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
  ...

19 files changed, 163 insertions, 165 deletions

diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 424b2c1e586d..db7a51acf9db 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -1793,7 +1793,7 @@ fail2:
 	return error;
 }
 
-static int ns_mkdir_op(struct user_namespace *mnt_userns, struct inode *dir,
+static int ns_mkdir_op(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode)
 {
 	struct aa_ns *ns, *parent;
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 6dd3cc5309bf..f3715cda59c5 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -313,7 +313,7 @@ static int aa_xattrs_match(const struct linux_binprm *bprm,
 	d = bprm->file->f_path.dentry;
 
 	for (i = 0; i < attach->xattr_count; i++) {
-		size = vfs_getxattr_alloc(&init_user_ns, d, attach->xattrs[i],
+		size = vfs_getxattr_alloc(&nop_mnt_idmap, d, attach->xattrs[i],
 					  &value, value_size, GFP_KERNEL);
 		if (size >= 0) {
 			u32 index, perm;
@@ -862,7 +862,7 @@ int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm)
 	const char *info = NULL;
 	int error = 0;
 	bool unsafe = false;
-	vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_user_ns(bprm->file),
+	vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_idmap(bprm->file),
 					    file_inode(bprm->file));
 	struct path_cond cond = {
 		vfsuid_into_kuid(vfsuid),
diff --git a/security/apparmor/file.c b/security/apparmor/file.c
index cb3d3060d104..9119ddda6217 100644
--- a/security/apparmor/file.c
+++ b/security/apparmor/file.c
@@ -459,7 +459,7 @@ static int __file_path_perm(const char *op, struct aa_label *label,
 {
 	struct aa_profile *profile;
 	struct aa_perms perms = {};
-	vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_user_ns(file),
+	vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_idmap(file),
 					    file_inode(file));
 	struct path_cond cond = {
 		.uid = vfsuid_into_kuid(vfsuid),
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index c6728a629437..d6cc4812ca53 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -227,8 +227,7 @@ static int common_perm(const char *op, const struct path *path, u32 mask,
  */
 static int common_perm_cond(const char *op, const struct path *path, u32 mask)
 {
-	struct user_namespace *mnt_userns = mnt_user_ns(path->mnt);
-	vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_userns,
+	vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_idmap(path->mnt),
 					    d_backing_inode(path->dentry));
 	struct path_cond cond = {
 		vfsuid_into_kuid(vfsuid),
@@ -273,14 +272,13 @@ static int common_perm_rm(const char *op, const struct path *dir,
 			  struct dentry *dentry, u32 mask)
 {
 	struct inode *inode = d_backing_inode(dentry);
-	struct user_namespace *mnt_userns = mnt_user_ns(dir->mnt);
 	struct path_cond cond = { };
 	vfsuid_t vfsuid;
 
 	if (!inode || !path_mediated_fs(dentry))
 		return 0;
 
-	vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
+	vfsuid = i_uid_into_vfsuid(mnt_idmap(dir->mnt), inode);
 	cond.uid = vfsuid_into_kuid(vfsuid);
 	cond.mode = inode->i_mode;
 
@@ -379,7 +377,7 @@ static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_d
 
 	label = begin_current_label_crit_section();
 	if (!unconfined(label)) {
-		struct user_namespace *mnt_userns = mnt_user_ns(old_dir->mnt);
+		struct mnt_idmap *idmap = mnt_idmap(old_dir->mnt);
 		vfsuid_t vfsuid;
 		struct path old_path = { .mnt = old_dir->mnt,
 					 .dentry = old_dentry };
@@ -388,14 +386,14 @@ static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_d
 		struct path_cond cond = {
 			.mode = d_backing_inode(old_dentry)->i_mode
 		};
-		vfsuid = i_uid_into_vfsuid(mnt_userns, d_backing_inode(old_dentry));
+		vfsuid = i_uid_into_vfsuid(idmap, d_backing_inode(old_dentry));
 		cond.uid = vfsuid_into_kuid(vfsuid);
 
 		if (flags & RENAME_EXCHANGE) {
 			struct path_cond cond_exchange = {
 				.mode = d_backing_inode(new_dentry)->i_mode,
 			};
-			vfsuid = i_uid_into_vfsuid(mnt_userns, d_backing_inode(old_dentry));
+			vfsuid = i_uid_into_vfsuid(idmap, d_backing_inode(old_dentry));
 			cond_exchange.uid = vfsuid_into_kuid(vfsuid);
 
 			error = aa_path_perm(OP_RENAME_SRC, label, &new_path, 0,
@@ -460,13 +458,13 @@ static int apparmor_file_open(struct file *file)
 
 	label = aa_get_newest_cred_label(file->f_cred);
 	if (!unconfined(label)) {
-		struct user_namespace *mnt_userns = file_mnt_user_ns(file);
+		struct mnt_idmap *idmap = file_mnt_idmap(file);
 		struct inode *inode = file_inode(file);
 		vfsuid_t vfsuid;
 		struct path_cond cond = {
 			.mode = inode->i_mode,
 		};
-		vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
+		vfsuid = i_uid_into_vfsuid(idmap, inode);
 		cond.uid = vfsuid_into_kuid(vfsuid);
 
 		error = aa_path_perm(OP_OPEN, label, &file->f_path, 0,
diff --git a/security/commoncap.c b/security/commoncap.c
index 1164278b97fd..aec62db55271 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -305,24 +305,24 @@ int cap_inode_need_killpriv(struct dentry *dentry)
 /**
  * cap_inode_killpriv - Erase the security markings 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 inode/dentry to alter
  *
  * Erase the privilege-enhancing security markings on an inode.
  *
- * 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.
  *
  * Return: 0 if successful, -ve on error.
  */
-int cap_inode_killpriv(struct user_namespace *mnt_userns, struct dentry *dentry)
+int cap_inode_killpriv(struct mnt_idmap *idmap, struct dentry *dentry)
 {
 	int error;
 
-	error = __vfs_removexattr(mnt_userns, dentry, XATTR_NAME_CAPS);
+	error = __vfs_removexattr(idmap, dentry, XATTR_NAME_CAPS);
 	if (error == -EOPNOTSUPP)
 		error = 0;
 	return error;
@@ -377,7 +377,7 @@ static bool is_v3header(int size, const struct vfs_cap_data *cap)
  * by the integrity subsystem, which really wants the unconverted values -
  * so that's good.
  */
-int cap_inode_getsecurity(struct user_namespace *mnt_userns,
+int cap_inode_getsecurity(struct mnt_idmap *idmap,
 			  struct inode *inode, const char *name, void **buffer,
 			  bool alloc)
 {
@@ -398,7 +398,7 @@ int cap_inode_getsecurity(struct user_namespace *mnt_userns,
 	dentry = d_find_any_alias(inode);
 	if (!dentry)
 		return -EINVAL;
-	size = vfs_getxattr_alloc(mnt_userns, dentry, XATTR_NAME_CAPS, &tmpbuf,
+	size = vfs_getxattr_alloc(idmap, dentry, XATTR_NAME_CAPS, &tmpbuf,
 				  sizeof(struct vfs_ns_cap_data), GFP_NOFS);
 	dput(dentry);
 	/* gcc11 complains if we don't check for !tmpbuf */
@@ -420,7 +420,7 @@ int cap_inode_getsecurity(struct user_namespace *mnt_userns,
 	kroot = make_kuid(fs_ns, root);
 
 	/* If this is an idmapped mount shift the kuid. */
-	vfsroot = make_vfsuid(mnt_userns, fs_ns, kroot);
+	vfsroot = make_vfsuid(idmap, fs_ns, kroot);
 
 	/* If the root kuid maps to a valid uid in current ns, then return
 	 * this as a nscap. */
@@ -510,7 +510,7 @@ static bool validheader(size_t size, const struct vfs_cap_data *cap)
 /**
  * cap_convert_nscap - check vfs caps
  *
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dentry:	used to retrieve inode to check permissions on
  * @ivalue:	vfs caps value which may be modified by this function
  * @size:	size of @ivalue
@@ -518,15 +518,15 @@ static bool validheader(size_t size, const struct vfs_cap_data *cap)
  * User requested a write of security.capability.  If needed, update the
  * xattr to change from v2 to v3, or to fixup the v3 rootid.
  *
- * 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.
  *
  * Return: On success, return the new size; on error, return < 0.
  */
-int cap_convert_nscap(struct user_namespace *mnt_userns, struct dentry *dentry,
+int cap_convert_nscap(struct mnt_idmap *idmap, struct dentry *dentry,
 		      const void **ivalue, size_t size)
 {
 	struct vfs_ns_cap_data *nscap;
@@ -544,9 +544,9 @@ int cap_convert_nscap(struct user_namespace *mnt_userns, struct dentry *dentry,
 		return -EINVAL;
 	if (!validheader(size, cap))
 		return -EINVAL;
-	if (!capable_wrt_inode_uidgid(mnt_userns, inode, CAP_SETFCAP))
+	if (!capable_wrt_inode_uidgid(idmap, inode, CAP_SETFCAP))
 		return -EPERM;
-	if (size == XATTR_CAPS_SZ_2 && (mnt_userns == fs_ns))
+	if (size == XATTR_CAPS_SZ_2 && (idmap == &nop_mnt_idmap))
 		if (ns_capable(inode->i_sb->s_user_ns, CAP_SETFCAP))
 			/* user is privileged, just write the v2 */
 			return size;
@@ -555,7 +555,7 @@ int cap_convert_nscap(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (!vfsuid_valid(vfsrootid))
 		return -EINVAL;
 
-	rootid = from_vfsuid(mnt_userns, fs_ns, vfsrootid);
+	rootid = from_vfsuid(idmap, fs_ns, vfsrootid);
 	if (!uid_valid(rootid))
 		return -EINVAL;
 
@@ -626,19 +626,19 @@ static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps,
 /**
  * get_vfs_caps_from_disk - retrieve vfs caps from disk
  *
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dentry:	dentry from which @inode is retrieved
  * @cpu_caps:	vfs capabilities
  *
  * Extract the on-exec-apply capability sets for an executable 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
+ * 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.
  */
-int get_vfs_caps_from_disk(struct user_namespace *mnt_userns,
+int get_vfs_caps_from_disk(struct mnt_idmap *idmap,
 			   const struct dentry *dentry,
 			   struct cpu_vfs_cap_data *cpu_caps)
 {
@@ -695,7 +695,7 @@ int get_vfs_caps_from_disk(struct user_namespace *mnt_userns,
 		return -EINVAL;
 	}
 
-	rootvfsuid = make_vfsuid(mnt_userns, fs_ns, rootkuid);
+	rootvfsuid = make_vfsuid(idmap, fs_ns, rootkuid);
 	if (!vfsuid_valid(rootvfsuid))
 		return -ENODATA;
 
@@ -747,7 +747,7 @@ static int get_file_caps(struct linux_binprm *bprm, struct file *file,
 	if (!current_in_userns(file->f_path.mnt->mnt_sb->s_user_ns))
 		return 0;
 
-	rc = get_vfs_caps_from_disk(file_mnt_user_ns(file),
+	rc = get_vfs_caps_from_disk(file_mnt_idmap(file),
 				    file->f_path.dentry, &vcaps);
 	if (rc < 0) {
 		if (rc == -EINVAL)
@@ -1016,23 +1016,23 @@ int cap_inode_setxattr(struct dentry *dentry, const char *name,
 /**
  * cap_inode_removexattr - Determine whether an xattr may be removed
  *
- * @mnt_userns:	User namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @dentry:	The inode/dentry being altered
  * @name:	The name of the xattr to be changed
  *
  * Determine whether an xattr may be removed from an inode, returning 0 if
  * permission is granted, -ve if denied.
  *
- * 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.
  *
  * This is used to make sure security xattrs don't get removed by those who
  * aren't privileged to remove them.
  */
-int cap_inode_removexattr(struct user_namespace *mnt_userns,
+int cap_inode_removexattr(struct mnt_idmap *idmap,
 			  struct dentry *dentry, const char *name)
 {
 	struct user_namespace *user_ns = dentry->d_sb->s_user_ns;
@@ -1047,7 +1047,7 @@ int cap_inode_removexattr(struct user_namespace *mnt_userns,
 		struct inode *inode = d_backing_inode(dentry);
 		if (!inode)
 			return -EINVAL;
-		if (!capable_wrt_inode_uidgid(mnt_userns, inode, CAP_SETFCAP))
+		if (!capable_wrt_inode_uidgid(idmap, inode, CAP_SETFCAP))
 			return -EPERM;
 		return 0;
 	}
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index fa5ff13fa8c9..52b811da6989 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -265,7 +265,7 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
 						    req_xattr_value_len);
 			continue;
 		}
-		size = vfs_getxattr_alloc(&init_user_ns, dentry, xattr->name,
+		size = vfs_getxattr_alloc(&nop_mnt_idmap, dentry, xattr->name,
 					  &xattr_value, xattr_size, GFP_NOFS);
 		if (size == -ENOMEM) {
 			error = -ENOMEM;
@@ -274,7 +274,7 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
 		if (size < 0)
 			continue;
 
-		user_space_size = vfs_getxattr(&init_user_ns, dentry,
+		user_space_size = vfs_getxattr(&nop_mnt_idmap, dentry,
 					       xattr->name, NULL, 0);
 		if (user_space_size != size)
 			pr_debug("file %s: xattr %s size mismatch (kernel: %d, user: %d)\n",
@@ -331,7 +331,7 @@ static int evm_is_immutable(struct dentry *dentry, struct inode *inode)
 		return 1;
 
 	/* Do this the hard way */
-	rc = vfs_getxattr_alloc(&init_user_ns, dentry, XATTR_NAME_EVM,
+	rc = vfs_getxattr_alloc(&nop_mnt_idmap, dentry, XATTR_NAME_EVM,
 				(char **)&xattr_data, 0, GFP_NOFS);
 	if (rc <= 0) {
 		if (rc == -ENODATA)
@@ -376,12 +376,12 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name,
 			   xattr_value_len, &data);
 	if (rc == 0) {
 		data.hdr.xattr.sha1.type = EVM_XATTR_HMAC;
-		rc = __vfs_setxattr_noperm(&init_user_ns, dentry,
+		rc = __vfs_setxattr_noperm(&nop_mnt_idmap, dentry,
 					   XATTR_NAME_EVM,
 					   &data.hdr.xattr.data[1],
 					   SHA1_DIGEST_SIZE + 1, 0);
 	} else if (rc == -ENODATA && (inode->i_opflags & IOP_XATTR)) {
-		rc = __vfs_removexattr(&init_user_ns, dentry, XATTR_NAME_EVM);
+		rc = __vfs_removexattr(&nop_mnt_idmap, dentry, XATTR_NAME_EVM);
 	}
 	return rc;
 }
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index f02e609460e2..cf24c5255583 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -184,7 +184,7 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
 	/* if status is not PASS, try to check again - against -ENOMEM */
 
 	/* first need to know the sig type */
-	rc = vfs_getxattr_alloc(&init_user_ns, dentry, XATTR_NAME_EVM,
+	rc = vfs_getxattr_alloc(&nop_mnt_idmap, dentry, XATTR_NAME_EVM,
 				(char **)&xattr_data, 0, GFP_NOFS);
 	if (rc <= 0) {
 		evm_status = INTEGRITY_FAIL;
@@ -436,7 +436,7 @@ static enum integrity_status evm_verify_current_integrity(struct dentry *dentry)
 
 /*
  * evm_xattr_change - check if passed xattr value differs from current value
- * @mnt_userns: user namespace of the idmapped mount
+ * @idmap: idmap of the mount
  * @dentry: pointer to the affected dentry
  * @xattr_name: requested xattr
  * @xattr_value: requested xattr value
@@ -446,14 +446,14 @@ static enum integrity_status evm_verify_current_integrity(struct dentry *dentry)
  *
  * Returns 1 if passed xattr value differs from current value, 0 otherwise.
  */
-static int evm_xattr_change(struct user_namespace *mnt_userns,
+static int evm_xattr_change(struct mnt_idmap *idmap,
 			    struct dentry *dentry, const char *xattr_name,
 			    const void *xattr_value, size_t xattr_value_len)
 {
 	char *xattr_data = NULL;
 	int rc = 0;
 
-	rc = vfs_getxattr_alloc(&init_user_ns, dentry, xattr_name, &xattr_data,
+	rc = vfs_getxattr_alloc(&nop_mnt_idmap, dentry, xattr_name, &xattr_data,
 				0, GFP_NOFS);
 	if (rc < 0) {
 		rc = 1;
@@ -482,7 +482,7 @@ out:
  * For posix xattr acls only, permit security.evm, even if it currently
  * doesn't exist, to be updated unless the EVM signature is immutable.
  */
-static int evm_protect_xattr(struct user_namespace *mnt_userns,
+static int evm_protect_xattr(struct mnt_idmap *idmap,
 			     struct dentry *dentry, const char *xattr_name,
 			     const void *xattr_value, size_t xattr_value_len)
 {
@@ -538,7 +538,7 @@ out:
 		return 0;
 
 	if (evm_status == INTEGRITY_PASS_IMMUTABLE &&
-	    !evm_xattr_change(mnt_userns, dentry, xattr_name, xattr_value,
+	    !evm_xattr_change(idmap, dentry, xattr_name, xattr_value,
 			      xattr_value_len))
 		return 0;
 
@@ -553,7 +553,7 @@ out:
 
 /**
  * evm_inode_setxattr - protect the EVM extended attribute
- * @mnt_userns: user namespace of the idmapped mount
+ * @idmap: idmap of the mount
  * @dentry: pointer to the affected dentry
  * @xattr_name: pointer to the affected extended attribute name
  * @xattr_value: pointer to the new extended attribute value
@@ -565,7 +565,7 @@ out:
  * userspace from writing HMAC value.  Writing 'security.evm' requires
  * requires CAP_SYS_ADMIN privileges.
  */
-int evm_inode_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int evm_inode_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		       const char *xattr_name, const void *xattr_value,
 		       size_t xattr_value_len)
 {
@@ -584,20 +584,20 @@ int evm_inode_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		    xattr_data->type != EVM_XATTR_PORTABLE_DIGSIG)
 			return -EPERM;
 	}
-	return evm_protect_xattr(mnt_userns, dentry, xattr_name, xattr_value,
+	return evm_protect_xattr(idmap, dentry, xattr_name, xattr_value,
 				 xattr_value_len);
 }
 
 /**
  * evm_inode_removexattr - protect the EVM extended attribute
- * @mnt_userns: user namespace of the idmapped mount
+ * @idmap: idmap of the mount
  * @dentry: pointer to the affected dentry
  * @xattr_name: pointer to the affected extended attribute name
  *
  * Removing 'security.evm' requires CAP_SYS_ADMIN privileges and that
  * the current value is valid.
  */
-int evm_inode_removexattr(struct user_namespace *mnt_userns,
+int evm_inode_removexattr(struct mnt_idmap *idmap,
 			  struct dentry *dentry, const char *xattr_name)
 {
 	/* Policy permits modification of the protected xattrs even though
@@ -606,11 +606,11 @@ int evm_inode_removexattr(struct user_namespace *mnt_userns,
 	if (evm_initialized & EVM_ALLOW_METADATA_WRITES)
 		return 0;
 
-	return evm_protect_xattr(mnt_userns, dentry, xattr_name, NULL, 0);
+	return evm_protect_xattr(idmap, dentry, xattr_name, NULL, 0);
 }
 
 #ifdef CONFIG_FS_POSIX_ACL
-static int evm_inode_set_acl_change(struct user_namespace *mnt_userns,
+static int evm_inode_set_acl_change(struct mnt_idmap *idmap,
 				    struct dentry *dentry, const char *name,
 				    struct posix_acl *kacl)
 {
@@ -622,14 +622,14 @@ static int evm_inode_set_acl_change(struct user_namespace *mnt_userns,
 	if (!kacl)
 		return 1;
 
-	rc = posix_acl_update_mode(mnt_userns, inode, &mode, &kacl);
+	rc = posix_acl_update_mode(idmap, inode, &mode, &kacl);
 	if (rc || (inode->i_mode != mode))
 		return 1;
 
 	return 0;
 }
 #else
-static inline int evm_inode_set_acl_change(struct user_namespace *mnt_userns,
+static inline int evm_inode_set_acl_change(struct mnt_idmap *idmap,
 					   struct dentry *dentry,
 					   const char *name,
 					   struct posix_acl *kacl)
@@ -640,7 +640,7 @@ static inline int evm_inode_set_acl_change(struct user_namespace *mnt_userns,
 
 /**
  * evm_inode_set_acl - protect the EVM extended attribute from posix acls
- * @mnt_userns: user namespace of the idmapped mount
+ * @idmap: idmap of the idmapped mount
  * @dentry: pointer to the affected dentry
  * @acl_name: name of the posix acl
  * @kacl: pointer to the posix acls
@@ -649,7 +649,7 @@ static inline int evm_inode_set_acl_change(struct user_namespace *mnt_userns,
  * and 'security.evm' xattr updated, unless the existing 'security.evm' is
  * valid.
  */
-int evm_inode_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int evm_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		      const char *acl_name, struct posix_acl *kacl)
 {
 	enum integrity_status evm_status;
@@ -678,7 +678,7 @@ int evm_inode_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 		return 0;
 
 	if (evm_status == INTEGRITY_PASS_IMMUTABLE &&
-	    !evm_inode_set_acl_change(mnt_userns, dentry, acl_name, kacl))
+	    !evm_inode_set_acl_change(idmap, dentry, acl_name, kacl))
 		return 0;
 
 	if (evm_status != INTEGRITY_PASS_IMMUTABLE)
@@ -779,14 +779,14 @@ void evm_inode_post_removexattr(struct dentry *dentry, const char *xattr_name)
 	evm_update_evmxattr(dentry, xattr_name, NULL, 0);
 }
 
-static int evm_attr_change(struct user_namespace *mnt_userns,
+static int evm_attr_change(struct mnt_idmap *idmap,
 			   struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = d_backing_inode(dentry);
 	unsigned int ia_valid = attr->ia_valid;
 
-	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) &&
 	    (!(ia_valid & ATTR_MODE) || attr->ia_mode == inode->i_mode))
 		return 0;
 
@@ -800,7 +800,7 @@ static int evm_attr_change(struct user_namespace *mnt_userns,
  * Permit update of file attributes when files have a valid EVM signature,
  * except in the case of them having an immutable portable signature.
  */
-int evm_inode_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int evm_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		      struct iattr *attr)
 {
 	unsigned int ia_valid = attr->ia_valid;
@@ -827,7 +827,7 @@ int evm_inode_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		return 0;
 
 	if (evm_status == INTEGRITY_PASS_IMMUTABLE &&
-	    !evm_attr_change(mnt_userns, dentry, attr))
+	    !evm_attr_change(idmap, dentry, attr))
 		return 0;
 
 	integrity_audit_msg(AUDIT_INTEGRITY_METADATA, d_backing_inode(dentry),
diff --git a/security/integrity/evm/evm_secfs.c b/security/integrity/evm/evm_secfs.c
index 8a9db7dfca7e..9b907c2fee60 100644
--- a/security/integrity/evm/evm_secfs.c
+++ b/security/integrity/evm/evm_secfs.c
@@ -228,7 +228,7 @@ static ssize_t evm_write_xattrs(struct file *file, const char __user *buf,
 		newattrs.ia_valid = ATTR_MODE;
 		inode = evm_xattrs->d_inode;
 		inode_lock(inode);
-		err = simple_setattr(&init_user_ns, evm_xattrs, &newattrs);
+		err = simple_setattr(&nop_mnt_idmap, evm_xattrs, &newattrs);
 		inode_unlock(inode);
 		if (!err)
 			err = count;
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 03b440921e61..d8530e722515 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -254,7 +254,7 @@ static inline void ima_process_queued_keys(void) {}
 #endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS */
 
 /* LIM API function definitions */
-int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
+int ima_get_action(struct mnt_idmap *idmap, struct inode *inode,
 		   const struct cred *cred, u32 secid, int mask,
 		   enum ima_hooks func, int *pcr,
 		   struct ima_template_desc **template_desc,
@@ -268,7 +268,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
 			   struct evm_ima_xattr_data *xattr_value,
 			   int xattr_len, const struct modsig *modsig, int pcr,
 			   struct ima_template_desc *template_desc);
-int process_buffer_measurement(struct user_namespace *mnt_userns,
+int process_buffer_measurement(struct mnt_idmap *idmap,
 			       struct inode *inode, const void *buf, int size,
 			       const char *eventname, enum ima_hooks func,
 			       int pcr, const char *func_data,
@@ -285,7 +285,7 @@ void ima_free_template_entry(struct ima_template_entry *entry);
 const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
 
 /* IMA policy related functions */
-int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
+int ima_match_policy(struct mnt_idmap *idmap, struct inode *inode,
 		     const struct cred *cred, u32 secid, enum ima_hooks func,
 		     int mask, int flags, int *pcr,
 		     struct ima_template_desc **template_desc,
@@ -318,7 +318,7 @@ int ima_appraise_measurement(enum ima_hooks func,
 			     struct file *file, const unsigned char *filename,
 			     struct evm_ima_xattr_data *xattr_value,
 			     int xattr_len, const struct modsig *modsig);
-int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode,
+int ima_must_appraise(struct mnt_idmap *idmap, struct inode *inode,
 		      int mask, enum ima_hooks func);
 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
@@ -346,7 +346,7 @@ static inline int ima_appraise_measurement(enum ima_hooks func,
 	return INTEGRITY_UNKNOWN;
 }
 
-static inline int ima_must_appraise(struct user_namespace *mnt_userns,
+static inline int ima_must_appraise(struct mnt_idmap *idmap,
 				    struct inode *inode, int mask,
 				    enum ima_hooks func)
 {
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index c1e76282b5ee..9345fd66f5b8 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -163,7 +163,7 @@ err_out:
 
 /**
  * ima_get_action - appraise & measure decision based on policy.
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @inode: pointer to the inode associated with the object being validated
  * @cred: pointer to credentials structure to validate
  * @secid: secid of the task being validated
@@ -186,7 +186,7 @@ err_out:
  * Returns IMA_MEASURE, IMA_APPRAISE mask.
  *
  */
-int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
+int ima_get_action(struct mnt_idmap *idmap, struct inode *inode,
 		   const struct cred *cred, u32 secid, int mask,
 		   enum ima_hooks func, int *pcr,
 		   struct ima_template_desc **template_desc,
@@ -196,7 +196,7 @@ int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
 
 	flags &= ima_policy_flag;
 
-	return ima_match_policy(mnt_userns, inode, cred, secid, func, mask,
+	return ima_match_policy(idmap, inode, cred, secid, func, mask,
 				flags, pcr, template_desc, func_data,
 				allowed_algos);
 }
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index ee6f7e237f2e..555342d337f9 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -70,7 +70,7 @@ bool is_ima_appraise_enabled(void)
  *
  * Return 1 to appraise or hash
  */
-int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode,
+int ima_must_appraise(struct mnt_idmap *idmap, struct inode *inode,
 		      int mask, enum ima_hooks func)
 {
 	u32 secid;
@@ -79,7 +79,7 @@ int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode,
 		return 0;
 
 	security_current_getsecid_subj(&secid);
-	return ima_match_policy(mnt_userns, inode, current_cred(), secid,
+	return ima_match_policy(idmap, inode, current_cred(), secid,
 				func, mask, IMA_APPRAISE | IMA_HASH, NULL,
 				NULL, NULL, NULL);
 }
@@ -98,7 +98,7 @@ static int ima_fix_xattr(struct dentry *dentry,
 		iint->ima_hash->xattr.ng.type = IMA_XATTR_DIGEST_NG;
 		iint->ima_hash->xattr.ng.algo = algo;
 	}
-	rc = __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_IMA,
+	rc = __vfs_setxattr_noperm(&nop_mnt_idmap, dentry, XATTR_NAME_IMA,
 				   &iint->ima_hash->xattr.data[offset],
 				   (sizeof(iint->ima_hash->xattr) - offset) +
 				   iint->ima_hash->length, 0);
@@ -225,7 +225,7 @@ int ima_read_xattr(struct dentry *dentry,
 {
 	int ret;
 
-	ret = vfs_getxattr_alloc(&init_user_ns, dentry, XATTR_NAME_IMA,
+	ret = vfs_getxattr_alloc(&nop_mnt_idmap, dentry, XATTR_NAME_IMA,
 				 (char **)xattr_value, xattr_len, GFP_NOFS);
 	if (ret == -EOPNOTSUPP)
 		ret = 0;
@@ -456,7 +456,7 @@ int ima_check_blacklist(struct integrity_iint_cache *iint,
 
 		rc = is_binary_blacklisted(digest, digestsize);
 		if ((rc == -EPERM) && (iint->flags & IMA_MEASURE))
-			process_buffer_measurement(&init_user_ns, NULL, digest, digestsize,
+			process_buffer_measurement(&nop_mnt_idmap, NULL, digest, digestsize,
 						   "blacklisted-hash", NONE,
 						   pcr, NULL, false, NULL, 0);
 	}
@@ -622,7 +622,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
 
 /**
  * ima_inode_post_setattr - reflect file metadata changes
- * @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 the affected dentry
  *
  * Changes to a dentry's metadata might result in needing to appraise.
@@ -630,7 +630,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
  * This function is called from notify_change(), which expects the caller
  * to lock the inode's i_mutex.
  */
-void ima_inode_post_setattr(struct user_namespace *mnt_userns,
+void ima_inode_post_setattr(struct mnt_idmap *idmap,
 			    struct dentry *dentry)
 {
 	struct inode *inode = d_backing_inode(dentry);
@@ -641,7 +641,7 @@ void ima_inode_post_setattr(struct user_namespace *mnt_userns,
 	    || !(inode->i_opflags & IOP_XATTR))
 		return;
 
-	action = ima_must_appraise(mnt_userns, inode, MAY_ACCESS, POST_SETATTR);
+	action = ima_must_appraise(idmap, inode, MAY_ACCESS, POST_SETATTR);
 	iint = integrity_iint_find(inode);
 	if (iint) {
 		set_bit(IMA_CHANGE_ATTR, &iint->atomic_flags);
@@ -774,7 +774,7 @@ int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
 	return result;
 }
 
-int ima_inode_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ima_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		      const char *acl_name, struct posix_acl *kacl)
 {
 	if (evm_revalidate_status(acl_name))
diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c
index f6aa0b47a772..caacfe6860b1 100644
--- a/security/integrity/ima/ima_asymmetric_keys.c
+++ b/security/integrity/ima/ima_asymmetric_keys.c
@@ -60,7 +60,7 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key,
 	 * if the IMA policy is configured to measure a key linked
 	 * to the given keyring.
 	 */
-	process_buffer_measurement(&init_user_ns, NULL, payload, payload_len,
+	process_buffer_measurement(&nop_mnt_idmap, NULL, payload, payload_len,
 				   keyring->description, KEY_CHECK, 0,
 				   keyring->description, false, NULL, 0);
 }
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 377300973e6c..358578267fea 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -224,7 +224,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
 	 * bitmask based on the appraise/audit/measurement policy.
 	 * Included is the appraise submask.
 	 */
-	action = ima_get_action(file_mnt_user_ns(file), inode, cred, secid,
+	action = ima_get_action(file_mnt_idmap(file), inode, cred, secid,
 				mask, func, &pcr, &template_desc, NULL,
 				&allowed_algos);
 	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
@@ -451,7 +451,7 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
 
 	security_current_getsecid_subj(&secid);
 	inode = file_inode(vma->vm_file);
-	action = ima_get_action(file_mnt_user_ns(vma->vm_file), inode,
+	action = ima_get_action(file_mnt_idmap(vma->vm_file), inode,
 				current_cred(), secid, MAY_EXEC, MMAP_CHECK,
 				&pcr, &template, NULL, NULL);
 
@@ -638,14 +638,14 @@ EXPORT_SYMBOL_GPL(ima_inode_hash);
 
 /**
  * ima_post_create_tmpfile - mark newly created tmpfile as new
- * @mnt_userns: user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @inode: inode of the newly created tmpfile
  *
  * No measuring, appraising or auditing of newly created tmpfiles is needed.
  * Skip calling process_measurement(), but indicate which newly, created
  * tmpfiles are in policy.
  */
-void ima_post_create_tmpfile(struct user_namespace *mnt_userns,
+void ima_post_create_tmpfile(struct mnt_idmap *idmap,
 			     struct inode *inode)
 {
 	struct integrity_iint_cache *iint;
@@ -654,7 +654,7 @@ void ima_post_create_tmpfile(struct user_namespace *mnt_userns,
 	if (!ima_policy_flag || !S_ISREG(inode->i_mode))
 		return;
 
-	must_appraise = ima_must_appraise(mnt_userns, inode, MAY_ACCESS,
+	must_appraise = ima_must_appraise(idmap, inode, MAY_ACCESS,
 					  FILE_CHECK);
 	if (!must_appraise)
 		return;
@@ -671,13 +671,13 @@ void ima_post_create_tmpfile(struct user_namespace *mnt_userns,
 
 /**
  * ima_post_path_mknod - mark as 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
  * @dentry: newly created dentry
  *
  * Mark files created via the mknodat syscall as new, so that the
  * file data can be written later.
  */
-void ima_post_path_mknod(struct user_namespace *mnt_userns,
+void ima_post_path_mknod(struct mnt_idmap *idmap,
 			 struct dentry *dentry)
 {
 	struct integrity_iint_cache *iint;
@@ -687,7 +687,7 @@ void ima_post_path_mknod(struct user_namespace *mnt_userns,
 	if (!ima_policy_flag || !S_ISREG(inode->i_mode))
 		return;
 
-	must_appraise = ima_must_appraise(mnt_userns, inode, MAY_ACCESS,
+	must_appraise = ima_must_appraise(idmap, inode, MAY_ACCESS,
 					  FILE_CHECK);
 	if (!must_appraise)
 		return;
@@ -869,7 +869,7 @@ int ima_post_load_data(char *buf, loff_t size,
 
 /**
  * process_buffer_measurement - Measure the buffer or the buffer data hash
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @inode: inode associated with the object being measured (NULL for KEY_CHECK)
  * @buf: pointer to the buffer that needs to be added to the log.
  * @size: size of buffer(in bytes).
@@ -887,7 +887,7 @@ int ima_post_load_data(char *buf, loff_t size,
  * has been written to the passed location but not added to a measurement entry,
  * a negative value otherwise.
  */
-int process_buffer_measurement(struct user_namespace *mnt_userns,
+int process_buffer_measurement(struct mnt_idmap *idmap,
 			       struct inode *inode, const void *buf, int size,
 			       const char *eventname, enum ima_hooks func,
 			       int pcr, const char *func_data,
@@ -931,7 +931,7 @@ int process_buffer_measurement(struct user_namespace *mnt_userns,
 	 */
 	if (func) {
 		security_current_getsecid_subj(&secid);
-		action = ima_get_action(mnt_userns, inode, current_cred(),
+		action = ima_get_action(idmap, inode, current_cred(),
 					secid, 0, func, &pcr, &template,
 					func_data, NULL);
 		if (!(action & IMA_MEASURE) && !digest)
@@ -1011,7 +1011,7 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size)
 	if (!f.file)
 		return;
 
-	process_buffer_measurement(file_mnt_user_ns(f.file), file_inode(f.file),
+	process_buffer_measurement(file_mnt_idmap(f.file), file_inode(f.file),
 				   buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0,
 				   NULL, false, NULL, 0);
 	fdput(f);
@@ -1044,7 +1044,7 @@ int ima_measure_critical_data(const char *event_label,
 	if (!event_name || !event_label || !buf || !buf_len)
 		return -ENOPARAM;
 
-	return process_buffer_measurement(&init_user_ns, NULL, buf, buf_len,
+	return process_buffer_measurement(&nop_mnt_idmap, NULL, buf, buf_len,
 					  event_name, CRITICAL_DATA, 0,
 					  event_label, hash, digest,
 					  digest_len);
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 6a68ec270822..fc128a6b4abe 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -552,7 +552,7 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule,
 /**
  * ima_match_rules - determine whether an inode matches the policy rule.
  * @rule: a pointer to a rule
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @inode: a pointer to an inode
  * @cred: a pointer to a credentials structure for user validation
  * @secid: the secid of the task to be validated
@@ -563,7 +563,7 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule,
  * Returns true on rule match, false on failure.
  */
 static bool ima_match_rules(struct ima_rule_entry *rule,
-			    struct user_namespace *mnt_userns,
+			    struct mnt_idmap *idmap,
 			    struct inode *inode, const struct cred *cred,
 			    u32 secid, enum ima_hooks func, int mask,
 			    const char *func_data)
@@ -624,11 +624,11 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
 			return false;
 	}
 	if ((rule->flags & IMA_FOWNER) &&
-	    !rule->fowner_op(i_uid_into_vfsuid(mnt_userns, inode),
+	    !rule->fowner_op(i_uid_into_vfsuid(idmap, inode),
 			     rule->fowner))
 		return false;
 	if ((rule->flags & IMA_FGROUP) &&
-	    !rule->fgroup_op(i_gid_into_vfsgid(mnt_userns, inode),
+	    !rule->fgroup_op(i_gid_into_vfsgid(idmap, inode),
 			     rule->fgroup))
 		return false;
 	for (i = 0; i < MAX_LSM_RULES; i++) {
@@ -713,7 +713,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
 
 /**
  * ima_match_policy - decision based on LSM and other conditions
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @inode: pointer to an inode for which the policy decision is being made
  * @cred: pointer to a credentials structure for which the policy decision is
  *        being made
@@ -732,7 +732,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
  * list when walking it.  Reads are many orders of magnitude more numerous
  * than writes so ima_match_policy() is classical RCU candidate.
  */
-int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
+int ima_match_policy(struct mnt_idmap *idmap, struct inode *inode,
 		     const struct cred *cred, u32 secid, enum ima_hooks func,
 		     int mask, int flags, int *pcr,
 		     struct ima_template_desc **template_desc,
@@ -752,7 +752,7 @@ int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
 		if (!(entry->action & actmask))
 			continue;
 
-		if (!ima_match_rules(entry, mnt_userns, inode, cred, secid,
+		if (!ima_match_rules(entry, idmap, inode, cred, secid,
 				     func, mask, func_data))
 			continue;
 
diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c
index 93056c03bf5a..4f0aea155bf9 100644
--- a/security/integrity/ima/ima_queue_keys.c
+++ b/security/integrity/ima/ima_queue_keys.c
@@ -159,7 +159,7 @@ void ima_process_queued_keys(void)
 
 	list_for_each_entry_safe(entry, tmp, &ima_keys, list) {
 		if (!timer_expired)
-			process_buffer_measurement(&init_user_ns, NULL,
+			process_buffer_measurement(&nop_mnt_idmap, NULL,
 						   entry->payload,
 						   entry->payload_len,
 						   entry->keyring_name,
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 4564faae7d67..6cd0add524cd 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -598,7 +598,7 @@ int ima_eventevmsig_init(struct ima_event_data *event_data,
 	if (!event_data->file)
 		return 0;
 
-	rc = vfs_getxattr_alloc(&init_user_ns, file_dentry(event_data->file),
+	rc = vfs_getxattr_alloc(&nop_mnt_idmap, file_dentry(event_data->file),
 				XATTR_NAME_EVM, (char **)&xattr_data, 0,
 				GFP_NOFS);
 	if (rc <= 0 || xattr_data->type != EVM_XATTR_PORTABLE_DIGSIG) {
diff --git a/security/security.c b/security/security.c
index d1571900a8c7..4e1150c44ab7 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1354,7 +1354,7 @@ int security_inode_permission(struct inode *inode, int mask)
 	return call_int_hook(inode_permission, 0, inode, mask);
 }
 
-int security_inode_setattr(struct user_namespace *mnt_userns,
+int security_inode_setattr(struct mnt_idmap *idmap,
 			   struct dentry *dentry, struct iattr *attr)
 {
 	int ret;
@@ -1364,7 +1364,7 @@ int security_inode_setattr(struct user_namespace *mnt_userns,
 	ret = call_int_hook(inode_setattr, 0, dentry, attr);
 	if (ret)
 		return ret;
-	return evm_inode_setattr(mnt_userns, dentry, attr);
+	return evm_inode_setattr(idmap, dentry, attr);
 }
 EXPORT_SYMBOL_GPL(security_inode_setattr);
 
@@ -1375,7 +1375,7 @@ int security_inode_getattr(const struct path *path)
 	return call_int_hook(inode_getattr, 0, path);
 }
 
-int security_inode_setxattr(struct user_namespace *mnt_userns,
+int security_inode_setxattr(struct mnt_idmap *idmap,
 			    struct dentry *dentry, const char *name,
 			    const void *value, size_t size, int flags)
 {
@@ -1387,7 +1387,7 @@ int security_inode_setxattr(struct user_namespace *mnt_userns,
 	 * SELinux and Smack integrate the cap call,
 	 * so assume that all LSMs supplying this call do so.
 	 */
-	ret = call_int_hook(inode_setxattr, 1, mnt_userns, dentry, name, value,
+	ret = call_int_hook(inode_setxattr, 1, idmap, dentry, name, value,
 			    size, flags);
 
 	if (ret == 1)
@@ -1397,10 +1397,10 @@ int security_inode_setxattr(struct user_namespace *mnt_userns,
 	ret = ima_inode_setxattr(dentry, name, value, size);
 	if (ret)
 		return ret;
-	return evm_inode_setxattr(mnt_userns, dentry, name, value, size);
+	return evm_inode_setxattr(idmap, dentry, name, value, size);
 }
 
-int security_inode_set_acl(struct user_namespace *mnt_userns,
+int security_inode_set_acl(struct mnt_idmap *idmap,
 			   struct dentry *dentry, const char *acl_name,
 			   struct posix_acl *kacl)
 {
@@ -1408,38 +1408,38 @@ int security_inode_set_acl(struct user_namespace *mnt_userns,
 
 	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
 		return 0;
-	ret = call_int_hook(inode_set_acl, 0, mnt_userns, dentry, acl_name,
+	ret = call_int_hook(inode_set_acl, 0, idmap, dentry, acl_name,
 			    kacl);
 	if (ret)
 		return ret;
-	ret = ima_inode_set_acl(mnt_userns, dentry, acl_name, kacl);
+	ret = ima_inode_set_acl(idmap, dentry, acl_name, kacl);
 	if (ret)
 		return ret;
-	return evm_inode_set_acl(mnt_userns, dentry, acl_name, kacl);
+	return evm_inode_set_acl(idmap, dentry, acl_name, kacl);
 }
 
-int security_inode_get_acl(struct user_namespace *mnt_userns,
+int security_inode_get_acl(struct mnt_idmap *idmap,
 			   struct dentry *dentry, const char *acl_name)
 {
 	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
 		return 0;
-	return call_int_hook(inode_get_acl, 0, mnt_userns, dentry, acl_name);
+	return call_int_hook(inode_get_acl, 0, idmap, dentry, acl_name);
 }
 
-int security_inode_remove_acl(struct user_namespace *mnt_userns,
+int security_inode_remove_acl(struct mnt_idmap *idmap,
 			      struct dentry *dentry, const char *acl_name)
 {
 	int ret;
 
 	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
 		return 0;
-	ret = call_int_hook(inode_remove_acl, 0, mnt_userns, dentry, acl_name);
+	ret = call_int_hook(inode_remove_acl, 0, idmap, dentry, acl_name);
 	if (ret)
 		return ret;
-	ret = ima_inode_remove_acl(mnt_userns, dentry, acl_name);
+	ret = ima_inode_remove_acl(idmap, dentry, acl_name);
 	if (ret)
 		return ret;
-	return evm_inode_remove_acl(mnt_userns, dentry, acl_name);
+	return evm_inode_remove_acl(idmap, dentry, acl_name);
 }
 
 void security_inode_post_setxattr(struct dentry *dentry, const char *name,
@@ -1465,7 +1465,7 @@ int security_inode_listxattr(struct dentry *dentry)
 	return call_int_hook(inode_listxattr, 0, dentry);
 }
 
-int security_inode_removexattr(struct user_namespace *mnt_userns,
+int security_inode_removexattr(struct mnt_idmap *idmap,
 			       struct dentry *dentry, const char *name)
 {
 	int ret;
@@ -1476,15 +1476,15 @@ int security_inode_removexattr(struct user_namespace *mnt_userns,
 	 * SELinux and Smack integrate the cap call,
 	 * so assume that all LSMs supplying this call do so.
 	 */
-	ret = call_int_hook(inode_removexattr, 1, mnt_userns, dentry, name);
+	ret = call_int_hook(inode_removexattr, 1, idmap, dentry, name);
 	if (ret == 1)
-		ret = cap_inode_removexattr(mnt_userns, dentry, name);
+		ret = cap_inode_removexattr(idmap, dentry, name);
 	if (ret)
 		return ret;
 	ret = ima_inode_removexattr(dentry, name);
 	if (ret)
 		return ret;
-	return evm_inode_removexattr(mnt_userns, dentry, name);
+	return evm_inode_removexattr(idmap, dentry, name);
 }
 
 int security_inode_need_killpriv(struct dentry *dentry)
@@ -1492,13 +1492,13 @@ int security_inode_need_killpriv(struct dentry *dentry)
 	return call_int_hook(inode_need_killpriv, 0, dentry);
 }
 
-int security_inode_killpriv(struct user_namespace *mnt_userns,
+int security_inode_killpriv(struct mnt_idmap *idmap,
 			    struct dentry *dentry)
 {
-	return call_int_hook(inode_killpriv, 0, mnt_userns, dentry);
+	return call_int_hook(inode_killpriv, 0, idmap, dentry);
 }
 
-int security_inode_getsecurity(struct user_namespace *mnt_userns,
+int security_inode_getsecurity(struct mnt_idmap *idmap,
 			       struct inode *inode, const char *name,
 			       void **buffer, bool alloc)
 {
@@ -1511,7 +1511,7 @@ int security_inode_getsecurity(struct user_namespace *mnt_userns,
 	 * Only one module will provide an attribute with a given name.
 	 */
 	hlist_for_each_entry(hp, &security_hook_heads.inode_getsecurity, list) {
-		rc = hp->hook.inode_getsecurity(mnt_userns, inode, name, buffer, alloc);
+		rc = hp->hook.inode_getsecurity(idmap, inode, name, buffer, alloc);
 		if (rc != LSM_RET_DEFAULT(inode_getsecurity))
 			return rc;
 	}
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 3c5be76a9199..9a5bdfc21314 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3145,7 +3145,7 @@ static bool has_cap_mac_admin(bool audit)
 	return true;
 }
 
-static int selinux_inode_setxattr(struct user_namespace *mnt_userns,
+static int selinux_inode_setxattr(struct mnt_idmap *idmap,
 				  struct dentry *dentry, const char *name,
 				  const void *value, size_t size, int flags)
 {
@@ -3167,13 +3167,13 @@ static int selinux_inode_setxattr(struct user_namespace *mnt_userns,
 	}
 
 	if (!selinux_initialized(&selinux_state))
-		return (inode_owner_or_capable(mnt_userns, inode) ? 0 : -EPERM);
+		return (inode_owner_or_capable(idmap, inode) ? 0 : -EPERM);
 
 	sbsec = selinux_superblock(inode->i_sb);
 	if (!(sbsec->flags & SBLABEL_MNT))
 		return -EOPNOTSUPP;
 
-	if (!inode_owner_or_capable(mnt_userns, inode))
+	if (!inode_owner_or_capable(idmap, inode))
 		return -EPERM;
 
 	ad.type = LSM_AUDIT_DATA_DENTRY;
@@ -3240,20 +3240,20 @@ static int selinux_inode_setxattr(struct user_namespace *mnt_userns,
 			    &ad);
 }
 
-static int selinux_inode_set_acl(struct user_namespace *mnt_userns,
+static int selinux_inode_set_acl(struct mnt_idmap *idmap,
 				 struct dentry *dentry, const char *acl_name,
 				 struct posix_acl *kacl)
 {
 	return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
 }
 
-static int selinux_inode_get_acl(struct user_namespace *mnt_userns,
+static int selinux_inode_get_acl(struct mnt_idmap *idmap,
 				 struct dentry *dentry, const char *acl_name)
 {
 	return dentry_has_perm(current_cred(), dentry, FILE__GETATTR);
 }
 
-static int selinux_inode_remove_acl(struct user_namespace *mnt_userns,
+static int selinux_inode_remove_acl(struct mnt_idmap *idmap,
 				    struct dentry *dentry, const char *acl_name)
 {
 	return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
@@ -3313,11 +3313,11 @@ static int selinux_inode_listxattr(struct dentry *dentry)
 	return dentry_has_perm(cred, dentry, FILE__GETATTR);
 }
 
-static int selinux_inode_removexattr(struct user_namespace *mnt_userns,
+static int selinux_inode_removexattr(struct mnt_idmap *idmap,
 				     struct dentry *dentry, const char *name)
 {
 	if (strcmp(name, XATTR_NAME_SELINUX)) {
-		int rc = cap_inode_removexattr(mnt_userns, dentry, name);
+		int rc = cap_inode_removexattr(idmap, dentry, name);
 		if (rc)
 			return rc;
 
@@ -3383,7 +3383,7 @@ static int selinux_path_notify(const struct path *path, u64 mask,
  *
  * Permission check is handled by selinux_inode_getxattr hook.
  */
-static int selinux_inode_getsecurity(struct user_namespace *mnt_userns,
+static int selinux_inode_getsecurity(struct mnt_idmap *idmap,
 				     struct inode *inode, const char *name,
 				     void **buffer, bool alloc)
 {
@@ -6588,14 +6588,14 @@ static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen
  */
 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
 {
-	return __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_SELINUX,
+	return __vfs_setxattr_noperm(&nop_mnt_idmap, dentry, XATTR_NAME_SELINUX,
 				     ctx, ctxlen, 0);
 }
 
 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
 {
 	int len = 0;
-	len = selinux_inode_getsecurity(&init_user_ns, inode,
+	len = selinux_inode_getsecurity(&nop_mnt_idmap, inode,
 					XATTR_SELINUX_SUFFIX, ctx, true);
 	if (len < 0)
 		return len;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 9a82a15685d1..cfcbb748da25 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1207,7 +1207,7 @@ static int smack_inode_getattr(const struct path *path)
 
 /**
  * smack_inode_setxattr - Smack check for setting xattrs
- * @mnt_userns: active user namespace
+ * @idmap: idmap of the mount
  * @dentry: the object
  * @name: name of the attribute
  * @value: value of the attribute
@@ -1218,7 +1218,7 @@ static int smack_inode_getattr(const struct path *path)
  *
  * Returns 0 if access is permitted, an error code otherwise
  */
-static int smack_inode_setxattr(struct user_namespace *mnt_userns,
+static int smack_inode_setxattr(struct mnt_idmap *idmap,
 				struct dentry *dentry, const char *name,
 				const void *value, size_t size, int flags)
 {
@@ -1334,7 +1334,7 @@ static int smack_inode_getxattr(struct dentry *dentry, const char *name)
 
 /**
  * smack_inode_removexattr - Smack check on removexattr
- * @mnt_userns: active user namespace
+ * @idmap: idmap of the mount
  * @dentry: the object
  * @name: name of the attribute
  *
@@ -1342,7 +1342,7 @@ static int smack_inode_getxattr(struct dentry *dentry, const char *name)
  *
  * Returns 0 if access is permitted, an error code otherwise
  */
-static int smack_inode_removexattr(struct user_namespace *mnt_userns,
+static int smack_inode_removexattr(struct mnt_idmap *idmap,
 				   struct dentry *dentry, const char *name)
 {
 	struct inode_smack *isp;
@@ -1358,7 +1358,7 @@ static int smack_inode_removexattr(struct user_namespace *mnt_userns,
 		if (!smack_privileged(CAP_MAC_ADMIN))
 			rc = -EPERM;
 	} else
-		rc = cap_inode_removexattr(mnt_userns, dentry, name);
+		rc = cap_inode_removexattr(idmap, dentry, name);
 
 	if (rc != 0)
 		return rc;
@@ -1394,14 +1394,14 @@ static int smack_inode_removexattr(struct user_namespace *mnt_userns,
 
 /**
  * smack_inode_set_acl - Smack check for setting posix acls
- * @mnt_userns: the userns attached to the mnt this request came from
+ * @idmap: idmap of the mnt this request came from
  * @dentry: the object
  * @acl_name: name of the posix acl
  * @kacl: the posix acls
  *
  * Returns 0 if access is permitted, an error code otherwise
  */
-static int smack_inode_set_acl(struct user_namespace *mnt_userns,
+static int smack_inode_set_acl(struct mnt_idmap *idmap,
 			       struct dentry *dentry, const char *acl_name,
 			       struct posix_acl *kacl)
 {
@@ -1418,13 +1418,13 @@ static int smack_inode_set_acl(struct user_namespace *mnt_userns,
 
 /**
  * smack_inode_get_acl - Smack check for getting posix acls
- * @mnt_userns: the userns attached to the mnt this request came from
+ * @idmap: idmap of the mnt this request came from
  * @dentry: the object
  * @acl_name: name of the posix acl
  *
  * Returns 0 if access is permitted, an error code otherwise
  */
-static int smack_inode_get_acl(struct user_namespace *mnt_userns,
+static int smack_inode_get_acl(struct mnt_idmap *idmap,
 			       struct dentry *dentry, const char *acl_name)
 {
 	struct smk_audit_info ad;
@@ -1440,13 +1440,13 @@ static int smack_inode_get_acl(struct user_namespace *mnt_userns,
 
 /**
  * smack_inode_remove_acl - Smack check for getting posix acls
- * @mnt_userns: the userns attached to the mnt this request came from
+ * @idmap: idmap of the mnt this request came from
  * @dentry: the object
  * @acl_name: name of the posix acl
  *
  * Returns 0 if access is permitted, an error code otherwise
  */
-static int smack_inode_remove_acl(struct user_namespace *mnt_userns,
+static int smack_inode_remove_acl(struct mnt_idmap *idmap,
 				  struct dentry *dentry, const char *acl_name)
 {
 	struct smk_audit_info ad;
@@ -1462,7 +1462,7 @@ static int smack_inode_remove_acl(struct user_namespace *mnt_userns,
 
 /**
  * smack_inode_getsecurity - get smack xattrs
- * @mnt_userns: active user namespace
+ * @idmap: idmap of the mount
  * @inode: the object
  * @name: attribute name
  * @buffer: where to put the result
@@ -1470,7 +1470,7 @@ static int smack_inode_remove_acl(struct user_namespace *mnt_userns,
  *
  * Returns the size of the attribute or an error code
  */
-static int smack_inode_getsecurity(struct user_namespace *mnt_userns,
+static int smack_inode_getsecurity(struct mnt_idmap *idmap,
 				   struct inode *inode, const char *name,
 				   void **buffer, bool alloc)
 {
@@ -3507,7 +3507,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
 			 */
 			if (isp->smk_flags & SMK_INODE_CHANGED) {
 				isp->smk_flags &= ~SMK_INODE_CHANGED;
-				rc = __vfs_setxattr(&init_user_ns, dp, inode,
+				rc = __vfs_setxattr(&nop_mnt_idmap, dp, inode,
 					XATTR_NAME_SMACKTRANSMUTE,
 					TRANS_TRUE, TRANS_TRUE_SIZE,
 					0);
@@ -4686,7 +4686,7 @@ static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
 
 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
 {
-	return __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_SMACK,
+	return __vfs_setxattr_noperm(&nop_mnt_idmap, dentry, XATTR_NAME_SMACK,
 				     ctx, ctxlen, 0);
 }