drivers/filesystems/btrfs/btrfs.h

   1 /* btrfs.h
   2  * Generic btrfs header file. Thanks to whoever it was who wrote
   3  * https://btrfs.wiki.kernel.org/index.php/On-disk_Format - you saved me a lot of time!
   4  *
   5  * I release this file, and this file only, into the public domain - do whatever
   6  * you want with it. You don't have to, but I'd appreciate if you let me know if you
   7  * use it anything cool - mark@harmstone.com. */
   8
   9 #pragma once
  10
  11 #include <stdint.h>
  12
  13 static const uint64_t superblock_addrs[] = { 0x10000, 0x4000000, 0x4000000000, 0x4000000000000, 0 };
  14
  15 #define BTRFS_MAGIC         0x4d5f53665248425f
  16 #define MAX_LABEL_SIZE      0x100
  17 #define SUBVOL_ROOT_INODE   0x100
  18
  19 #define TYPE_INODE_ITEM        0x01
  20 #define TYPE_INODE_REF         0x0C
  21 #define TYPE_INODE_EXTREF      0x0D
  22 #define TYPE_XATTR_ITEM        0x18
  23 #define TYPE_ORPHAN_INODE      0x30
  24 #define TYPE_DIR_ITEM          0x54
  25 #define TYPE_DIR_INDEX         0x60
  26 #define TYPE_EXTENT_DATA       0x6C
  27 #define TYPE_EXTENT_CSUM       0x80
  28 #define TYPE_ROOT_ITEM         0x84
  29 #define TYPE_ROOT_BACKREF      0x90
  30 #define TYPE_ROOT_REF          0x9C
  31 #define TYPE_EXTENT_ITEM       0xA8
  32 #define TYPE_METADATA_ITEM     0xA9
  33 #define TYPE_TREE_BLOCK_REF    0xB0
  34 #define TYPE_EXTENT_DATA_REF   0xB2
  35 #define TYPE_EXTENT_REF_V0     0xB4
  36 #define TYPE_SHARED_BLOCK_REF  0xB6
  37 #define TYPE_SHARED_DATA_REF   0xB8
  38 #define TYPE_BLOCK_GROUP_ITEM  0xC0
  39 #define TYPE_FREE_SPACE_INFO   0xC6
  40 #define TYPE_FREE_SPACE_EXTENT 0xC7
  41 #define TYPE_FREE_SPACE_BITMAP 0xC8
  42 #define TYPE_DEV_EXTENT        0xCC
  43 #define TYPE_DEV_ITEM          0xD8
  44 #define TYPE_CHUNK_ITEM        0xE4
  45 #define TYPE_TEMP_ITEM         0xF8
  46 #define TYPE_DEV_STATS         0xF9
  47 #define TYPE_SUBVOL_UUID       0xFB
  48 #define TYPE_SUBVOL_REC_UUID   0xFC
  49
  50 #define BTRFS_ROOT_ROOT         1
  51 #define BTRFS_ROOT_EXTENT       2
  52 #define BTRFS_ROOT_CHUNK        3
  53 #define BTRFS_ROOT_DEVTREE      4
  54 #define BTRFS_ROOT_FSTREE       5
  55 #define BTRFS_ROOT_TREEDIR      6
  56 #define BTRFS_ROOT_CHECKSUM     7
  57 #define BTRFS_ROOT_UUID         9
  58 #define BTRFS_ROOT_FREE_SPACE   0xa
  59 #define BTRFS_ROOT_DATA_RELOC   0xFFFFFFFFFFFFFFF7
  60
  61 #define BTRFS_COMPRESSION_NONE  0
  62 #define BTRFS_COMPRESSION_ZLIB  1
  63 #define BTRFS_COMPRESSION_LZO   2
  64 #define BTRFS_COMPRESSION_ZSTD  3
  65
  66 #define BTRFS_ENCRYPTION_NONE   0
  67
  68 #define BTRFS_ENCODING_NONE     0
  69
  70 #define EXTENT_TYPE_INLINE      0
  71 #define EXTENT_TYPE_REGULAR     1
  72 #define EXTENT_TYPE_PREALLOC    2
  73
  74 #define BLOCK_FLAG_DATA         0x001
  75 #define BLOCK_FLAG_SYSTEM       0x002
  76 #define BLOCK_FLAG_METADATA     0x004
  77 #define BLOCK_FLAG_RAID0        0x008
  78 #define BLOCK_FLAG_RAID1        0x010
  79 #define BLOCK_FLAG_DUPLICATE    0x020
  80 #define BLOCK_FLAG_RAID10       0x040
  81 #define BLOCK_FLAG_RAID5        0x080
  82 #define BLOCK_FLAG_RAID6        0x100
  83
  84 #define FREE_SPACE_CACHE_ID     0xFFFFFFFFFFFFFFF5
  85 #define EXTENT_CSUM_ID          0xFFFFFFFFFFFFFFF6
  86 #define BALANCE_ITEM_ID         0xFFFFFFFFFFFFFFFC
  87
  88 #define BTRFS_INODE_NODATASUM   0x001
  89 #define BTRFS_INODE_NODATACOW   0x002
  90 #define BTRFS_INODE_READONLY    0x004
  91 #define BTRFS_INODE_NOCOMPRESS  0x008
  92 #define BTRFS_INODE_PREALLOC    0x010
  93 #define BTRFS_INODE_SYNC        0x020
  94 #define BTRFS_INODE_IMMUTABLE   0x040
  95 #define BTRFS_INODE_APPEND      0x080
  96 #define BTRFS_INODE_NODUMP      0x100
  97 #define BTRFS_INODE_NOATIME     0x200
  98 #define BTRFS_INODE_DIRSYNC     0x400
  99 #define BTRFS_INODE_COMPRESS    0x800
 100
 101 #define BTRFS_SUBVOL_READONLY   0x1
 102
 103 #define BTRFS_COMPAT_RO_FLAGS_FREE_SPACE_CACHE          0x1
 104 #define BTRFS_COMPAT_RO_FLAGS_FREE_SPACE_CACHE_VALID    0x2
 105
 106 #define BTRFS_INCOMPAT_FLAGS_MIXED_BACKREF      0x0001
 107 #define BTRFS_INCOMPAT_FLAGS_DEFAULT_SUBVOL     0x0002
 108 #define BTRFS_INCOMPAT_FLAGS_MIXED_GROUPS       0x0004
 109 #define BTRFS_INCOMPAT_FLAGS_COMPRESS_LZO       0x0008
 110 #define BTRFS_INCOMPAT_FLAGS_COMPRESS_ZSTD      0x0010
 111 #define BTRFS_INCOMPAT_FLAGS_BIG_METADATA       0x0020
 112 #define BTRFS_INCOMPAT_FLAGS_EXTENDED_IREF      0x0040
 113 #define BTRFS_INCOMPAT_FLAGS_RAID56             0x0080
 114 #define BTRFS_INCOMPAT_FLAGS_SKINNY_METADATA    0x0100
 115 #define BTRFS_INCOMPAT_FLAGS_NO_HOLES           0x0200
 116
 117 #define BTRFS_SUPERBLOCK_FLAGS_SEEDING   0x100000000
 118
 119 #define BTRFS_ORPHAN_INODE_OBJID         0xFFFFFFFFFFFFFFFB
 120
 121 #pragma pack(push, 1)
 122
 123 typedef struct {
 124     uint8_t uuid[16];
 125 } BTRFS_UUID;
 126
 127 typedef struct {
 128     uint64_t obj_id;
 129     uint8_t obj_type;
 130     uint64_t offset;
 131 } KEY;
 132
 133 #define HEADER_FLAG_WRITTEN         0x000000000000001
 134 #define HEADER_FLAG_SHARED_BACKREF  0x000000000000002
 135 #define HEADER_FLAG_MIXED_BACKREF   0x100000000000000
 136
 137 typedef struct {
 138     uint8_t csum[32];
 139     BTRFS_UUID fs_uuid;
 140     uint64_t address;
 141     uint64_t flags;
 142     BTRFS_UUID chunk_tree_uuid;
 143     uint64_t generation;
 144     uint64_t tree_id;
 145     uint32_t num_items;
 146     uint8_t level;
 147 } tree_header;
 148
 149 typedef struct {
 150     KEY key;
 151     uint32_t offset;
 152     uint32_t size;
 153 } leaf_node;
 154
 155 typedef struct {
 156     KEY key;
 157     uint64_t address;
 158     uint64_t generation;
 159 } internal_node;
 160
 161 typedef struct {
 162     uint64_t dev_id;
 163     uint64_t num_bytes;
 164     uint64_t bytes_used;
 165     uint32_t optimal_io_align;
 166     uint32_t optimal_io_width;
 167     uint32_t minimal_io_size;
 168     uint64_t type;
 169     uint64_t generation;
 170     uint64_t start_offset;
 171     uint32_t dev_group;
 172     uint8_t seek_speed;
 173     uint8_t bandwidth;
 174     BTRFS_UUID device_uuid;
 175     BTRFS_UUID fs_uuid;
 176 } DEV_ITEM;
 177
 178 #define SYS_CHUNK_ARRAY_SIZE 0x800
 179 #define BTRFS_NUM_BACKUP_ROOTS 4
 180
 181 typedef struct {
 182     uint64_t root_tree_addr;
 183     uint64_t root_tree_generation;
 184     uint64_t chunk_tree_addr;
 185     uint64_t chunk_tree_generation;
 186     uint64_t extent_tree_addr;
 187     uint64_t extent_tree_generation;
 188     uint64_t fs_tree_addr;
 189     uint64_t fs_tree_generation;
 190     uint64_t dev_root_addr;
 191     uint64_t dev_root_generation;
 192     uint64_t csum_root_addr;
 193     uint64_t csum_root_generation;
 194     uint64_t total_bytes;
 195     uint64_t bytes_used;
 196     uint64_t num_devices;
 197     uint64_t reserved[4];
 198     uint8_t root_level;
 199     uint8_t chunk_root_level;
 200     uint8_t extent_root_level;
 201     uint8_t fs_root_level;
 202     uint8_t dev_root_level;
 203     uint8_t csum_root_level;
 204     uint8_t reserved2[10];
 205 } superblock_backup;
 206
 207 typedef struct {
 208     uint8_t checksum[32];
 209     BTRFS_UUID uuid;
 210     uint64_t sb_phys_addr;
 211     uint64_t flags;
 212     uint64_t magic;
 213     uint64_t generation;
 214     uint64_t root_tree_addr;
 215     uint64_t chunk_tree_addr;
 216     uint64_t log_tree_addr;
 217     uint64_t log_root_transid;
 218     uint64_t total_bytes;
 219     uint64_t bytes_used;
 220     uint64_t root_dir_objectid;
 221     uint64_t num_devices;
 222     uint32_t sector_size;
 223     uint32_t node_size;
 224     uint32_t leaf_size;
 225     uint32_t stripe_size;
 226     uint32_t n;
 227     uint64_t chunk_root_generation;
 228     uint64_t compat_flags;
 229     uint64_t compat_ro_flags;
 230     uint64_t incompat_flags;
 231     uint16_t csum_type;
 232     uint8_t root_level;
 233     uint8_t chunk_root_level;
 234     uint8_t log_root_level;
 235     DEV_ITEM dev_item;
 236     char label[MAX_LABEL_SIZE];
 237     uint64_t cache_generation;
 238     uint64_t uuid_tree_generation;
 239     uint64_t reserved[30];
 240     uint8_t sys_chunk_array[SYS_CHUNK_ARRAY_SIZE];
 241     superblock_backup backup[BTRFS_NUM_BACKUP_ROOTS];
 242     uint8_t reserved2[565];
 243 } superblock;
 244
 245 #define BTRFS_TYPE_UNKNOWN   0
 246 #define BTRFS_TYPE_FILE      1
 247 #define BTRFS_TYPE_DIRECTORY 2
 248 #define BTRFS_TYPE_CHARDEV   3
 249 #define BTRFS_TYPE_BLOCKDEV  4
 250 #define BTRFS_TYPE_FIFO      5
 251 #define BTRFS_TYPE_SOCKET    6
 252 #define BTRFS_TYPE_SYMLINK   7
 253 #define BTRFS_TYPE_EA        8
 254
 255 typedef struct {
 256     KEY key;
 257     uint64_t transid;
 258     uint16_t m;
 259     uint16_t n;
 260     uint8_t type;
 261     char name[1];
 262 } DIR_ITEM;
 263
 264 typedef struct {
 265     uint64_t seconds;
 266     uint32_t nanoseconds;
 267 } BTRFS_TIME;
 268
 269 typedef struct {
 270     uint64_t generation;
 271     uint64_t transid;
 272     uint64_t st_size;
 273     uint64_t st_blocks;
 274     uint64_t block_group;
 275     uint32_t st_nlink;
 276     uint32_t st_uid;
 277     uint32_t st_gid;
 278     uint32_t st_mode;
 279     uint64_t st_rdev;
 280     uint64_t flags;
 281     uint64_t sequence;
 282     uint8_t reserved[32];
 283     BTRFS_TIME st_atime;
 284     BTRFS_TIME st_ctime;
 285     BTRFS_TIME st_mtime;
 286     BTRFS_TIME otime;
 287 } INODE_ITEM;
 288
 289 typedef struct {
 290     INODE_ITEM inode;
 291     uint64_t generation;
 292     uint64_t objid;
 293     uint64_t block_number;
 294     uint64_t byte_limit;
 295     uint64_t bytes_used;
 296     uint64_t last_snapshot_generation;
 297     uint64_t flags;
 298     uint32_t num_references;
 299     KEY drop_progress;
 300     uint8_t drop_level;
 301     uint8_t root_level;
 302     uint64_t generation2;
 303     BTRFS_UUID uuid;
 304     BTRFS_UUID parent_uuid;
 305     BTRFS_UUID received_uuid;
 306     uint64_t ctransid;
 307     uint64_t otransid;
 308     uint64_t stransid;
 309     uint64_t rtransid;
 310     BTRFS_TIME ctime;
 311     BTRFS_TIME otime;
 312     BTRFS_TIME stime;
 313     BTRFS_TIME rtime;
 314     uint64_t reserved[8];
 315 } ROOT_ITEM;
 316
 317 typedef struct {
 318     uint64_t size;
 319     uint64_t root_id;
 320     uint64_t stripe_length;
 321     uint64_t type;
 322     uint32_t opt_io_alignment;
 323     uint32_t opt_io_width;
 324     uint32_t sector_size;
 325     uint16_t num_stripes;
 326     uint16_t sub_stripes;
 327 } CHUNK_ITEM;
 328
 329 typedef struct {
 330     uint64_t dev_id;
 331     uint64_t offset;
 332     BTRFS_UUID dev_uuid;
 333 } CHUNK_ITEM_STRIPE;
 334
 335 typedef struct {
 336     uint64_t generation;
 337     uint64_t decoded_size;
 338     uint8_t compression;
 339     uint8_t encryption;
 340     uint16_t encoding;
 341     uint8_t type;
 342     uint8_t data[1];
 343 } EXTENT_DATA;
 344
 345 typedef struct {
 346     uint64_t address;
 347     uint64_t size;
 348     uint64_t offset;
 349     uint64_t num_bytes;
 350 } EXTENT_DATA2;
 351
 352 typedef struct {
 353     uint64_t index;
 354     uint16_t n;
 355     char name[1];
 356 } INODE_REF;
 357
 358 typedef struct {
 359     uint64_t dir;
 360     uint64_t index;
 361     uint16_t n;
 362     char name[1];
 363 } INODE_EXTREF;
 364
 365 #define EXTENT_ITEM_DATA            0x001
 366 #define EXTENT_ITEM_TREE_BLOCK      0x002
 367 #define EXTENT_ITEM_SHARED_BACKREFS 0x100
 368
 369 typedef struct {
 370     uint64_t refcount;
 371     uint64_t generation;
 372     uint64_t flags;
 373 } EXTENT_ITEM;
 374
 375 typedef struct {
 376     KEY firstitem;
 377     uint8_t level;
 378 } EXTENT_ITEM2;
 379
 380 typedef struct {
 381     uint32_t refcount;
 382 } EXTENT_ITEM_V0;
 383
 384 typedef struct {
 385     EXTENT_ITEM extent_item;
 386     KEY firstitem;
 387     uint8_t level;
 388 } EXTENT_ITEM_TREE;
 389
 390 typedef struct {
 391     uint64_t offset;
 392 } TREE_BLOCK_REF;
 393
 394 typedef struct {
 395     uint64_t root;
 396     uint64_t objid;
 397     uint64_t offset;
 398     uint32_t count;
 399 } EXTENT_DATA_REF;
 400
 401 typedef struct {
 402     uint64_t used;
 403     uint64_t chunk_tree;
 404     uint64_t flags;
 405 } BLOCK_GROUP_ITEM;
 406
 407 typedef struct {
 408     uint64_t root;
 409     uint64_t gen;
 410     uint64_t objid;
 411     uint32_t count;
 412 } EXTENT_REF_V0;
 413
 414 typedef struct {
 415     uint64_t offset;
 416 } SHARED_BLOCK_REF;
 417
 418 typedef struct {
 419     uint64_t offset;
 420     uint32_t count;
 421 } SHARED_DATA_REF;
 422
 423 #define FREE_SPACE_EXTENT 1
 424 #define FREE_SPACE_BITMAP 2
 425
 426 typedef struct {
 427     uint64_t offset;
 428     uint64_t size;
 429     uint8_t type;
 430 } FREE_SPACE_ENTRY;
 431
 432 typedef struct {
 433     KEY key;
 434     uint64_t generation;
 435     uint64_t num_entries;
 436     uint64_t num_bitmaps;
 437 } FREE_SPACE_ITEM;
 438
 439 typedef struct {
 440     uint64_t dir;
 441     uint64_t index;
 442     uint16_t n;
 443     char name[1];
 444 } ROOT_REF;
 445
 446 typedef struct {
 447     uint64_t chunktree;
 448     uint64_t objid;
 449     uint64_t address;
 450     uint64_t length;
 451     BTRFS_UUID chunktree_uuid;
 452 } DEV_EXTENT;
 453
 454 #define BALANCE_FLAGS_DATA          0x1
 455 #define BALANCE_FLAGS_SYSTEM        0x2
 456 #define BALANCE_FLAGS_METADATA      0x4
 457
 458 #define BALANCE_ARGS_FLAGS_PROFILES         0x001
 459 #define BALANCE_ARGS_FLAGS_USAGE            0x002
 460 #define BALANCE_ARGS_FLAGS_DEVID            0x004
 461 #define BALANCE_ARGS_FLAGS_DRANGE           0x008
 462 #define BALANCE_ARGS_FLAGS_VRANGE           0x010
 463 #define BALANCE_ARGS_FLAGS_LIMIT            0x020
 464 #define BALANCE_ARGS_FLAGS_LIMIT_RANGE      0x040
 465 #define BALANCE_ARGS_FLAGS_STRIPES_RANGE    0x080
 466 #define BALANCE_ARGS_FLAGS_CONVERT          0x100
 467 #define BALANCE_ARGS_FLAGS_SOFT             0x200
 468 #define BALANCE_ARGS_FLAGS_USAGE_RANGE      0x400
 469
 470 typedef struct {
 471     uint64_t profiles;
 472
 473     union {
 474             uint64_t usage;
 475             struct {
 476                     uint32_t usage_start;
 477                     uint32_t usage_end;
 478             };
 479     };
 480
 481     uint64_t devid;
 482     uint64_t drange_start;
 483     uint64_t drange_end;
 484     uint64_t vrange_start;
 485     uint64_t vrange_end;
 486     uint64_t convert;
 487     uint64_t flags;
 488
 489     union {
 490             uint64_t limit;
 491             struct {
 492                     uint32_t limit_start;
 493                     uint32_t limit_end;
 494             };
 495     };
 496
 497     uint32_t stripes_start;
 498     uint32_t stripes_end;
 499     uint8_t reserved[48];
 500 } BALANCE_ARGS;
 501
 502 typedef struct {
 503     uint64_t flags;
 504     BALANCE_ARGS data;
 505     BALANCE_ARGS metadata;
 506     BALANCE_ARGS system;
 507     uint8_t reserved[32];
 508 } BALANCE_ITEM;
 509
 510 #define BTRFS_FREE_SPACE_USING_BITMAPS      1
 511
 512 typedef struct {
 513     uint32_t count;
 514     uint32_t flags;
 515 } FREE_SPACE_INFO;
 516
 517 #define BTRFS_DEV_STAT_WRITE_ERRORS          0
 518 #define BTRFS_DEV_STAT_READ_ERRORS           1
 519 #define BTRFS_DEV_STAT_FLUSH_ERRORS          2
 520 #define BTRFS_DEV_STAT_CORRUPTION_ERRORS     3
 521 #define BTRFS_DEV_STAT_GENERATION_ERRORS     4
 522
 523 #define BTRFS_SEND_CMD_SUBVOL          1
 524 #define BTRFS_SEND_CMD_SNAPSHOT        2
 525 #define BTRFS_SEND_CMD_MKFILE          3
 526 #define BTRFS_SEND_CMD_MKDIR           4
 527 #define BTRFS_SEND_CMD_MKNOD           5
 528 #define BTRFS_SEND_CMD_MKFIFO          6
 529 #define BTRFS_SEND_CMD_MKSOCK          7
 530 #define BTRFS_SEND_CMD_SYMLINK         8
 531 #define BTRFS_SEND_CMD_RENAME          9
 532 #define BTRFS_SEND_CMD_LINK           10
 533 #define BTRFS_SEND_CMD_UNLINK         11
 534 #define BTRFS_SEND_CMD_RMDIR          12
 535 #define BTRFS_SEND_CMD_SET_XATTR      13
 536 #define BTRFS_SEND_CMD_REMOVE_XATTR   14
 537 #define BTRFS_SEND_CMD_WRITE          15
 538 #define BTRFS_SEND_CMD_CLONE          16
 539 #define BTRFS_SEND_CMD_TRUNCATE       17
 540 #define BTRFS_SEND_CMD_CHMOD          18
 541 #define BTRFS_SEND_CMD_CHOWN          19
 542 #define BTRFS_SEND_CMD_UTIMES         20
 543 #define BTRFS_SEND_CMD_END            21
 544 #define BTRFS_SEND_CMD_UPDATE_EXTENT  22
 545
 546 #define BTRFS_SEND_TLV_UUID             1
 547 #define BTRFS_SEND_TLV_TRANSID          2
 548 #define BTRFS_SEND_TLV_INODE            3
 549 #define BTRFS_SEND_TLV_SIZE             4
 550 #define BTRFS_SEND_TLV_MODE             5
 551 #define BTRFS_SEND_TLV_UID              6
 552 #define BTRFS_SEND_TLV_GID              7
 553 #define BTRFS_SEND_TLV_RDEV             8
 554 #define BTRFS_SEND_TLV_CTIME            9
 555 #define BTRFS_SEND_TLV_MTIME           10
 556 #define BTRFS_SEND_TLV_ATIME           11
 557 #define BTRFS_SEND_TLV_OTIME           12
 558 #define BTRFS_SEND_TLV_XATTR_NAME      13
 559 #define BTRFS_SEND_TLV_XATTR_DATA      14
 560 #define BTRFS_SEND_TLV_PATH            15
 561 #define BTRFS_SEND_TLV_PATH_TO         16
 562 #define BTRFS_SEND_TLV_PATH_LINK       17
 563 #define BTRFS_SEND_TLV_OFFSET          18
 564 #define BTRFS_SEND_TLV_DATA            19
 565 #define BTRFS_SEND_TLV_CLONE_UUID      20
 566 #define BTRFS_SEND_TLV_CLONE_CTRANSID  21
 567 #define BTRFS_SEND_TLV_CLONE_PATH      22
 568 #define BTRFS_SEND_TLV_CLONE_OFFSET    23
 569 #define BTRFS_SEND_TLV_CLONE_LENGTH    24
 570
 571 #define BTRFS_SEND_MAGIC "btrfs-stream"
 572
 573 typedef struct {
 574     uint8_t magic[13];
 575     uint32_t version;
 576 } btrfs_send_header;
 577
 578 typedef struct {
 579     uint32_t length;
 580     uint16_t cmd;
 581     uint32_t csum;
 582 } btrfs_send_command;
 583
 584 typedef struct {
 585     uint16_t type;
 586     uint16_t length;
 587 } btrfs_send_tlv;
 588
 589 #pragma pack(pop)