From 3561b9db70928f207be4570b48fc19898eeaef54 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Wed, 14 Sep 2016 08:51:46 -0700 Subject: [PATCH] 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: Liu Bo Reviewed-by: Josef Bacik Signed-off-by: David Sterba --- fs/btrfs/relocation.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 83fc51f786ab..8e7c78ba77d9 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -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) { - err = ret; + 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]; -- 2.45.2