lib: feat: ScanOneDevice: Subsume ScanForNotes, checksum as we go, look for csum items

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2 files changed, 114 insertions, 114 deletions

diff --git a/lib/btrfsprogs/btrfsinspect/scan.go b/lib/btrfsprogs/btrfsinspect/scan.go
deleted file mode 100644
index ef1079f..0000000
--- a/lib/btrfsprogs/btrfsinspect/scan.go
+++ /dev/null
@@ -1,57 +0,0 @@
-// 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
-}
diff --git a/lib/btrfsprogs/btrfsinspect/scandevices.go b/lib/btrfsprogs/btrfsinspect/scandevices.go
index 8094ab0..c590d81 100644
--- a/lib/btrfsprogs/btrfsinspect/scandevices.go
+++ b/lib/btrfsprogs/btrfsinspect/scandevices.go
@@ -6,20 +6,25 @@ package btrfsinspect
 
 import (
 	"context"
+	"errors"
+	"fmt"
 
 	"github.com/datawire/dlib/dlog"
 
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsitem"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol"
-	"git.lukeshu.com/btrfs-progs-ng/lib/diskio"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfsprogs/btrfsutil"
+	"git.lukeshu.com/btrfs-progs-ng/lib/slices"
 )
 
 type ScanOneDeviceResult struct {
+	Checksums        SumRun[btrfsvol.PhysicalAddr]
 	FoundNodes       map[btrfsvol.LogicalAddr][]btrfsvol.PhysicalAddr
 	FoundChunks      []btrfs.SysChunk
 	FoundBlockGroups []SysBlockGroup
 	FoundDevExtents  []SysDevExtent
+	FoundExtentCSums []SysExtentCSum
 }
 
 type SysBlockGroup struct {
@@ -32,77 +37,129 @@ type SysDevExtent struct {
 	DevExt btrfsitem.DevExtent
 }
 
+type SysExtentCSum struct {
+	Key  btrfs.Key
+	Sums btrfsitem.ExtentCSum
+}
+
 // ScanOneDevice mostly mimics btrfs-progs
 // cmds/rescue-chunk-recover.c:scan_one_device().
-func ScanOneDevice(ctx context.Context, dev *btrfs.Device, superblock btrfs.Superblock) (ScanOneDeviceResult, error) {
+func ScanOneDevice(ctx context.Context, dev *btrfs.Device, sb btrfs.Superblock) (ScanOneDeviceResult, error) {
 	result := ScanOneDeviceResult{
 		FoundNodes: make(map[btrfsvol.LogicalAddr][]btrfsvol.PhysicalAddr),
 	}
 
 	devSize := dev.Size()
-	lastProgress := -1
+	if sb.NodeSize < sb.SectorSize {
+		return result, fmt.Errorf("node_size(%v) < sector_size(%v)",
+			sb.NodeSize, sb.SectorSize)
+	}
+	if sb.SectorSize != btrfsitem.CSumBlockSize {
+		// TODO: probably handle this?
+		return result, fmt.Errorf("sector_size(%v) != btrfsitem.CSumBlockSize",
+			sb.SectorSize)
+	}
+	alg := sb.ChecksumType
+	csumSize := alg.Size()
+	numSums := int(devSize / btrfsitem.CSumBlockSize)
+	sums := make([]byte, numSums*csumSize)
 
-	err := ScanForNodes(ctx, dev, superblock, func(nodeRef *diskio.Ref[btrfsvol.PhysicalAddr, btrfs.Node], err error) {
-		if err != nil {
-			dlog.Infof(ctx, "... dev[%q] error: %v", dev.Name(), err)
-			return
-		}
-		result.FoundNodes[nodeRef.Data.Head.Addr] = append(result.FoundNodes[nodeRef.Data.Head.Addr], nodeRef.Addr)
-		for i, item := range nodeRef.Data.BodyLeaf {
-			switch item.Key.ItemType {
-			case btrfsitem.CHUNK_ITEM_KEY:
-				chunk, ok := item.Body.(btrfsitem.Chunk)
-				if !ok {
-					dlog.Errorf(ctx, "... dev[%q] node@%v: item %v: error: type is CHUNK_ITEM_KEY, but struct is %T",
-						dev.Name(), nodeRef.Addr, i, item.Body)
-					continue
-				}
-				//dlog.Tracef(ctx, "... dev[%q] node@%v: item %v: found chunk",
-				//	dev.Name(), nodeRef.Addr, i)
-				result.FoundChunks = append(result.FoundChunks, btrfs.SysChunk{
-					Key:   item.Key,
-					Chunk: chunk,
-				})
-			case btrfsitem.BLOCK_GROUP_ITEM_KEY:
-				bg, ok := item.Body.(btrfsitem.BlockGroup)
-				if !ok {
-					dlog.Errorf(ctx, "... dev[%q] node@%v: item %v: error: type is BLOCK_GROUP_ITEM_KEY, but struct is %T",
-						dev.Name(), nodeRef.Addr, i, item.Body)
-					continue
-				}
-				//dlog.Tracef(ctx, "... dev[%q] node@%v: item %v: found block group",
-				//	dev.Name(), nodeRef.Addr, i)
-				result.FoundBlockGroups = append(result.FoundBlockGroups, SysBlockGroup{
-					Key: item.Key,
-					BG:  bg,
-				})
-			case btrfsitem.DEV_EXTENT_KEY:
-				devext, ok := item.Body.(btrfsitem.DevExtent)
-				if !ok {
-					dlog.Errorf(ctx, "... dev[%q] node@%v: item %v: error: type is DEV_EXTENT_KEY, but struct is %T",
-						dev.Name(), nodeRef.Addr, i, item.Body)
-					continue
-				}
-				//dlog.Tracef(ctx, "... dev[%q] node@%v: item %v: found dev extent",
-				//	dev.Name(), nodeRef.Addr, i)
-				result.FoundDevExtents = append(result.FoundDevExtents, SysDevExtent{
-					Key:    item.Key,
-					DevExt: devext,
-				})
-			}
-		}
-	}, func(pos btrfsvol.PhysicalAddr) {
+	lastProgress := -1
+	progress := func(pos btrfsvol.PhysicalAddr) {
 		pct := int(100 * float64(pos) / float64(devSize))
 		if pct != lastProgress || pos == devSize {
-			dlog.Infof(ctx, "... dev[%q] scanned %v%% (found: %v nodes, %v chunks, %v block groups, %v dev extents)",
+			dlog.Infof(ctx, "... dev[%q] scanned %v%% (found: %v nodes, %v chunks, %v block groups, %v dev extents, %v sum items)",
 				dev.Name(), pct,
 				len(result.FoundNodes),
 				len(result.FoundChunks),
 				len(result.FoundBlockGroups),
-				len(result.FoundDevExtents))
+				len(result.FoundDevExtents),
+				len(result.FoundExtentCSums))
 			lastProgress = pct
 		}
-	})
+	}
+
+	for i := 0; i < numSums; i++ {
+		if ctx.Err() != nil {
+			return result, ctx.Err()
+		}
+		pos := btrfsvol.PhysicalAddr(i * btrfsitem.CSumBlockSize)
+		progress(pos)
+
+		sum, err := btrfsutil.ChecksumPhysical(dev, alg, pos)
+		if err != nil {
+			return result, err
+		}
+		copy(sums[i*csumSize:], sum[:csumSize])
+
+		if !slices.Contains(pos, btrfs.SuperblockAddrs) {
+			nodeRef, err := btrfs.ReadNode[btrfsvol.PhysicalAddr](dev, sb, pos, nil)
+			if err != nil {
+				if !errors.Is(err, btrfs.ErrNotANode) {
+					dlog.Infof(ctx, "... dev[%q] error: %v", dev.Name(), err)
+				}
+			} else {
+				result.FoundNodes[nodeRef.Data.Head.Addr] = append(result.FoundNodes[nodeRef.Data.Head.Addr], nodeRef.Addr)
+				for i, item := range nodeRef.Data.BodyLeaf {
+					switch item.Key.ItemType {
+					case btrfsitem.CHUNK_ITEM_KEY:
+						chunk, ok := item.Body.(btrfsitem.Chunk)
+						if !ok {
+							dlog.Errorf(ctx, "... dev[%q] node@%v: item %v: error: type is CHUNK_ITEM_KEY, but struct is %T",
+								dev.Name(), nodeRef.Addr, i, item.Body)
+							continue
+						}
+						//dlog.Tracef(ctx, "... dev[%q] node@%v: item %v: found chunk",
+						//	dev.Name(), nodeRef.Addr, i)
+						result.FoundChunks = append(result.FoundChunks, btrfs.SysChunk{
+							Key:   item.Key,
+							Chunk: chunk,
+						})
+					case btrfsitem.BLOCK_GROUP_ITEM_KEY:
+						bg, ok := item.Body.(btrfsitem.BlockGroup)
+						if !ok {
+							dlog.Errorf(ctx, "... dev[%q] node@%v: item %v: error: type is BLOCK_GROUP_ITEM_KEY, but struct is %T",
+								dev.Name(), nodeRef.Addr, i, item.Body)
+							continue
+						}
+						//dlog.Tracef(ctx, "... dev[%q] node@%v: item %v: found block group",
+						//	dev.Name(), nodeRef.Addr, i)
+						result.FoundBlockGroups = append(result.FoundBlockGroups, SysBlockGroup{
+							Key: item.Key,
+							BG:  bg,
+						})
+					case btrfsitem.DEV_EXTENT_KEY:
+						devext, ok := item.Body.(btrfsitem.DevExtent)
+						if !ok {
+							dlog.Errorf(ctx, "... dev[%q] node@%v: item %v: error: type is DEV_EXTENT_KEY, but struct is %T",
+								dev.Name(), nodeRef.Addr, i, item.Body)
+							continue
+						}
+						//dlog.Tracef(ctx, "... dev[%q] node@%v: item %v: found dev extent",
+						//	dev.Name(), nodeRef.Addr, i)
+						result.FoundDevExtents = append(result.FoundDevExtents, SysDevExtent{
+							Key:    item.Key,
+							DevExt: devext,
+						})
+					case btrfsitem.EXTENT_CSUM_KEY:
+						sums, ok := item.Body.(btrfsitem.ExtentCSum)
+						if !ok {
+							dlog.Errorf(ctx, "... dev[%q] node@%v: item %v: error: type is EXTENT_CSUM_OBJECTID, but struct is %T",
+								dev.Name(), nodeRef.Addr, i, item.Body)
+							continue
+						}
+						//dlog.Tracef(ctx, "... dev[%q] node@%v: item %v: found csums",
+						//	dev.Name(), nodeRef.Addr, i)
+						result.FoundExtentCSums = append(result.FoundExtentCSums, SysExtentCSum{
+							Key:  item.Key,
+							Sums: sums,
+						})
+					}
+				}
+			}
+		}
+	}
+	progress(devSize)
 
-	return result, err
+	return result, nil
 }