factor out a btrfsmisc pacage

4 files changed, 9 insertions, 88 deletions

diff --git a/pkg/btrfs/fsck.go b/pkg/btrfs/fsck.go
deleted file mode 100644
index 33ccd44..0000000
--- a/pkg/btrfs/fsck.go
+++ /dev/null
@@ -1,52 +0,0 @@
-package btrfs
-
-import (
-	"fmt"
-
-	"lukeshu.com/btrfs-tools/pkg/binstruct"
-)
-
-// ScanForNodes mimics btrfs-progs
-// cmds/rescue-chunk-recover.c:scan_one_device(), except it doesn't do
-// anything but log when it finds a node.
-func ScanForNodes(dev *Device, sb Superblock) error {
-	devSize, err := dev.Size()
-	if err != nil {
-		return err
-	}
-
-	if sb.NodeSize < sb.SectorSize {
-		return fmt.Errorf("node_size(%d) < sector_size(%d)",
-			sb.NodeSize, sb.SectorSize)
-	}
-
-	nodeBuf := make([]byte, sb.NodeSize)
-	for pos := PhysicalAddr(0); pos+PhysicalAddr(sb.SectorSize) < devSize; pos += PhysicalAddr(sb.SectorSize) {
-		if inSlice(pos, superblockAddrs) {
-			fmt.Printf("sector@%d is a superblock\n", pos)
-			continue
-		}
-		if _, err := dev.ReadAt(nodeBuf, pos); err != nil {
-			return fmt.Errorf("sector@%d: %w", pos, err)
-		}
-		var nodeHeader NodeHeader
-		if _, err := binstruct.Unmarshal(nodeBuf, &nodeHeader); err != nil {
-			return fmt.Errorf("sector@%d: %w", pos, err)
-		}
-		if !nodeHeader.MetadataUUID.Equal(sb.EffectiveMetadataUUID()) {
-			//fmt.Printf("sector@%d does not look like a node\n", pos)
-			continue
-		}
-		if !nodeHeader.Checksum.Equal(CRC32c(nodeBuf[0x20:])) {
-			fmt.Printf("sector@%d looks like a node but is corrupt (checksum doesn't match)\n", pos)
-			continue
-		}
-
-		fmt.Printf("node@%d: physical_addr=0x%0X logical_addr=0x%0X generation=%d owner=%v level=%d\n",
-			pos, pos, nodeHeader.Addr, nodeHeader.Generation, nodeHeader.Owner, nodeHeader.Level)
-
-		pos += PhysicalAddr(sb.NodeSize) - PhysicalAddr(sb.SectorSize)
-	}
-
-	return nil
-}
diff --git a/pkg/btrfs/io1_device.go b/pkg/btrfs/io1_device.go
index efd8cb9..55b7525 100644
--- a/pkg/btrfs/io1_device.go
+++ b/pkg/btrfs/io1_device.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 
+	"lukeshu.com/btrfs-tools/pkg/binstruct"
 	"lukeshu.com/btrfs-tools/pkg/util"
 )
 
@@ -19,7 +20,7 @@ func (dev Device) Size() (PhysicalAddr, error) {
 	return PhysicalAddr(fi.Size()), nil
 }
 
-var superblockAddrs = []PhysicalAddr{
+var SuperblockAddrs = []PhysicalAddr{
 	0x00_0001_0000, // 64KiB
 	0x00_0400_0000, // 64MiB
 	0x40_0000_0000, // 256GiB
@@ -30,7 +31,7 @@ func (dev *Device) ReadAt(dat []byte, paddr PhysicalAddr) (int, error) {
 }
 
 func (dev *Device) Superblocks() ([]util.Ref[PhysicalAddr, Superblock], error) {
-	const superblockSize = 0x1000
+	superblockSize := PhysicalAddr(binstruct.StaticSize(Superblock{}))
 
 	sz, err := dev.Size()
 	if err != nil {
@@ -38,7 +39,7 @@ func (dev *Device) Superblocks() ([]util.Ref[PhysicalAddr, Superblock], error) {
 	}
 
 	var ret []util.Ref[PhysicalAddr, Superblock]
-	for i, addr := range superblockAddrs {
+	for i, addr := range SuperblockAddrs {
 		if addr+superblockSize <= sz {
 			superblock := util.Ref[PhysicalAddr, Superblock]{
 				File: dev,
diff --git a/pkg/btrfs/types_btree.go b/pkg/btrfs/types_btree.go
index d65e599..96b069a 100644
--- a/pkg/btrfs/types_btree.go
+++ b/pkg/btrfs/types_btree.go
@@ -137,18 +137,18 @@ func (node *Node) UnmarshalBinary(nodeBuf []byte) (int, error) {
 			dataOff := binstruct.StaticSize(NodeHeader{}) + int(item.Head.DataOffset)
 			dataSize := int(item.Head.DataSize)
 			if dataOff+dataSize > len(nodeBuf) {
-				return max(n, lastRead), fmt.Errorf("(leaf): item references byte %d, but node only has %d bytes",
+				return util.Max(n, lastRead), fmt.Errorf("(leaf): item references byte %d, but node only has %d bytes",
 					dataOff+dataSize, len(nodeBuf))
 			}
 			dataBuf := nodeBuf[dataOff : dataOff+dataSize]
-			firstRead = min(firstRead, dataOff)
-			lastRead = max(lastRead, dataOff+dataSize)
+			firstRead = util.Min(firstRead, dataOff)
+			lastRead = util.Max(lastRead, dataOff+dataSize)
 			item.Body = btrfsitem.UnmarshalItem(item.Head.Key, dataBuf)
 
 			node.BodyLeaf = append(node.BodyLeaf, item)
 		}
 		node.Padding = nodeBuf[n:firstRead]
-		return max(n, lastRead), nil
+		return util.Max(n, lastRead), nil
 	}
 }
 
@@ -201,7 +201,7 @@ func (node Node) MarshalBinary() ([]byte, error) {
 				return ret, err
 			}
 			dataOff := binstruct.StaticSize(NodeHeader{}) + int(item.Head.DataOffset)
-			minData = min(minData, dataOff)
+			minData = util.Min(minData, dataOff)
 			if copy(ret[dataOff:], dat) < len(dat) {
 				return ret, fmt.Errorf("btrfs.Node.MarshalBinary: need at least %d bytes, but .Size is only %d",
 					dataOff+len(dat), node.Size)
diff --git a/pkg/btrfs/util.go b/pkg/btrfs/util.go
deleted file mode 100644
index 671d6fc..0000000
--- a/pkg/btrfs/util.go
+++ /dev/null
@@ -1,28 +0,0 @@
-package btrfs
-
-import (
-	"golang.org/x/exp/constraints"
-)
-
-func inSlice[T comparable](needle T, haystack []T) bool {
-	for _, straw := range haystack {
-		if needle == straw {
-			return true
-		}
-	}
-	return false
-}
-
-func max[T constraints.Ordered](a, b T) T {
-	if a > b {
-		return a
-	}
-	return b
-}
-
-func min[T constraints.Ordered](a, b T) T {
-	if a < b {
-		return a
-	}
-	return b
-}