fs: port ->setattr() to pass mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to 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 relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

2 files changed, 7 insertions, 5 deletions

diff --git a/fs/ntfs3/file.c b/fs/ntfs3/file.c
index e5399ebc3a2b..3303b6c88680 100644
--- a/fs/ntfs3/file.c
+++ b/fs/ntfs3/file.c
@@ -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(mnt_idmap_owner(idmap), dentry);
 		if (err)
 			goto out;
 
diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index 0e051c5595a2..870733297122 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -494,8 +494,10 @@ extern const struct file_operations ntfs_dir_operations;
 /* Globals from file.c */
 int ntfs_getattr(struct user_namespace *mnt_userns, 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);