From ee2564cc3164e2c235b3d617a1a4fed2f9d9efc6 Mon Sep 17 00:00:00 2001 From: Luke Shumaker Date: Fri, 7 Apr 2023 15:30:46 -0600 Subject: btrfsutil.RebuiltForrest, rebuildtrees: Be more permissive of broken UUID_TREEs --- lib/btrfsutil/rebuilt_callbacks.go | 42 +++++++++++++++++++++++++++++++++++++- 1 file changed, 41 insertions(+), 1 deletion(-) (limited to 'lib/btrfsutil') diff --git a/lib/btrfsutil/rebuilt_callbacks.go b/lib/btrfsutil/rebuilt_callbacks.go index b5fbc91..8d96c41 100644 --- a/lib/btrfsutil/rebuilt_callbacks.go +++ b/lib/btrfsutil/rebuilt_callbacks.go @@ -57,11 +57,17 @@ func (cb noopRebuiltForrestCallbacks) LookupRoot(ctx context.Context, tree btrfs func (cb noopRebuiltForrestCallbacks) LookupUUID(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, err error) { uuidTree, err := cb.forrest.ForrestLookup(ctx, btrfsprim.UUID_TREE_OBJECTID) if err != nil { + if id, ok := cb.slowLookupUUID(ctx, uuid); ok { + return id, nil + } return 0, err } tgt := btrfsitem.UUIDToKey(uuid) item, err := uuidTree.TreeLookup(ctx, tgt) if err != nil { + if id, ok := cb.slowLookupUUID(ctx, uuid); ok { + return id, nil + } return 0, err } defer item.Body.Free() @@ -69,10 +75,44 @@ func (cb noopRebuiltForrestCallbacks) LookupUUID(ctx context.Context, uuid btrfs case *btrfsitem.UUIDMap: return itemBody.ObjID, nil case *btrfsitem.Error: - return 0, itemBody.Err + if id, ok := cb.slowLookupUUID(ctx, uuid); ok { + return id, nil + } + return 0, err default: // This is a panic because the item decoder should not emit UUID_SUBVOL items as anything but // btrfsitem.UUIDMap or btrfsitem.Error without this code also being updated. panic(fmt.Errorf("should not happen: UUID_SUBVOL item has unexpected type: %T", itemBody)) } } + +func (cb noopRebuiltForrestCallbacks) slowLookupUUID(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, ok bool) { + rootTree, err := cb.forrest.ForrestLookup(ctx, btrfsprim.ROOT_TREE_OBJECTID) + if err != nil { + return 0, false + } + var ret btrfsprim.ObjID + _ = rootTree.TreeRange(ctx, func(item btrfstree.Item) bool { + if item.Key.ItemType != btrfsprim.ROOT_ITEM_KEY { + return true + } + switch itemBody := item.Body.(type) { + case *btrfsitem.Root: + if itemBody.UUID == uuid { + ret = item.Key.ObjectID + return false + } + case *btrfsitem.Error: + // do nothing + default: + // This is a panic because the item decoder should not emit ROOT_ITEM items as anything but + // btrfsitem.Root or btrfsitem.Error without this code also being updated. + panic(fmt.Errorf("should not happen: ROOT_ITEM item has unexpected type: %T", itemBody)) + } + return true + }) + if ret == 0 { + return 0, false + } + return ret, true +} -- cgit v1.2.3-2-g168b