btrfsutil: RebuiltForrest: Have LookupRoot return an error

4 files changed, 23 insertions, 23 deletions

diff --git a/cmd/btrfs-rec/inspect/rebuildtrees/rebuild_treecb.go b/cmd/btrfs-rec/inspect/rebuildtrees/rebuild_treecb.go
index cfef623..b8205ae 100644
--- a/cmd/btrfs-rec/inspect/rebuildtrees/rebuild_treecb.go
+++ b/cmd/btrfs-rec/inspect/rebuildtrees/rebuild_treecb.go
@@ -37,7 +37,7 @@ func (o forrestCallbacks) AddedRoot(_ context.Context, tree btrfsprim.ObjID, _ b
 }
 
 // LookupRoot implements btrfsutil.RebuiltForrestCallbacks.
-func (o forrestCallbacks) LookupRoot(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, _item btrfsitem.Root, ok bool) {
+func (o forrestCallbacks) LookupRoot(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, _item btrfsitem.Root, err error) {
 	wantKey := wantWithTree{
 		TreeID: btrfsprim.ROOT_TREE_OBJECTID,
 		Key: want{
@@ -50,16 +50,16 @@ func (o forrestCallbacks) LookupRoot(ctx context.Context, tree btrfsprim.ObjID)
 	foundKey, ok := o._want(ctx, wantKey)
 	if !ok {
 		o.enqueueRetry(btrfsprim.ROOT_TREE_OBJECTID)
-		return 0, btrfsitem.Root{}, false
+		return 0, btrfsitem.Root{}, btrfstree.ErrNoItem
 	}
 	item, _ := discardErr(o.rebuilt.RebuiltTree(ctx, wantKey.TreeID)).TreeLookup(ctx, foundKey)
 	defer item.Body.Free()
 	switch itemBody := item.Body.(type) {
 	case *btrfsitem.Root:
-		return btrfsprim.Generation(foundKey.Offset), *itemBody, true
+		return btrfsprim.Generation(foundKey.Offset), *itemBody, nil
 	case *btrfsitem.Error:
 		graphCallbacks(o).FSErr(ctx, fmt.Errorf("error decoding item: %v: %w", foundKey, itemBody.Err))
-		return 0, btrfsitem.Root{}, false
+		return 0, btrfsitem.Root{}, itemBody.Err
 	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.
diff --git a/lib/btrfsutil/rebuilt_callbacks.go b/lib/btrfsutil/rebuilt_callbacks.go
index 9ed3177..b5fbc91 100644
--- a/lib/btrfsutil/rebuilt_callbacks.go
+++ b/lib/btrfsutil/rebuilt_callbacks.go
@@ -16,7 +16,7 @@ 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)
+	LookupRoot(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, item btrfsitem.Root, err error)
 	LookupUUID(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, err error)
 }
 
@@ -32,21 +32,21 @@ type noopRebuiltForrestCallbacks struct {
 func (noopRebuiltForrestCallbacks) AddedRoot(context.Context, btrfsprim.ObjID, btrfsvol.LogicalAddr) {
 }
 
-func (cb noopRebuiltForrestCallbacks) LookupRoot(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, _item btrfsitem.Root, ok bool) {
+func (cb noopRebuiltForrestCallbacks) LookupRoot(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, _item btrfsitem.Root, err error) {
 	rootTree, err := cb.forrest.ForrestLookup(ctx, btrfsprim.ROOT_TREE_OBJECTID)
 	if err != nil {
-		return 0, btrfsitem.Root{}, false
+		return 0, btrfsitem.Root{}, err
 	}
 	item, err := rootTree.TreeSearch(ctx, btrfstree.SearchRootItem(tree))
 	if err != nil {
-		return 0, btrfsitem.Root{}, false
+		return 0, btrfsitem.Root{}, err
 	}
 	defer item.Body.Free()
 	switch itemBody := item.Body.(type) {
 	case *btrfsitem.Root:
-		return btrfsprim.Generation(item.Key.Offset), *itemBody, true
+		return btrfsprim.Generation(item.Key.Offset), *itemBody, nil
 	case *btrfsitem.Error:
-		return 0, btrfsitem.Root{}, false
+		return 0, btrfsitem.Root{}, itemBody.Err
 	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.
diff --git a/lib/btrfsutil/rebuilt_forrest.go b/lib/btrfsutil/rebuilt_forrest.go
index 3c53af7..3e40103 100644
--- a/lib/btrfsutil/rebuilt_forrest.go
+++ b/lib/btrfsutil/rebuilt_forrest.go
@@ -212,9 +212,9 @@ func (ts *RebuiltForrest) rebuildTree(ctx context.Context, treeID btrfsprim.ObjI
 		sb, _ := ts.Superblock()
 		ts.trees[treeID].Root = sb.BlockGroupRoot
 	default:
-		rootOff, rootItem, ok := ts.cb.LookupRoot(ctx, treeID)
-		if !ok {
-			ts.trees[treeID].rootErr = btrfstree.ErrNoTree
+		rootOff, rootItem, err := ts.cb.LookupRoot(ctx, treeID)
+		if err != nil {
+			ts.trees[treeID].rootErr = fmt.Errorf("%w: %s", btrfstree.ErrNoTree, err)
 			return
 		}
 		ts.trees[treeID].Root = rootItem.ByteNr
diff --git a/lib/btrfsutil/rebuilt_forrest_test.go b/lib/btrfsutil/rebuilt_forrest_test.go
index ef0ed72..86ae9a7 100644
--- a/lib/btrfsutil/rebuilt_forrest_test.go
+++ b/lib/btrfsutil/rebuilt_forrest_test.go
@@ -20,7 +20,7 @@ import (
 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)
+	lookupRoot func(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, item btrfsitem.Root, err error)
 	lookupUUID func(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, err error)
 }
 
@@ -32,7 +32,7 @@ func (cbs rebuiltForrestCallbacks) AddedRoot(ctx context.Context, tree btrfsprim
 	cbs.addedRoot(ctx, tree, root)
 }
 
-func (cbs rebuiltForrestCallbacks) LookupRoot(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, item btrfsitem.Root, ok bool) {
+func (cbs rebuiltForrestCallbacks) LookupRoot(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, item btrfsitem.Root, err error) {
 	return cbs.lookupRoot(ctx, tree)
 }
 
@@ -85,17 +85,17 @@ func TestRebuiltTreeCycles(t *testing.T) {
 		addedRoot: func(ctx context.Context, tree btrfsprim.ObjID, root btrfsvol.LogicalAddr) {
 			// do nothing
 		},
-		lookupRoot: func(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, item btrfsitem.Root, ok bool) {
+		lookupRoot: func(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, item btrfsitem.Root, err error) {
 			for _, root := range roots {
 				if root.ID == tree {
 					return root.ParentGen, btrfsitem.Root{
 						Generation: 2000,
 						UUID:       root.UUID,
 						ParentUUID: root.ParentUUID,
-					}, true
+					}, nil
 				}
 			}
-			return 0, btrfsitem.Root{}, false
+			return 0, btrfsitem.Root{}, btrfstree.ErrNoItem
 		},
 		lookupUUID: func(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, err error) {
 			for _, root := range roots {
@@ -194,10 +194,10 @@ func TestRebuiltTreeParentErr(t *testing.T) {
 		addedRoot: func(ctx context.Context, tree btrfsprim.ObjID, root btrfsvol.LogicalAddr) {
 			// do nothing
 		},
-		lookupRoot: func(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, item btrfsitem.Root, ok bool) {
+		lookupRoot: func(ctx context.Context, tree btrfsprim.ObjID) (offset btrfsprim.Generation, item btrfsitem.Root, err error) {
 			if tree == 304 {
 				// Force a fault.
-				return 0, btrfsitem.Root{}, false
+				return 0, btrfsitem.Root{}, btrfstree.ErrNoItem
 			}
 			for _, root := range roots {
 				if root.ID == tree {
@@ -205,10 +205,10 @@ func TestRebuiltTreeParentErr(t *testing.T) {
 						Generation: 2000,
 						UUID:       root.UUID,
 						ParentUUID: root.ParentUUID,
-					}, true
+					}, nil
 				}
 			}
-			return 0, btrfsitem.Root{}, false
+			return 0, btrfsitem.Root{}, btrfstree.ErrNoItem
 		},
 		lookupUUID: func(ctx context.Context, uuid btrfsprim.UUID) (id btrfsprim.ObjID, err error) {
 			for _, root := range roots {
@@ -225,7 +225,7 @@ func TestRebuiltTreeParentErr(t *testing.T) {
 		rfs := NewRebuiltForrest(nil, Graph{}, cbs, false)
 
 		tree, err := rfs.RebuiltTree(ctx, 305)
-		assert.EqualError(t, err, `failed to rebuild parent tree: 304: tree does not exist`)
+		assert.EqualError(t, err, `failed to rebuild parent tree: 304: tree does not exist: item does not exist`)
 		assert.Nil(t, tree)
 	})