1 files changed, 137 insertions, 0 deletions
diff --git a/lib/btrfsprogs/btrfsinspect/rebuildnodes/s3_reinit.go b/lib/btrfsprogs/btrfsinspect/rebuildnodes/s3_reinit.go
new file mode 100644
index 0000000..a4b8f0f
--- /dev/null
+++ b/lib/btrfsprogs/btrfsinspect/rebuildnodes/s3_reinit.go
@@ -0,0 +1,137 @@
+// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package rebuildnodes
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+	"sort"
+
+	"github.com/datawire/dlib/dlog"
+
+	"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/containers"
+	"git.lukeshu.com/btrfs-progs-ng/lib/slices"
+)
+
+type RebuiltNode struct {
+	Err            string
+	MinKey, MaxKey btrfsprim.Key
+	InTrees        containers.Set[btrfsprim.ObjID]
+	btrfstree.Node
+}
+
+func (a RebuiltNode) Compat(b RebuiltNode) bool {
+	a.Node.Head.Generation = b.Node.Head.Generation
+	return reflect.DeepEqual(a.Node, b.Node)
+}
+
+func (a RebuiltNode) Merge(b RebuiltNode) (RebuiltNode, error) {
+	if !a.Compat(b) {
+		switch {
+		case a.Node.Head.Generation > b.Node.Head.Generation:
+			return a, nil
+		case a.Node.Head.Generation < b.Node.Head.Generation:
+			return b, nil
+		default:
+			return a, fmt.Errorf("mismatch: %v != %v", a, b)
+		}
+	}
+
+	// take the broadest region
+	if a.MinKey.Cmp(b.MinKey) > 0 { // if a.MinKey > b.MinKey {
+		a.MinKey = b.MinKey // take the min of the two
+	}
+	if a.MaxKey.Cmp(b.MaxKey) < 0 { // if a.MaxKey < b.MaxKey {
+		a.MaxKey = b.MaxKey // take the min of the two
+	}
+
+	// take the highest generation
+	a.Node.Head.Generation = slices.Max(a.Node.Head.Generation, b.Node.Head.Generation)
+
+	// take the union
+	a.InTrees.InsertFrom(b.InTrees)
+
+	return a, nil
+}
+
+func reInitBrokenNodes(ctx context.Context, fs _FS, badNodes []badNode) (map[btrfsvol.LogicalAddr]*RebuiltNode, error) {
+	dlog.Info(ctx, "Re-initializing bad nodes...")
+
+	sb, err := fs.Superblock()
+	if err != nil {
+		return nil, err
+	}
+	chunkTreeUUID, ok := getChunkTreeUUID(ctx, fs)
+	if !ok {
+		return nil, fmt.Errorf("could not look up chunk tree UUID")
+	}
+
+	sort.Slice(badNodes, func(i, j int) bool {
+		iGen := badNodes[i].Path.Node(-1).FromGeneration
+		jGen := badNodes[j].Path.Node(-1).FromGeneration
+		switch {
+		case iGen < jGen:
+			return true
+		case iGen > jGen:
+			return false
+		default:
+			iAddr := badNodes[i].Path.Node(-1).ToNodeAddr
+			jAddr := badNodes[j].Path.Node(-1).ToNodeAddr
+			return iAddr < jAddr
+		}
+	})
+
+	lastPct := -1
+	progress := func(done int) {
+		pct := int(100 * float64(done) / float64(len(badNodes)))
+		if pct != lastPct || done == len(badNodes) {
+			dlog.Infof(ctx, "... %v%% (%v/%v)",
+				pct, done, len(badNodes))
+			lastPct = pct
+		}
+	}
+
+	rebuiltNodes := make(map[btrfsvol.LogicalAddr]*RebuiltNode)
+	for i, badNode := range badNodes {
+		progress(i)
+		path := badNode.Path
+
+		min, max := spanOfTreePath(fs, path)
+		node := RebuiltNode{
+			Err:     err.Error(),
+			MinKey:  min,
+			MaxKey:  max,
+			InTrees: containers.Set[btrfsprim.ObjID]{path.Node(-1).FromTree: struct{}{}},
+			Node: btrfstree.Node{
+				Size:         sb.NodeSize,
+				ChecksumType: sb.ChecksumType,
+				Head: btrfstree.NodeHeader{
+					MetadataUUID:  sb.EffectiveMetadataUUID(),
+					Addr:          path.Node(-1).ToNodeAddr,
+					ChunkTreeUUID: chunkTreeUUID,
+					//Owner:      TBD, // see RebuiltNode.InTrees
+					Generation: path.Node(-1).FromGeneration,
+					Level:      path.Node(-1).ToNodeLevel,
+				},
+			},
+		}
+		if other, ok := rebuiltNodes[path.Node(-1).ToNodeAddr]; ok {
+			*other, err = other.Merge(node)
+			if err != nil {
+				dlog.Errorf(ctx, "... %v", err)
+			}
+		} else {
+			rebuiltNodes[path.Node(-1).ToNodeAddr] = &node
+		}
+	}
+	progress(len(badNodes))
+
+	dlog.Infof(ctx, "... initialized %d nodes", len(rebuiltNodes))
+	return rebuiltNodes, nil
+}