_uidgid(&init_user_ns, inode, CAP_FSETID)) {
+	    !capable_wrt_inode_uidgid(&nop_mnt_idmap, inode, CAP_FSETID)) {
 		struct iattr iattr = { .ia_valid = ATTR_KILL_SGID };
 
-		err = ovl_setattr(&init_user_ns, dentry, &iattr);
+		err = ovl_setattr(&nop_mnt_idmap, dentry, &iattr);
 		if (err)
 			return err;
 	}
@@ -755,10 +755,10 @@ int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa)
 	if (err)
 		return err;
 
-	return vfs_fileattr_set(mnt_user_ns(realpath->mnt), realpath->dentry, fa);
+	return vfs_fileattr_set(mnt_idmap(realpath->mnt), realpath->dentry, fa);
 }
 
-int ovl_fileattr_set(struct user_namespace *mnt_userns,
+int ovl_fileattr_set(struct mnt_idmap *idmap,
 		     struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 46753134533a..cfb3420b7df0 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -204,7 +204,7 @@ static struct dentry *ovl_lookup_positive_unlocked(struct ovl_lookup_data *d,
 						   struct dentry *base, int len,
 						   bool drop_negative)
 {
-	struct dentry *ret = lookup_one_unlocked(mnt_user_ns(d->mnt), name, base, len);
+	struct dentry *ret = lookup_one_unlocked(mnt_idmap(d->mnt), name, base, len);
 
 	if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) {
 		if (drop_negative && ret->d_lockref.count == 1) {
@@ -711,7 +711,7 @@ struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
 	if (err)
 		return ERR_PTR(err);
 
-	index = lookup_one_positive_unlocked(ovl_upper_mnt_userns(ofs), name.name,
+	index = lookup_one_positive_unlocked(ovl_upper_mnt_idmap(ofs), name.name,
 					     ofs->indexdir, name.len);
 	if (IS_ERR(index)) {
 		err = PTR_ERR(index);
@@ -1182,7 +1182,7 @@ bool ovl_lower_positive(struct dentry *dentry)
 		struct dentry *this;
 		struct dentry *lowerdir = poe->lowerstack[i].dentry;
 
-		this = lookup_one_positive_unlocked(mnt_user_ns(poe->lowerstack[i].layer->mnt),
+		this = lookup_one_positive_unlocked(mnt_idmap(poe->lowerstack[i].layer->mnt),
 						   name->name, lowerdir, name->len);
 		if (IS_ERR(this)) {
 			switch (PTR_ERR(this)) {
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 1df7f850ff3b..4d0b278f5630 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -141,13 +141,13 @@ static inline int ovl_do_notify_change(struct ovl_fs *ofs,
 				       struct dentry *upperdentry,
 				       struct iattr *attr)
 {
-	return notify_change(ovl_upper_mnt_userns(ofs), upperdentry, attr, NULL);
+	return notify_change(ovl_upper_mnt_idmap(ofs), upperdentry, attr, NULL);
 }
 
 static inline int ovl_do_rmdir(struct ovl_fs *ofs,
 			       struct inode *dir, struct dentry *dentry)
 {
-	int err = vfs_rmdir(ovl_upper_mnt_userns(ofs), dir, dentry);
+	int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry);
 
 	pr_debug("rmdir(%pd2) = %i\n", dentry, err);
 	return err;
@@ -156,7 +156,7 @@ static inline int ovl_do_rmdir(struct ovl_fs *ofs,
 static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir,
 				struct dentry *dentry)
 {
-	int err = vfs_unlink(ovl_upper_mnt_userns(ofs), dir, dentry, NULL);
+	int err = vfs_unlink(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL);
 
 	pr_debug("unlink(%pd2) = %i\n", dentry, err);
 	return err;
@@ -165,7 +165,8 @@ static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir,
 static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry,
 			      struct inode *dir, struct dentry *new_dentry)
 {
-	int err = vfs_link(old_dentry, ovl_upper_mnt_userns(ofs), dir, new_dentry, NULL);
+	int err = vfs_link(old_dentry, ovl_upper_mnt_idmap(ofs), dir,
+			   new_dentry, NULL);
 
 	pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err);
 	return err;
@@ -175,7 +176,7 @@ static inline int ovl_do_create(struct ovl_fs *ofs,
 				struct inode *dir, struct dentry *dentry,
 				umode_t mode)
 {
-	int err = vfs_create(ovl_upper_mnt_userns(ofs), dir, dentry, mode, true);
+	int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true);
 
 	pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
 	return err;
@@ -185,7 +186,7 @@ static inline int ovl_do_mkdir(struct ovl_fs *ofs,
 			       struct inode *dir, struct dentry *dentry,
 			       umode_t mode)
 {
-	int err = vfs_mkdir(ovl_upper_mnt_userns(ofs), dir, dentry, mode);
+	int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode);
 	pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
 	return err;
 }
@@ -194,7 +195,7 @@ static inline int ovl_do_mknod(struct ovl_fs *ofs,
 			       struct inode *dir, struct dentry *dentry,
 			       umode_t mode, dev_t dev)
 {
-	int err = vfs_mknod(ovl_upper_mnt_userns(ofs), dir, dentry, mode, dev);
+	int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev);
 
 	pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
 	return err;
@@ -204,7 +205,7 @@ static inline int ovl_do_symlink(struct ovl_fs *ofs,
 				 struct inode *dir, struct dentry *dentry,
 				 const char *oldname)
 {
-	int err = vfs_symlink(ovl_upper_mnt_userns(ofs), dir, dentry, oldname);
+	int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname);
 
 	pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
 	return err;
@@ -217,7 +218,7 @@ static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name,
 
 	WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb);
 
-	err = vfs_getxattr(mnt_user_ns(path->mnt), path->dentry,
+	err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry,
 			       name, value, size);
 	len = (value && err > 0) ? err : 0;
 
@@ -251,7 +252,7 @@ static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
 				  const char *name, const void *value,
 				  size_t size, int flags)
 {
-	int err = vfs_setxattr(ovl_upper_mnt_userns(ofs), dentry, name,
+	int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name,
 			       value, size, flags);
 
 	pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n",
@@ -269,7 +270,7 @@ static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry,
 				     const char *name)
 {
-	int err = vfs_removexattr(ovl_upper_mnt_userns(ofs), dentry, name);
+	int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name);
 	pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
 	return err;
 }
@@ -283,13 +284,13 @@ static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry,
 static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry,
 				 const char *acl_name, struct posix_acl *acl)
 {
-	return vfs_set_acl(ovl_upper_mnt_userns(ofs), dentry, acl_name, acl);
+	return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl);
 }
 
 static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry,
 				    const char *acl_name)
 {
-	return vfs_remove_acl(ovl_upper_mnt_userns(ofs), dentry, acl_name);
+	return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name);
 }
 
 static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir,
@@ -298,10 +299,10 @@ static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir,
 {
 	int err;
 	struct renamedata rd = {
-		.old_mnt_userns	= ovl_upper_mnt_userns(ofs),
+		.old_mnt_idmap	= ovl_upper_mnt_idmap(ofs),
 		.old_dir 	= olddir,
 		.old_dentry 	= olddentry,
-		.new_mnt_userns	= ovl_upper_mnt_userns(ofs),
+		.new_mnt_idmap	= ovl_upper_mnt_idmap(ofs),
 		.new_dir 	= newdir,
 		.new_dentry 	= newdentry,
 		.flags 		= flags,
@@ -319,7 +320,7 @@ static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir,
 static inline int ovl_do_whiteout(struct ovl_fs *ofs,
 				  struct inode *dir, struct dentry *dentry)
 {
-	int err = vfs_whiteout(ovl_upper_mnt_userns(ofs), dir, dentry);
+	int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry);
 	pr_debug("whiteout(%pd2) = %i\n", dentry, err);
 	return err;
 }
@@ -328,7 +329,7 @@ static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs,
 					  struct dentry *dentry, umode_t mode)
 {
 	struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry };
-	struct file *file = vfs_tmpfile_open(ovl_upper_mnt_userns(ofs), &path, mode,
+	struct file *file = vfs_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, mode,
 					O_LARGEFILE | O_WRONLY, current_cred());
 	int err = PTR_ERR_OR_ZERO(file);
 
@@ -340,7 +341,7 @@ static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs,
 					      const char *name,
 					      struct dentry *base, int len)
 {
-	return lookup_one(ovl_upper_mnt_userns(ofs), name, base, len);
+	return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len);
 }
 
 static inline bool ovl_open_flags_need_copy_up(int flags)
@@ -596,11 +597,11 @@ int ovl_set_nlink_lower(struct dentry *dentry);
 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry,
 			   struct dentry *upperdentry,
 			   unsigned int fallback);
-int ovl_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct iattr *attr);
-int ovl_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ovl_getattr(struct mnt_idmap *idmap, const struct path *path,
 		struct kstat *stat, u32 request_mask, unsigned int flags);
-int ovl_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int ovl_permission(struct mnt_idmap *idmap, struct inode *inode,
 		   int mask);
 int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
 		  const void *value, size_t size, int flags);
@@ -609,20 +610,20 @@ int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
 
 #ifdef CONFIG_FS_POSIX_ACL
-struct posix_acl *do_ovl_get_acl(struct user_namespace *mnt_userns,
+struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap,
 				 struct inode *inode, int type,
 				 bool rcu, bool noperm);
 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type,
 						  bool rcu)
 {
-	return do_ovl_get_acl(&init_user_ns, inode, type, rcu, true);
+	return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true);
 }
-static inline struct posix_acl *ovl_get_acl(struct user_namespace *mnt_userns,
+static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap,
 					    struct dentry *dentry, int type)
 {
-	return do_ovl_get_acl(mnt_userns, d_inode(dentry), type, false, false);
+	return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false);
 }
-int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct posix_acl *acl, int type);
 struct posix_acl *ovl_get_acl_path(const struct path *path,
 				   const char *acl_name, bool noperm);
@@ -717,7 +718,7 @@ void ovl_aio_request_cache_destroy(void);
 int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa);
 int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa);
 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-int ovl_fileattr_set(struct user_namespace *mnt_userns,
+int ovl_fileattr_set(struct mnt_idmap *idmap,
 		     struct dentry *dentry, struct fileattr *fa);
 
 /* copy_up.c */
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index e1af8f660698..fd11fe6d6d45 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -90,9 +90,9 @@ static inline struct vfsmount *ovl_upper_mnt(struct ovl_fs *ofs)
 	return ofs->layers[0].mnt;
 }
 
-static inline struct user_namespace *ovl_upper_mnt_userns(struct ovl_fs *ofs)
+static inline struct mnt_idmap *ovl_upper_mnt_idmap(struct ovl_fs *ofs)
 {
-	return mnt_user_ns(ovl_upper_mnt(ofs));
+	return mnt_idmap(ovl_upper_mnt(ofs));
 }
 
 static inline struct ovl_fs *OVL_FS(struct super_block *sb)
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 8cd2b9947de1..b6952b21a7ee 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -278,7 +278,7 @@ static int ovl_check_whiteouts(const struct path *path, struct ovl_readdir_data
 		while (rdd->first_maybe_whiteout) {
 			p = rdd->first_maybe_whiteout;
 			rdd->first_maybe_whiteout = p->next_maybe_whiteout;
-			dentry = lookup_one(mnt_user_ns(path->mnt), p->name, dir, p->len);
+			dentry = lookup_one(mnt_idmap(path->mnt), p->name, dir, p->len);
 			if (!IS_ERR(dentry)) {
 				p->is_whiteout = ovl_is_whiteout(dentry);
 				dput(dentry);
@@ -480,7 +480,7 @@ static int ovl_cache_update_ino(const struct path *path, struct ovl_cache_entry
 			goto get;
 		}
 	}
-	this = lookup_one(mnt_user_ns(path->mnt), p->name, dir, p->len);
+	this = lookup_one(mnt_idmap(path->mnt), p->name, dir, p->len);
 	if (IS_ERR_OR_NULL(this) || !this->d_inode) {
 		/* Mark a stale entry */
 		p->is_whiteout = true;
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 85b891152a2c..f1d9f75f8786 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1012,7 +1012,7 @@ static int ovl_own_xattr_get(const struct xattr_handler *handler,
 }
 
 static int ovl_own_xattr_set(const struct xattr_handler *handler,
-			     struct user_namespace *mnt_userns,
+			     struct mnt_idmap *idmap,
 			     struct dentry *dentry, struct inode *inode,
 			     const char *name, const void *value,
 			     size_t size, int flags)
@@ -1028,7 +1028,7 @@ static int ovl_other_xattr_get(const struct xattr_handler *handler,
 }
 
 static int ovl_other_xattr_set(const struct xattr_handler *handler,
-			       struct user_namespace *mnt_userns,
+			       struct mnt_idmap *idmap,
 			       struct dentry *dentry, struct inode *inode,
 			       const char *name, const void *value,
 			       size_t size, int flags)
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index bde291623c8c..923d66d131c1 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -491,7 +491,7 @@ bool ovl_is_whiteout(struct dentry *dentry)
 struct file *ovl_path_open(const struct path *path, int flags)
 {
 	struct inode *inode = d_inode(path->dentry);
-	struct user_namespace *real_mnt_userns = mnt_user_ns(path->mnt);
+	struct mnt_idmap *real_idmap = mnt_idmap(path->mnt);
 	int err, acc_mode;
 
 	if (flags & ~(O_ACCMODE | O_LARGEFILE))
@@ -508,12 +508,12 @@ struct file *ovl_path_open(const struct path *path, int flags)
 		BUG();
 	}
 
-	err = inode_permission(real_mnt_userns, inode, acc_mode | MAY_OPEN);
+	err = inode_permission(real_idmap, inode, acc_mode | MAY_OPEN);
 	if (err)
 		return ERR_PTR(err);
 
 	/* O_NOATIME is an optimization, don't fail if not permitted */
-	if (inode_owner_or_capable(real_mnt_userns, inode))
+	if (inode_owner_or_capable(real_idmap, inode))
 		flags |= O_NOATIME;
 
 	return dentry_open(path, flags, current_cred());
@@ -1101,16 +1101,16 @@ void ovl_copyattr(struct inode *inode)
 {
 	struct path realpath;
 	struct inode *realinode;
-	struct user_namespace *real_mnt_userns;
+	struct mnt_idmap *real_idmap;
 	vfsuid_t vfsuid;
 	vfsgid_t vfsgid;
 
 	ovl_i_path_real(inode, &realpath);
 	realinode = d_inode(realpath.dentry);
-	real_mnt_userns = mnt_user_ns(realpath.mnt);
+	real_idmap = mnt_idmap(realpath.mnt);
 
-	vfsuid = i_uid_into_vfsuid(real_mnt_userns, realinode);
-	vfsgid = i_gid_into_vfsgid(real_mnt_userns, realinode);
+	vfsuid = i_uid_into_vfsuid(real_idmap, realinode);
+	vfsgid = i_gid_into_vfsgid(real_idmap, realinode);
 
 	inode->i_uid = vfsuid_into_kuid(vfsuid);
 	inode->i_gid = vfsgid_into_kgid(vfsgid);
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index d2271431f344..fda167069617 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -112,7 +112,7 @@ void forget_all_cached_acls(struct inode *inode)
 }
 EXPORT_SYMBOL(forget_all_cached_acls);
 
-static struct posix_acl *__get_acl(struct user_namespace *mnt_userns,
+static struct posix_acl *__get_acl(struct mnt_idmap *idmap,
 				   struct dentry *dentry, struct inode *inode,
 				   int type)
 {
@@ -155,7 +155,7 @@ static struct posix_acl *__get_acl(struct user_namespace *mnt_userns,
 	 * we'll just create the negative cache entry.
 	 */
 	if (dentry && inode->i_op->get_acl) {
-		acl = inode->i_op->get_acl(mnt_userns, dentry, type);
+		acl = inode->i_op->get_acl(idmap, dentry, type);
 	} else if (inode->i_op->get_inode_acl) {
 		acl = inode->i_op->get_inode_acl(inode, type, false);
 	} else {
@@ -182,7 +182,7 @@ static struct posix_acl *__get_acl(struct user_namespace *mnt_userns,
 
 struct posix_acl *get_inode_acl(struct inode *inode, int type)
 {
-	return __get_acl(&init_user_ns, NULL, inode, type);
+	return __get_acl(&nop_mnt_idmap, NULL, inode, type);
 }
 EXPORT_SYMBOL(get_inode_acl);
 
@@ -373,7 +373,7 @@ EXPORT_SYMBOL(posix_acl_from_mode);
  * by the acl. Returns -E... otherwise.
  */
 int
-posix_acl_permission(struct user_namespace *mnt_userns, struct inode *inode,
+posix_acl_permission(struct mnt_idmap *idmap, struct inode *inode,
 		     const struct posix_acl *acl, int want)
 {
 	const struct posix_acl_entry *pa, *pe, *mask_obj;
@@ -388,18 +388,18 @@ posix_acl_permission(struct user_namespace *mnt_userns, struct inode *inode,
                 switch(pa->e_tag) {
                         case ACL_USER_OBJ:
 				/* (May have been checked already) */
-				vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
+				vfsuid = i_uid_into_vfsuid(idmap, inode);
 				if (vfsuid_eq_kuid(vfsuid, current_fsuid()))
                                         goto check_perm;
                                 break;
                         case ACL_USER:
-				vfsuid = make_vfsuid(mnt_userns, fs_userns,
+				vfsuid = make_vfsuid(idmap, fs_userns,
 						     pa->e_uid);
 				if (vfsuid_eq_kuid(vfsuid, current_fsuid()))
                                         goto mask;
 				break;
                         case ACL_GROUP_OBJ:
-				vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
+				vfsgid = i_gid_into_vfsgid(idmap, inode);
 				if (vfsgid_in_group_p(vfsgid)) {
 					found = 1;
 					if ((pa->e_perm & want) == want)
@@ -407,7 +407,7 @@ posix_acl_permission(struct user_namespace *mnt_userns, struct inode *inode,
                                 }
 				break;
                         case ACL_GROUP:
-				vfsgid = make_vfsgid(mnt_userns, fs_userns,
+				vfsgid = make_vfsgid(idmap, fs_userns,
 						     pa->e_gid);
 				if (vfsgid_in_group_p(vfsgid)) {
 					found = 1;
@@ -592,18 +592,18 @@ EXPORT_SYMBOL(__posix_acl_chmod);
 /**
  * posix_acl_chmod - chmod a posix acl
  *
- * @mnt_userns:	user namespace of the mount @inode was found from
+ * @idmap:	idmap of the mount @inode was found from
  * @dentry:	dentry to check permissions on
  * @mode:	the new mode of @inode
  *
- * If the dentry has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then
- * take care to map the inode according to @mnt_userns before checking
+ * If the dentry has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then
+ * take care to map the inode according to @idmap before checking
  * permissions. On non-idmapped mounts or if permission checking is to be
- * performed on the raw inode simply passs init_user_ns.
+ * performed on the raw inode simply passs @nop_mnt_idmap.
  */
 int
- posix_acl_chmod(struct user_namespace *mnt_userns, struct dentry *dentry,
+ posix_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry,
 		    umode_t mode)
 {
 	struct inode *inode = d_inode(dentry);
@@ -625,7 +625,7 @@ int
 	ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode);
 	if (ret)
 		return ret;
-	ret = inode->i_op->set_acl(mnt_userns, dentry, acl, ACL_TYPE_ACCESS);
+	ret = inode->i_op->set_acl(idmap, dentry, acl, ACL_TYPE_ACCESS);
 	posix_acl_release(acl);
 	return ret;
 }
@@ -684,7 +684,7 @@ EXPORT_SYMBOL_GPL(posix_acl_create);
 
 /**
  * posix_acl_update_mode  -  update mode in set_acl
- * @mnt_userns:	user namespace of the mount @inode was found from
+ * @idmap:	idmap of the mount @inode was found from
  * @inode:	target inode
  * @mode_p:	mode (pointer) for update
  * @acl:	acl pointer
@@ -696,15 +696,15 @@ EXPORT_SYMBOL_GPL(posix_acl_create);
  * As with chmod, clear the setgid bit if the caller is not in the owning group
  * or capable of CAP_FSETID (see inode_change_ok).
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then
- * take care to map the inode according to @mnt_userns before checking
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then
+ * take care to map the inode according to @idmap before checking
  * permissions. On non-idmapped mounts or if permission checking is to be
- * performed on the raw inode simply passs init_user_ns.
+ * performed on the raw inode simply passs @nop_mnt_idmap.
  *
  * Called from set_acl inode operations.
  */
-int posix_acl_update_mode(struct user_namespace *mnt_userns,
+int posix_acl_update_mode(struct mnt_idmap *idmap,
 			  struct inode *inode, umode_t *mode_p,
 			  struct posix_acl **acl)
 {
@@ -716,8 +716,8 @@ int posix_acl_update_mode(struct user_namespace *mnt_userns,
 		return error;
 	if (error == 0)
 		*acl = NULL;
-	if (!vfsgid_in_group_p(i_gid_into_vfsgid(mnt_userns, inode)) &&
-	    !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
+	if (!vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)) &&
+	    !capable_wrt_inode_uidgid(idmap, inode, CAP_FSETID))
 		mode &= ~S_ISGID;
 	*mode_p = mode;
 	return 0;
@@ -894,7 +894,6 @@ static ssize_t vfs_posix_acl_to_xattr(struct mnt_idmap *idmap,
 	struct posix_acl_xattr_header *ext_acl = buffer;
 	struct posix_acl_xattr_entry *ext_entry;
 	struct user_namespace *fs_userns, *caller_userns;
-	struct user_namespace *mnt_userns;
 	ssize_t real_size, n;
 	vfsuid_t vfsuid;
 	vfsgid_t vfsgid;
@@ -910,19 +909,18 @@ static ssize_t vfs_posix_acl_to_xattr(struct mnt_idmap *idmap,
 
 	fs_userns = i_user_ns(inode);
 	caller_userns = current_user_ns();
-	mnt_userns = mnt_idmap_owner(idmap);
 	for (n=0; n < acl->a_count; n++, ext_entry++) {
 		const struct posix_acl_entry *acl_e = &acl->a_entries[n];
 		ext_entry->e_tag  = cpu_to_le16(acl_e->e_tag);
 		ext_entry->e_perm = cpu_to_le16(acl_e->e_perm);
 		switch(acl_e->e_tag) {
 		case ACL_USER:
-			vfsuid = make_vfsuid(mnt_userns, fs_userns, acl_e->e_uid);
+			vfsuid = make_vfsuid(idmap, fs_userns, acl_e->e_uid);
 			ext_entry->e_id = cpu_to_le32(from_kuid(
 				caller_userns, vfsuid_into_kuid(vfsuid)));
 			break;
 		case ACL_GROUP:
-			vfsgid = make_vfsgid(mnt_userns, fs_userns, acl_e->e_gid);
+			vfsgid = make_vfsgid(idmap, fs_userns, acl_e->e_gid);
 			ext_entry->e_id = cpu_to_le32(from_kgid(
 				caller_userns, vfsgid_into_kgid(vfsgid)));
 			break;
@@ -935,7 +933,7 @@ static ssize_t vfs_posix_acl_to_xattr(struct mnt_idmap *idmap,
 }
 
 int
-set_posix_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+set_posix_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	      int type, struct posix_acl *acl)
 {
 	struct inode *inode = d_inode(dentry);
@@ -947,7 +945,7 @@ set_posix_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
 		return acl ? -EACCES : 0;
-	if (!inode_owner_or_capable(mnt_userns, inode))
+	if (!inode_owner_or_capable(idmap, inode))
 		return -EPERM;
 
 	if (acl) {
@@ -955,7 +953,7 @@ set_posix_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 		if (ret)
 			return ret;
 	}
-	return inode->i_op->set_acl(mnt_userns, dentry, acl, type);
+	return inode->i_op->set_acl(idmap, dentry, acl, type);
 }
 EXPORT_SYMBOL(set_posix_acl);
 
@@ -979,14 +977,14 @@ const struct xattr_handler posix_acl_default_xattr_handler = {
 };
 EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler);
 
-int simple_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int simple_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		   struct posix_acl *acl, int type)
 {
 	int error;
 	struct inode *inode = d_inode(dentry);
 
 	if (type == ACL_TYPE_ACCESS) {
-		error = posix_acl_update_mode(mnt_userns, inode,
+		error = posix_acl_update_mode(idmap, inode,
 				&inode->i_mode, &acl);
 		if (error)
 			return error;
@@ -1018,7 +1016,7 @@ int simple_acl_create(struct inode *dir, struct inode *inode)
 	return 0;
 }
 
-static int vfs_set_acl_idmapped_mnt(struct user_namespace *mnt_userns,
+static int vfs_set_acl_idmapped_mnt(struct mnt_idmap *idmap,
 				    struct user_namespace *fs_userns,
 				    struct posix_acl *acl)
 {
@@ -1027,11 +1025,11 @@ static int vfs_set_acl_idmapped_mnt(struct user_namespace *mnt_userns,
 
 		switch (acl_e->e_tag) {
 		case ACL_USER:
-			acl_e->e_uid = from_vfsuid(mnt_userns, fs_userns,
+			acl_e->e_uid = from_vfsuid(idmap, fs_userns,
 						   VFSUIDT_INIT(acl_e->e_uid));
 			break;
 		case ACL_GROUP:
-			acl_e->e_gid = from_vfsgid(mnt_userns, fs_userns,
+			acl_e->e_gid = from_vfsgid(idmap, fs_userns,
 						   VFSGIDT_INIT(acl_e->e_gid));
 			break;
 		}
@@ -1042,7 +1040,7 @@ static int vfs_set_acl_idmapped_mnt(struct user_namespace *mnt_userns,
 
 /**
  * vfs_set_acl - set posix acls
- * @mnt_userns: user namespace of the mount
+ * @idmap: idmap of the mount
  * @dentry: the dentry based on which to set the posix acls
  * @acl_name: the name of the posix acl
  * @kacl: the posix acls in the appropriate VFS format
@@ -1052,7 +1050,7 @@ static int vfs_set_acl_idmapped_mnt(struct user_namespace *mnt_userns,
  *
  * Return: On success 0, on error negative errno.
  */
-int vfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		const char *acl_name, struct posix_acl *kacl)
 {
 	int acl_type;
@@ -1072,7 +1070,7 @@ int vfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 		 * if this is a filesystem with a backing store - ultimately
 		 * translate them to backing store values.
 		 */
-		error = vfs_set_acl_idmapped_mnt(mnt_userns, i_user_ns(inode), kacl);
+		error = vfs_set_acl_idmapped_mnt(idmap, i_user_ns(inode), kacl);
 		if (error)
 			return error;
 	}
@@ -1084,11 +1082,11 @@ retry_deleg:
 	 * We only care about restrictions the inode struct itself places upon
 	 * us otherwise POSIX ACLs aren't subject to any VFS restrictions.
 	 */
-	error = may_write_xattr(mnt_userns, inode);
+	error = may_write_xattr(idmap, inode);
 	if (error)
 		goto out_inode_unlock;
 
-	error = security_inode_set_acl(mnt_userns, dentry, acl_name, kacl);
+	error = security_inode_set_acl(idmap, dentry, acl_name, kacl);
 	if (error)
 		goto out_inode_unlock;
 
@@ -1097,7 +1095,7 @@ retry_deleg:
 		goto out_inode_unlock;
 
 	if (inode->i_opflags & IOP_XATTR)
-		error = set_posix_acl(mnt_userns, dentry, acl_type, kacl);
+		error = set_posix_acl(idmap, dentry, acl_type, kacl);
 	else if (unlikely(is_bad_inode(inode)))
 		error = -EIO;
 	else
@@ -1122,7 +1120,7 @@ EXPORT_SYMBOL_GPL(vfs_set_acl);
 
 /**
  * vfs_get_acl - get posix acls
- * @mnt_userns: user namespace of the mount
+ * @idmap: idmap of the mount
  * @dentry: the dentry based on which to retrieve the posix acls
  * @acl_name: the name of the posix acl
  *
@@ -1131,7 +1129,7 @@ EXPORT_SYMBOL_GPL(vfs_set_acl);
  *
  * Return: On success POSIX ACLs in VFS format, on error negative errno.
  */
-struct posix_acl *vfs_get_acl(struct user_namespace *mnt_userns,
+struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
 			      struct dentry *dentry, const char *acl_name)
 {
 	struct inode *inode = d_inode(dentry);
@@ -1146,7 +1144,7 @@ struct posix_acl *vfs_get_acl(struct user_namespace *mnt_userns,
 	 * The VFS has no restrictions on reading POSIX ACLs so calling
 	 * something like xattr_permission() isn't needed. Only LSMs get a say.
 	 */
-	error = security_inode_get_acl(mnt_userns, dentry, acl_name);
+	error = security_inode_get_acl(idmap, dentry, acl_name);
 	if (error)
 		return ERR_PTR(error);
 
@@ -1155,7 +1153,7 @@ struct posix_acl *vfs_get_acl(struct user_namespace *mnt_userns,
 	if (S_ISLNK(inode->i_mode))
 		return ERR_PTR(-EOPNOTSUPP);
 
-	acl = __get_acl(mnt_userns, dentry, inode, acl_type);
+	acl = __get_acl(idmap, dentry, inode, acl_type);
 	if (IS_ERR(acl))
 		return acl;
 	if (!acl)
@@ -1167,7 +1165,7 @@ EXPORT_SYMBOL_GPL(vfs_get_acl);
 
 /**
  * vfs_remove_acl - remove posix acls
- * @mnt_userns: user namespace of the mount
+ * @idmap: idmap of the mount
  * @dentry: the dentry based on which to retrieve the posix acls
  * @acl_name: the name of the posix acl
  *
@@ -1175,7 +1173,7 @@ EXPORT_SYMBOL_GPL(vfs_get_acl);
  *
  * Return: On success 0, on error negative errno.
  */
-int vfs_remove_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		   const char *acl_name)
 {
 	int acl_type;
@@ -1194,11 +1192,11 @@ retry_deleg:
 	 * We only care about restrictions the inode struct itself places upon
 	 * us otherwise POSIX ACLs aren't subject to any VFS restrictions.
 	 */
-	error = may_write_xattr(mnt_userns, inode);
+	error = may_write_xattr(idmap, inode);
 	if (error)
 		goto out_inode_unlock;
 
-	error = security_inode_remove_acl(mnt_userns, dentry, acl_name);
+	error = security_inode_remove_acl(idmap, dentry, acl_name);
 	if (error)
 		goto out_inode_unlock;
 
@@ -1207,14 +1205,14 @@ retry_deleg:
 		goto out_inode_unlock;
 
 	if (inode->i_opflags & IOP_XATTR)
-		error = set_posix_acl(mnt_userns, dentry, acl_type, NULL);
+		error = set_posix_acl(idmap, dentry, acl_type, NULL);
 	else if (unlikely(is_bad_inode(inode)))
 		error = -EIO;
 	else
 		error = -EOPNOTSUPP;
 	if (!error) {
 		fsnotify_xattr(dentry);
-		evm_inode_post_remove_acl(mnt_userns, dentry, acl_name);
+		evm_inode_post_remove_acl(idmap, dentry, acl_name);
 	}
 
 out_inode_unlock:
@@ -1246,7 +1244,7 @@ int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 			return PTR_ERR(acl);
 	}
 
-	error = vfs_set_acl(mnt_idmap_owner(idmap), dentry, acl_name, acl);
+	error = vfs_set_acl(idmap, dentry, acl_name, acl);
 	posix_acl_release(acl);
 	return error;
 }
@@ -1257,7 +1255,7 @@ ssize_t do_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	ssize_t error;
 	struct posix_acl *acl;
 
-	acl = vfs_get_acl(mnt_idmap_owner(idmap), dentry, acl_name);
+	acl = vfs_get_acl(idmap, dentry, acl_name);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
 
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 9e479d7d202b..5e0e0ccd47aa 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -685,7 +685,7 @@ static bool proc_fd_access_allowed(struct inode *inode)
 	return allowed;
 }
 
-int proc_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int proc_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct iattr *attr)
 {
 	int error;
@@ -694,11 +694,11 @@ int proc_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (attr->ia_valid & ATTR_MODE)
 		return -EPERM;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
@@ -727,7 +727,7 @@ static bool has_pid_permissions(struct proc_fs_info *fs_info,
 }
 
 
-static int proc_pid_permission(struct user_namespace *mnt_userns,
+static int proc_pid_permission(struct mnt_idmap *idmap,
 			       struct inode *inode, int mask)
 {
 	struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
@@ -753,7 +753,7 @@ static int proc_pid_permission(struct user_namespace *mnt_userns,
 
 		return -EPERM;
 	}
-	return generic_permission(&init_user_ns, inode, mask);
+	return generic_permission(&nop_mnt_idmap, inode, mask);
 }
 
 
@@ -1959,14 +1959,14 @@ static struct inode *proc_pid_make_base_inode(struct super_block *sb,
 	return inode;
 }
 
-int pid_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int pid_getattr(struct mnt_idmap *idmap, const struct path *path,
 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
 	struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
 	struct task_struct *task;
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 
 	stat->uid = GLOBAL_ROOT_UID;
 	stat->gid = GLOBAL_ROOT_GID;
@@ -3557,7 +3557,7 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx)
  * This function makes sure that the node is always accessible for members of
  * same thread group.
  */
-static int proc_tid_comm_permission(struct user_namespace *mnt_userns,
+static int proc_tid_comm_permission(struct mnt_idmap *idmap,
 				    struct inode *inode, int mask)
 {
 	bool is_same_tgroup;
@@ -3577,7 +3577,7 @@ static int proc_tid_comm_permission(struct user_namespace *mnt_userns,
 		return 0;
 	}
 
-	return generic_permission(&init_user_ns, inode, mask);
+	return generic_permission(&nop_mnt_idmap, inode, mask);
 }
 
 static const struct inode_operations proc_tid_comm_inode_operations = {
@@ -3891,13 +3891,13 @@ static int proc_task_readdir(struct file *file, struct dir_context *ctx)
 	return 0;
 }
 
-static int proc_task_getattr(struct user_namespace *mnt_userns,
+static int proc_task_getattr(struct mnt_idmap *idmap,
 			     const struct path *path, struct kstat *stat,
 			     u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
 	struct task_struct *p = get_proc_task(inode);
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 
 	if (p) {
 		stat->nlink += get_nr_threads(p);
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index 53e4919ef860..b3140deebbbf 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -326,13 +326,13 @@ static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
  * /proc/pid/fd needs a special permission handler so that a process can still
  * access /proc/self/fd after it has executed a setuid().
  */
-int proc_fd_permission(struct user_namespace *mnt_userns,
+int proc_fd_permission(struct mnt_idmap *idmap,
 		       struct inode *inode, int mask)
 {
 	struct task_struct *p;
 	int rv;
 
-	rv = generic_permission(&init_user_ns, inode, mask);
+	rv = generic_permission(&nop_mnt_idmap, inode, mask);
 	if (rv == 0)
 		return rv;
 
@@ -345,14 +345,14 @@ int proc_fd_permission(struct user_namespace *mnt_userns,
 	return rv;
 }
 
-static int proc_fd_getattr(struct user_namespace *mnt_userns,
+static int proc_fd_getattr(struct mnt_idmap *idmap,
 			const struct path *path, struct kstat *stat,
 			u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
 	int rv = 0;
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 
 	/* If it's a directory, put the number of open fds there */
 	if (S_ISDIR(inode->i_mode)) {
diff --git a/fs/proc/fd.h b/fs/proc/fd.h
index c5a921a06a0b..7e7265f7e06f 100644
--- a/fs/proc/fd.h
+++ b/fs/proc/fd.h
@@ -10,7 +10,7 @@ extern const struct inode_operations proc_fd_inode_operations;
 extern const struct file_operations proc_fdinfo_operations;
 extern const struct inode_operations proc_fdinfo_inode_operations;
 
-extern int proc_fd_permission(struct user_namespace *mnt_userns,
+extern int proc_fd_permission(struct mnt_idmap *idmap,
 			      struct inode *inode, int mask);
 
 static inline unsigned int proc_fd(struct inode *inode)
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 587b91d9d998..8379593fa4bb 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -115,18 +115,18 @@ static bool pde_subdir_insert(struct proc_dir_entry *dir,
 	return true;
 }
 
-static int proc_notify_change(struct user_namespace *mnt_userns,
+static int proc_notify_change(struct mnt_idmap *idmap,
 			      struct dentry *dentry, struct iattr *iattr)
 {
 	struct inode *inode = d_inode(dentry);
 	struct proc_dir_entry *de = PDE(inode);
 	int error;
 
-	error = setattr_prepare(&init_user_ns, dentry, iattr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (error)
 		return error;
 
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 	mark_inode_dirty(inode);
 
 	proc_set_user(de, inode->i_uid, inode->i_gid);
@@ -134,7 +134,7 @@ static int proc_notify_change(struct user_namespace *mnt_userns,
 	return 0;
 }
 
-static int proc_getattr(struct user_namespace *mnt_userns,
+static int proc_getattr(struct mnt_idmap *idmap,
 			const struct path *path, struct kstat *stat,
 			u32 request_mask, unsigned int query_flags)
 {
@@ -147,7 +147,7 @@ static int proc_getattr(struct user_namespace *mnt_userns,
 		}
 	}
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	return 0;
 }
 
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index b701d0207edf..9dda7e54b2d0 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -162,9 +162,9 @@ extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
  * base.c
  */
 extern const struct dentry_operations pid_dentry_operations;
-extern int pid_getattr(struct user_namespace *, const struct path *,
+extern int pid_getattr(struct mnt_idmap *, const struct path *,
 		       struct kstat *, u32, unsigned int);
-extern int proc_setattr(struct user_namespace *, struct dentry *,
+extern int proc_setattr(struct mnt_idmap *, struct dentry *,
 			struct iattr *);
 extern void proc_pid_evict_inode(struct proc_inode *);
 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c
index 856839b8ae8b..a0c0419872e3 100644
--- a/fs/proc/proc_net.c
+++ b/fs/proc/proc_net.c
@@ -299,7 +299,7 @@ static struct dentry *proc_tgid_net_lookup(struct inode *dir,
 	return de;
 }
 
-static int proc_tgid_net_getattr(struct user_namespace *mnt_userns,
+static int proc_tgid_net_getattr(struct mnt_idmap *idmap,
 				 const struct path *path, struct kstat *stat,
 				 u32 request_mask, unsigned int query_flags)
 {
@@ -308,7 +308,7 @@ static int proc_tgid_net_getattr(struct user_namespace *mnt_userns,
 
 	net = get_proc_task_net(inode);
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 
 	if (net != NULL) {
 		stat->nlink = net->proc_net->nlink;
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 48f2d60bd78a..e89bd8f1368b 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -798,7 +798,7 @@ out:
 	return 0;
 }
 
-static int proc_sys_permission(struct user_namespace *mnt_userns,
+static int proc_sys_permission(struct mnt_idmap *idmap,
 			       struct inode *inode, int mask)
 {
 	/*
@@ -827,7 +827,7 @@ static int proc_sys_permission(struct user_namespace *mnt_userns,
 	return error;
 }
 
-static int proc_sys_setattr(struct user_namespace *mnt_userns,
+static int proc_sys_setattr(struct mnt_idmap *idmap,
 			    struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -836,16 +836,16 @@ static int proc_sys_setattr(struct user_namespace *mnt_userns,
 	if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))
 		return -EPERM;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
 
-static int proc_sys_getattr(struct user_namespace *mnt_userns,
+static int proc_sys_getattr(struct mnt_idmap *idmap,
 			    const struct path *path, struct kstat *stat,
 			    u32 request_mask, unsigned int query_flags)
 {
@@ -856,7 +856,7 @@ static int proc_sys_getattr(struct user_namespace *mnt_userns,
 	if (IS_ERR(head))
 		return PTR_ERR(head);
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	if (table)
 		stat->mode = (stat->mode & S_IFMT) | table->mode;
 
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 3c2ee3eb1138..a86e65a608da 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -310,11 +310,11 @@ void __init proc_root_init(void)
 	register_filesystem(&proc_fs_type);
 }
 
-static int proc_root_getattr(struct user_namespace *mnt_userns,
+static int proc_root_getattr(struct mnt_idmap *idmap,
 			     const struct path *path, struct kstat *stat,
 			     u32 request_mask, unsigned int query_flags)
 {
-	generic_fillattr(&init_user_ns, d_inode(path->dentry), stat);
+	generic_fillattr(&nop_mnt_idmap, d_inode(path->dentry), stat);
 	stat->nlink = proc_root.nlink + nr_processes();
 	return 0;
 }
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index f27faf5db554..a6357f728034 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2085,7 +2085,7 @@ EXPORT_SYMBOL(__dquot_transfer);
 /* Wrapper for transferring ownership of an inode for uid/gid only
  * Called from FSXXX_setattr()
  */
-int dquot_transfer(struct user_namespace *mnt_userns, struct inode *inode,
+int dquot_transfer(struct mnt_idmap *idmap, struct inode *inode,
 		   struct iattr *iattr)
 {
 	struct dquot *transfer_to[MAXQUOTAS] = {};
@@ -2096,8 +2096,8 @@ int dquot_transfer(struct user_namespace *mnt_userns, struct inode *inode,
 	if (!dquot_active(inode))
 		return 0;
 
-	if (i_uid_needs_update(mnt_userns, iattr, inode)) {
-		kuid_t kuid = from_vfsuid(mnt_userns, i_user_ns(inode),
+	if (i_uid_needs_update(idmap, iattr, inode)) {
+		kuid_t kuid = from_vfsuid(idmap, i_user_ns(inode),
 					  iattr->ia_vfsuid);
 
 		dquot = dqget(sb, make_kqid_uid(kuid));
@@ -2110,8 +2110,8 @@ int dquot_transfer(struct user_namespace *mnt_userns, struct inode *inode,
 		}
 		transfer_to[USRQUOTA] = dquot;
 	}
-	if (i_gid_needs_update(mnt_userns, iattr, inode)) {
-		kgid_t kgid = from_vfsgid(mnt_userns, i_user_ns(inode),
+	if (i_gid_needs_update(idmap, iattr, inode)) {
+		kgid_t kgid = from_vfsgid(idmap, i_user_ns(inode),
 					  iattr->ia_vfsgid);
 
 		dquot = dqget(sb, make_kqid_gid(kgid));
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index cb240eac5036..5bf74c2f6042 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -22,7 +22,7 @@
 #include <linux/uaccess.h>
 #include "internal.h"
 
-static int ramfs_nommu_setattr(struct user_namespace *, struct dentry *, struct iattr *);
+static int ramfs_nommu_setattr(struct mnt_idmap *, struct dentry *, struct iattr *);
 static unsigned long ramfs_nommu_get_unmapped_area(struct file *file,
 						   unsigned long addr,
 						   unsigned long len,
@@ -158,7 +158,7 @@ static int ramfs_nommu_resize(struct inode *inode, loff_t newsize, loff_t size)
  * handle a change of attributes
  * - we're specifically interested in a change of size
  */
-static int ramfs_nommu_setattr(struct user_namespace *mnt_userns,
+static int ramfs_nommu_setattr(struct mnt_idmap *idmap,
 			       struct dentry *dentry, struct iattr *ia)
 {
 	struct inode *inode = d_inode(dentry);
@@ -166,7 +166,7 @@ static int ramfs_nommu_setattr(struct user_namespace *mnt_userns,
 	int ret = 0;
 
 	/* POSIX UID/GID verification for setting inode attributes */
-	ret = setattr_prepare(&init_user_ns, dentry, ia);
+	ret = setattr_prepare(&nop_mnt_idmap, dentry, ia);
 	if (ret)
 		return ret;
 
@@ -186,7 +186,7 @@ static int ramfs_nommu_setattr(struct user_namespace *mnt_userns,
 		}
 	}
 
-	setattr_copy(&init_user_ns, inode, ia);
+	setattr_copy(&nop_mnt_idmap, inode, ia);
  out:
 	ia->ia_valid = old_ia_valid;
 	return ret;
diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index b3257e852820..5ba580c78835 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -61,7 +61,7 @@ struct inode *ramfs_get_inode(struct super_block *sb,
 
 	if (inode) {
 		inode->i_ino = get_next_ino();
-		inode_init_owner(&init_user_ns, inode, dir, mode);
+		inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 		inode->i_mapping->a_ops = &ram_aops;
 		mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER);
 		mapping_set_unevictable(inode->i_mapping);
@@ -95,7 +95,7 @@ struct inode *ramfs_get_inode(struct super_block *sb,
  */
 /* SMP-safe */
 static int
-ramfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+ramfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	    struct dentry *dentry, umode_t mode, dev_t dev)
 {
 	struct inode * inode = ramfs_get_inode(dir->i_sb, dir, mode, dev);
@@ -110,22 +110,22 @@ ramfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	return error;
 }
 
-static int ramfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int ramfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode)
 {
-	int retval = ramfs_mknod(&init_user_ns, dir, dentry, mode | S_IFDIR, 0);
+	int retval = ramfs_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFDIR, 0);
 	if (!retval)
 		inc_nlink(dir);
 	return retval;
 }
 
-static int ramfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int ramfs_create(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, umode_t mode, bool excl)
 {
-	return ramfs_mknod(&init_user_ns, dir, dentry, mode | S_IFREG, 0);
+	return ramfs_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFREG, 0);
 }
 
-static int ramfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int ramfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			 struct dentry *dentry, const char *symname)
 {
 	struct inode *inode;
@@ -145,7 +145,7 @@ static int ramfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 	return error;
 }
 
-static int ramfs_tmpfile(struct user_namespace *mnt_userns,
+static int ramfs_tmpfile(struct mnt_idmap *idmap,
 			 struct inode *dir, struct file *file, umode_t mode)
 {
 	struct inode *inode;
diff --git a/fs/reiserfs/acl.h b/fs/reiserfs/acl.h
index 29c503a06db4..2571b1a8be84 100644
--- a/fs/reiserfs/acl.h
+++ b/fs/reiserfs/acl.h
@@ -49,7 +49,7 @@ static inline int reiserfs_acl_count(size_t size)
 
 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
 struct posix_acl *reiserfs_get_acl(struct inode *inode, int type, bool rcu);
-int reiserfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int reiserfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct posix_acl *acl, int type);
 int reiserfs_acl_chmod(struct dentry *dentry);
 int reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index c7d1fa526dea..d54cab854f60 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -3262,21 +3262,21 @@ static ssize_t reiserfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 	return ret;
 }
 
-int reiserfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int reiserfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	unsigned int ia_valid;
 	int error;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
 	/* must be turned off for recursive notify_change calls */
 	ia_valid = attr->ia_valid &= ~(ATTR_KILL_SUID|ATTR_KILL_SGID);
 
-	if (is_quota_modification(mnt_userns, inode, attr)) {
+	if (is_quota_modification(&nop_mnt_idmap, inode, attr)) {
 		error = dquot_initialize(inode);
 		if (error)
 			return error;
@@ -3359,7 +3359,7 @@ int reiserfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		reiserfs_write_unlock(inode->i_sb);
 		if (error)
 			goto out;
-		error = dquot_transfer(mnt_userns, inode, attr);
+		error = dquot_transfer(&nop_mnt_idmap, inode, attr);
 		reiserfs_write_lock(inode->i_sb);
 		if (error) {
 			journal_end(&th);
@@ -3398,7 +3398,7 @@ int reiserfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	}
 
 	if (!error) {
-		setattr_copy(&init_user_ns, inode, attr);
+		setattr_copy(&nop_mnt_idmap, inode, attr);
 		mark_inode_dirty(inode);
 	}
 
diff --git a/fs/reiserfs/ioctl.c b/fs/reiserfs/ioctl.c
index 4b86ecf5817e..6bf9b54e58ca 100644
--- a/fs/reiserfs/ioctl.c
+++ b/fs/reiserfs/ioctl.c
@@ -24,7 +24,7 @@ int reiserfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return 0;
 }
 
-int reiserfs_fileattr_set(struct user_namespace *mnt_userns,
+int reiserfs_fileattr_set(struct mnt_idmap *idmap,
 			  struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
@@ -96,7 +96,7 @@ long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		err = put_user(inode->i_generation, (int __user *)arg);
 		break;
 	case REISERFS_IOC_SETVERSION:
-		if (!inode_owner_or_capable(&init_user_ns, inode)) {
+		if (!inode_owner_or_capable(&nop_mnt_idmap, inode)) {
 			err = -EPERM;
 			break;
 		}
diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index 0b8aa99749f1..42d2c20e1345 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -616,11 +616,11 @@ static int new_inode_init(struct inode *inode, struct inode *dir, umode_t mode)
 	 * the quota init calls have to know who to charge the quota to, so
 	 * we have to set uid and gid here
 	 */
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 	return dquot_initialize(inode);
 }
 
-static int reiserfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int reiserfs_create(struct mnt_idmap *idmap, struct inode *dir,
 			   struct dentry *dentry, umode_t mode, bool excl)
 {
 	int retval;
@@ -700,7 +700,7 @@ out_failed:
 	return retval;
 }
 
-static int reiserfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int reiserfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 			  struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	int retval;
@@ -784,7 +784,7 @@ out_failed:
 	return retval;
 }
 
-static int reiserfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int reiserfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			  struct dentry *dentry, umode_t mode)
 {
 	int retval;
@@ -1099,7 +1099,7 @@ out_unlink:
 	return retval;
 }
 
-static int reiserfs_symlink(struct user_namespace *mnt_userns,
+static int reiserfs_symlink(struct mnt_idmap *idmap,
 			    struct inode *parent_dir, struct dentry *dentry,
 			    const char *symname)
 {
@@ -1311,7 +1311,7 @@ static void set_ino_in_dir_entry(struct reiserfs_dir_entry *de,
  * one path. If it holds 2 or more, it can get into endless waiting in
  * get_empty_nodes or its clones
  */
-static int reiserfs_rename(struct user_namespace *mnt_userns,
+static int reiserfs_rename(struct mnt_idmap *idmap,
 			   struct inode *old_dir, struct dentry *old_dentry,
 			   struct inode *new_dir, struct dentry *new_dentry,
 			   unsigned int flags)
diff --git a/fs/reiserfs/reiserfs.h b/fs/reiserfs/reiserfs.h
index 3aa928ec527a..98e6f53c2fe0 100644
--- a/fs/reiserfs/reiserfs.h
+++ b/fs/reiserfs/reiserfs.h
@@ -3100,7 +3100,7 @@ static inline void reiserfs_update_sd(struct reiserfs_transaction_handle *th,
 }
 
 void sd_attrs_to_i_attrs(__u16 sd_attrs, struct inode *inode);
-int reiserfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int reiserfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct iattr *attr);
 
 int __reiserfs_write_begin(struct page *page, unsigned from, unsigned len);
@@ -3407,7 +3407,7 @@ __u32 r5_hash(const signed char *msg, int len);
 
 /* prototypes from ioctl.c */
 int reiserfs_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-int reiserfs_fileattr_set(struct user_namespace *mnt_userns,
+int reiserfs_fileattr_set(struct mnt_idmap *idmap,
 			  struct dentry *dentry, struct fileattr *fa);
 long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
 long reiserfs_compat_ioctl(struct file *filp,
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 8b2d52443f41..06d810c72c52 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -66,14 +66,14 @@
 static int xattr_create(struct inode *dir, struct dentry *dentry, int mode)
 {
 	BUG_ON(!inode_is_locked(dir));
-	return dir->i_op->create(&init_user_ns, dir, dentry, mode, true);
+	return dir->i_op->create(&nop_mnt_idmap, dir, dentry, mode, true);
 }
 #endif
 
 static int xattr_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
 	BUG_ON(!inode_is_locked(dir));
-	return dir->i_op->mkdir(&init_user_ns, dir, dentry, mode);
+	return dir->i_op->mkdir(&nop_mnt_idmap, dir, dentry, mode);
 }
 
 /*
@@ -352,7 +352,7 @@ static int chown_one_xattr(struct dentry *dentry, void *data)
 	 * ATTR_MODE is set.
 	 */
 	attrs->ia_valid &= (ATTR_UID|ATTR_GID);
-	err = reiserfs_setattr(&init_user_ns, dentry, attrs);
+	err = reiserfs_setattr(&nop_mnt_idmap, dentry, attrs);
 	attrs->ia_valid = ia_valid;
 
 	return err;
@@ -597,7 +597,7 @@ reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *th,
 		inode_lock_nested(d_inode(dentry), I_MUTEX_XATTR);
 		inode_dio_wait(d_inode(dentry));
 
-		err = reiserfs_setattr(&init_user_ns, dentry, &newattrs);
+		err = reiserfs_setattr(&nop_mnt_idmap, dentry, &newattrs);
 		inode_unlock(d_inode(dentry));
 	} else
 		update_ctime(inode);
@@ -941,7 +941,7 @@ static int xattr_mount_check(struct super_block *s)
 	return 0;
 }
 
-int reiserfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int reiserfs_permission(struct mnt_idmap *idmap, struct inode *inode,
 			int mask)
 {
 	/*
@@ -951,7 +951,7 @@ int reiserfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
 	if (IS_PRIVATE(inode))
 		return 0;
 
-	return generic_permission(&init_user_ns, inode, mask);
+	return generic_permission(&nop_mnt_idmap, inode, mask);
 }
 
 static int xattr_hide_revalidate(struct dentry *dentry, unsigned int flags)
diff --git a/fs/reiserfs/xattr.h b/fs/reiserfs/xattr.h
index e47fde1182de..5868a4e990e3 100644
--- a/fs/reiserfs/xattr.h
+++ b/fs/reiserfs/xattr.h
@@ -16,7 +16,7 @@ int reiserfs_xattr_init(struct super_block *sb, int mount_flags);
 int reiserfs_lookup_privroot(struct super_block *sb);
 int reiserfs_delete_xattrs(struct inode *inode);
 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs);
-int reiserfs_permission(struct user_namespace *mnt_userns,
+int reiserfs_permission(struct mnt_idmap *idmap,
 			struct inode *inode, int mask);
 
 #ifdef CONFIG_REISERFS_FS_XATTR
diff --git a/fs/reiserfs/xattr_acl.c b/fs/reiserfs/xattr_acl.c
index 93fe414fed18..138060452678 100644
--- a/fs/reiserfs/xattr_acl.c
+++ b/fs/reiserfs/xattr_acl.c
@@ -18,7 +18,7 @@ static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th,
 
 
 int
-reiserfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+reiserfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type)
 {
 	int error, error2;
@@ -42,7 +42,7 @@ reiserfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 	reiserfs_write_unlock(inode->i_sb);
 	if (error == 0) {
 		if (type == ACL_TYPE_ACCESS && acl) {
-			error = posix_acl_update_mode(&init_user_ns, inode,
+			error = posix_acl_update_mode(&nop_mnt_idmap, inode,
 						      &mode, &acl);
 			if (error)
 				goto unlock;
@@ -407,5 +407,5 @@ int reiserfs_acl_chmod(struct dentry *dentry)
 	    !reiserfs_posixacl(inode->i_sb))
 		return 0;
 
-	return posix_acl_chmod(&init_user_ns, dentry, inode->i_mode);
+	return posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
 }
diff --git a/fs/reiserfs/xattr_security.c b/fs/reiserfs/xattr_security.c
index 857a65b05726..41c0ea84fbff 100644
--- a/fs/reiserfs/xattr_security.c
+++ b/fs/reiserfs/xattr_security.c
@@ -22,7 +22,7 @@ security_get(const struct xattr_handler *handler, struct dentry *unused,
 
 static int
 security_set(const struct xattr_handler *handler,
-	     struct user_namespace *mnt_userns, struct dentry *unused,
+	     struct mnt_idmap *idmap, struct dentry *unused,
 	     struct inode *inode, const char *name, const void *buffer,
 	     size_t size, int flags)
 {
diff --git a/fs/reiserfs/xattr_trusted.c b/fs/reiserfs/xattr_trusted.c
index d853cea2afcd..0c0c74d8db0e 100644
--- a/fs/reiserfs/xattr_trusted.c
+++ b/fs/reiserfs/xattr_trusted.c
@@ -21,7 +21,7 @@ trusted_get(const struct xattr_handler *handler, struct dentry *unused,
 
 static int
 trusted_set(const struct xattr_handler *handler,
-	    struct user_namespace *mnt_userns, struct dentry *unused,
+	    struct mnt_idmap *idmap, struct dentry *unused,
 	    struct inode *inode, const char *name, const void *buffer,
 	    size_t size, int flags)
 {
diff --git a/fs/reiserfs/xattr_user.c b/fs/reiserfs/xattr_user.c
index 65d9cd10a5ea..88195181e1d7 100644
--- a/fs/reiserfs/xattr_user.c
+++ b/fs/reiserfs/xattr_user.c
@@ -18,7 +18,7 @@ user_get(const struct xattr_handler *handler, struct dentry *unused,
 }
 
 static int
-user_set(const struct xattr_handler *handler, struct user_namespace *mnt_userns,
+user_set(const struct xattr_handler *handler, struct mnt_idmap *idmap,
 	 struct dentry *unused,
 	 struct inode *inode, const char *name, const void *buffer,
 	 size_t size, int flags)
diff --git a/fs/remap_range.c b/fs/remap_range.c
index 41f60477bb41..1331a890f2f2 100644
--- a/fs/remap_range.c
+++ b/fs/remap_range.c
@@ -419,16 +419,16 @@ EXPORT_SYMBOL(vfs_clone_file_range);
 /* Check whether we are allowed to dedupe the destination file */
 static bool allow_file_dedupe(struct file *file)
 {
-	struct user_namespace *mnt_userns = file_mnt_user_ns(file);
+	struct mnt_idmap *idmap = file_mnt_idmap(file);
 	struct inode *inode = file_inode(file);
 
 	if (capable(CAP_SYS_ADMIN))
 		return true;
 	if (file->f_mode & FMODE_WRITE)
 		return true;
-	if (vfsuid_eq_kuid(i_uid_into_vfsuid(mnt_userns, inode), current_fsuid()))
+	if (vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode), current_fsuid()))
 		return true;
-	if (!inode_permission(mnt_userns, inode, MAY_WRITE))
+	if (!inode_permission(idmap, inode, MAY_WRITE))
 		return true;
 	return false;
 }
diff --git a/fs/stat.c b/fs/stat.c
index f43afe0081fe..7c238da22ef0 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -28,7 +28,7 @@
 
 /**
  * generic_fillattr - Fill in the basic attributes from the inode struct
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @inode:	Inode to use as the source
  * @stat:	Where to fill in the attributes
  *
@@ -36,17 +36,17 @@
  * found on the VFS inode structure.  This is the default if no getattr inode
  * operation is supplied.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then
- * take care to map the inode according to @mnt_userns before filling in the
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then
+ * take care to map the inode according to @idmap before filling in the
  * uid and gid filds. On non-idmapped mounts or if permission checking is to be
- * performed on the raw inode simply passs init_user_ns.
+ * performed on the raw inode simply passs @nop_mnt_idmap.
  */
-void generic_fillattr(struct user_namespace *mnt_userns, struct inode *inode,
+void generic_fillattr(struct mnt_idmap *idmap, struct inode *inode,
 		      struct kstat *stat)
 {
-	vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
-	vfsgid_t vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
+	vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
+	vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
 
 	stat->dev = inode->i_sb->s_dev;
 	stat->ino = inode->i_ino;
@@ -98,7 +98,7 @@ EXPORT_SYMBOL(generic_fill_statx_attr);
 int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
 		      u32 request_mask, unsigned int query_flags)
 {
-	struct user_namespace *mnt_userns;
+	struct mnt_idmap *idmap;
 	struct inode *inode = d_backing_inode(path->dentry);
 
 	memset(stat, 0, sizeof(*stat));
@@ -128,12 +128,12 @@ int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
 		stat->change_cookie = inode_query_iversion(inode);
 	}
 
-	mnt_userns = mnt_user_ns(path->mnt);
+	idmap = mnt_idmap(path->mnt);
 	if (inode->i_op->getattr)
-		return inode->i_op->getattr(mnt_userns, path, stat,
+		return inode->i_op->getattr(idmap, path, stat,
 					    request_mask, query_flags);
 
-	generic_fillattr(mnt_userns, inode, stat);
+	generic_fillattr(idmap, inode, stat);
 	return 0;
 }
 EXPORT_SYMBOL(vfs_getattr_nosec);
diff --git a/fs/sysv/file.c b/fs/sysv/file.c
index 90e00124ea07..50eb92557a0f 100644
--- a/fs/sysv/file.c
+++ b/fs/sysv/file.c
@@ -29,13 +29,13 @@ const struct file_operations sysv_file_operations = {
 	.splice_read	= generic_file_splice_read,
 };
 
-static int sysv_setattr(struct user_namespace *mnt_userns,
+static int sysv_setattr(struct mnt_idmap *idmap,
 			struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	int error;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
@@ -48,7 +48,7 @@ static int sysv_setattr(struct user_namespace *mnt_userns,
 		sysv_truncate(inode);
 	}
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
diff --git a/fs/sysv/ialloc.c b/fs/sysv/ialloc.c
index 50df794a3c1f..e732879036ab 100644
--- a/fs/sysv/ialloc.c
+++ b/fs/sysv/ialloc.c
@@ -163,7 +163,7 @@ struct inode * sysv_new_inode(const struct inode * dir, umode_t mode)
 	*sbi->s_sb_fic_count = cpu_to_fs16(sbi, count);
 	fs16_add(sbi, sbi->s_sb_total_free_inodes, -1);
 	dirty_sb(sb);
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 	inode->i_ino = fs16_to_cpu(sbi, ino);
 	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 	inode->i_blocks = 0;
diff --git a/fs/sysv/itree.c b/fs/sysv/itree.c
index 3b8567564e7e..b22764fe669c 100644
--- a/fs/sysv/itree.c
+++ b/fs/sysv/itree.c
@@ -441,11 +441,11 @@ static unsigned sysv_nblocks(struct super_block *s, loff_t size)
 	return res;
 }
 
-int sysv_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int sysv_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	struct super_block *s = path->dentry->d_sb;
-	generic_fillattr(&init_user_ns, d_inode(path->dentry), stat);
+	generic_fillattr(&nop_mnt_idmap, d_inode(path->dentry), stat);
 	stat->blocks = (s->s_blocksize / 512) * sysv_nblocks(s, stat->size);
 	stat->blksize = s->s_blocksize;
 	return 0;
diff --git a/fs/sysv/namei.c b/fs/sysv/namei.c
index b2e6abc06a2d..ecd424461511 100644
--- a/fs/sysv/namei.c
+++ b/fs/sysv/namei.c
@@ -41,7 +41,7 @@ static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, un
 	return d_splice_alias(inode, dentry);
 }
 
-static int sysv_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int sysv_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct inode * inode;
@@ -61,13 +61,13 @@ static int sysv_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	return err;
 }
 
-static int sysv_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int sysv_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
-	return sysv_mknod(&init_user_ns, dir, dentry, mode, 0);
+	return sysv_mknod(&nop_mnt_idmap, dir, dentry, mode, 0);
 }
 
-static int sysv_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int sysv_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, const char *symname)
 {
 	int err = -ENAMETOOLONG;
@@ -110,7 +110,7 @@ static int sysv_link(struct dentry * old_dentry, struct inode * dir,
 	return add_nondir(dentry, inode);
 }
 
-static int sysv_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int sysv_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
 	struct inode * inode;
@@ -189,7 +189,7 @@ static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
  * Anybody can rename anything with this: the permission checks are left to the
  * higher-level routines.
  */
-static int sysv_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int sysv_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		       struct dentry *old_dentry, struct inode *new_dir,
 		       struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/sysv/sysv.h b/fs/sysv/sysv.h
index 99ddf033da4f..5e122a5673c1 100644
--- a/fs/sysv/sysv.h
+++ b/fs/sysv/sysv.h
@@ -141,7 +141,7 @@ extern struct inode *sysv_iget(struct super_block *, unsigned int);
 extern int sysv_write_inode(struct inode *, struct writeback_control *wbc);
 extern int sysv_sync_inode(struct inode *);
 extern void sysv_set_inode(struct inode *, dev_t);
-extern int sysv_getattr(struct user_namespace *, const struct path *,
+extern int sysv_getattr(struct mnt_idmap *, const struct path *,
 			struct kstat *, u32, unsigned int);
 extern int sysv_init_icache(void);
 extern void sysv_destroy_icache(void);
diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index da85b3979195..57ac8aa4a724 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -67,7 +67,7 @@ static char *get_dname(struct dentry *dentry)
 	return name;
 }
 
-static int tracefs_syscall_mkdir(struct user_namespace *mnt_userns,
+static int tracefs_syscall_mkdir(struct mnt_idmap *idmap,
 				 struct inode *inode, struct dentry *dentry,
 				 umode_t mode)
 {
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 0f29cf201136..1e92c1730c16 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -95,7 +95,7 @@ struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir,
 	 */
 	inode->i_flags |= S_NOCMTIME;
 
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 	inode->i_mtime = inode->i_atime = inode->i_ctime =
 			 current_time(inode);
 	inode->i_mapping->nrpages = 0;
@@ -283,7 +283,7 @@ static int ubifs_prepare_create(struct inode *dir, struct dentry *dentry,
 	return fscrypt_setup_filename(dir, &dentry->d_name, 0, nm);
 }
 
-static int ubifs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int ubifs_create(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct inode *inode;
@@ -426,7 +426,7 @@ static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
 	mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
 }
 
-static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+static int ubifs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 			 struct file *file, umode_t mode)
 {
 	struct dentry *dentry = file->f_path.dentry;
@@ -979,7 +979,7 @@ out_fname:
 	return err;
 }
 
-static int ubifs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int ubifs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode;
@@ -1052,7 +1052,7 @@ out_budg:
 	return err;
 }
 
-static int ubifs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int ubifs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct inode *inode;
@@ -1141,7 +1141,7 @@ out_budg:
 	return err;
 }
 
-static int ubifs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int ubifs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			 struct dentry *dentry, const char *symname)
 {
 	struct inode *inode;
@@ -1606,7 +1606,7 @@ static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
 	return err;
 }
 
-static int ubifs_rename(struct user_namespace *mnt_userns,
+static int ubifs_rename(struct mnt_idmap *idmap,
 			struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
@@ -1631,7 +1631,7 @@ static int ubifs_rename(struct user_namespace *mnt_userns,
 	return do_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
 }
 
-int ubifs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ubifs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	loff_t size;
@@ -1654,7 +1654,7 @@ int ubifs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 				STATX_ATTR_ENCRYPTED |
 				STATX_ATTR_IMMUTABLE);
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	stat->blksize = UBIFS_BLOCK_SIZE;
 	stat->size = ui->ui_size;
 
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index f2353dd676ef..8cb5d76b301c 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1258,7 +1258,7 @@ static int do_setattr(struct ubifs_info *c, struct inode *inode,
 	return err;
 }
 
-int ubifs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ubifs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr)
 {
 	int err;
@@ -1267,7 +1267,7 @@ int ubifs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 	dbg_gen("ino %lu, mode %#x, ia_valid %#x",
 		inode->i_ino, inode->i_mode, attr->ia_valid);
-	err = setattr_prepare(&init_user_ns, dentry, attr);
+	err = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (err)
 		return err;
 
@@ -1608,11 +1608,11 @@ static const char *ubifs_get_link(struct dentry *dentry,
 	return fscrypt_get_symlink(inode, ui->data, ui->data_len, done);
 }
 
-static int ubifs_symlink_getattr(struct user_namespace *mnt_userns,
+static int ubifs_symlink_getattr(struct mnt_idmap *idmap,
 				 const struct path *path, struct kstat *stat,
 				 u32 request_mask, unsigned int query_flags)
 {
-	ubifs_getattr(mnt_userns, path, stat, request_mask, query_flags);
+	ubifs_getattr(idmap, path, stat, request_mask, query_flags);
 
 	if (IS_ENCRYPTED(d_inode(path->dentry)))
 		return fscrypt_symlink_getattr(path, stat);
diff --git a/fs/ubifs/ioctl.c b/fs/ubifs/ioctl.c
index 71bcebe45f9c..67c5108abd89 100644
--- a/fs/ubifs/ioctl.c
+++ b/fs/ubifs/ioctl.c
@@ -144,7 +144,7 @@ int ubifs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return 0;
 }
 
-int ubifs_fileattr_set(struct user_namespace *mnt_userns,
+int ubifs_fileattr_set(struct mnt_idmap *idmap,
 		       struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 478bbbb5382f..9063b73536f8 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -2020,15 +2020,15 @@ int ubifs_calc_dark(const struct ubifs_info *c, int spc);
 
 /* file.c */
 int ubifs_fsync(struct file *file, loff_t start, loff_t end, int datasync);
-int ubifs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ubifs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr);
 int ubifs_update_time(struct inode *inode, struct timespec64 *time, int flags);
 
 /* dir.c */
 struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir,
 			      umode_t mode, bool is_xattr);
-int ubifs_getattr(struct user_namespace *mnt_userns, const struct path *path, struct kstat *stat,
-		  u32 request_mask, unsigned int flags);
+int ubifs_getattr(struct mnt_idmap *idmap, const struct path *path,
+		  struct kstat *stat, u32 request_mask, unsigned int flags);
 int ubifs_check_dir_empty(struct inode *dir);
 
 /* xattr.c */
@@ -2085,7 +2085,7 @@ void ubifs_destroy_size_tree(struct ubifs_info *c);
 
 /* ioctl.c */
 int ubifs_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-int ubifs_fileattr_set(struct user_namespace *mnt_userns,
+int ubifs_fileattr_set(struct mnt_idmap *idmap,
 		       struct dentry *dentry, struct fileattr *fa);
 long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 void ubifs_set_inode_flags(struct inode *inode);
diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
index 3db8486e3725..349228dd1191 100644
--- a/fs/ubifs/xattr.c
+++ b/fs/ubifs/xattr.c
@@ -699,7 +699,7 @@ static int xattr_get(const struct xattr_handler *handler,
 }
 
 static int xattr_set(const struct xattr_handler *handler,
-			   struct user_namespace *mnt_userns,
+			   struct mnt_idmap *idmap,
 			   struct dentry *dentry, struct inode *inode,
 			   const char *name, const void *value,
 			   size_t size, int flags)
diff --git a/fs/udf/file.c b/fs/udf/file.c
index 5c659e23e578..2efbbbaa2da7 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -256,14 +256,14 @@ const struct file_operations udf_file_operations = {
 	.llseek			= generic_file_llseek,
 };
 
-static int udf_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+static int udf_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		       struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	struct super_block *sb = inode->i_sb;
 	int error;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
@@ -286,7 +286,7 @@ static int udf_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (attr->ia_valid & ATTR_MODE)
 		udf_update_extra_perms(inode, attr->ia_mode);
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
diff --git a/fs/udf/ialloc.c b/fs/udf/ialloc.c
index b5d611cee749..e78a859d13e3 100644
--- a/fs/udf/ialloc.c
+++ b/fs/udf/ialloc.c
@@ -105,7 +105,7 @@ struct inode *udf_new_inode(struct inode *dir, umode_t mode)
 		mutex_unlock(&sbi->s_alloc_mutex);
 	}
 
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 	if (UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET))
 		inode->i_uid = sbi->s_uid;
 	if (UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET))
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index 7c95c549dd64..bdba2206a678 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -606,7 +606,7 @@ static int udf_add_nondir(struct dentry *dentry, struct inode *inode)
 	return 0;
 }
 
-static int udf_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int udf_create(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct inode *inode = udf_new_inode(dir, mode);
@@ -625,7 +625,7 @@ static int udf_create(struct user_namespace *mnt_userns, struct inode *dir,
 	return udf_add_nondir(dentry, inode);
 }
 
-static int udf_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+static int udf_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 		       struct file *file, umode_t mode)
 {
 	struct inode *inode = udf_new_inode(dir, mode);
@@ -645,7 +645,7 @@ static int udf_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	return finish_open_simple(file, 0);
 }
 
-static int udf_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int udf_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct inode *inode;
@@ -661,7 +661,7 @@ static int udf_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	return udf_add_nondir(dentry, inode);
 }
 
-static int udf_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int udf_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode;
@@ -881,7 +881,7 @@ out:
 	return retval;
 }
 
-static int udf_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int udf_symlink(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, const char *symname)
 {
 	struct inode *inode = udf_new_inode(dir, S_IFLNK | 0777);
@@ -1073,7 +1073,7 @@ static int udf_link(struct dentry *old_dentry, struct inode *dir,
 /* Anybody can rename anything with this: the permission checks are left to the
  * higher-level routines.
  */
-static int udf_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int udf_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		      struct dentry *old_dentry, struct inode *new_dir,
 		      struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/udf/symlink.c b/fs/udf/symlink.c
index f3642f9c23f8..5cf763911aef 100644
--- a/fs/udf/symlink.c
+++ b/fs/udf/symlink.c
@@ -153,7 +153,7 @@ out_unmap:
 	return err;
 }
 
-static int udf_symlink_getattr(struct user_namespace *mnt_userns,
+static int udf_symlink_getattr(struct mnt_idmap *idmap,
 			       const struct path *path, struct kstat *stat,
 			       u32 request_mask, unsigned int flags)
 {
@@ -161,7 +161,7 @@ static int udf_symlink_getattr(struct user_namespace *mnt_userns,
 	struct inode *inode = d_backing_inode(dentry);
 	struct page *page;
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	page = read_mapping_page(inode->i_mapping, 0, NULL);
 	if (IS_ERR(page))
 		return PTR_ERR(page);
diff --git a/fs/ufs/ialloc.c b/fs/ufs/ialloc.c
index 7e3e08c0166f..06bd84d555bd 100644
--- a/fs/ufs/ialloc.c
+++ b/fs/ufs/ialloc.c
@@ -289,7 +289,7 @@ cg_found:
 	ufs_mark_sb_dirty(sb);
 
 	inode->i_ino = cg * uspi->s_ipg + bit;
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 	inode->i_blocks = 0;
 	inode->i_generation = 0;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index a873de7dec1c..a4246c83a8cd 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -1212,14 +1212,14 @@ out:
 	return err;
 }
 
-int ufs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ufs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	unsigned int ia_valid = attr->ia_valid;
 	int error;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
@@ -1229,7 +1229,7 @@ int ufs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 			return error;
 	}
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c
index 29d5a0e0c8f0..36154b5aca6d 100644
--- a/fs/ufs/namei.c
+++ b/fs/ufs/namei.c
@@ -69,7 +69,7 @@ static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, unsi
  * If the create succeeds, we fill in the inode information
  * with d_instantiate(). 
  */
-static int ufs_create (struct user_namespace * mnt_userns,
+static int ufs_create (struct mnt_idmap * idmap,
 		struct inode * dir, struct dentry * dentry, umode_t mode,
 		bool excl)
 {
@@ -86,7 +86,7 @@ static int ufs_create (struct user_namespace * mnt_userns,
 	return ufs_add_nondir(dentry, inode);
 }
 
-static int ufs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int ufs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		     struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct inode *inode;
@@ -106,7 +106,7 @@ static int ufs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	return err;
 }
 
-static int ufs_symlink (struct user_namespace * mnt_userns, struct inode * dir,
+static int ufs_symlink (struct mnt_idmap * idmap, struct inode * dir,
 	struct dentry * dentry, const char * symname)
 {
 	struct super_block * sb = dir->i_sb;
@@ -166,7 +166,7 @@ static int ufs_link (struct dentry * old_dentry, struct inode * dir,
 	return error;
 }
 
-static int ufs_mkdir(struct user_namespace * mnt_userns, struct inode * dir,
+static int ufs_mkdir(struct mnt_idmap * idmap, struct inode * dir,
 	struct dentry * dentry, umode_t mode)
 {
 	struct inode * inode;
@@ -243,7 +243,7 @@ static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
 	return err;
 }
 
-static int ufs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int ufs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		      struct dentry *old_dentry, struct inode *new_dir,
 		      struct dentry *new_dentry, unsigned int flags)
 {
diff --git a/fs/ufs/ufs.h b/fs/ufs/ufs.h
index 550f7c5a3636..6b499180643b 100644
--- a/fs/ufs/ufs.h
+++ b/fs/ufs/ufs.h
@@ -123,7 +123,7 @@ extern struct inode *ufs_iget(struct super_block *, unsigned long);
 extern int ufs_write_inode (struct inode *, struct writeback_control *);
 extern int ufs_sync_inode (struct inode *);
 extern void ufs_evict_inode (struct inode *);
-extern int ufs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+extern int ufs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		       struct iattr *attr);
 
 /* namei.c */
diff --git a/fs/utimes.c b/fs/utimes.c
index 00499e4ba955..3701b3946f88 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -63,7 +63,7 @@ int vfs_utimes(const struct path *path, struct timespec64 *times)
 	}
 retry_deleg:
 	inode_lock(inode);
-	error = notify_change(mnt_user_ns(path->mnt), path->dentry, &newattrs,
+	error = notify_change(mnt_idmap(path->mnt), path->dentry, &newattrs,
 			      &delegated_inode);
 	inode_unlock(inode);
 	if (delegated_inode) {
diff --git a/fs/vboxsf/dir.c b/fs/vboxsf/dir.c
index c4769a9396c5..075f15c43c78 100644
--- a/fs/vboxsf/dir.c
+++ b/fs/vboxsf/dir.c
@@ -294,14 +294,14 @@ out:
 	return err;
 }
 
-static int vboxsf_dir_mkfile(struct user_namespace *mnt_userns,
+static int vboxsf_dir_mkfile(struct mnt_idmap *idmap,
 			     struct inode *parent, struct dentry *dentry,
 			     umode_t mode, bool excl)
 {
 	return vboxsf_dir_create(parent, dentry, mode, false, excl, NULL);
 }
 
-static int vboxsf_dir_mkdir(struct user_namespace *mnt_userns,
+static int vboxsf_dir_mkdir(struct mnt_idmap *idmap,
 			    struct inode *parent, struct dentry *dentry,
 			    umode_t mode)
 {
@@ -387,7 +387,7 @@ static int vboxsf_dir_unlink(struct inode *parent, struct dentry *dentry)
 	return 0;
 }
 
-static int vboxsf_dir_rename(struct user_namespace *mnt_userns,
+static int vboxsf_dir_rename(struct mnt_idmap *idmap,
 			     struct inode *old_parent,
 			     struct dentry *old_dentry,
 			     struct inode *new_parent,
@@ -430,7 +430,7 @@ err_put_old_path:
 	return err;
 }
 
-static int vboxsf_dir_symlink(struct user_namespace *mnt_userns,
+static int vboxsf_dir_symlink(struct mnt_idmap *idmap,
 			      struct inode *parent, struct dentry *dentry,
 			      const char *symname)
 {
diff --git a/fs/vboxsf/utils.c b/fs/vboxsf/utils.c
index e1db0f3f7e5e..dd0ae1188e87 100644
--- a/fs/vboxsf/utils.c
+++ b/fs/vboxsf/utils.c
@@ -231,7 +231,7 @@ int vboxsf_inode_revalidate(struct dentry *dentry)
 	return 0;
 }
 
-int vboxsf_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int vboxsf_getattr(struct mnt_idmap *idmap, const struct path *path,
 		   struct kstat *kstat, u32 request_mask, unsigned int flags)
 {
 	int err;
@@ -252,11 +252,11 @@ int vboxsf_getattr(struct user_namespace *mnt_userns, const struct path *path,
 	if (err)
 		return err;
 
-	generic_fillattr(&init_user_ns, d_inode(dentry), kstat);
+	generic_fillattr(&nop_mnt_idmap, d_inode(dentry), kstat);
 	return 0;
 }
 
-int vboxsf_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int vboxsf_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		   struct iattr *iattr)
 {
 	struct vboxsf_inode *sf_i = VBOXSF_I(d_inode(dentry));
diff --git a/fs/vboxsf/vfsmod.h b/fs/vboxsf/vfsmod.h
index 9047befa66c5..05973eb89d52 100644
--- a/fs/vboxsf/vfsmod.h
+++ b/fs/vboxsf/vfsmod.h
@@ -97,10 +97,10 @@ int vboxsf_stat(struct vboxsf_sbi *sbi, struct shfl_string *path,
 		struct shfl_fsobjinfo *info);
 int vboxsf_stat_dentry(struct dentry *dentry, struct shfl_fsobjinfo *info);
 int vboxsf_inode_revalidate(struct dentry *dentry);
-int vboxsf_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int vboxsf_getattr(struct mnt_idmap *idmap, const struct path *path,
 		   struct kstat *kstat, u32 request_mask,
 		   unsigned int query_flags);
-int vboxsf_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int vboxsf_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		   struct iattr *iattr);
 struct shfl_string *vboxsf_path_from_dentry(struct vboxsf_sbi *sbi,
 					    struct dentry *dentry);
diff --git a/fs/xattr.c b/fs/xattr.c
index 3fead374901b..14a7eb3c8fa8 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -83,7 +83,7 @@ xattr_resolve_name(struct inode *inode, const char **name)
 
 /**
  * may_write_xattr - check whether inode allows writing xattr
- * @mnt_userns:	User namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @inode: the inode on which to set an xattr
  *
  * Check whether the inode allows writing xattrs. Specifically, we can never
@@ -95,13 +95,13 @@ xattr_resolve_name(struct inode *inode, const char **name)
  *
  * Return: On success zero is returned. On error a negative errno is returned.
  */
-int may_write_xattr(struct user_namespace *mnt_userns, struct inode *inode)
+int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode)
 {
 	if (IS_IMMUTABLE(inode))
 		return -EPERM;
 	if (IS_APPEND(inode))
 		return -EPERM;
-	if (HAS_UNMAPPED_ID(mnt_userns, inode))
+	if (HAS_UNMAPPED_ID(idmap, inode))
 		return -EPERM;
 	return 0;
 }
@@ -111,13 +111,13 @@ int may_write_xattr(struct user_namespace *mnt_userns, struct inode *inode)
  * because different namespaces have very different rules.
  */
 static int
-xattr_permission(struct user_namespace *mnt_userns, struct inode *inode,
+xattr_permission(struct mnt_idmap *idmap, struct inode *inode,
 		 const char *name, int mask)
 {
 	if (mask & MAY_WRITE) {
 		int ret;
 
-		ret = may_write_xattr(mnt_userns, inode);
+		ret = may_write_xattr(idmap, inode);
 		if (ret)
 			return ret;
 	}
@@ -149,11 +149,11 @@ xattr_permission(struct user_namespace *mnt_userns, struct inode *inode,
 			return (mask & MAY_WRITE) ? -EPERM : -ENODATA;
 		if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) &&
 		    (mask & MAY_WRITE) &&
-		    !inode_owner_or_capable(mnt_userns, inode))
+		    !inode_owner_or_capable(idmap, inode))
 			return -EPERM;
 	}
 
-	return inode_permission(mnt_userns, inode, mask);
+	return inode_permission(idmap, inode, mask);
 }
 
 /*
@@ -184,7 +184,7 @@ xattr_supported_namespace(struct inode *inode, const char *prefix)
 EXPORT_SYMBOL(xattr_supported_namespace);
 
 int
-__vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+__vfs_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	       struct inode *inode, const char *name, const void *value,
 	       size_t size, int flags)
 {
@@ -200,7 +200,7 @@ __vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		return -EOPNOTSUPP;
 	if (size == 0)
 		value = "";  /* empty EA, do not remove */
-	return handler->set(handler, mnt_userns, dentry, inode, name, value,
+	return handler->set(handler, idmap, dentry, inode, name, value,
 			    size, flags);
 }
 EXPORT_SYMBOL(__vfs_setxattr);
@@ -209,7 +209,7 @@ EXPORT_SYMBOL(__vfs_setxattr);
  *  __vfs_setxattr_noperm - perform setxattr operation without performing
  *  permission checks.
  *
- *  @mnt_userns: user namespace of the mount the inode was found from
+ *  @idmap: idmap of the mount the inode was found from
  *  @dentry: object to perform setxattr on
  *  @name: xattr name to set
  *  @value: value to set @name to
@@ -222,7 +222,7 @@ EXPORT_SYMBOL(__vfs_setxattr);
  *  is executed. It also assumes that the caller will make the appropriate
  *  permission checks.
  */
-int __vfs_setxattr_noperm(struct user_namespace *mnt_userns,
+int __vfs_setxattr_noperm(struct mnt_idmap *idmap,
 			  struct dentry *dentry, const char *name,
 			  const void *value, size_t size, int flags)
 {
@@ -234,7 +234,7 @@ int __vfs_setxattr_noperm(struct user_namespace *mnt_userns,
 	if (issec)
 		inode->i_flags &= ~S_NOSEC;
 	if (inode->i_opflags & IOP_XATTR) {
-		error = __vfs_setxattr(mnt_userns, dentry, inode, name, value,
+		error = __vfs_setxattr(idmap, dentry, inode, name, value,
 				       size, flags);
 		if (!error) {
 			fsnotify_xattr(dentry);
@@ -265,7 +265,7 @@ int __vfs_setxattr_noperm(struct user_namespace *mnt_userns,
  * __vfs_setxattr_locked - set an extended attribute while holding the inode
  * lock
  *
- *  @mnt_userns: user namespace of the mount of the target inode
+ *  @idmap: idmap of the mount of the target inode
  *  @dentry: object to perform setxattr on
  *  @name: xattr name to set
  *  @value: value to set @name to
@@ -275,18 +275,18 @@ int __vfs_setxattr_noperm(struct user_namespace *mnt_userns,
  *  a delegation was broken on, NULL if none.
  */
 int
-__vfs_setxattr_locked(struct user_namespace *mnt_userns, struct dentry *dentry,
+__vfs_setxattr_locked(struct mnt_idmap *idmap, struct dentry *dentry,
 		      const char *name, const void *value, size_t size,
 		      int flags, struct inode **delegated_inode)
 {
 	struct inode *inode = dentry->d_inode;
 	int error;
 
-	error = xattr_permission(mnt_userns, inode, name, MAY_WRITE);
+	error = xattr_permission(idmap, inode, name, MAY_WRITE);
 	if (error)
 		return error;
 
-	error = security_inode_setxattr(mnt_userns, dentry, name, value, size,
+	error = security_inode_setxattr(idmap, dentry, name, value, size,
 					flags);
 	if (error)
 		goto out;
@@ -295,7 +295,7 @@ __vfs_setxattr_locked(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (error)
 		goto out;
 
-	error = __vfs_setxattr_noperm(mnt_userns, dentry, name, value,
+	error = __vfs_setxattr_noperm(idmap, dentry, name, value,
 				      size, flags);
 
 out:
@@ -304,7 +304,7 @@ out:
 EXPORT_SYMBOL_GPL(__vfs_setxattr_locked);
 
 int
-vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+vfs_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	     const char *name, const void *value, size_t size, int flags)
 {
 	struct inode *inode = dentry->d_inode;
@@ -313,7 +313,7 @@ vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	int error;
 
 	if (size && strcmp(name, XATTR_NAME_CAPS) == 0) {
-		error = cap_convert_nscap(mnt_userns, dentry, &value, size);
+		error = cap_convert_nscap(idmap, dentry, &value, size);
 		if (error < 0)
 			return error;
 		size = error;
@@ -321,7 +321,7 @@ vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 retry_deleg:
 	inode_lock(inode);
-	error = __vfs_setxattr_locked(mnt_userns, dentry, name, value, size,
+	error = __vfs_setxattr_locked(idmap, dentry, name, value, size,
 				      flags, &delegated_inode);
 	inode_unlock(inode);
 
@@ -338,19 +338,19 @@ retry_deleg:
 EXPORT_SYMBOL_GPL(vfs_setxattr);
 
 static ssize_t
-xattr_getsecurity(struct user_namespace *mnt_userns, struct inode *inode,
+xattr_getsecurity(struct mnt_idmap *idmap, struct inode *inode,
 		  const char *name, void *value, size_t size)
 {
 	void *buffer = NULL;
 	ssize_t len;
 
 	if (!value || !size) {
-		len = security_inode_getsecurity(mnt_userns, inode, name,
+		len = security_inode_getsecurity(idmap, inode, name,
 						 &buffer, false);
 		goto out_noalloc;
 	}
 
-	len = security_inode_getsecurity(mnt_userns, inode, name, &buffer,
+	len = security_inode_getsecurity(idmap, inode, name, &buffer,
 					 true);
 	if (len < 0)
 		return len;
@@ -375,7 +375,7 @@ out_noalloc:
  * Returns the result of alloc, if failed, or the getxattr operation.
  */
 int
-vfs_getxattr_alloc(struct user_namespace *mnt_userns, struct dentry *dentry,
+vfs_getxattr_alloc(struct mnt_idmap *idmap, struct dentry *dentry,
 		   const char *name, char **xattr_value, size_t xattr_size,
 		   gfp_t flags)
 {
@@ -384,7 +384,7 @@ vfs_getxattr_alloc(struct user_namespace *mnt_userns, struct dentry *dentry,
 	char *value = *xattr_value;
 	int error;
 
-	error = xattr_permission(mnt_userns, inode, name, MAY_READ);
+	error = xattr_permission(idmap, inode, name, MAY_READ);
 	if (error)
 		return error;
 
@@ -428,13 +428,13 @@ __vfs_getxattr(struct dentry *dentry, struct inode *inode, const char *name,
 EXPORT_SYMBOL(__vfs_getxattr);
 
 ssize_t
-vfs_getxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+vfs_getxattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	     const char *name, void *value, size_t size)
 {
 	struct inode *inode = dentry->d_inode;
 	int error;
 
-	error = xattr_permission(mnt_userns, inode, name, MAY_READ);
+	error = xattr_permission(idmap, inode, name, MAY_READ);
 	if (error)
 		return error;
 
@@ -445,7 +445,7 @@ vfs_getxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (!strncmp(name, XATTR_SECURITY_PREFIX,
 				XATTR_SECURITY_PREFIX_LEN)) {
 		const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
-		int ret = xattr_getsecurity(mnt_userns, inode, suffix, value,
+		int ret = xattr_getsecurity(idmap, inode, suffix, value,
 					    size);
 		/*
 		 * Only overwrite the return value if a security module
@@ -481,7 +481,7 @@ vfs_listxattr(struct dentry *dentry, char *list, size_t size)
 EXPORT_SYMBOL_GPL(vfs_listxattr);
 
 int
-__vfs_removexattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+__vfs_removexattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  const char *name)
 {
 	struct inode *inode = d_inode(dentry);
@@ -495,7 +495,7 @@ __vfs_removexattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		return PTR_ERR(handler);
 	if (!handler->set)
 		return -EOPNOTSUPP;
-	return handler->set(handler, mnt_userns, dentry, inode, name, NULL, 0,
+	return handler->set(handler, idmap, dentry, inode, name, NULL, 0,
 			    XATTR_REPLACE);
 }
 EXPORT_SYMBOL(__vfs_removexattr);
@@ -504,25 +504,25 @@ EXPORT_SYMBOL(__vfs_removexattr);
  * __vfs_removexattr_locked - set an extended attribute while holding the inode
  * lock
  *
- *  @mnt_userns: user namespace of the mount of the target inode
+ *  @idmap: idmap of the mount of the target inode
  *  @dentry: object to perform setxattr on
  *  @name: name of xattr to remove
  *  @delegated_inode: on return, will contain an inode pointer that
  *  a delegation was broken on, NULL if none.
  */
 int
-__vfs_removexattr_locked(struct user_namespace *mnt_userns,
+__vfs_removexattr_locked(struct mnt_idmap *idmap,
 			 struct dentry *dentry, const char *name,
 			 struct inode **delegated_inode)
 {
 	struct inode *inode = dentry->d_inode;
 	int error;
 
-	error = xattr_permission(mnt_userns, inode, name, MAY_WRITE);
+	error = xattr_permission(idmap, inode, name, MAY_WRITE);
 	if (error)
 		return error;
 
-	error = security_inode_removexattr(mnt_userns, dentry, name);
+	error = security_inode_removexattr(idmap, dentry, name);
 	if (error)
 		goto out;
 
@@ -530,7 +530,7 @@ __vfs_removexattr_locked(struct user_namespace *mnt_userns,
 	if (error)
 		goto out;
 
-	error = __vfs_removexattr(mnt_userns, dentry, name);
+	error = __vfs_removexattr(idmap, dentry, name);
 
 	if (!error) {
 		fsnotify_xattr(dentry);
@@ -543,7 +543,7 @@ out:
 EXPORT_SYMBOL_GPL(__vfs_removexattr_locked);
 
 int
-vfs_removexattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+vfs_removexattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		const char *name)
 {
 	struct inode *inode = dentry->d_inode;
@@ -552,7 +552,7 @@ vfs_removexattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 retry_deleg:
 	inode_lock(inode);
-	error = __vfs_removexattr_locked(mnt_userns, dentry,
+	error = __vfs_removexattr_locked(idmap, dentry,
 					 name, &delegated_inode);
 	inode_unlock(inode);
 
@@ -606,7 +606,7 @@ int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		return do_set_acl(idmap, dentry, ctx->kname->name,
 				  ctx->kvalue, ctx->size);
 
-	return vfs_setxattr(mnt_idmap_owner(idmap), dentry, ctx->kname->name,
+	return vfs_setxattr(idmap, dentry, ctx->kname->name,
 			ctx->kvalue, ctx->size, ctx->flags);
 }
 
@@ -715,8 +715,7 @@ do_getxattr(struct mnt_idmap *idmap, struct dentry *d,
 	if (is_posix_acl_xattr(ctx->kname->name))
 		error = do_get_acl(idmap, d, kname, ctx->kvalue, ctx->size);
 	else
-		error = vfs_getxattr(mnt_idmap_owner(idmap), d, kname,
-				     ctx->kvalue, ctx->size);
+		error = vfs_getxattr(idmap, d, kname, ctx->kvalue, ctx->size);
 	if (error > 0) {
 		if (ctx->size && copy_to_user(ctx->value, ctx->kvalue, error))
 			error = -EFAULT;
@@ -893,9 +892,9 @@ removexattr(struct mnt_idmap *idmap, struct dentry *d,
 		return error;
 
 	if (is_posix_acl_xattr(kname))
-		return vfs_remove_acl(mnt_idmap_owner(idmap), d, kname);
+		return vfs_remove_acl(idmap, d, kname);
 
-	return vfs_removexattr(mnt_idmap_owner(idmap), d, kname);
+	return vfs_removexattr(idmap, d, kname);
 }
 
 static int path_removexattr(const char __user *pathname,
diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
index a05f44eb8178..791db7d9c849 100644
--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -242,7 +242,7 @@ xfs_acl_set_mode(
 }
 
 int
-xfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+xfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	    struct posix_acl *acl, int type)
 {
 	umode_t mode;
@@ -258,7 +258,7 @@ xfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 		return error;
 
 	if (type == ACL_TYPE_ACCESS) {
-		error = posix_acl_update_mode(mnt_userns, inode, &mode, &acl);
+		error = posix_acl_update_mode(idmap, inode, &mode, &acl);
 		if (error)
 			return error;
 		set_mode = true;
diff --git a/fs/xfs/xfs_acl.h b/fs/xfs/xfs_acl.h
index dcd176149c7a..bf7f960997d3 100644
--- a/fs/xfs/xfs_acl.h
+++ b/fs/xfs/xfs_acl.h
@@ -11,7 +11,7 @@ struct posix_acl;
 
 #ifdef CONFIG_XFS_POSIX_ACL
 extern struct posix_acl *xfs_get_acl(struct inode *inode, int type, bool rcu);
-extern int xfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+extern int xfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		       struct posix_acl *acl, int type);
 extern int __xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 void xfs_forget_acl(struct inode *inode, const char *name);
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 595a5bcf46b9..d06c0cc62f61 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1047,7 +1047,7 @@ xfs_file_fallocate(
 
 		iattr.ia_valid = ATTR_SIZE;
 		iattr.ia_size = new_size;
-		error = xfs_vn_setattr_size(file_mnt_user_ns(file),
+		error = xfs_vn_setattr_size(file_mnt_idmap(file),
 					    file_dentry(file), &iattr);
 		if (error)
 			goto out_unlock;
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index d354ea2b74f9..7f1d715faab5 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -777,7 +777,7 @@ xfs_inode_inherit_flags2(
  */
 int
 xfs_init_new_inode(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct xfs_trans	*tp,
 	struct xfs_inode	*pip,
 	xfs_ino_t		ino,
@@ -823,11 +823,11 @@ xfs_init_new_inode(
 	ip->i_projid = prid;
 
 	if (dir && !(dir->i_mode & S_ISGID) && xfs_has_grpid(mp)) {
-		inode_fsuid_set(inode, mnt_userns);
+		inode_fsuid_set(inode, idmap);
 		inode->i_gid = dir->i_gid;
 		inode->i_mode = mode;
 	} else {
-		inode_init_owner(mnt_userns, inode, dir, mode);
+		inode_init_owner(idmap, inode, dir, mode);
 	}
 
 	/*
@@ -836,7 +836,7 @@ xfs_init_new_inode(
 	 * (and only if the irix_sgid_inherit compatibility variable is set).
 	 */
 	if (irix_sgid_inherit && (inode->i_mode & S_ISGID) &&
-	    !vfsgid_in_group_p(i_gid_into_vfsgid(mnt_userns, inode)))
+	    !vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)))
 		inode->i_mode &= ~S_ISGID;
 
 	ip->i_disk_size = 0;
@@ -946,7 +946,7 @@ xfs_bumplink(
 
 int
 xfs_create(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	xfs_inode_t		*dp,
 	struct xfs_name		*name,
 	umode_t			mode,
@@ -978,8 +978,8 @@ xfs_create(
 	/*
 	 * Make sure that we have allocated dquot(s) on disk.
 	 */
-	error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(mnt_userns, &init_user_ns),
-			mapped_fsgid(mnt_userns, &init_user_ns), prid,
+	error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(idmap, &init_user_ns),
+			mapped_fsgid(idmap, &init_user_ns), prid,
 			XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
 			&udqp, &gdqp, &pdqp);
 	if (error)
@@ -1020,7 +1020,7 @@ xfs_create(
 	 */
 	error = xfs_dialloc(&tp, dp->i_ino, mode, &ino);
 	if (!error)
-		error = xfs_init_new_inode(mnt_userns, tp, dp, ino, mode,
+		error = xfs_init_new_inode(idmap, tp, dp, ino, mode,
 				is_dir ? 2 : 1, rdev, prid, init_xattrs, &ip);
 	if (error)
 		goto out_trans_cancel;
@@ -1102,7 +1102,7 @@ xfs_create(
 
 int
 xfs_create_tmpfile(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct xfs_inode	*dp,
 	umode_t			mode,
 	struct xfs_inode	**ipp)
@@ -1127,8 +1127,8 @@ xfs_create_tmpfile(
 	/*
 	 * Make sure that we have allocated dquot(s) on disk.
 	 */
-	error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(mnt_userns, &init_user_ns),
-			mapped_fsgid(mnt_userns, &init_user_ns), prid,
+	error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(idmap, &init_user_ns),
+			mapped_fsgid(idmap, &init_user_ns), prid,
 			XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
 			&udqp, &gdqp, &pdqp);
 	if (error)
@@ -1144,7 +1144,7 @@ xfs_create_tmpfile(
 
 	error = xfs_dialloc(&tp, dp->i_ino, mode, &ino);
 	if (!error)
-		error = xfs_init_new_inode(mnt_userns, tp, dp, ino, mode,
+		error = xfs_init_new_inode(idmap, tp, dp, ino, mode,
 				0, 0, prid, false, &ip);
 	if (error)
 		goto out_trans_cancel;
@@ -2709,7 +2709,7 @@ out_trans_abort:
  */
 static int
 xfs_rename_alloc_whiteout(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct xfs_name		*src_name,
 	struct xfs_inode	*dp,
 	struct xfs_inode	**wip)
@@ -2718,7 +2718,7 @@ xfs_rename_alloc_whiteout(
 	struct qstr		name;
 	int			error;
 
-	error = xfs_create_tmpfile(mnt_userns, dp, S_IFCHR | WHITEOUT_MODE,
+	error = xfs_create_tmpfile(idmap, dp, S_IFCHR | WHITEOUT_MODE,
 				   &tmpfile);
 	if (error)
 		return error;
@@ -2750,7 +2750,7 @@ xfs_rename_alloc_whiteout(
  */
 int
 xfs_rename(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct xfs_inode	*src_dp,
 	struct xfs_name		*src_name,
 	struct xfs_inode	*src_ip,
@@ -2782,7 +2782,7 @@ xfs_rename(
 	 * appropriately.
 	 */
 	if (flags & RENAME_WHITEOUT) {
-		error = xfs_rename_alloc_whiteout(mnt_userns, src_name,
+		error = xfs_rename_alloc_whiteout(idmap, src_name,
 						  target_dp, &wip);
 		if (error)
 			return error;
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index fa780f08dc89..69d21e42c10a 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -473,18 +473,18 @@ int		xfs_release(struct xfs_inode *ip);
 void		xfs_inactive(struct xfs_inode *ip);
 int		xfs_lookup(struct xfs_inode *dp, const struct xfs_name *name,
 			   struct xfs_inode **ipp, struct xfs_name *ci_name);
-int		xfs_create(struct user_namespace *mnt_userns,
+int		xfs_create(struct mnt_idmap *idmap,
 			   struct xfs_inode *dp, struct xfs_name *name,
 			   umode_t mode, dev_t rdev, bool need_xattr,
 			   struct xfs_inode **ipp);
-int		xfs_create_tmpfile(struct user_namespace *mnt_userns,
+int		xfs_create_tmpfile(struct mnt_idmap *idmap,
 			   struct xfs_inode *dp, umode_t mode,
 			   struct xfs_inode **ipp);
 int		xfs_remove(struct xfs_inode *dp, struct xfs_name *name,
 			   struct xfs_inode *ip);
 int		xfs_link(struct xfs_inode *tdp, struct xfs_inode *sip,
 			 struct xfs_name *target_name);
-int		xfs_rename(struct user_namespace *mnt_userns,
+int		xfs_rename(struct mnt_idmap *idmap,
 			   struct xfs_inode *src_dp, struct xfs_name *src_name,
 			   struct xfs_inode *src_ip, struct xfs_inode *target_dp,
 			   struct xfs_name *target_name,
@@ -515,7 +515,7 @@ void		xfs_lock_two_inodes(struct xfs_inode *ip0, uint ip0_mode,
 xfs_extlen_t	xfs_get_extsz_hint(struct xfs_inode *ip);
 xfs_extlen_t	xfs_get_cowextsz_hint(struct xfs_inode *ip);
 
-int xfs_init_new_inode(struct user_namespace *mnt_userns, struct xfs_trans *tp,
+int xfs_init_new_inode(struct mnt_idmap *idmap, struct xfs_trans *tp,
 		struct xfs_inode *pip, xfs_ino_t ino, umode_t mode,
 		xfs_nlink_t nlink, dev_t rdev, prid_t prid, bool init_xattrs,
 		struct xfs_inode **ipp);
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 736510bc241b..55bb01173cde 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -665,7 +665,7 @@ xfs_ioc_fsbulkstat(
 	struct xfs_fsop_bulkreq	bulkreq;
 	struct xfs_ibulk	breq = {
 		.mp		= mp,
-		.mnt_userns	= file_mnt_user_ns(file),
+		.idmap		= file_mnt_idmap(file),
 		.ocount		= 0,
 	};
 	xfs_ino_t		lastino;
@@ -844,7 +844,7 @@ xfs_ioc_bulkstat(
 	struct xfs_bulk_ireq		hdr;
 	struct xfs_ibulk		breq = {
 		.mp			= mp,
-		.mnt_userns		= file_mnt_user_ns(file),
+		.idmap			= file_mnt_idmap(file),
 	};
 	int				error;
 
@@ -1297,7 +1297,7 @@ xfs_ioctl_setattr_check_projid(
 
 int
 xfs_fileattr_set(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct dentry		*dentry,
 	struct fileattr		*fa)
 {
@@ -1371,7 +1371,7 @@ xfs_fileattr_set(
 	 */
 
 	if ((VFS_I(ip)->i_mode & (S_ISUID|S_ISGID)) &&
-	    !capable_wrt_inode_uidgid(mnt_userns, VFS_I(ip), CAP_FSETID))
+	    !capable_wrt_inode_uidgid(idmap, VFS_I(ip), CAP_FSETID))
 		VFS_I(ip)->i_mode &= ~(S_ISUID|S_ISGID);
 
 	/* Change the ownerships and register project quota modifications */
diff --git a/fs/xfs/xfs_ioctl.h b/fs/xfs/xfs_ioctl.h
index d4abba2c13c1..38be600b5e1e 100644
--- a/fs/xfs/xfs_ioctl.h
+++ b/fs/xfs/xfs_ioctl.h
@@ -49,7 +49,7 @@ xfs_fileattr_get(
 
 extern int
 xfs_fileattr_set(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct dentry		*dentry,
 	struct fileattr		*fa);
 
diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c
index 2f54b701eead..ee35eea1ecce 100644
--- a/fs/xfs/xfs_ioctl32.c
+++ b/fs/xfs/xfs_ioctl32.c
@@ -204,7 +204,7 @@ xfs_compat_ioc_fsbulkstat(
 	struct xfs_fsop_bulkreq	bulkreq;
 	struct xfs_ibulk	breq = {
 		.mp		= mp,
-		.mnt_userns	= file_mnt_user_ns(file),
+		.idmap		= file_mnt_idmap(file),
 		.ocount		= 0,
 	};
 	xfs_ino_t		lastino;
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 515318dfbc38..24718adb3c16 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -162,12 +162,12 @@ xfs_create_need_xattr(
 
 STATIC int
 xfs_generic_create(
-	struct user_namespace	*mnt_userns,
-	struct inode	*dir,
-	struct dentry	*dentry,
-	umode_t		mode,
-	dev_t		rdev,
-	struct file	*tmpfile)	/* unnamed file */
+	struct mnt_idmap	*idmap,
+	struct inode		*dir,
+	struct dentry		*dentry,
+	umode_t			mode,
+	dev_t			rdev,
+	struct file		*tmpfile)	/* unnamed file */
 {
 	struct inode	*inode;
 	struct xfs_inode *ip = NULL;
@@ -196,11 +196,11 @@ xfs_generic_create(
 		goto out_free_acl;
 
 	if (!tmpfile) {
-		error = xfs_create(mnt_userns, XFS_I(dir), &name, mode, rdev,
+		error = xfs_create(idmap, XFS_I(dir), &name, mode, rdev,
 				xfs_create_need_xattr(dir, default_acl, acl),
 				&ip);
 	} else {
-		error = xfs_create_tmpfile(mnt_userns, XFS_I(dir), mode, &ip);
+		error = xfs_create_tmpfile(idmap, XFS_I(dir), mode, &ip);
 	}
 	if (unlikely(error))
 		goto out_free_acl;
@@ -255,35 +255,34 @@ xfs_generic_create(
 
 STATIC int
 xfs_vn_mknod(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct inode		*dir,
 	struct dentry		*dentry,
 	umode_t			mode,
 	dev_t			rdev)
 {
-	return xfs_generic_create(mnt_userns, dir, dentry, mode, rdev, NULL);
+	return xfs_generic_create(idmap, dir, dentry, mode, rdev, NULL);
 }
 
 STATIC int
 xfs_vn_create(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct inode		*dir,
 	struct dentry		*dentry,
 	umode_t			mode,
 	bool			flags)
 {
-	return xfs_generic_create(mnt_userns, dir, dentry, mode, 0, NULL);
+	return xfs_generic_create(idmap, dir, dentry, mode, 0, NULL);
 }
 
 STATIC int
 xfs_vn_mkdir(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct inode		*dir,
 	struct dentry		*dentry,
 	umode_t			mode)
 {
-	return xfs_generic_create(mnt_userns, dir, dentry, mode | S_IFDIR, 0,
-				  NULL);
+	return xfs_generic_create(idmap, dir, dentry, mode | S_IFDIR, 0, NULL);
 }
 
 STATIC struct dentry *
@@ -400,7 +399,7 @@ xfs_vn_unlink(
 
 STATIC int
 xfs_vn_symlink(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct inode		*dir,
 	struct dentry		*dentry,
 	const char		*symname)
@@ -417,7 +416,7 @@ xfs_vn_symlink(
 	if (unlikely(error))
 		goto out;
 
-	error = xfs_symlink(mnt_userns, XFS_I(dir), &name, symname, mode, &cip);
+	error = xfs_symlink(idmap, XFS_I(dir), &name, symname, mode, &cip);
 	if (unlikely(error))
 		goto out;
 
@@ -443,7 +442,7 @@ xfs_vn_symlink(
 
 STATIC int
 xfs_vn_rename(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct inode		*odir,
 	struct dentry		*odentry,
 	struct inode		*ndir,
@@ -472,7 +471,7 @@ xfs_vn_rename(
 	if (unlikely(error))
 		return error;
 
-	return xfs_rename(mnt_userns, XFS_I(odir), &oname,
+	return xfs_rename(idmap, XFS_I(odir), &oname,
 			  XFS_I(d_inode(odentry)), XFS_I(ndir), &nname,
 			  new_inode ? XFS_I(new_inode) : NULL, flags);
 }
@@ -549,7 +548,7 @@ xfs_stat_blksize(
 
 STATIC int
 xfs_vn_getattr(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	const struct path	*path,
 	struct kstat		*stat,
 	u32			request_mask,
@@ -558,8 +557,8 @@ xfs_vn_getattr(
 	struct inode		*inode = d_inode(path->dentry);
 	struct xfs_inode	*ip = XFS_I(inode);
 	struct xfs_mount	*mp = ip->i_mount;
-	vfsuid_t		vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
-	vfsgid_t		vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
+	vfsuid_t		vfsuid = i_uid_into_vfsuid(idmap, inode);
+	vfsgid_t		vfsgid = i_gid_into_vfsgid(idmap, inode);
 
 	trace_xfs_getattr(ip);
 
@@ -627,7 +626,7 @@ xfs_vn_getattr(
 
 static int
 xfs_vn_change_ok(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct dentry		*dentry,
 	struct iattr		*iattr)
 {
@@ -639,7 +638,7 @@ xfs_vn_change_ok(
 	if (xfs_is_shutdown(mp))
 		return -EIO;
 
-	return setattr_prepare(mnt_userns, dentry, iattr);
+	return setattr_prepare(idmap, dentry, iattr);
 }
 
 /*
@@ -650,7 +649,7 @@ xfs_vn_change_ok(
  */
 static int
 xfs_setattr_nonsize(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct dentry		*dentry,
 	struct xfs_inode	*ip,
 	struct iattr		*iattr)
@@ -679,14 +678,14 @@ xfs_setattr_nonsize(
 		uint	qflags = 0;
 
 		if ((mask & ATTR_UID) && XFS_IS_UQUOTA_ON(mp)) {
-			uid = from_vfsuid(mnt_userns, i_user_ns(inode),
+			uid = from_vfsuid(idmap, i_user_ns(inode),
 					  iattr->ia_vfsuid);
 			qflags |= XFS_QMOPT_UQUOTA;
 		} else {
 			uid = inode->i_uid;
 		}
 		if ((mask & ATTR_GID) && XFS_IS_GQUOTA_ON(mp)) {
-			gid = from_vfsgid(mnt_userns, i_user_ns(inode),
+			gid = from_vfsgid(idmap, i_user_ns(inode),
 					  iattr->ia_vfsgid);
 			qflags |= XFS_QMOPT_GQUOTA;
 		}  else {
@@ -719,18 +718,18 @@ xfs_setattr_nonsize(
 	 * also.
 	 */
 	if (XFS_IS_UQUOTA_ON(mp) &&
-	    i_uid_needs_update(mnt_userns, iattr, inode)) {
+	    i_uid_needs_update(idmap, iattr, inode)) {
 		ASSERT(udqp);
 		old_udqp = xfs_qm_vop_chown(tp, ip, &ip->i_udquot, udqp);
 	}
 	if (XFS_IS_GQUOTA_ON(mp) &&
-	    i_gid_needs_update(mnt_userns, iattr, inode)) {
+	    i_gid_needs_update(idmap, iattr, inode)) {
 		ASSERT(xfs_has_pquotino(mp) || !XFS_IS_PQUOTA_ON(mp));
 		ASSERT(gdqp);
 		old_gdqp = xfs_qm_vop_chown(tp, ip, &ip->i_gdquot, gdqp);
 	}
 
-	setattr_copy(mnt_userns, inode, iattr);
+	setattr_copy(idmap, inode, iattr);
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 
 	XFS_STATS_INC(mp, xs_ig_attrchg);
@@ -758,7 +757,7 @@ xfs_setattr_nonsize(
 	 * 	     Posix ACL code seems to care about this issue either.
 	 */
 	if (mask & ATTR_MODE) {
-		error = posix_acl_chmod(mnt_userns, dentry, inode->i_mode);
+		error = posix_acl_chmod(idmap, dentry, inode->i_mode);
 		if (error)
 			return error;
 	}
@@ -779,7 +778,7 @@ out_dqrele:
  */
 STATIC int
 xfs_setattr_size(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct dentry		*dentry,
 	struct xfs_inode	*ip,
 	struct iattr		*iattr)
@@ -812,7 +811,7 @@ xfs_setattr_size(
 		 * Use the regular setattr path to update the timestamps.
 		 */
 		iattr->ia_valid &= ~ATTR_SIZE;
-		return xfs_setattr_nonsize(mnt_userns, dentry, ip, iattr);
+		return xfs_setattr_nonsize(idmap, dentry, ip, iattr);
 	}
 
 	/*
@@ -956,7 +955,7 @@ xfs_setattr_size(
 	}
 
 	ASSERT(!(iattr->ia_valid & (ATTR_UID | ATTR_GID)));
-	setattr_copy(mnt_userns, inode, iattr);
+	setattr_copy(idmap, inode, iattr);
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 
 	XFS_STATS_INC(mp, xs_ig_attrchg);
@@ -977,7 +976,7 @@ out_trans_cancel:
 
 int
 xfs_vn_setattr_size(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct dentry		*dentry,
 	struct iattr		*iattr)
 {
@@ -986,15 +985,15 @@ xfs_vn_setattr_size(
 
 	trace_xfs_setattr(ip);
 
-	error = xfs_vn_change_ok(mnt_userns, dentry, iattr);
+	error = xfs_vn_change_ok(idmap, dentry, iattr);
 	if (error)
 		return error;
-	return xfs_setattr_size(mnt_userns, dentry, ip, iattr);
+	return xfs_setattr_size(idmap, dentry, ip, iattr);
 }
 
 STATIC int
 xfs_vn_setattr(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct dentry		*dentry,
 	struct iattr		*iattr)
 {
@@ -1014,14 +1013,14 @@ xfs_vn_setattr(
 			return error;
 		}
 
-		error = xfs_vn_setattr_size(mnt_userns, dentry, iattr);
+		error = xfs_vn_setattr_size(idmap, dentry, iattr);
 		xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
 	} else {
 		trace_xfs_setattr(ip);
 
-		error = xfs_vn_change_ok(mnt_userns, dentry, iattr);
+		error = xfs_vn_change_ok(idmap, dentry, iattr);
 		if (!error)
-			error = xfs_setattr_nonsize(mnt_userns, dentry, ip, iattr);
+			error = xfs_setattr_nonsize(idmap, dentry, ip, iattr);
 	}
 
 	return error;
@@ -1092,12 +1091,12 @@ xfs_vn_fiemap(
 
 STATIC int
 xfs_vn_tmpfile(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct inode		*dir,
 	struct file		*file,
 	umode_t			mode)
 {
-	int err = xfs_generic_create(mnt_userns, dir, file->f_path.dentry, mode, 0, file);
+	int err = xfs_generic_create(idmap, dir, file->f_path.dentry, mode, 0, file);
 
 	return finish_open_simple(file, err);
 }
diff --git a/fs/xfs/xfs_iops.h b/fs/xfs/xfs_iops.h
index e570dcb5df8d..7f84a0843b24 100644
--- a/fs/xfs/xfs_iops.h
+++ b/fs/xfs/xfs_iops.h
@@ -13,7 +13,7 @@ extern const struct file_operations xfs_dir_file_operations;
 
 extern ssize_t xfs_vn_listxattr(struct dentry *, char *data, size_t size);
 
-int xfs_vn_setattr_size(struct user_namespace *mnt_userns,
+int xfs_vn_setattr_size(struct mnt_idmap *idmap,
 		struct dentry *dentry, struct iattr *vap);
 
 int xfs_inode_init_security(struct inode *inode, struct inode *dir,
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index a1c2bcf65d37..f225413a993c 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -55,7 +55,7 @@ struct xfs_bstat_chunk {
 STATIC int
 xfs_bulkstat_one_int(
 	struct xfs_mount	*mp,
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct xfs_trans	*tp,
 	xfs_ino_t		ino,
 	struct xfs_bstat_chunk	*bc)
@@ -83,8 +83,8 @@ xfs_bulkstat_one_int(
 	ASSERT(ip != NULL);
 	ASSERT(ip->i_imap.im_blkno != 0);
 	inode = VFS_I(ip);
-	vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
-	vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
+	vfsuid = i_uid_into_vfsuid(idmap, inode);
+	vfsgid = i_gid_into_vfsgid(idmap, inode);
 
 	/* xfs_iget returns the following without needing
 	 * further change.
@@ -178,7 +178,7 @@ xfs_bulkstat_one(
 	struct xfs_trans	*tp;
 	int			error;
 
-	if (breq->mnt_userns != &init_user_ns) {
+	if (breq->idmap != &nop_mnt_idmap) {
 		xfs_warn_ratelimited(breq->mp,
 			"bulkstat not supported inside of idmapped mounts.");
 		return -EINVAL;
@@ -199,7 +199,7 @@ xfs_bulkstat_one(
 	if (error)
 		goto out;
 
-	error = xfs_bulkstat_one_int(breq->mp, breq->mnt_userns, tp,
+	error = xfs_bulkstat_one_int(breq->mp, breq->idmap, tp,
 			breq->startino, &bc);
 	xfs_trans_cancel(tp);
 out:
@@ -225,7 +225,7 @@ xfs_bulkstat_iwalk(
 	struct xfs_bstat_chunk	*bc = data;
 	int			error;
 
-	error = xfs_bulkstat_one_int(mp, bc->breq->mnt_userns, tp, ino, data);
+	error = xfs_bulkstat_one_int(mp, bc->breq->idmap, tp, ino, data);
 	/* bulkstat just skips over missing inodes */
 	if (error == -ENOENT || error == -EINVAL)
 		return 0;
@@ -270,7 +270,7 @@ xfs_bulkstat(
 	unsigned int		iwalk_flags = 0;
 	int			error;
 
-	if (breq->mnt_userns != &init_user_ns) {
+	if (breq->idmap != &nop_mnt_idmap) {
 		xfs_warn_ratelimited(breq->mp,
 			"bulkstat not supported inside of idmapped mounts.");
 		return -EINVAL;
diff --git a/fs/xfs/xfs_itable.h b/fs/xfs/xfs_itable.h
index e2d0eba43f35..1659f13f17a8 100644
--- a/fs/xfs/xfs_itable.h
+++ b/fs/xfs/xfs_itable.h
@@ -8,7 +8,7 @@
 /* In-memory representation of a userspace request for batch inode data. */
 struct xfs_ibulk {
 	struct xfs_mount	*mp;
-	struct user_namespace   *mnt_userns;
+	struct mnt_idmap	*idmap;
 	void __user		*ubuffer; /* user output buffer */
 	xfs_ino_t		startino; /* start with this inode */
 	unsigned int		icount;   /* number of elements in ubuffer */
diff --git a/fs/xfs/xfs_pnfs.c b/fs/xfs/xfs_pnfs.c
index 38d23f0e703a..23d16186e1a3 100644
--- a/fs/xfs/xfs_pnfs.c
+++ b/fs/xfs/xfs_pnfs.c
@@ -322,7 +322,7 @@ xfs_fs_commit_blocks(
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 
 	ASSERT(!(iattr->ia_valid & (ATTR_UID | ATTR_GID)));
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 	if (update_isize) {
 		i_size_write(inode, iattr->ia_size);
 		ip->i_disk_size = iattr->ia_size;
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index e2c542f6dcd4..7dc0db7f5a76 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -787,7 +787,7 @@ xfs_qm_qino_alloc(
 
 		error = xfs_dialloc(&tp, 0, S_IFREG, &ino);
 		if (!error)
-			error = xfs_init_new_inode(&init_user_ns, tp, NULL, ino,
+			error = xfs_init_new_inode(&nop_mnt_idmap, tp, NULL, ino,
 					S_IFREG, 1, 0, 0, false, ipp);
 		if (error) {
 			xfs_trans_cancel(tp);
diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
index 8389f3ef88ef..85e433df6a3f 100644
--- a/fs/xfs/xfs_symlink.c
+++ b/fs/xfs/xfs_symlink.c
@@ -144,7 +144,7 @@ xfs_readlink(
 
 int
 xfs_symlink(
-	struct user_namespace	*mnt_userns,
+	struct mnt_idmap	*idmap,
 	struct xfs_inode	*dp,
 	struct xfs_name		*link_name,
 	const char		*target_path,
@@ -193,8 +193,8 @@ xfs_symlink(
 	/*
 	 * Make sure that we have allocated dquot(s) on disk.
 	 */
-	error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(mnt_userns, &init_user_ns),
-			mapped_fsgid(mnt_userns, &init_user_ns), prid,
+	error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(idmap, &init_user_ns),
+			mapped_fsgid(idmap, &init_user_ns), prid,
 			XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
 			&udqp, &gdqp, &pdqp);
 	if (error)
@@ -231,7 +231,7 @@ xfs_symlink(
 	 */
 	error = xfs_dialloc(&tp, dp->i_ino, S_IFLNK, &ino);
 	if (!error)
-		error = xfs_init_new_inode(mnt_userns, tp, dp, ino,
+		error = xfs_init_new_inode(idmap, tp, dp, ino,
 				S_IFLNK | (mode & ~S_IFMT), 1, 0, prid,
 				false, &ip);
 	if (error)
diff --git a/fs/xfs/xfs_symlink.h b/fs/xfs/xfs_symlink.h
index 2586b7e393f3..d1ca1ce62a93 100644
--- a/fs/xfs/xfs_symlink.h
+++ b/fs/xfs/xfs_symlink.h
@@ -7,7 +7,7 @@
 
 /* Kernel only symlink definitions */
 
-int xfs_symlink(struct user_namespace *mnt_userns, struct xfs_inode *dp,
+int xfs_symlink(struct mnt_idmap *idmap, struct xfs_inode *dp,
 		struct xfs_name *link_name, const char *target_path,
 		umode_t mode, struct xfs_inode **ipp);
 int xfs_readlink_bmap_ilocked(struct xfs_inode *ip, char *link);
diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
index 10aa1fd39d2b..7b9a0ed1b11f 100644
--- a/fs/xfs/xfs_xattr.c
+++ b/fs/xfs/xfs_xattr.c
@@ -133,7 +133,7 @@ xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused,
 
 static int
 xfs_xattr_set(const struct xattr_handler *handler,
-	      struct user_namespace *mnt_userns, struct dentry *unused,
+	      struct mnt_idmap *idmap, struct dentry *unused,
 	      struct inode *inode, const char *name, const void *value,
 	      size_t size, int flags)
 {
diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index a9c5c3f720ad..72ef97320b99 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -604,7 +604,7 @@ unlock:
 	return ret;
 }
 
-static int zonefs_inode_setattr(struct user_namespace *mnt_userns,
+static int zonefs_inode_setattr(struct mnt_idmap *idmap,
 				struct dentry *dentry, struct iattr *iattr)
 {
 	struct inode *inode = d_inode(dentry);
@@ -613,7 +613,7 @@ static int zonefs_inode_setattr(struct user_namespace *mnt_userns,
 	if (unlikely(IS_IMMUTABLE(inode)))
 		return -EPERM;
 
-	ret = setattr_prepare(&init_user_ns, dentry, iattr);
+	ret = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (ret)
 		return ret;
 
@@ -630,7 +630,7 @@ static int zonefs_inode_setattr(struct user_namespace *mnt_userns,
 	     !uid_eq(iattr->ia_uid, inode->i_uid)) ||
 	    ((iattr->ia_valid & ATTR_GID) &&
 	     !gid_eq(iattr->ia_gid, inode->i_gid))) {
-		ret = dquot_transfer(mnt_userns, inode, iattr);
+		ret = dquot_transfer(&nop_mnt_idmap, inode, iattr);
 		if (ret)
 			return ret;
 	}
@@ -641,7 +641,7 @@ static int zonefs_inode_setattr(struct user_namespace *mnt_userns,
 			return ret;
 	}
 
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 
 	return 0;
 }
@@ -1427,7 +1427,7 @@ static void zonefs_init_dir_inode(struct inode *parent, struct inode *inode,
 	struct super_block *sb = parent->i_sb;
 
 	inode->i_ino = bdev_nr_zones(sb->s_bdev) + type + 1;
-	inode_init_owner(&init_user_ns, inode, parent, S_IFDIR | 0555);
+	inode_init_owner(&nop_mnt_idmap, inode, parent, S_IFDIR | 0555);
 	inode->i_op = &zonefs_dir_inode_operations;
 	inode->i_fop = &simple_dir_operations;
 	set_nlink(inode, 2);