From 4609e1f18e19c3b302e1eb4858334bca1532f780 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 13 Jan 2023 12:49:22 +0100 Subject: fs: port ->permission() 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 Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Microsoft) --- fs/open.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 60a81db586ef..94e2afb2c603 100644 --- a/fs/open.c +++ b/fs/open.c @@ -71,7 +71,6 @@ int do_truncate(struct mnt_idmap *idmap, struct dentry *dentry, long vfs_truncate(const struct path *path, loff_t length) { struct mnt_idmap *idmap; - struct user_namespace *mnt_userns; struct inode *inode; long error; @@ -88,8 +87,7 @@ long vfs_truncate(const struct path *path, loff_t length) goto out; idmap = mnt_idmap(path->mnt); - mnt_userns = mnt_idmap_owner(idmap); - error = inode_permission(mnt_userns, inode, MAY_WRITE); + error = inode_permission(idmap, inode, MAY_WRITE); if (error) goto mnt_drop_write_and_out; @@ -462,7 +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; -- cgit v1.2.3