btrfs: use may_create_dentry() in btrfs_mksubvol()

There is no longer the need to use btrfs_may_create(), which was a copy
of the VFS private function may_create(), since now that functionality
is exported by the VFS as a function named may_create_dentry(). So change
btrfs_mksubvol() to use the VFS function and remove btrfs_may_create().

Note that the btrfs copy was missing an audit_inode_child() call that we
have in the VFS function. This only reinforces the need to use a common
function, as it's very easy for the btrfs copy to get out of sync and
therefore a maintenance burden.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Link: https://patch.msgid.link/adf8c802c77ec1c855ea9fe12491120ccc29a294.1768307858.git.fdmanana@suse.com
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 2d0b2619309d76403bdd567c3d2b779abedcd603..d1ab03691606c6314d6cec69b9c06cb094e3c64f 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -815,19 +815,6 @@ free_pending:
        return ret;
 }
 
-/* copy of may_create in fs/namei.c() */
-static inline int btrfs_may_create(struct mnt_idmap *idmap,
-                                  struct inode *dir, const struct dentry *child)
-{
-       if (d_really_is_positive(child))
-               return -EEXIST;
-       if (IS_DEADDIR(dir))
-               return -ENOENT;
-       if (!fsuidgid_has_mapping(dir->i_sb, idmap))
-               return -EOVERFLOW;
-       return inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
-}
-
 /*
  * Create a new subvolume below @parent.  This is largely modeled after
  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
@@ -849,7 +836,7 @@ static noinline int btrfs_mksubvol(struct dentry *parent,
        if (IS_ERR(dentry))
                return PTR_ERR(dentry);
 
-       ret = btrfs_may_create(idmap, dir, dentry);
+       ret = may_create_dentry(idmap, dir, dentry);
        if (ret)
                goto out_dput;