Commit 3561b9db authored by Liu Bo's avatar Liu Bo Committed by David Sterba
Browse files

Btrfs: return gracefully from balance if fs tree is corrupted 



When relocating tree blocks, we firstly get block information from
back references in the extent tree, we then search fs tree to try to
find all parents of a block.

However, if fs tree is corrupted, eg. if there're some missing
items, we could come across these WARN_ONs and BUG_ONs.

This makes us print some error messages and return gracefully
from balance.

Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: default avatarJosef Bacik <jbacik@fb.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 9c8e63db

fs/btrfs/relocation.c

+17 −6
Original line number Diff line number Diff line
@@ -923,9 +923,16 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, 
			path2->slots[level]--;



		eb = path2->nodes[level];

		WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=

			cur->bytenr);



		if (btrfs_node_blockptr(eb, path2->slots[level]) !=

		    cur->bytenr) {

			btrfs_err(root->fs_info,

	"couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)",

				  cur->bytenr, level - 1, root->objectid,

				  node_key->objectid, node_key->type,

				  node_key->offset);

			err = -ENOENT;

			goto out;

		}

		lower = cur;

		need_check = true;

		for (; level < BTRFS_MAX_LEVEL; level++) {
@@ -2686,11 +2693,15 @@ static int do_relocation(struct btrfs_trans_handle *trans, 


		if (!upper->eb) {

			ret = btrfs_search_slot(trans, root, key, path, 0, 1);

			if (ret < 0) {

			if (ret) {

				if (ret < 0)

					err = ret;

				else

					err = -ENOENT;



				btrfs_release_path(path);

				break;

			}

			BUG_ON(ret > 0);



			if (!upper->eb) {

				upper->eb = path->nodes[upper->level];