fix

6 files changed, 128 insertions, 107 deletions

diff --git a/pkg/binstruct/structs.go b/pkg/binstruct/structs.go
index 7a0c74b..8ecea6a 100644
--- a/pkg/binstruct/structs.go
+++ b/pkg/binstruct/structs.go
@@ -113,6 +113,12 @@ func genStructHandler(structInfo reflect.Type) (structHandler, error) {
 	for i := 0; i < structInfo.NumField(); i++ {
 		var fieldInfo reflect.StructField = structInfo.Field(i)
 
+		if fieldInfo.Anonymous && fieldInfo.Type != endType {
+			err := fmt.Errorf("binstruct does not support embedded fields")
+			return ret, fmt.Errorf("struct %q field %d %q: %w",
+				ret.name, i, fieldInfo.Name, err)
+		}
+
 		fieldTag, err := parseStructTag(fieldInfo.Tag.Get("bin"))
 		if err != nil {
 			return ret, fmt.Errorf("struct %q field %d %q: %w",
diff --git a/pkg/btrfs/btrfsitem/item_chunk.go b/pkg/btrfs/btrfsitem/item_chunk.go
index 5c573b0..7bb65b1 100644
--- a/pkg/btrfs/btrfsitem/item_chunk.go
+++ b/pkg/btrfs/btrfsitem/item_chunk.go
@@ -1,6 +1,8 @@
 package btrfsitem
 
 import (
+	"fmt"
+
 	"lukeshu.com/btrfs-tools/pkg/binstruct"
 	"lukeshu.com/btrfs-tools/pkg/btrfs/internal"
 )
@@ -21,11 +23,10 @@ type Chunk struct { // CHUNK_ITEM=228
 }
 
 type ChunkStripe struct {
-	// Stripes follow (for each number of stripes):
-	DeviceID      internal.ObjID `bin:"off=0,  siz=8"`  // device ID
-	Offset        uint64         `bin:"off=8,  siz=8"`  // offset
-	DeviceUUID    internal.UUID  `bin:"off=10, siz=10"` // device UUID
-	binstruct.End `bin:"off=20"`
+	DeviceID      internal.ObjID `bin:"off=0x0,  siz=0x8"`
+	Offset        uint64         `bin:"off=0x8,  siz=0x8"`
+	DeviceUUID    internal.UUID  `bin:"off=0x10, siz=0x10"`
+	binstruct.End `bin:"off=0x20"`
 }
 
 func (chunk *Chunk) UnmarshalBinary(dat []byte) (int, error) {
diff --git a/pkg/btrfs/internal/misc.go b/pkg/btrfs/internal/misc.go
index e7d9dd6..de8120a 100644
--- a/pkg/btrfs/internal/misc.go
+++ b/pkg/btrfs/internal/misc.go
@@ -13,16 +13,16 @@ type (
 )
 
 type Key struct {
-	ObjectID      ObjID    `bin:"off=0, siz=8"` // Each tree has its own set of Object IDs.
-	ItemType      ItemType `bin:"off=8, siz=1"`
-	Offset        uint64   `bin:"off=9, siz=8"` // The meaning depends on the item type.
-	binstruct.End `bin:"off=11"`
+	ObjectID      ObjID    `bin:"off=0x0, siz=0x8"` // Each tree has its own set of Object IDs.
+	ItemType      ItemType `bin:"off=0x8, siz=0x1"`
+	Offset        uint64   `bin:"off=0x9, siz=0x8"` // The meaning depends on the item type.
+	binstruct.End `bin:"off=0x11"`
 }
 
 type Time struct {
-	Sec           int64  `bin:"off=0, siz=8"` // Number of seconds since 1970-01-01T00:00:00Z.
-	NSec          uint32 `bin:"off=8, siz=4"` // Number of nanoseconds since the beginning of the second.
-	binstruct.End `bin:"off=c"`
+	Sec           int64  `bin:"off=0x0, siz=0x8"` // Number of seconds since 1970-01-01T00:00:00Z.
+	NSec          uint32 `bin:"off=0x8, siz=0x4"` // Number of nanoseconds since the beginning of the second.
+	binstruct.End `bin:"off=0xc"`
 }
 
 func (t Time) ToStd() time.Time {
diff --git a/pkg/btrfs/io2_fs.go b/pkg/btrfs/io2_fs.go
index bf19d4b..bcf9777 100644
--- a/pkg/btrfs/io2_fs.go
+++ b/pkg/btrfs/io2_fs.go
@@ -164,8 +164,8 @@ func (fs *FS) maybeShortReadAt(dat []byte, laddr LogicalAddr) (int, error) {
 	paddrs := make(map[physicalAddr]struct{})
 
 	for _, chunk := range fs.chunks {
-		if chunk.Offset <= uint64(laddr) && uint64(laddr) < chunk.Offset+uint64(chunk.Chunk.Size) {
-			offsetWithinChunk := uint64(laddr) - chunk.Offset
+		if chunk.Key.Offset <= uint64(laddr) && uint64(laddr) < chunk.Key.Offset+uint64(chunk.Chunk.Size) {
+			offsetWithinChunk := uint64(laddr) - chunk.Key.Offset
 			if offsetWithinChunk+uint64(len(dat)) > chunk.Chunk.Size {
 				dat = dat[:chunk.Chunk.Size-offsetWithinChunk]
 			}
diff --git a/pkg/btrfs/types_btree.go b/pkg/btrfs/types_btree.go
index b8ad14b..8e25eb4 100644
--- a/pkg/btrfs/types_btree.go
+++ b/pkg/btrfs/types_btree.go
@@ -72,17 +72,17 @@ func (f NodeFlags) Has(req NodeFlags) bool { return f&req == req }
 func (f NodeFlags) String() string         { return util.BitfieldString(f, nodeFlagNames) }
 
 type KeyPointer struct {
-	Key           Key         `bin:"off=0, siz=11"`
-	BlockPtr      LogicalAddr `bin:"off=11, siz=8"`
-	Generation    Generation  `bin:"off=19, siz=8"`
-	binstruct.End `bin:"off=21"`
+	Key           Key         `bin:"off=0x0, siz=0x11"`
+	BlockPtr      LogicalAddr `bin:"off=0x11, siz=0x8"`
+	Generation    Generation  `bin:"off=0x19, siz=0x8"`
+	binstruct.End `bin:"off=0x21"`
 }
 
 type ItemHeader struct {
-	Key           Key    `bin:"off=0, siz=11"`
-	DataOffset    uint32 `bin:"off=11, siz=4"` // relative to the end of the header (0x65)
-	DataSize      uint32 `bin:"off=15, siz=4"`
-	binstruct.End `bin:"off=19"`
+	Key           Key    `bin:"off=0x0, siz=0x11"`
+	DataOffset    uint32 `bin:"off=0x11, siz=0x4"` // relative to the end of the header (0x65)
+	DataSize      uint32 `bin:"off=0x15, siz=0x4"`
+	binstruct.End `bin:"off=0x19"`
 }
 
 type Item struct {
diff --git a/pkg/btrfs/types_superblock.go b/pkg/btrfs/types_superblock.go
index 47dd3b0..a8db86c 100644
--- a/pkg/btrfs/types_superblock.go
+++ b/pkg/btrfs/types_superblock.go
@@ -10,63 +10,63 @@ import (
 )
 
 type Superblock struct {
-	Checksum   CSum         `bin:"off=0,  siz=20"` // Checksum of everything past this field (from 20 to 1000)
-	FSUUID     UUID         `bin:"off=20, siz=10"` // FS UUID
-	Self       PhysicalAddr `bin:"off=30, siz=8"`  // physical address of this block (different for mirrors)
-	Flags      uint64       `bin:"off=38, siz=8"`  // flags
-	Magic      [8]byte      `bin:"off=40, siz=8"`  // magic ('_BHRfS_M')
-	Generation Generation   `bin:"off=48, siz=8"`
-
-	RootTree  LogicalAddr `bin:"off=50, siz=8"` // logical address of the root tree root
-	ChunkTree LogicalAddr `bin:"off=58, siz=8"` // logical address of the chunk tree root
-	LogTree   LogicalAddr `bin:"off=60, siz=8"` // logical address of the log tree root
-
-	LogRootTransID  uint64 `bin:"off=68, siz=8"` // log_root_transid
-	TotalBytes      uint64 `bin:"off=70, siz=8"` // total_bytes
-	BytesUsed       uint64 `bin:"off=78, siz=8"` // bytes_used
-	RootDirObjectID ObjID  `bin:"off=80, siz=8"` // root_dir_objectid (usually 6)
-	NumDevices      uint64 `bin:"off=88, siz=8"` // num_devices
-
-	SectorSize        uint32 `bin:"off=90, siz=4"`
-	NodeSize          uint32 `bin:"off=94, siz=4"`
-	LeafSize          uint32 `bin:"off=98, siz=4"` // unused; must be the same as NodeSize
-	StripeSize        uint32 `bin:"off=9c, siz=4"`
-	SysChunkArraySize uint32 `bin:"off=a0, siz=4"`
-
-	ChunkRootGeneration Generation    `bin:"off=a4, siz=8"`
-	CompatFlags         uint64        `bin:"off=ac, siz=8"` // compat_flags
-	CompatROFlags       uint64        `bin:"off=b4, siz=8"` // compat_ro_flags - only implementations that support the flags can write to the filesystem
-	IncompatFlags       IncompatFlags `bin:"off=bc, siz=8"` // incompat_flags - only implementations that support the flags can use the filesystem
-	ChecksumType        uint16        `bin:"off=c4, siz=2"` // csum_type - Btrfs currently uses the CRC32c little-endian hash function with seed -1.
-
-	RootLevel  uint8 `bin:"off=c6, siz=1"` // root_level
-	ChunkLevel uint8 `bin:"off=c7, siz=1"` // chunk_root_level
-	LogLevel   uint8 `bin:"off=c8, siz=1"` // log_root_level
-
-	DevItem            btrfsitem.Dev `bin:"off=c9,  siz=62"`  // DEV_ITEM data for this device
-	Label              [0x100]byte   `bin:"off=12b, siz=100"` // label (may not contain '/' or '\\')
-	CacheGeneration    Generation    `bin:"off=22b, siz=8"`
-	UUIDTreeGeneration uint64        `bin:"off=233, siz=8"` // uuid_tree_generation
+	Checksum   CSum         `bin:"off=0x0,  siz=0x20"` // Checksum of everything past this field (from 20 to 1000)
+	FSUUID     UUID         `bin:"off=0x20, siz=0x10"` // FS UUID
+	Self       PhysicalAddr `bin:"off=0x30, siz=0x8"`  // physical address of this block (different for mirrors)
+	Flags      uint64       `bin:"off=0x38, siz=0x8"`  // flags
+	Magic      [8]byte      `bin:"off=0x40, siz=0x8"`  // magic ('_BHRfS_M')
+	Generation Generation   `bin:"off=0x48, siz=0x8"`
+
+	RootTree  LogicalAddr `bin:"off=0x50, siz=0x8"` // logical address of the root tree root
+	ChunkTree LogicalAddr `bin:"off=0x58, siz=0x8"` // logical address of the chunk tree root
+	LogTree   LogicalAddr `bin:"off=0x60, siz=0x8"` // logical address of the log tree root
+
+	LogRootTransID  uint64 `bin:"off=0x68, siz=0x8"` // log_root_transid
+	TotalBytes      uint64 `bin:"off=0x70, siz=0x8"` // total_bytes
+	BytesUsed       uint64 `bin:"off=0x78, siz=0x8"` // bytes_used
+	RootDirObjectID ObjID  `bin:"off=0x80, siz=0x8"` // root_dir_objectid (usually 6)
+	NumDevices      uint64 `bin:"off=0x88, siz=0x8"` // num_devices
+
+	SectorSize        uint32 `bin:"off=0x90, siz=0x4"`
+	NodeSize          uint32 `bin:"off=0x94, siz=0x4"`
+	LeafSize          uint32 `bin:"off=0x98, siz=0x4"` // unused; must be the same as NodeSize
+	StripeSize        uint32 `bin:"off=0x9c, siz=0x4"`
+	SysChunkArraySize uint32 `bin:"off=0xa0, siz=0x4"`
+
+	ChunkRootGeneration Generation    `bin:"off=0xa4, siz=0x8"`
+	CompatFlags         uint64        `bin:"off=0xac, siz=0x8"` // compat_flags
+	CompatROFlags       uint64        `bin:"off=0xb4, siz=0x8"` // compat_ro_flags - only implementations that support the flags can write to the filesystem
+	IncompatFlags       IncompatFlags `bin:"off=0xbc, siz=0x8"` // incompat_flags - only implementations that support the flags can use the filesystem
+	ChecksumType        uint16        `bin:"off=0xc4, siz=0x2"` // csum_type - Btrfs currently uses the CRC32c little-endian hash function with seed -1.
+
+	RootLevel  uint8 `bin:"off=0xc6, siz=0x1"` // root_level
+	ChunkLevel uint8 `bin:"off=0xc7, siz=0x1"` // chunk_root_level
+	LogLevel   uint8 `bin:"off=0xc8, siz=0x1"` // log_root_level
+
+	DevItem            btrfsitem.Dev `bin:"off=0xc9,  siz=0x62"`  // DEV_ITEM data for this device
+	Label              [0x100]byte   `bin:"off=0x12b, siz=0x100"` // label (may not contain '/' or '\\')
+	CacheGeneration    Generation    `bin:"off=0x22b, siz=0x8"`
+	UUIDTreeGeneration uint64        `bin:"off=0x233, siz=0x8"` // uuid_tree_generation
 
 	// FeatureIncompatMetadataUUID
-	MetadataUUID UUID `bin:"off=23b, siz=10"`
+	MetadataUUID UUID `bin:"off=0x23b, siz=0x10"`
 
 	// FeatureIncompatExtentTreeV2
-	NumGlobalRoots uint64 `bin:"off=24b, siz=8"`
+	NumGlobalRoots uint64 `bin:"off=0x24b, siz=0x8"`
 
 	// FeatureIncompatExtentTreeV2
-	BlockGroupRoot           LogicalAddr `bin:"off=253, siz=8"`
-	BlockGroupRootGeneration Generation  `bin:"off=25b, siz=8"`
-	BlockGroupRootLevel      uint8       `bin:"off=263, siz=1"`
+	BlockGroupRoot           LogicalAddr `bin:"off=0x253, siz=0x8"`
+	BlockGroupRootGeneration Generation  `bin:"off=0x25b, siz=0x8"`
+	BlockGroupRootLevel      uint8       `bin:"off=0x263, siz=0x1"`
 
-	Reserved [199]byte `bin:"off=264, siz=c7"` // future expansion
+	Reserved [199]byte `bin:"off=0x264, siz=0xc7"` // future expansion
 
-	SysChunkArray [0x800]byte   `bin:"off=32b, siz=800"` // sys_chunk_array:(n bytes valid) Contains (KEY . CHUNK_ITEM) pairs for all SYSTEM chunks. This is needed to bootstrap the mapping from logical addresses to physical.
-	SuperRoots    [4]RootBackup `bin:"off=b2b, siz=2a0"`
+	SysChunkArray [0x800]byte   `bin:"off=0x32b, siz=0x800"` // sys_chunk_array:(n bytes valid) Contains (KEY . CHUNK_ITEM) pairs for all SYSTEM chunks. This is needed to bootstrap the mapping from logical addresses to physical.
+	SuperRoots    [4]RootBackup `bin:"off=0xb2b, siz=0x2a0"`
 
 	// Padded to 4096 bytes
-	Padding       [565]byte `bin:"off=dcb, siz=235"`
-	binstruct.End `bin:"off=1000"`
+	Padding       [565]byte `bin:"off=0xdcb, siz=0x235"`
+	binstruct.End `bin:"off=0x1000"`
 }
 
 func (sb Superblock) CalculateChecksum() (CSum, error) {
@@ -108,9 +108,34 @@ func (sb Superblock) EffectiveMetadataUUID() UUID {
 }
 
 type SysChunk struct {
-	Key             `bin:"off=0, siz=11"`
-	btrfsitem.Chunk `bin:"off=11, siz=30"`
-	binstruct.End   `bin:"off=41"`
+	Key   Key
+	Chunk btrfsitem.Chunk
+}
+
+func (sc SysChunk) MarshalBinary() ([]byte, error) {
+	dat, err := binstruct.Marshal(sc.Key)
+	if err != nil {
+		return dat, fmt.Errorf("%T.MarshalBinary: %w", sc, err)
+	}
+	_dat, err := binstruct.Marshal(sc.Chunk)
+	dat = append(dat, _dat...)
+	if err != nil {
+		return dat, fmt.Errorf("%T.MarshalBinary: %w", sc, err)
+	}
+	return dat, nil
+}
+
+func (sc *SysChunk) UnmarshalBinary(dat []byte) (int, error) {
+	n, err := binstruct.Unmarshal(dat, &sc.Key)
+	if err != nil {
+		return n, fmt.Errorf("%T.UnmarshalBinary: %w", *sc, err)
+	}
+	_n, err := binstruct.Unmarshal(dat[n:], &sc.Chunk)
+	n += _n
+	if err != nil {
+		return n, fmt.Errorf("%T.UnmarshalBinary: %w", *sc, err)
+	}
+	return n, nil
 }
 
 func (sb Superblock) ParseSysChunkArray() ([]SysChunk, error) {
@@ -123,56 +148,45 @@ func (sb Superblock) ParseSysChunkArray() ([]SysChunk, error) {
 		if err != nil {
 			return nil, err
 		}
-
-		for i := 0; i < int(pair.Chunk.NumStripes); i++ {
-			var stripe btrfsitem.ChunkStripe
-			n, err := binstruct.Unmarshal(dat, &stripe)
-			dat = dat[n:]
-			if err != nil {
-				return nil, err
-			}
-			pair.Chunk.Stripes = append(pair.Chunk.Stripes, stripe)
-		}
-
 		ret = append(ret, pair)
 	}
 	return ret, nil
 }
 
 type RootBackup struct {
-	TreeRoot    ObjID      `bin:"off=0, siz=8"`
-	TreeRootGen Generation `bin:"off=8, siz=8"`
+	TreeRoot    ObjID      `bin:"off=0x0, siz=0x8"`
+	TreeRootGen Generation `bin:"off=0x8, siz=0x8"`
 
-	ChunkRoot    ObjID      `bin:"off=10, siz=8"`
-	ChunkRootGen Generation `bin:"off=18, siz=8"`
+	ChunkRoot    ObjID      `bin:"off=0x10, siz=0x8"`
+	ChunkRootGen Generation `bin:"off=0x18, siz=0x8"`
 
-	ExtentRoot    ObjID      `bin:"off=20, siz=8"`
-	ExtentRootGen Generation `bin:"off=28, siz=8"`
+	ExtentRoot    ObjID      `bin:"off=0x20, siz=0x8"`
+	ExtentRootGen Generation `bin:"off=0x28, siz=0x8"`
 
-	FSRoot    ObjID      `bin:"off=30, siz=8"`
-	FSRootGen Generation `bin:"off=38, siz=8"`
+	FSRoot    ObjID      `bin:"off=0x30, siz=0x8"`
+	FSRootGen Generation `bin:"off=0x38, siz=0x8"`
 
-	DevRoot    ObjID      `bin:"off=40, siz=8"`
-	DevRootGen Generation `bin:"off=48, siz=8"`
+	DevRoot    ObjID      `bin:"off=0x40, siz=0x8"`
+	DevRootGen Generation `bin:"off=0x48, siz=0x8"`
 
-	ChecksumRoot    ObjID      `bin:"off=50, siz=8"`
-	ChecksumRootGen Generation `bin:"off=58, siz=8"`
+	ChecksumRoot    ObjID      `bin:"off=0x50, siz=0x8"`
+	ChecksumRootGen Generation `bin:"off=0x58, siz=0x8"`
 
-	TotalBytes uint64 `bin:"off=60, siz=8"`
-	BytesUsed  uint64 `bin:"off=68, siz=8"`
-	NumDevices uint64 `bin:"off=70, siz=8"`
+	TotalBytes uint64 `bin:"off=0x60, siz=0x8"`
+	BytesUsed  uint64 `bin:"off=0x68, siz=0x8"`
+	NumDevices uint64 `bin:"off=0x70, siz=0x8"`
 
-	Unused [8 * 4]byte `bin:"off=78, siz=20"`
+	Unused [8 * 4]byte `bin:"off=0x78, siz=0x20"`
 
-	TreeRootLevel     uint8 `bin:"off=98, siz=1"`
-	ChunkRootLevel    uint8 `bin:"off=99, siz=1"`
-	ExtentRootLevel   uint8 `bin:"off=9a, siz=1"`
-	FSRootLevel       uint8 `bin:"off=9b, siz=1"`
-	DevRootLevel      uint8 `bin:"off=9c, siz=1"`
-	ChecksumRootLevel uint8 `bin:"off=9d, siz=1"`
+	TreeRootLevel     uint8 `bin:"off=0x98, siz=0x1"`
+	ChunkRootLevel    uint8 `bin:"off=0x99, siz=0x1"`
+	ExtentRootLevel   uint8 `bin:"off=0x9a, siz=0x1"`
+	FSRootLevel       uint8 `bin:"off=0x9b, siz=0x1"`
+	DevRootLevel      uint8 `bin:"off=0x9c, siz=0x1"`
+	ChecksumRootLevel uint8 `bin:"off=0x9d, siz=0x1"`
 
-	Padding       [10]byte `bin:"off=9e, siz=a"`
-	binstruct.End `bin:"off=a8"`
+	Padding       [10]byte `bin:"off=0x9e, siz=0xa"`
+	binstruct.End `bin:"off=0xa8"`
 }
 
 type IncompatFlags uint64