btrfs: free data reloc tree on failed mount

While testing a weird problem with -o degraded, I noticed I was getting
leaked root errors

  BTRFS warning (device loop0): writable mount is not allowed due to too many missing devices
  BTRFS error (device loop0): open_ctree failed
  BTRFS error (device loop0): leaked root -9-0 refcount 1

This is the DATA_RELOC root, which gets read before the other fs roots,
but is included in the fs roots radix tree.  Handle this by adding a
btrfs_drop_and_free_fs_root() on the data reloc root if it exists.  This
is ok to do here if we fail further up because we will only drop the ref
if we delete the root from the radix tree, and all other cleanup won't
be duplicated.

CC: stable@vger.kernel.org # 5.8+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Josef Bacik 2020-09-03 14:29:50 -04:00 committed by David Sterba
parent ea57788eb7
commit 9e3aa80544

View file

@ -3441,6 +3441,8 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
btrfs_put_block_group_cache(fs_info);
fail_tree_roots:
if (fs_info->data_reloc_root)
btrfs_drop_and_free_fs_root(fs_info, fs_info->data_reloc_root);
free_root_pointers(fs_info, true);
invalidate_inode_pages2(fs_info->btree_inode->i_mapping);