btrfsutil: RebuiltForrest: Have LookupUUID return an error

4 files changed, 23 insertions, 21 deletions

diff --git a/cmd/btrfs-rec/inspect/rebuildtrees/rebuild_treecb.go b/cmd/btrfs-rec/inspect/rebuildtrees/rebuild_treecb.go
index 15ad42c..cfef623 100644
--- a/cmd/btrfs-rec/inspect/rebuildtrees/rebuild_treecb.go
+++ b/cmd/btrfs-rec/inspect/rebuildtrees/rebuild_treecb.go
@@ -10,6 +10,7 @@ import (
 
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsitem"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsprim"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfstree"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfsutil"
 )
@@ -67,7 +68,7 @@ func (o forrestCallbacks) LookupRoot(ctx context.Context, tree btrfsprim.ObjID)
 }
 
 // LookupUUID implements btrfsutil.RebuiltForrestCallbacks.
-func (o forrestCallbacks) LookupUUID(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, ok bool) {
+func (o forrestCallbacks) LookupUUID(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, err error) {
 	wantKey := wantWithTree{
 		TreeID: btrfsprim.UUID_TREE_OBJECTID,
 		Key:    wantFromKey(btrfsitem.UUIDToKey(uuid)),
@@ -75,16 +76,16 @@ func (o forrestCallbacks) LookupUUID(ctx context.Context, uuid btrfsprim.UUID) (
 	ctx = withWant(ctx, logFieldTreeWant, "resolve parent UUID", wantKey)
 	if !o._wantOff(ctx, wantKey) {
 		o.enqueueRetry(btrfsprim.UUID_TREE_OBJECTID)
-		return 0, false
+		return 0, btrfstree.ErrNoItem
 	}
 	item, _ := discardErr(o.rebuilt.RebuiltTree(ctx, wantKey.TreeID)).TreeLookup(ctx, wantKey.Key.Key())
 	defer item.Body.Free()
 	switch itemBody := item.Body.(type) {
 	case *btrfsitem.UUIDMap:
-		return itemBody.ObjID, true
+		return itemBody.ObjID, nil
 	case *btrfsitem.Error:
 		graphCallbacks(o).FSErr(ctx, fmt.Errorf("error decoding item: %v: %w", wantKey, itemBody.Err))
-		return 0, false
+		return 0, itemBody.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.
diff --git a/lib/btrfsutil/rebuilt_callbacks.go b/lib/btrfsutil/rebuilt_callbacks.go
index 0b51d08..9ed3177 100644
--- a/lib/btrfsutil/rebuilt_callbacks.go
+++ b/lib/btrfsutil/rebuilt_callbacks.go
@@ -17,7 +17,7 @@ import (
 type RebuiltForrestCallbacks interface {
 	AddedRoot(ctx context.Context, tree btrfsprim.ObjID, root btrfsvol.LogicalAddr)
 	LookupRoot(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, item btrfsitem.Root, ok bool)
-	LookupUUID(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, ok bool)
+	LookupUUID(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, err error)
 }
 
 type RebuiltForrestExtendedCallbacks interface {
@@ -54,22 +54,22 @@ func (cb noopRebuiltForrestCallbacks) LookupRoot(ctx context.Context, tree btrfs
 	}
 }
 
-func (cb noopRebuiltForrestCallbacks) LookupUUID(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, ok bool) {
+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 {
-		return 0, false
+		return 0, err
 	}
 	tgt := btrfsitem.UUIDToKey(uuid)
 	item, err := uuidTree.TreeLookup(ctx, tgt)
 	if err != nil {
-		return 0, false
+		return 0, err
 	}
 	defer item.Body.Free()
 	switch itemBody := item.Body.(type) {
 	case *btrfsitem.UUIDMap:
-		return itemBody.ObjID, true
+		return itemBody.ObjID, nil
 	case *btrfsitem.Error:
-		return 0, false
+		return 0, itemBody.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.
diff --git a/lib/btrfsutil/rebuilt_forrest.go b/lib/btrfsutil/rebuilt_forrest.go
index 5741072..3c53af7 100644
--- a/lib/btrfsutil/rebuilt_forrest.go
+++ b/lib/btrfsutil/rebuilt_forrest.go
@@ -221,9 +221,9 @@ func (ts *RebuiltForrest) rebuildTree(ctx context.Context, treeID btrfsprim.ObjI
 		ts.trees[treeID].UUID = rootItem.UUID
 		if rootItem.ParentUUID != (btrfsprim.UUID{}) {
 			ts.trees[treeID].ParentGen = rootOff
-			parentID, ok := ts.cb.LookupUUID(ctx, rootItem.ParentUUID)
-			if !ok {
-				err := fmt.Errorf("failed to look up UUID: %v", rootItem.ParentUUID)
+			parentID, err := ts.cb.LookupUUID(ctx, rootItem.ParentUUID)
+			if err != nil {
+				err := fmt.Errorf("failed to look up UUID: %v: %w", rootItem.ParentUUID, err)
 				if ts.laxAncestors {
 					ts.trees[treeID].parentErr = err
 				} else {
diff --git a/lib/btrfsutil/rebuilt_forrest_test.go b/lib/btrfsutil/rebuilt_forrest_test.go
index 8bbb50a..ef0ed72 100644
--- a/lib/btrfsutil/rebuilt_forrest_test.go
+++ b/lib/btrfsutil/rebuilt_forrest_test.go
@@ -13,6 +13,7 @@ import (
 
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsitem"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsprim"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfstree"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol"
 )
 
@@ -20,7 +21,7 @@ type rebuiltForrestCallbacks struct {
 	addedItem  func(ctx context.Context, tree btrfsprim.ObjID, key btrfsprim.Key)
 	addedRoot  func(ctx context.Context, tree btrfsprim.ObjID, root btrfsvol.LogicalAddr)
 	lookupRoot func(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, item btrfsitem.Root, ok bool)
-	lookupUUID func(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, ok bool)
+	lookupUUID func(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, err error)
 }
 
 func (cbs rebuiltForrestCallbacks) AddedItem(ctx context.Context, tree btrfsprim.ObjID, key btrfsprim.Key) {
@@ -35,7 +36,7 @@ func (cbs rebuiltForrestCallbacks) LookupRoot(ctx context.Context, tree btrfspri
 	return cbs.lookupRoot(ctx, tree)
 }
 
-func (cbs rebuiltForrestCallbacks) LookupUUID(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, ok bool) {
+func (cbs rebuiltForrestCallbacks) LookupUUID(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, err error) {
 	return cbs.lookupUUID(ctx, uuid)
 }
 
@@ -96,13 +97,13 @@ func TestRebuiltTreeCycles(t *testing.T) {
 			}
 			return 0, btrfsitem.Root{}, false
 		},
-		lookupUUID: func(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, ok bool) {
+		lookupUUID: func(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, err error) {
 			for _, root := range roots {
 				if root.UUID == uuid {
-					return root.ID, true
+					return root.ID, nil
 				}
 			}
-			return 0, false
+			return 0, btrfstree.ErrNoItem
 		},
 	}
 
@@ -209,13 +210,13 @@ func TestRebuiltTreeParentErr(t *testing.T) {
 			}
 			return 0, btrfsitem.Root{}, false
 		},
-		lookupUUID: func(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, ok bool) {
+		lookupUUID: func(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, err error) {
 			for _, root := range roots {
 				if root.UUID == uuid {
-					return root.ID, true
+					return root.ID, nil
 				}
 			}
-			return 0, false
+			return 0, btrfstree.ErrNoItem
 		},
 	}