From 7151acadd5efd7e2ad18b07f9e51cf4e203b9c8b Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Mon, 6 Jun 2022 21:24:23 -0600
Subject: better node reading/writing

---
 pkg/btrfsmisc/fsck.go | 49 ++++---------------------------------------------
 1 file changed, 4 insertions(+), 45 deletions(-)

(limited to 'pkg/btrfsmisc')

diff --git a/pkg/btrfsmisc/fsck.go b/pkg/btrfsmisc/fsck.go
index 28b93ba..1334900 100644
--- a/pkg/btrfsmisc/fsck.go
+++ b/pkg/btrfsmisc/fsck.go
@@ -1,9 +1,9 @@
 package btrfsmisc
 
 import (
+	"errors"
 	"fmt"
 
-	"lukeshu.com/btrfs-tools/pkg/binstruct"
 	"lukeshu.com/btrfs-tools/pkg/btrfs"
 	"lukeshu.com/btrfs-tools/pkg/util"
 )
@@ -22,7 +22,6 @@ func ScanForNodes(dev *btrfs.Device, sb btrfs.Superblock, fn func(*util.Ref[btrf
 			sb.NodeSize, sb.SectorSize)
 	}
 
-	nodeBuf := make([]byte, sb.NodeSize)
 	for pos := btrfs.PhysicalAddr(0); pos+btrfs.PhysicalAddr(sb.NodeSize) < devSize; pos += btrfs.PhysicalAddr(sb.SectorSize) {
 		if util.InSlice(pos, btrfs.SuperblockAddrs) {
 			//fmt.Printf("sector@%d is a superblock\n", pos)
@@ -33,51 +32,11 @@ func ScanForNodes(dev *btrfs.Device, sb btrfs.Superblock, fn func(*util.Ref[btrf
 			prog(pos)
 		}
 
-		// read
-
-		if _, err := dev.ReadAt(nodeBuf, pos); err != nil {
-			fn(nil, fmt.Errorf("sector@%d: %w", pos, err))
-			continue
-		}
-
-		// parse (early)
-
-		nodeRef := &util.Ref[btrfs.PhysicalAddr, btrfs.Node]{
-			File: dev,
-			Addr: pos,
-			Data: btrfs.Node{
-				Size: sb.NodeSize,
-			},
-		}
-		if _, err := binstruct.Unmarshal(nodeBuf, &nodeRef.Data.Head); err != nil {
-			fn(nil, fmt.Errorf("sector@%d: %w", pos, err))
-		}
-
-		// sanity checking
-
-		if nodeRef.Data.Head.MetadataUUID != sb.EffectiveMetadataUUID() {
-			//fmt.Printf("sector@%d does not look like a node\n", pos)
+		nodeRef, err := btrfs.ReadNode[btrfs.PhysicalAddr](dev, sb, pos, nil)
+		if err != nil && errors.Is(err, btrfs.ErrNotANode) {
 			continue
 		}
-
-		stored := nodeRef.Data.Head.Checksum
-		calced := btrfs.CRC32c(nodeBuf[binstruct.StaticSize(btrfs.CSum{}):])
-		if stored != calced {
-			fn(nodeRef, fmt.Errorf("sector@%d: looks like a node but is corrupt: checksum doesn't match: stored=%s calculated=%s",
-				pos, stored, calced))
-			continue
-		}
-
-		// parse (main)
-
-		if _, err := nodeRef.Data.UnmarshalBinary(nodeBuf); err != nil {
-			fn(nil, fmt.Errorf("sector@%d: %w", pos, err))
-			continue
-		}
-
-		// finally, process the node
-
-		fn(nodeRef, nil)
+		fn(nodeRef, err)
 
 		pos += btrfs.PhysicalAddr(sb.NodeSize) - btrfs.PhysicalAddr(sb.SectorSize)
 	}
-- 
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