1 files changed, 57 insertions, 0 deletions
diff --git a/lib/btrfsprogs/btrfsinspect/scan.go b/lib/btrfsprogs/btrfsinspect/scan.go
new file mode 100644
index 0000000..ef1079f
--- /dev/null
+++ b/lib/btrfsprogs/btrfsinspect/scan.go
@@ -0,0 +1,57 @@
+// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package btrfsinspect
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol"
+	"git.lukeshu.com/btrfs-progs-ng/lib/diskio"
+	"git.lukeshu.com/btrfs-progs-ng/lib/slices"
+)
+
+// ScanForNodes mimics btrfs-progs
+// cmds/rescue-chunk-recover.c:scan_one_device(), except rather than
+// doing something itself when it finds a node, it simply calls a
+// callback function.
+func ScanForNodes(ctx context.Context, dev *btrfs.Device, sb btrfs.Superblock, fn func(*diskio.Ref[btrfsvol.PhysicalAddr, btrfs.Node], error), prog func(btrfsvol.PhysicalAddr)) error {
+	devSize := dev.Size()
+
+	if sb.NodeSize < sb.SectorSize {
+		return fmt.Errorf("node_size(%v) < sector_size(%v)",
+			sb.NodeSize, sb.SectorSize)
+	}
+
+	for pos := btrfsvol.PhysicalAddr(0); pos+btrfsvol.PhysicalAddr(sb.NodeSize) < devSize; pos += btrfsvol.PhysicalAddr(sb.SectorSize) {
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+		if slices.Contains(pos, btrfs.SuperblockAddrs) {
+			//fmt.Printf("sector@%v is a superblock\n", pos)
+			continue
+		}
+
+		if prog != nil {
+			prog(pos)
+		}
+
+		nodeRef, err := btrfs.ReadNode[btrfsvol.PhysicalAddr](dev, sb, pos, nil)
+		if err != nil && errors.Is(err, btrfs.ErrNotANode) {
+			continue
+		}
+		fn(nodeRef, err)
+
+		pos += btrfsvol.PhysicalAddr(sb.NodeSize) - btrfsvol.PhysicalAddr(sb.SectorSize)
+	}
+
+	if prog != nil {
+		prog(devSize)
+	}
+
+	return nil
+}