diff options
author | Luke Shumaker <lukeshu@lukeshu.com> | 2022-05-11 23:14:21 -0600 |
---|---|---|
committer | Luke Shumaker <lukeshu@lukeshu.com> | 2022-05-11 23:14:21 -0600 |
commit | b0dd4d1f0c8262e3680570d529d00c9ebead1a91 (patch) | |
tree | a3fd72e9fc03583015a437753adbc3d80d45a818 | |
parent | 490cffb1f4ee99b013302cfed9ef849c0676735c (diff) |
touch up
-rw-r--r-- | pkg/btrfs/image.go | 6 | ||||
-rw-r--r-- | pkg/btrfs/structs.go | 87 |
2 files changed, 65 insertions, 28 deletions
diff --git a/pkg/btrfs/image.go b/pkg/btrfs/image.go index 9faded5..ec49940 100644 --- a/pkg/btrfs/image.go +++ b/pkg/btrfs/image.go @@ -85,7 +85,7 @@ func (img *Img) ScanForNodes(sb Superblock) error { } nodeBuf := make([]byte, sb.NodeSize) - for pos := int64(0); pos < devSize; pos += int64(sb.SectorSize) { + for pos := int64(0); pos+int64(sb.SectorSize) <= devSize; pos += int64(sb.SectorSize) { if inSlice(pos, superblockAddrs) { fmt.Printf("sector@%d is a superblock\n", pos) continue @@ -106,8 +106,8 @@ func (img *Img) ScanForNodes(sb Superblock) error { continue } - fmt.Printf("node@%d: physical_addr=0x%0X logical_addr=0x%0X generation=%d owner_tree=%v level=%d\n", - pos, pos, nodeHeader.Addr, nodeHeader.Generation, nodeHeader.OwnerTree, nodeHeader.Level) + 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 += int64(sb.NodeSize) - int64(sb.SectorSize) } diff --git a/pkg/btrfs/structs.go b/pkg/btrfs/structs.go index 92db216..a3f7862 100644 --- a/pkg/btrfs/structs.go +++ b/pkg/btrfs/structs.go @@ -9,6 +9,7 @@ import ( type ( PhysicalAddr int64 LogicalAddr int64 + Generation uint64 ) type Key struct { @@ -34,7 +35,7 @@ type Superblock struct { 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 uint64 `bin:"off=48, siz=8"` // generation + 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 @@ -46,13 +47,13 @@ type Superblock struct { 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"` // sectorsize - NodeSize uint32 `bin:"off=94, siz=4"` // nodesize - LeafSize uint32 `bin:"off=98, siz=4"` // leafsize - StripeSize uint32 `bin:"off=9c, siz=4"` // stripesize - SysChunkArraySize uint32 `bin:"off=a0, siz=4"` // sys_chunk_array_size + 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 uint64 `bin:"off=a4, siz=8"` // chunk_root_generation + 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 @@ -64,8 +65,8 @@ type Superblock struct { DevItem DevItem `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 uint64 `bin:"off=22b, siz=8"` // cache_generation - UUIDTreeGeneration uint64 `bin:"off=233, siz=8"` // uuid_tree_generation + CacheGeneration Generation `bin:"off=22b, siz=8"` + UUIDTreeGeneration uint64 `bin:"off=233, siz=8"` // uuid_tree_generation // FeatureIncompatMetadataUUID MetadataUUID UUID `bin:"off=23b, siz=10"` @@ -74,14 +75,14 @@ type Superblock struct { NumGlobalRoots uint64 `bin:"off=24b, siz=8"` // FeatureIncompatExtentTreeV2 - BlockGroupRoot uint64 `bin:"off=253, siz=8"` - BlockGroupRootGeneration uint64 `bin:"off=25b, siz=8"` - BlockGroupRootLevel uint8 `bin:"off=263, siz=1"` + BlockGroupRoot ObjID `bin:"off=253, siz=8"` + BlockGroupRootGeneration Generation `bin:"off=25b, siz=8"` + BlockGroupRootLevel uint8 `bin:"off=263, siz=1"` Reserved [199]byte `bin:"off=264, siz=c7"` // 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. - TODOSuperRoots [0x2a0]byte `bin:"off=b2b, siz=2a0"` // Contain super_roots (4 btrfs_root_backup) + 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"` // Padded to 4096 bytes Padding [565]byte `bin:"off=dcb, siz=235"` @@ -133,14 +134,50 @@ func (sb Superblock) ParseSysChunkArray() ([]SysChunk, error) { return ret, nil } +type RootBackup struct { + TreeRoot ObjID `bin:"off=0, siz=8"` + TreeRootGen Generation `bin:"off=8, siz=8"` + + ChunkRoot ObjID `bin:"off=10, siz=8"` + ChunkRootGen Generation `bin:"off=18, siz=8"` + + ExtentRoot ObjID `bin:"off=20, siz=8"` + ExtentRootGen Generation `bin:"off=28, siz=8"` + + FSRoot ObjID `bin:"off=30, siz=8"` + FSRootGen Generation `bin:"off=38, siz=8"` + + DevRoot ObjID `bin:"off=40, siz=8"` + DevRootGen Generation `bin:"off=48, siz=8"` + + ChecksumRoot ObjID `bin:"off=50, siz=8"` + ChecksumRootGen Generation `bin:"off=58, siz=8"` + + TotalBytes uint64 `bin:"off=60, siz=8"` + BytesUsed uint64 `bin:"off=68, siz=8"` + NumDevices uint64 `bin:"off=70, siz=8"` + + Unused [8 * 4]byte `bin:"off=78, siz=20"` + + 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"` + + Padding [10]byte `bin:"off=9e, siz=a"` + binstruct.End `bin:"off=a8"` +} + type NodeHeader struct { Checksum CSum `bin:"off=0, siz=20"` // Checksum of everything after this field (from 20 to the end of the node) MetadataUUID UUID `bin:"off=20, siz=10"` // FS UUID Addr LogicalAddr `bin:"off=30, siz=8"` // Logical address of this node Flags uint64 `bin:"off=38, siz=8"` // Flags ChunkTreeUUID UUID `bin:"off=40, siz=10"` // Chunk tree UUID - Generation uint64 `bin:"off=50, siz=8"` // Generation - OwnerTree TreeObjID `bin:"off=58, siz=8"` // The ID of the tree that contains this node + Generation Generation `bin:"off=50, siz=8"` // Generation + Owner TreeObjID `bin:"off=58, siz=8"` // The ID of the tree that contains this node NumItems uint32 `bin:"off=60, siz=4"` // Number of items Level uint8 `bin:"off=64, siz=1"` // Level (0 for leaf nodes) binstruct.End `bin:"off=65"` @@ -152,9 +189,9 @@ type InternalNode struct { } type KeyPointer struct { - Key Key `bin:"off=0, siz=11"` - BlockNumber uint64 `bin:"off=11, siz=8"` - Generation uint64 `bin:"off=19, siz=8"` + Key Key `bin:"off=0, siz=11"` + BlockNumber uint64 `bin:"off=11, siz=8"` + Generation Generation `bin:"off=19, siz=8"` binstruct.End `bin:"off=21"` } @@ -180,12 +217,12 @@ type DevItem struct { IOOptimalWidth uint32 `bin:"off=1c, siz=4"` // optimal I/O width IOMinSize uint32 `bin:"off=20, siz=4"` // minimal I/O size (sector size) - Type uint64 `bin:"off=24, siz=8"` // type - Generation uint64 `bin:"off=2c, siz=8"` // generation - StartOffset uint64 `bin:"off=34, siz=8"` // start offset - DevGroup uint32 `bin:"off=3c, siz=4"` // dev group - SeekSpeed uint8 `bin:"off=40, siz=1"` // seek speed - Bandwidth uint8 `bin:"off=41, siz=1"` // bandwidth + Type uint64 `bin:"off=24, siz=8"` // type + Generation Generation `bin:"off=2c, siz=8"` // generation + StartOffset uint64 `bin:"off=34, siz=8"` // start offset + DevGroup uint32 `bin:"off=3c, siz=4"` // dev group + SeekSpeed uint8 `bin:"off=40, siz=1"` // seek speed + Bandwidth uint8 `bin:"off=41, siz=1"` // bandwidth DevUUID UUID `bin:"off=42, siz=10"` // device UUID FSUUID UUID `bin:"off=52, siz=10"` // FS UUID |