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, 4 insertions, 4 deletions

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);