Commit 576164bd authored Jan 23, 2024 by David Sterba Committed by Greg Kroah-Hartman Apr 13, 2024

btrfs: handle chunk tree lookup error in btrfs_relocate_sys_chunks()



[ Upstream commit 7411055db5ce64f836aaffd422396af0075fdc99 ]

The unhandled case in btrfs_relocate_sys_chunks() loop is a corruption,
as it could be caused only by two impossible conditions:

- at first the search key is set up to look for a chunk tree item, with
  offset -1, this is an inexact search and the key->offset will contain
  the correct offset upon a successful search, a valid chunk tree item
  cannot have an offset -1

- after first successful search, the found_key corresponds to a chunk
  item, the offset is decremented by 1 before the next loop, it's
  impossible to find a chunk item there due to alignment and size
  constraints

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 41aff62b

fs/btrfs/volumes.c

+11 −1

Original line number	Diff line number	Diff line
		@@ -3268,7 +3268,17 @@ static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info)
		mutex_unlock(&fs_info->delete_unused_bgs_mutex);
		goto error;
		}
		BUG_ON(ret == 0); /* Corruption */
		if (ret == 0) {
		/*
		* On the first search we would find chunk tree with
		* offset -1, which is not possible. On subsequent
		* loops this would find an existing item on an invalid
		* offset (one less than the previous one, wrong
		* alignment and size).
		*/
		ret = -EUCLEAN;
		goto error;
		}

		ret = btrfs_previous_item(chunk_root, path, key.objectid,
		key.type);