btrfs: simplify error handling in btrfs_lookup_dentry

In btrfs_lookup_dentry releasing the reference of the sub_root and the
running orphan cleanup should only happen if the dentry found actually
represents a subvolume. This can only be true in the 'else' branch as
otherwise either fixup_tree_root_location returned an ENOENT error, in
which case sub_root wouldn't have been changed or if we got a different
errno this means btrfs_get_fs_root couldn't have executed successfully
again meaning sub_root will equal to root. So simplify all the branches
by moving the code into the 'else'.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 16789bbacf75a71f7a68764e3692cb0d48be1b42..f20740812e5bf3b921a888ec0119120223a6bf22 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5866,14 +5866,14 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
                if (ret != -ENOENT)
                        inode = ERR_PTR(ret);
                else
-                       inode = new_simple_dir(dir->i_sb, &location, sub_root);
+                       inode = new_simple_dir(dir->i_sb, &location, root);
        } else {
                inode = btrfs_iget(dir->i_sb, location.objectid, sub_root);
-       }
-       if (root != sub_root)
                btrfs_put_root(sub_root);
 
-       if (!IS_ERR(inode) && root != sub_root) {
+               if (IS_ERR(inode))
+                       return inode;
+
                down_read(&fs_info->cleanup_work_sem);
                if (!sb_rdonly(inode->i_sb))
                        ret = btrfs_orphan_cleanup(sub_root);