1 files changed, 66 insertions, 0 deletions
diff --git a/lib/btrfsutil/listnodes.go b/lib/btrfsutil/listnodes.go
new file mode 100644
index 0000000..16300da
--- /dev/null
+++ b/lib/btrfsutil/listnodes.go
@@ -0,0 +1,66 @@
+// Copyright (C) 2023  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package btrfsutil
+
+import (
+	"context"
+
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs"
+	"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/diskio"
+	"git.lukeshu.com/btrfs-progs-ng/lib/maps"
+	"git.lukeshu.com/btrfs-progs-ng/lib/textui"
+)
+
+type nodeScanner struct {
+	nodes containers.Set[btrfsvol.LogicalAddr]
+}
+
+type nodeStats struct {
+	numNodes int
+}
+
+func (s nodeStats) String() string {
+	return textui.Sprintf("found: %d nodes", s.numNodes)
+}
+
+var _ DeviceScanner[nodeStats, containers.Set[btrfsvol.LogicalAddr]] = (*nodeScanner)(nil)
+
+func newNodeScanner(ctx context.Context, sb btrfstree.Superblock, numBytes btrfsvol.PhysicalAddr, numSectors int) DeviceScanner[nodeStats, containers.Set[btrfsvol.LogicalAddr]] {
+	s := new(nodeScanner)
+	s.nodes = make(containers.Set[btrfsvol.LogicalAddr])
+	return s
+}
+
+func (s *nodeScanner) ScanStats() nodeStats {
+	return nodeStats{numNodes: len(s.nodes)}
+}
+
+func (*nodeScanner) ScanSector(ctx context.Context, dev *btrfs.Device, paddr btrfsvol.PhysicalAddr) error {
+	return nil
+}
+
+func (s *nodeScanner) ScanNode(ctx context.Context, nodeRef *diskio.Ref[btrfsvol.PhysicalAddr, btrfstree.Node]) error {
+	s.nodes.Insert(nodeRef.Data.Head.Addr)
+	return nil
+}
+
+func (s *nodeScanner) ScanDone(ctx context.Context) (containers.Set[btrfsvol.LogicalAddr], error) {
+	return s.nodes, nil
+}
+
+func ListNodes(ctx context.Context, fs *btrfs.FS) ([]btrfsvol.LogicalAddr, error) {
+	perDev, err := ScanDevices[nodeStats, containers.Set[btrfsvol.LogicalAddr]](ctx, fs, newNodeScanner)
+	if err != nil {
+		return nil, err
+	}
+	set := make(containers.Set[btrfsvol.LogicalAddr])
+	for _, devSet := range perDev {
+		set.InsertFrom(devSet)
+	}
+	return maps.SortedKeys(set), nil
+}