diff options
Diffstat (limited to 'cmd')
| -rw-r--r-- | cmd/btrfs-dbg/main.go | 71 | ||||
| -rw-r--r-- | cmd/btrfs-dbg/types.go | 156 |
2 files changed, 4 insertions, 223 deletions
diff --git a/cmd/btrfs-dbg/main.go b/cmd/btrfs-dbg/main.go index 0990378..3d2103a 100644 --- a/cmd/btrfs-dbg/main.go +++ b/cmd/btrfs-dbg/main.go @@ -6,7 +6,7 @@ import ( "github.com/davecgh/go-spew/spew" - "lukeshu.com/btrfs-tools/pkg/binstruct" + "lukeshu.com/btrfs-tools/pkg/btrfs" ) func main() { @@ -27,7 +27,7 @@ func Main(imgfilename string) (err error) { if err != nil { return err } - img := &Img{ + img := &btrfs.Img{ File: fh, } defer func() { @@ -42,8 +42,8 @@ func Main(imgfilename string) (err error) { spew := spew.NewDefaultConfig() spew.DisablePointerAddresses = true - spew.Dump(superblocks[0].data) - sum, err := superblocks[0].data.CalculateChecksum() + spew.Dump(superblocks[0].Data) + sum, err := superblocks[0].Data.CalculateChecksum() if err != nil { return err } @@ -51,66 +51,3 @@ func Main(imgfilename string) (err error) { return nil } - -type Img struct { - *os.File -} - -func (img *Img) Size() (int64, error) { - fi, err := img.Stat() - if err != nil { - return 0, err - } - return fi.Size(), nil -} - -type Ref[T any] struct { - img *Img - addr int64 - data T -} - -func (r *Ref[T]) Read() error { - size, err := binstruct.Size(r.data) - if err != nil { - return err - } - buf := make([]byte, size) - if _, err := r.img.ReadAt(buf, r.addr); err != nil { - return err - } - return binstruct.Unmarshal(buf, &r.data) -} - -func (img *Img) Superblocks() ([]Ref[Superblock], error) { - const superblockSize = 0x1000 - - var superblockAddrs = []int64{ - 0x00_0001_0000, // 64KiB - 0x00_0400_0000, // 64MiB - 0x40_0000_0000, // 256GiB - } - - sz, err := img.Size() - if err != nil { - return nil, err - } - - var ret []Ref[Superblock] - for i, addr := range superblockAddrs { - if addr+superblockSize <= sz { - superblock := Ref[Superblock]{ - img: img, - addr: addr, - } - if err := superblock.Read(); err != nil { - return nil, fmt.Errorf("superblock %d: %w", i, err) - } - ret = append(ret, superblock) - } - } - if len(ret) == 0 { - return nil, fmt.Errorf("no superblocks") - } - return ret, nil -} diff --git a/cmd/btrfs-dbg/types.go b/cmd/btrfs-dbg/types.go deleted file mode 100644 index 3cd348d..0000000 --- a/cmd/btrfs-dbg/types.go +++ /dev/null @@ -1,156 +0,0 @@ -package main - -import ( - "encoding/binary" - "encoding/hex" - "hash/crc32" - "strings" - "time" - - "lukeshu.com/btrfs-tools/pkg/binstruct" -) - -type ( - PhysicalAddr int64 - LogicalAddr int64 - ObjID int64 - CSum [0x20]byte - UUID [16]byte -) - -func (uuid UUID) String() string { - str := hex.EncodeToString(uuid[:]) - return strings.Join([]string{ - str[:8], - str[8:12], - str[12:16], - str[16:20], - str[20:32], - }, "-") -} - -func crc32c(data []byte) CSum { - sum := crc32.Update(0xFFFFFFFF, crc32.MakeTable(0x1EDC6F41), data) - var buf CSum - binary.LittleEndian.PutUint32(buf[:], sum) - return buf -} - -type Key struct { - ObjectID ObjID `bin:"off=0, siz=8, desc=Object ID. Each tree has its own set of Object IDs."` - ItemType uint8 `bin:"off=8, siz=1, desc=Item type."` - Offset uint64 `bin:"off=9, siz=8, desc=Offset. The meaning depends on the item type."` - binstruct.End `bin:"off=11"` -} - -type Time struct { - Sec int64 `bin:"off=0, siz=8, desc=Number of seconds since 1970-01-01T00:00:00Z."` - NSec uint64 `bin:"off=8, siz=4, desc=Number of nanoseconds since the beginning of the second."` - binstruct.End `bin:"off=c"` -} - -func (t Time) ToStd() time.Time { - return time.Unix(t.Sec, int64(t.NSec)) -} - -type Superblock struct { - Checksum CSum `bin:"off=0, siz=20, desc=Checksum of everything past this field (from 20 to 1000)"` - FSUUID UUID `bin:"off=20, siz=10, desc=FS UUID"` - Self PhysicalAddr `bin:"off=30, siz=8, desc=physical address of this block (different for mirrors)"` - Flags uint64 `bin:"off=38, siz=8, desc=flags"` - Magic [8]byte `bin:"off=40, siz=8, desc=magic ('_BHRfS_M')"` - Generation uint64 `bin:"off=48, siz=8, desc=generation"` - - RootTree LogicalAddr `bin:"off=50, siz=8, desc=logical address of the root tree root"` - ChunkTree LogicalAddr `bin:"off=58, siz=8, desc=logical address of the chunk tree root"` - LogTree LogicalAddr `bin:"off=60, siz=8, desc=logical address of the log tree root"` - - LogRootTransID uint64 `bin:"off=68, siz=8, desc=log_root_transid"` - TotalBytes uint64 `bin:"off=70, siz=8, desc=total_bytes"` - BytesUsed uint64 `bin:"off=78, siz=8, desc=bytes_used"` - RootDirObjectID uint64 `bin:"off=80, siz=8, desc=root_dir_objectid (usually 6)"` - NumDevices uint64 `bin:"off=88, siz=8, desc=num_devices"` - - SectorSize uint32 `bin:"off=90, siz=4, desc=sectorsize"` - NodeSize uint32 `bin:"off=94, siz=4, desc=nodesize"` - LeafSize uint32 `bin:"off=98, siz=4, desc=leafsize"` - StripeSize uint32 `bin:"off=9c, siz=4, desc=stripesize"` - SysChunkArraySize uint32 `bin:"off=a0, siz=4, desc=sys_chunk_array_size"` - - ChunkRootGeneration uint64 `bin:"off=a4, siz=8, desc=chunk_root_generation"` - CompatFlags uint64 `bin:"off=ac, siz=8, desc=compat_flags"` - CompatROFlags uint64 `bin:"off=b4, siz=8, desc=compat_ro_flags - only implementations that support the flags can write to the filesystem"` - IncompatFlags uint64 `bin:"off=bc, siz=8, desc=incompat_flags - only implementations that support the flags can use the filesystem"` - ChecksumType uint16 `bin:"off=c4, siz=2, desc=csum_type - Btrfs currently uses the CRC32c little-endian hash function with seed -1."` - - RootLevel uint8 `bin:"off=c6, siz=1, desc=root_level"` - ChunkLevel uint8 `bin:"off=c7, siz=1, desc=chunk_root_level"` - LogLevel uint8 `bin:"off=c8, siz=1, desc=log_root_level"` - - DevItem DevItem `bin:"off=c9, siz=62, desc=DEV_ITEM data for this device"` - Label [0x100]byte `bin:"off=12b, siz=100, desc=label (may not contain '/' or '\\')"` - CacheGeneration uint64 `bin:"off=22b, siz=8, desc=cache_generation"` - UUIDTreeGeneration uint64 `bin:"off=233, siz=8, desc=uuid_tree_generation"` - - Reserved [0xf0]byte `bin:"off=23b, siz=f0, desc=reserved /* future expansion */"` - - TODOSysChunkArray [0x800]byte `bin:"off=32b, siz=800, desc=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. "` - TODOSuperRoots [0x2a0]byte `bin:"off=b2b, siz=2a0, desc=Contain super_roots (4 btrfs_root_backup)"` - - Unused [0x235]byte `bin:"off=dcb, siz=235, desc=current unused"` - - binstruct.End `bin:"off=1000"` -} - -func (sb Superblock) CalculateChecksum() (CSum, error) { - data, err := binstruct.Marshal(sb) - if err != nil { - return CSum{}, err - } - return crc32c(data[0x20:]), nil -} - -type DevItem struct { - DeviceID uint64 `bin:"off=0, siz=8, desc=device id"` - - NumBytes uint64 `bin:"off=8, siz=8, desc=number of bytes"` - NumBytesUsed uint64 `bin:"off=10, siz=8, desc=number of bytes used"` - - IOOptimalAlign uint32 `bin:"off=18, siz=4, desc=optimal I/O align"` - IOOptimalWidth uint32 `bin:"off=1c, siz=4, desc=optimal I/O width"` - IOMinSize uint32 `bin:"off=20, siz=4, desc=minimal I/O size (sector size)"` - - Type uint64 `bin:"off=24, siz=8, desc=type"` - Generation uint64 `bin:"off=2c, siz=8, desc=generation"` - StartOffset uint64 `bin:"off=34, siz=8, desc=start offset"` - DevGroup uint32 `bin:"off=3c, siz=4, desc=dev group"` - SeekSpeed uint8 `bin:"off=40, siz=1, desc=seek speed"` - Bandwidth uint8 `bin:"off=41, siz=1, desc=bandwidth"` - - DevUUID UUID `bin:"off=42, siz=10, desc=device UUID"` - FSUUID UUID `bin:"off=52, siz=10, desc=FS UUID"` - - binstruct.End `bin:"off=62"` -} - -type ChunkItem struct { - // Maps logical address to physical. - Size uint64 `bin:"off=0, siz=8, desc=size of chunk (bytes)"` - Root ObjID `bin:"off=8, siz=8, desc=root referencing this chunk (2)"` - StripeLen uint64 `bin:"off=10, siz=8, desc=stripe length"` - Type uint64 `bin:"off=18, siz=8, desc=type (same as flags for block group?)"` - IOOptimalAlign uint32 `bin:"off=20, siz=4, desc=optimal io alignment"` - IOOptimalWidth uint32 `bin:"off=24, siz=4, desc=optimal io width"` - IoMinSize uint32 `bin:"off=28, siz=4, desc=minimal io size (sector size)"` - NumStripes uint16 `bin:"off=2c, siz=2, desc=number of stripes"` - SubStripes uint16 `bin:"off=2e, siz=2, desc=sub stripes"` - binstruct.End `bin:"off=30"` -} - -type ChunkItemStripe struct { - // Stripes follow (for each number of stripes): - DeviceID ObjID `bin:"off=0, siz=8, desc=device id"` - Offset uint64 `bin:"off=8, siz=8, desc=offset"` - DeviceUUID UUID `bin:"off=10, siz=10, desc=device UUID"` - binstruct.End `bin:"off=20"` -} |