fs: port ->set_acl() 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/overlayfs/inode.c b/fs/overlayfs/inode.c
index 3ea4fc54f4699..f52d9304d7e42 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -653,7 +653,7 @@ 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;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 1e8b0be85e4b8..0f2ac8402f10b 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -284,13 +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,
@@ -623,7 +623,7 @@ static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap,
 {
 	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);