Commit ed4e6b5d authored by David Sterba's avatar David Sterba
Browse files

btrfs: ref-verify: handle damaged extent root tree 



Syzbot hits a problem with enabled ref-verify, ignorebadroots and a
fuzzed/damaged extent tree. There's no fallback option like in other
places that can deal with it so disable the whole ref-verify as it is
just a debugging feature.

Reported-by: default avatar <syzbot+9c3e0cdfbfe351b0bc0e@syzkaller.appspotmail.com>
Link: https://lore.kernel.org/all/0000000000001b6052062139be1c@google.com/


Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 96fa515e

fs/btrfs/ref-verify.c

+8 −1
Original line number Diff line number Diff line
@@ -980,11 +980,18 @@ int btrfs_build_ref_tree(struct btrfs_fs_info *fs_info) 
	if (!btrfs_test_opt(fs_info, REF_VERIFY))

		return 0;



	extent_root = btrfs_extent_root(fs_info, 0);

	/* If the extent tree is damaged we cannot ignore it (IGNOREBADROOTS). */

	if (IS_ERR(extent_root)) {

		btrfs_warn(fs_info, "ref-verify: extent tree not available, disabling");

		btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY);

		return 0;

	}



	path = btrfs_alloc_path();

	if (!path)

		return -ENOMEM;



	extent_root = btrfs_extent_root(fs_info, 0);

	eb = btrfs_read_lock_root_node(extent_root);

	level = btrfs_header_level(eb);

	path->nodes[level] = eb;