better clear bad nodes

1 files changed, 26 insertions, 55 deletions

diff --git a/cmd/btrfs-clear-bad-nodes/main.go b/cmd/btrfs-clear-bad-nodes/main.go
index 098d862..ddd8cd3 100644
--- a/cmd/btrfs-clear-bad-nodes/main.go
+++ b/cmd/btrfs-clear-bad-nodes/main.go
@@ -5,7 +5,6 @@ import (
 	"os"
 
 	"lukeshu.com/btrfs-tools/pkg/btrfs"
-	"lukeshu.com/btrfs-tools/pkg/btrfs/btrfsitem"
 	"lukeshu.com/btrfs-tools/pkg/btrfs/btrfsvol"
 	"lukeshu.com/btrfs-tools/pkg/btrfsmisc"
 	"lukeshu.com/btrfs-tools/pkg/util"
@@ -33,6 +32,9 @@ func Main(imgfilenames ...string) (err error) {
 		maybeSetErr(fs.Close())
 	}()
 
+	var uuidsInited bool
+	var metadataUUID, chunkTreeUUID btrfs.UUID
+
 	var treeName string
 	var treeID btrfs.ObjID
 	btrfsmisc.WalkFS(fs, btrfsmisc.WalkFSHandler{
@@ -47,63 +49,32 @@ func Main(imgfilenames ...string) (err error) {
 		TreeWalkHandler: btrfs.TreeWalkHandler{
 			Node: func(path btrfs.TreePath, node *util.Ref[btrfsvol.LogicalAddr, btrfs.Node], err error) error {
 				if node == nil || err == nil {
+					if !uuidsInited {
+						metadataUUID = node.Data.Head.MetadataUUID
+						chunkTreeUUID = node.Data.Head.ChunkTreeUUID
+						uuidsInited = true
+					}
 					return nil
 				}
 				origErr := err
-				if len(path) < 2 {
-					sb, err := fs.Superblock()
-					if err != nil {
-						return err
-					}
-					chunkRoot, err := fs.TreeLookup(sb.Data.RootTree, btrfs.Key{
-						ObjectID: btrfs.CHUNK_TREE_OBJECTID,
-						ItemType: btrfsitem.ROOT_ITEM_KEY,
-						Offset:   0,
-					})
-					if err != nil {
-						return err
-					}
-					chunkRootBody, ok := chunkRoot.Body.(btrfsitem.Root)
-					if !ok {
-						return fmt.Errorf("CHUNK_TREE_OBJECTID ROOT_ITEM has malformed body")
-					}
-					node.Data = btrfs.Node{
-						Size:         node.Data.Size,
-						ChecksumType: node.Data.ChecksumType,
-						Head: btrfs.NodeHeader{
-							//Checksum:   filled below,
-							MetadataUUID:  sb.Data.EffectiveMetadataUUID(),
-							Addr:          node.Addr,
-							Flags:         btrfs.NodeWritten,
-							BackrefRev:    btrfs.MixedBackrefRev,
-							ChunkTreeUUID: chunkRootBody.UUID,
-							Generation:    0,
-							Owner:         treeID,
-							NumItems:      0,
-							Level:         0,
-						},
-					}
-				} else {
-					parentNode, err := fs.ReadNode(path[len(path)-2].NodeAddr)
-					if err != nil {
-						return err
-					}
-					node.Data = btrfs.Node{
-						Size:         node.Data.Size,
-						ChecksumType: node.Data.ChecksumType,
-						Head: btrfs.NodeHeader{
-							//Checksum:   filled below,
-							MetadataUUID:  parentNode.Data.Head.MetadataUUID,
-							Addr:          node.Addr,
-							Flags:         btrfs.NodeWritten,
-							BackrefRev:    parentNode.Data.Head.BackrefRev,
-							ChunkTreeUUID: parentNode.Data.Head.ChunkTreeUUID,
-							Generation:    0,
-							Owner:         parentNode.Data.Head.Owner,
-							NumItems:      0,
-							Level:         parentNode.Data.Head.Level - 1,
-						},
-					}
+				if !uuidsInited {
+					return fmt.Errorf("cannot repair node@%v: not (yet?) sure what the chunk tree UUID is", node.Addr)
+				}
+				node.Data = btrfs.Node{
+					Size:         node.Data.Size,
+					ChecksumType: node.Data.ChecksumType,
+					Head: btrfs.NodeHeader{
+						//Checksum:   filled below,
+						MetadataUUID:  metadataUUID,
+						Addr:          node.Addr,
+						Flags:         btrfs.NodeWritten,
+						BackrefRev:    btrfs.MixedBackrefRev,
+						ChunkTreeUUID: chunkTreeUUID,
+						Generation:    0,
+						Owner:         treeID,
+						NumItems:      0,
+						Level:         path[len(path)-1].NodeLevel,
+					},
 				}
 				node.Data.Head.Checksum, err = node.Data.CalculateChecksum()
 				if err != nil {