1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef _BTRFS_CTREE_H_ 3 #define _BTRFS_CTREE_H_ 4 5 #include <linux/btrfs.h> 6 #include <linux/types.h> 7 #ifdef __KERNEL__ 8 #include <linux/stddef.h> 9 #else 10 #include <stddef.h> 11 #endif 12 13 /* ASCII for _BHRfS_M, no terminating nul */ 14 #define BTRFS_MAGIC 0x4D5F53665248425FULL 15 16 #define BTRFS_MAX_LEVEL 8 17 18 /* 19 * We can actually store much bigger names, but lets not confuse the rest of 20 * linux. 21 */ 22 #define BTRFS_NAME_LEN 255 23 24 /* 25 * Theoretical limit is larger, but we keep this down to a sane value. That 26 * should limit greatly the possibility of collisions on inode ref items. 27 */ 28 #define BTRFS_LINK_MAX 65535U 29 30 /* 31 * This header contains the structure definitions and constants used 32 * by file system objects that can be retrieved using 33 * the BTRFS_IOC_SEARCH_TREE ioctl. That means basically anything that 34 * is needed to describe a leaf node's key or item contents. 35 */ 36 37 /* holds pointers to all of the tree roots */ 38 #define BTRFS_ROOT_TREE_OBJECTID 1ULL 39 40 /* stores information about which extents are in use, and reference counts */ 41 #define BTRFS_EXTENT_TREE_OBJECTID 2ULL 42 43 /* 44 * chunk tree stores translations from logical -> physical block numbering 45 * the super block points to the chunk tree 46 */ 47 #define BTRFS_CHUNK_TREE_OBJECTID 3ULL 48 49 /* 50 * stores information about which areas of a given device are in use. 51 * one per device. The tree of tree roots points to the device tree 52 */ 53 #define BTRFS_DEV_TREE_OBJECTID 4ULL 54 55 /* one per subvolume, storing files and directories */ 56 #define BTRFS_FS_TREE_OBJECTID 5ULL 57 58 /* directory objectid inside the root tree */ 59 #define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL 60 61 /* holds checksums of all the data extents */ 62 #define BTRFS_CSUM_TREE_OBJECTID 7ULL 63 64 /* holds quota configuration and tracking */ 65 #define BTRFS_QUOTA_TREE_OBJECTID 8ULL 66 67 /* for storing items that use the BTRFS_UUID_KEY* types */ 68 #define BTRFS_UUID_TREE_OBJECTID 9ULL 69 70 /* tracks free space in block groups. */ 71 #define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL 72 73 /* Holds the block group items for extent tree v2. */ 74 #define BTRFS_BLOCK_GROUP_TREE_OBJECTID 11ULL 75 76 /* device stats in the device tree */ 77 #define BTRFS_DEV_STATS_OBJECTID 0ULL 78 79 /* for storing balance parameters in the root tree */ 80 #define BTRFS_BALANCE_OBJECTID -4ULL 81 82 /* orphan objectid for tracking unlinked/truncated files */ 83 #define BTRFS_ORPHAN_OBJECTID -5ULL 84 85 /* does write ahead logging to speed up fsyncs */ 86 #define BTRFS_TREE_LOG_OBJECTID -6ULL 87 #define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL 88 89 /* for space balancing */ 90 #define BTRFS_TREE_RELOC_OBJECTID -8ULL 91 #define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL 92 93 /* 94 * extent checksums all have this objectid 95 * this allows them to share the logging tree 96 * for fsyncs 97 */ 98 #define BTRFS_EXTENT_CSUM_OBJECTID -10ULL 99 100 /* For storing free space cache */ 101 #define BTRFS_FREE_SPACE_OBJECTID -11ULL 102 103 /* 104 * The inode number assigned to the special inode for storing 105 * free ino cache 106 */ 107 #define BTRFS_FREE_INO_OBJECTID -12ULL 108 109 /* dummy objectid represents multiple objectids */ 110 #define BTRFS_MULTIPLE_OBJECTIDS -255ULL 111 112 /* 113 * All files have objectids in this range. 114 */ 115 #define BTRFS_FIRST_FREE_OBJECTID 256ULL 116 #define BTRFS_LAST_FREE_OBJECTID -256ULL 117 #define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL 118 119 120 /* 121 * the device items go into the chunk tree. The key is in the form 122 * [ 1 BTRFS_DEV_ITEM_KEY device_id ] 123 */ 124 #define BTRFS_DEV_ITEMS_OBJECTID 1ULL 125 126 #define BTRFS_BTREE_INODE_OBJECTID 1 127 128 #define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2 129 130 #define BTRFS_DEV_REPLACE_DEVID 0ULL 131 132 /* 133 * inode items have the data typically returned from stat and store other 134 * info about object characteristics. There is one for every file and dir in 135 * the FS 136 */ 137 #define BTRFS_INODE_ITEM_KEY 1 138 #define BTRFS_INODE_REF_KEY 12 139 #define BTRFS_INODE_EXTREF_KEY 13 140 #define BTRFS_XATTR_ITEM_KEY 24 141 142 /* 143 * fs verity items are stored under two different key types on disk. 144 * The descriptor items: 145 * [ inode objectid, BTRFS_VERITY_DESC_ITEM_KEY, offset ] 146 * 147 * At offset 0, we store a btrfs_verity_descriptor_item which tracks the size 148 * of the descriptor item and some extra data for encryption. 149 * Starting at offset 1, these hold the generic fs verity descriptor. The 150 * latter are opaque to btrfs, we just read and write them as a blob for the 151 * higher level verity code. The most common descriptor size is 256 bytes. 152 * 153 * The merkle tree items: 154 * [ inode objectid, BTRFS_VERITY_MERKLE_ITEM_KEY, offset ] 155 * 156 * These also start at offset 0, and correspond to the merkle tree bytes. When 157 * fsverity asks for page 0 of the merkle tree, we pull up one page starting at 158 * offset 0 for this key type. These are also opaque to btrfs, we're blindly 159 * storing whatever fsverity sends down. 160 */ 161 #define BTRFS_VERITY_DESC_ITEM_KEY 36 162 #define BTRFS_VERITY_MERKLE_ITEM_KEY 37 163 164 #define BTRFS_ORPHAN_ITEM_KEY 48 165 /* reserve 2-15 close to the inode for later flexibility */ 166 167 /* 168 * dir items are the name -> inode pointers in a directory. There is one 169 * for every name in a directory. BTRFS_DIR_LOG_ITEM_KEY is no longer used 170 * but it's still defined here for documentation purposes and to help avoid 171 * having its numerical value reused in the future. 172 */ 173 #define BTRFS_DIR_LOG_ITEM_KEY 60 174 #define BTRFS_DIR_LOG_INDEX_KEY 72 175 #define BTRFS_DIR_ITEM_KEY 84 176 #define BTRFS_DIR_INDEX_KEY 96 177 /* 178 * extent data is for file data 179 */ 180 #define BTRFS_EXTENT_DATA_KEY 108 181 182 /* 183 * extent csums are stored in a separate tree and hold csums for 184 * an entire extent on disk. 185 */ 186 #define BTRFS_EXTENT_CSUM_KEY 128 187 188 /* 189 * root items point to tree roots. They are typically in the root 190 * tree used by the super block to find all the other trees 191 */ 192 #define BTRFS_ROOT_ITEM_KEY 132 193 194 /* 195 * root backrefs tie subvols and snapshots to the directory entries that 196 * reference them 197 */ 198 #define BTRFS_ROOT_BACKREF_KEY 144 199 200 /* 201 * root refs make a fast index for listing all of the snapshots and 202 * subvolumes referenced by a given root. They point directly to the 203 * directory item in the root that references the subvol 204 */ 205 #define BTRFS_ROOT_REF_KEY 156 206 207 /* 208 * extent items are in the extent map tree. These record which blocks 209 * are used, and how many references there are to each block 210 */ 211 #define BTRFS_EXTENT_ITEM_KEY 168 212 213 /* 214 * The same as the BTRFS_EXTENT_ITEM_KEY, except it's metadata we already know 215 * the length, so we save the level in key->offset instead of the length. 216 */ 217 #define BTRFS_METADATA_ITEM_KEY 169 218 219 #define BTRFS_TREE_BLOCK_REF_KEY 176 220 221 #define BTRFS_EXTENT_DATA_REF_KEY 178 222 223 #define BTRFS_EXTENT_REF_V0_KEY 180 224 225 #define BTRFS_SHARED_BLOCK_REF_KEY 182 226 227 #define BTRFS_SHARED_DATA_REF_KEY 184 228 229 /* 230 * block groups give us hints into the extent allocation trees. Which 231 * blocks are free etc etc 232 */ 233 #define BTRFS_BLOCK_GROUP_ITEM_KEY 192 234 235 /* 236 * Every block group is represented in the free space tree by a free space info 237 * item, which stores some accounting information. It is keyed on 238 * (block_group_start, FREE_SPACE_INFO, block_group_length). 239 */ 240 #define BTRFS_FREE_SPACE_INFO_KEY 198 241 242 /* 243 * A free space extent tracks an extent of space that is free in a block group. 244 * It is keyed on (start, FREE_SPACE_EXTENT, length). 245 */ 246 #define BTRFS_FREE_SPACE_EXTENT_KEY 199 247 248 /* 249 * When a block group becomes very fragmented, we convert it to use bitmaps 250 * instead of extents. A free space bitmap is keyed on 251 * (start, FREE_SPACE_BITMAP, length); the corresponding item is a bitmap with 252 * (length / sectorsize) bits. 253 */ 254 #define BTRFS_FREE_SPACE_BITMAP_KEY 200 255 256 #define BTRFS_DEV_EXTENT_KEY 204 257 #define BTRFS_DEV_ITEM_KEY 216 258 #define BTRFS_CHUNK_ITEM_KEY 228 259 260 /* 261 * Records the overall state of the qgroups. 262 * There's only one instance of this key present, 263 * (0, BTRFS_QGROUP_STATUS_KEY, 0) 264 */ 265 #define BTRFS_QGROUP_STATUS_KEY 240 266 /* 267 * Records the currently used space of the qgroup. 268 * One key per qgroup, (0, BTRFS_QGROUP_INFO_KEY, qgroupid). 269 */ 270 #define BTRFS_QGROUP_INFO_KEY 242 271 /* 272 * Contains the user configured limits for the qgroup. 273 * One key per qgroup, (0, BTRFS_QGROUP_LIMIT_KEY, qgroupid). 274 */ 275 #define BTRFS_QGROUP_LIMIT_KEY 244 276 /* 277 * Records the child-parent relationship of qgroups. For 278 * each relation, 2 keys are present: 279 * (childid, BTRFS_QGROUP_RELATION_KEY, parentid) 280 * (parentid, BTRFS_QGROUP_RELATION_KEY, childid) 281 */ 282 #define BTRFS_QGROUP_RELATION_KEY 246 283 284 /* 285 * Obsolete name, see BTRFS_TEMPORARY_ITEM_KEY. 286 */ 287 #define BTRFS_BALANCE_ITEM_KEY 248 288 289 /* 290 * The key type for tree items that are stored persistently, but do not need to 291 * exist for extended period of time. The items can exist in any tree. 292 * 293 * [subtype, BTRFS_TEMPORARY_ITEM_KEY, data] 294 * 295 * Existing items: 296 * 297 * - balance status item 298 * (BTRFS_BALANCE_OBJECTID, BTRFS_TEMPORARY_ITEM_KEY, 0) 299 */ 300 #define BTRFS_TEMPORARY_ITEM_KEY 248 301 302 /* 303 * Obsolete name, see BTRFS_PERSISTENT_ITEM_KEY 304 */ 305 #define BTRFS_DEV_STATS_KEY 249 306 307 /* 308 * The key type for tree items that are stored persistently and usually exist 309 * for a long period, eg. filesystem lifetime. The item kinds can be status 310 * information, stats or preference values. The item can exist in any tree. 311 * 312 * [subtype, BTRFS_PERSISTENT_ITEM_KEY, data] 313 * 314 * Existing items: 315 * 316 * - device statistics, store IO stats in the device tree, one key for all 317 * stats 318 * (BTRFS_DEV_STATS_OBJECTID, BTRFS_DEV_STATS_KEY, 0) 319 */ 320 #define BTRFS_PERSISTENT_ITEM_KEY 249 321 322 /* 323 * Persistently stores the device replace state in the device tree. 324 * The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0). 325 */ 326 #define BTRFS_DEV_REPLACE_KEY 250 327 328 /* 329 * Stores items that allow to quickly map UUIDs to something else. 330 * These items are part of the filesystem UUID tree. 331 * The key is built like this: 332 * (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits). 333 */ 334 #if BTRFS_UUID_SIZE != 16 335 #error "UUID items require BTRFS_UUID_SIZE == 16!" 336 #endif 337 #define BTRFS_UUID_KEY_SUBVOL 251 /* for UUIDs assigned to subvols */ 338 #define BTRFS_UUID_KEY_RECEIVED_SUBVOL 252 /* for UUIDs assigned to 339 * received subvols */ 340 341 /* 342 * string items are for debugging. They just store a short string of 343 * data in the FS 344 */ 345 #define BTRFS_STRING_ITEM_KEY 253 346 347 /* Maximum metadata block size (nodesize) */ 348 #define BTRFS_MAX_METADATA_BLOCKSIZE 65536 349 350 /* 32 bytes in various csum fields */ 351 #define BTRFS_CSUM_SIZE 32 352 353 /* csum types */ 354 enum btrfs_csum_type { 355 BTRFS_CSUM_TYPE_CRC32 = 0, 356 BTRFS_CSUM_TYPE_XXHASH = 1, 357 BTRFS_CSUM_TYPE_SHA256 = 2, 358 BTRFS_CSUM_TYPE_BLAKE2 = 3, 359 }; 360 361 /* 362 * flags definitions for directory entry item type 363 * 364 * Used by: 365 * struct btrfs_dir_item.type 366 * 367 * Values 0..7 must match common file type values in fs_types.h. 368 */ 369 #define BTRFS_FT_UNKNOWN 0 370 #define BTRFS_FT_REG_FILE 1 371 #define BTRFS_FT_DIR 2 372 #define BTRFS_FT_CHRDEV 3 373 #define BTRFS_FT_BLKDEV 4 374 #define BTRFS_FT_FIFO 5 375 #define BTRFS_FT_SOCK 6 376 #define BTRFS_FT_SYMLINK 7 377 #define BTRFS_FT_XATTR 8 378 #define BTRFS_FT_MAX 9 379 380 /* 381 * Inode flags 382 */ 383 #define BTRFS_INODE_NODATASUM (1U << 0) 384 #define BTRFS_INODE_NODATACOW (1U << 1) 385 #define BTRFS_INODE_READONLY (1U << 2) 386 #define BTRFS_INODE_NOCOMPRESS (1U << 3) 387 #define BTRFS_INODE_PREALLOC (1U << 4) 388 #define BTRFS_INODE_SYNC (1U << 5) 389 #define BTRFS_INODE_IMMUTABLE (1U << 6) 390 #define BTRFS_INODE_APPEND (1U << 7) 391 #define BTRFS_INODE_NODUMP (1U << 8) 392 #define BTRFS_INODE_NOATIME (1U << 9) 393 #define BTRFS_INODE_DIRSYNC (1U << 10) 394 #define BTRFS_INODE_COMPRESS (1U << 11) 395 396 #define BTRFS_INODE_ROOT_ITEM_INIT (1U << 31) 397 398 #define BTRFS_INODE_FLAG_MASK \ 399 (BTRFS_INODE_NODATASUM | \ 400 BTRFS_INODE_NODATACOW | \ 401 BTRFS_INODE_READONLY | \ 402 BTRFS_INODE_NOCOMPRESS | \ 403 BTRFS_INODE_PREALLOC | \ 404 BTRFS_INODE_SYNC | \ 405 BTRFS_INODE_IMMUTABLE | \ 406 BTRFS_INODE_APPEND | \ 407 BTRFS_INODE_NODUMP | \ 408 BTRFS_INODE_NOATIME | \ 409 BTRFS_INODE_DIRSYNC | \ 410 BTRFS_INODE_COMPRESS | \ 411 BTRFS_INODE_ROOT_ITEM_INIT) 412 413 #define BTRFS_INODE_RO_VERITY (1U << 0) 414 415 #define BTRFS_INODE_RO_FLAG_MASK (BTRFS_INODE_RO_VERITY) 416 417 /* 418 * The key defines the order in the tree, and so it also defines (optimal) 419 * block layout. 420 * 421 * objectid corresponds to the inode number. 422 * 423 * type tells us things about the object, and is a kind of stream selector. 424 * so for a given inode, keys with type of 1 might refer to the inode data, 425 * type of 2 may point to file data in the btree and type == 3 may point to 426 * extents. 427 * 428 * offset is the starting byte offset for this key in the stream. 429 * 430 * btrfs_disk_key is in disk byte order. struct btrfs_key is always 431 * in cpu native order. Otherwise they are identical and their sizes 432 * should be the same (ie both packed) 433 */ 434 struct btrfs_disk_key { 435 __le64 objectid; 436 __u8 type; 437 __le64 offset; 438 } __attribute__ ((__packed__)); 439 440 struct btrfs_key { 441 __u64 objectid; 442 __u8 type; 443 __u64 offset; 444 } __attribute__ ((__packed__)); 445 446 /* 447 * Every tree block (leaf or node) starts with this header. 448 */ 449 struct btrfs_header { 450 /* These first four must match the super block */ 451 __u8 csum[BTRFS_CSUM_SIZE]; 452 /* FS specific uuid */ 453 __u8 fsid[BTRFS_FSID_SIZE]; 454 /* Which block this node is supposed to live in */ 455 __le64 bytenr; 456 __le64 flags; 457 458 /* Allowed to be different from the super from here on down */ 459 __u8 chunk_tree_uuid[BTRFS_UUID_SIZE]; 460 __le64 generation; 461 __le64 owner; 462 __le32 nritems; 463 __u8 level; 464 } __attribute__ ((__packed__)); 465 466 /* 467 * This is a very generous portion of the super block, giving us room to 468 * translate 14 chunks with 3 stripes each. 469 */ 470 #define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048 471 472 /* 473 * Just in case we somehow lose the roots and are not able to mount, we store 474 * an array of the roots from previous transactions in the super. 475 */ 476 #define BTRFS_NUM_BACKUP_ROOTS 4 477 struct btrfs_root_backup { 478 __le64 tree_root; 479 __le64 tree_root_gen; 480 481 __le64 chunk_root; 482 __le64 chunk_root_gen; 483 484 __le64 extent_root; 485 __le64 extent_root_gen; 486 487 __le64 fs_root; 488 __le64 fs_root_gen; 489 490 __le64 dev_root; 491 __le64 dev_root_gen; 492 493 __le64 csum_root; 494 __le64 csum_root_gen; 495 496 __le64 total_bytes; 497 __le64 bytes_used; 498 __le64 num_devices; 499 /* future */ 500 __le64 unused_64[4]; 501 502 __u8 tree_root_level; 503 __u8 chunk_root_level; 504 __u8 extent_root_level; 505 __u8 fs_root_level; 506 __u8 dev_root_level; 507 __u8 csum_root_level; 508 /* future and to align */ 509 __u8 unused_8[10]; 510 } __attribute__ ((__packed__)); 511 512 /* 513 * A leaf is full of items. offset and size tell us where to find the item in 514 * the leaf (relative to the start of the data area) 515 */ 516 struct btrfs_item { 517 struct btrfs_disk_key key; 518 __le32 offset; 519 __le32 size; 520 } __attribute__ ((__packed__)); 521 522 /* 523 * Leaves have an item area and a data area: 524 * [item0, item1....itemN] [free space] [dataN...data1, data0] 525 * 526 * The data is separate from the items to get the keys closer together during 527 * searches. 528 */ 529 struct btrfs_leaf { 530 struct btrfs_header header; 531 struct btrfs_item items[]; 532 } __attribute__ ((__packed__)); 533 534 /* 535 * All non-leaf blocks are nodes, they hold only keys and pointers to other 536 * blocks. 537 */ 538 struct btrfs_key_ptr { 539 struct btrfs_disk_key key; 540 __le64 blockptr; 541 __le64 generation; 542 } __attribute__ ((__packed__)); 543 544 struct btrfs_node { 545 struct btrfs_header header; 546 struct btrfs_key_ptr ptrs[]; 547 } __attribute__ ((__packed__)); 548 549 struct btrfs_dev_item { 550 /* the internal btrfs device id */ 551 __le64 devid; 552 553 /* size of the device */ 554 __le64 total_bytes; 555 556 /* bytes used */ 557 __le64 bytes_used; 558 559 /* optimal io alignment for this device */ 560 __le32 io_align; 561 562 /* optimal io width for this device */ 563 __le32 io_width; 564 565 /* minimal io size for this device */ 566 __le32 sector_size; 567 568 /* type and info about this device */ 569 __le64 type; 570 571 /* expected generation for this device */ 572 __le64 generation; 573 574 /* 575 * starting byte of this partition on the device, 576 * to allow for stripe alignment in the future 577 */ 578 __le64 start_offset; 579 580 /* grouping information for allocation decisions */ 581 __le32 dev_group; 582 583 /* seek speed 0-100 where 100 is fastest */ 584 __u8 seek_speed; 585 586 /* bandwidth 0-100 where 100 is fastest */ 587 __u8 bandwidth; 588 589 /* btrfs generated uuid for this device */ 590 __u8 uuid[BTRFS_UUID_SIZE]; 591 592 /* uuid of FS who owns this device */ 593 __u8 fsid[BTRFS_UUID_SIZE]; 594 } __attribute__ ((__packed__)); 595 596 struct btrfs_stripe { 597 __le64 devid; 598 __le64 offset; 599 __u8 dev_uuid[BTRFS_UUID_SIZE]; 600 } __attribute__ ((__packed__)); 601 602 struct btrfs_chunk { 603 /* size of this chunk in bytes */ 604 __le64 length; 605 606 /* objectid of the root referencing this chunk */ 607 __le64 owner; 608 609 __le64 stripe_len; 610 __le64 type; 611 612 /* optimal io alignment for this chunk */ 613 __le32 io_align; 614 615 /* optimal io width for this chunk */ 616 __le32 io_width; 617 618 /* minimal io size for this chunk */ 619 __le32 sector_size; 620 621 /* 2^16 stripes is quite a lot, a second limit is the size of a single 622 * item in the btree 623 */ 624 __le16 num_stripes; 625 626 /* sub stripes only matter for raid10 */ 627 __le16 sub_stripes; 628 struct btrfs_stripe stripe; 629 /* additional stripes go here */ 630 } __attribute__ ((__packed__)); 631 632 /* 633 * The super block basically lists the main trees of the FS. 634 */ 635 struct btrfs_super_block { 636 /* The first 4 fields must match struct btrfs_header */ 637 __u8 csum[BTRFS_CSUM_SIZE]; 638 /* FS specific UUID, visible to user */ 639 __u8 fsid[BTRFS_FSID_SIZE]; 640 /* This block number */ 641 __le64 bytenr; 642 __le64 flags; 643 644 /* Allowed to be different from the btrfs_header from here own down */ 645 __le64 magic; 646 __le64 generation; 647 __le64 root; 648 __le64 chunk_root; 649 __le64 log_root; 650 651 /* 652 * This member has never been utilized since the very beginning, thus 653 * it's always 0 regardless of kernel version. We always use 654 * generation + 1 to read log tree root. So here we mark it deprecated. 655 */ 656 __le64 __unused_log_root_transid; 657 __le64 total_bytes; 658 __le64 bytes_used; 659 __le64 root_dir_objectid; 660 __le64 num_devices; 661 __le32 sectorsize; 662 __le32 nodesize; 663 __le32 __unused_leafsize; 664 __le32 stripesize; 665 __le32 sys_chunk_array_size; 666 __le64 chunk_root_generation; 667 __le64 compat_flags; 668 __le64 compat_ro_flags; 669 __le64 incompat_flags; 670 __le16 csum_type; 671 __u8 root_level; 672 __u8 chunk_root_level; 673 __u8 log_root_level; 674 struct btrfs_dev_item dev_item; 675 676 char label[BTRFS_LABEL_SIZE]; 677 678 __le64 cache_generation; 679 __le64 uuid_tree_generation; 680 681 /* The UUID written into btree blocks */ 682 __u8 metadata_uuid[BTRFS_FSID_SIZE]; 683 684 /* Future expansion */ 685 __u8 reserved8[8]; 686 __le64 reserved[27]; 687 __u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE]; 688 struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS]; 689 690 /* Padded to 4096 bytes */ 691 __u8 padding[565]; 692 } __attribute__ ((__packed__)); 693 694 #define BTRFS_FREE_SPACE_EXTENT 1 695 #define BTRFS_FREE_SPACE_BITMAP 2 696 697 struct btrfs_free_space_entry { 698 __le64 offset; 699 __le64 bytes; 700 __u8 type; 701 } __attribute__ ((__packed__)); 702 703 struct btrfs_free_space_header { 704 struct btrfs_disk_key location; 705 __le64 generation; 706 __le64 num_entries; 707 __le64 num_bitmaps; 708 } __attribute__ ((__packed__)); 709 710 #define BTRFS_HEADER_FLAG_WRITTEN (1ULL << 0) 711 #define BTRFS_HEADER_FLAG_RELOC (1ULL << 1) 712 713 /* Super block flags */ 714 /* Errors detected */ 715 #define BTRFS_SUPER_FLAG_ERROR (1ULL << 2) 716 717 #define BTRFS_SUPER_FLAG_SEEDING (1ULL << 32) 718 #define BTRFS_SUPER_FLAG_METADUMP (1ULL << 33) 719 #define BTRFS_SUPER_FLAG_METADUMP_V2 (1ULL << 34) 720 #define BTRFS_SUPER_FLAG_CHANGING_FSID (1ULL << 35) 721 #define BTRFS_SUPER_FLAG_CHANGING_FSID_V2 (1ULL << 36) 722 723 724 /* 725 * items in the extent btree are used to record the objectid of the 726 * owner of the block and the number of references 727 */ 728 729 struct btrfs_extent_item { 730 __le64 refs; 731 __le64 generation; 732 __le64 flags; 733 } __attribute__ ((__packed__)); 734 735 struct btrfs_extent_item_v0 { 736 __le32 refs; 737 } __attribute__ ((__packed__)); 738 739 740 #define BTRFS_EXTENT_FLAG_DATA (1ULL << 0) 741 #define BTRFS_EXTENT_FLAG_TREE_BLOCK (1ULL << 1) 742 743 /* following flags only apply to tree blocks */ 744 745 /* use full backrefs for extent pointers in the block */ 746 #define BTRFS_BLOCK_FLAG_FULL_BACKREF (1ULL << 8) 747 748 #define BTRFS_BACKREF_REV_MAX 256 749 #define BTRFS_BACKREF_REV_SHIFT 56 750 #define BTRFS_BACKREF_REV_MASK (((u64)BTRFS_BACKREF_REV_MAX - 1) << \ 751 BTRFS_BACKREF_REV_SHIFT) 752 753 #define BTRFS_OLD_BACKREF_REV 0 754 #define BTRFS_MIXED_BACKREF_REV 1 755 756 /* 757 * this flag is only used internally by scrub and may be changed at any time 758 * it is only declared here to avoid collisions 759 */ 760 #define BTRFS_EXTENT_FLAG_SUPER (1ULL << 48) 761 762 struct btrfs_tree_block_info { 763 struct btrfs_disk_key key; 764 __u8 level; 765 } __attribute__ ((__packed__)); 766 767 struct btrfs_extent_data_ref { 768 __le64 root; 769 __le64 objectid; 770 __le64 offset; 771 __le32 count; 772 } __attribute__ ((__packed__)); 773 774 struct btrfs_shared_data_ref { 775 __le32 count; 776 } __attribute__ ((__packed__)); 777 778 struct btrfs_extent_inline_ref { 779 __u8 type; 780 __le64 offset; 781 } __attribute__ ((__packed__)); 782 783 /* dev extents record free space on individual devices. The owner 784 * field points back to the chunk allocation mapping tree that allocated 785 * the extent. The chunk tree uuid field is a way to double check the owner 786 */ 787 struct btrfs_dev_extent { 788 __le64 chunk_tree; 789 __le64 chunk_objectid; 790 __le64 chunk_offset; 791 __le64 length; 792 __u8 chunk_tree_uuid[BTRFS_UUID_SIZE]; 793 } __attribute__ ((__packed__)); 794 795 struct btrfs_inode_ref { 796 __le64 index; 797 __le16 name_len; 798 /* name goes here */ 799 } __attribute__ ((__packed__)); 800 801 struct btrfs_inode_extref { 802 __le64 parent_objectid; 803 __le64 index; 804 __le16 name_len; 805 __u8 name[]; 806 /* name goes here */ 807 } __attribute__ ((__packed__)); 808 809 struct btrfs_timespec { 810 __le64 sec; 811 __le32 nsec; 812 } __attribute__ ((__packed__)); 813 814 struct btrfs_inode_item { 815 /* nfs style generation number */ 816 __le64 generation; 817 /* transid that last touched this inode */ 818 __le64 transid; 819 __le64 size; 820 __le64 nbytes; 821 __le64 block_group; 822 __le32 nlink; 823 __le32 uid; 824 __le32 gid; 825 __le32 mode; 826 __le64 rdev; 827 __le64 flags; 828 829 /* modification sequence number for NFS */ 830 __le64 sequence; 831 832 /* 833 * a little future expansion, for more than this we can 834 * just grow the inode item and version it 835 */ 836 __le64 reserved[4]; 837 struct btrfs_timespec atime; 838 struct btrfs_timespec ctime; 839 struct btrfs_timespec mtime; 840 struct btrfs_timespec otime; 841 } __attribute__ ((__packed__)); 842 843 struct btrfs_dir_log_item { 844 __le64 end; 845 } __attribute__ ((__packed__)); 846 847 struct btrfs_dir_item { 848 struct btrfs_disk_key location; 849 __le64 transid; 850 __le16 data_len; 851 __le16 name_len; 852 __u8 type; 853 } __attribute__ ((__packed__)); 854 855 #define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0) 856 857 /* 858 * Internal in-memory flag that a subvolume has been marked for deletion but 859 * still visible as a directory 860 */ 861 #define BTRFS_ROOT_SUBVOL_DEAD (1ULL << 48) 862 863 struct btrfs_root_item { 864 struct btrfs_inode_item inode; 865 __le64 generation; 866 __le64 root_dirid; 867 __le64 bytenr; 868 __le64 byte_limit; 869 __le64 bytes_used; 870 __le64 last_snapshot; 871 __le64 flags; 872 __le32 refs; 873 struct btrfs_disk_key drop_progress; 874 __u8 drop_level; 875 __u8 level; 876 877 /* 878 * The following fields appear after subvol_uuids+subvol_times 879 * were introduced. 880 */ 881 882 /* 883 * This generation number is used to test if the new fields are valid 884 * and up to date while reading the root item. Every time the root item 885 * is written out, the "generation" field is copied into this field. If 886 * anyone ever mounted the fs with an older kernel, we will have 887 * mismatching generation values here and thus must invalidate the 888 * new fields. See btrfs_update_root and btrfs_find_last_root for 889 * details. 890 * the offset of generation_v2 is also used as the start for the memset 891 * when invalidating the fields. 892 */ 893 __le64 generation_v2; 894 __u8 uuid[BTRFS_UUID_SIZE]; 895 __u8 parent_uuid[BTRFS_UUID_SIZE]; 896 __u8 received_uuid[BTRFS_UUID_SIZE]; 897 __le64 ctransid; /* updated when an inode changes */ 898 __le64 otransid; /* trans when created */ 899 __le64 stransid; /* trans when sent. non-zero for received subvol */ 900 __le64 rtransid; /* trans when received. non-zero for received subvol */ 901 struct btrfs_timespec ctime; 902 struct btrfs_timespec otime; 903 struct btrfs_timespec stime; 904 struct btrfs_timespec rtime; 905 __le64 reserved[8]; /* for future */ 906 } __attribute__ ((__packed__)); 907 908 /* 909 * Btrfs root item used to be smaller than current size. The old format ends 910 * at where member generation_v2 is. 911 */ 912 static inline __u32 btrfs_legacy_root_item_size(void) 913 { 914 return offsetof(struct btrfs_root_item, generation_v2); 915 } 916 917 /* 918 * this is used for both forward and backward root refs 919 */ 920 struct btrfs_root_ref { 921 __le64 dirid; 922 __le64 sequence; 923 __le16 name_len; 924 } __attribute__ ((__packed__)); 925 926 struct btrfs_disk_balance_args { 927 /* 928 * profiles to operate on, single is denoted by 929 * BTRFS_AVAIL_ALLOC_BIT_SINGLE 930 */ 931 __le64 profiles; 932 933 /* 934 * usage filter 935 * BTRFS_BALANCE_ARGS_USAGE with a single value means '0..N' 936 * BTRFS_BALANCE_ARGS_USAGE_RANGE - range syntax, min..max 937 */ 938 union { 939 __le64 usage; 940 struct { 941 __le32 usage_min; 942 __le32 usage_max; 943 }; 944 }; 945 946 /* devid filter */ 947 __le64 devid; 948 949 /* devid subset filter [pstart..pend) */ 950 __le64 pstart; 951 __le64 pend; 952 953 /* btrfs virtual address space subset filter [vstart..vend) */ 954 __le64 vstart; 955 __le64 vend; 956 957 /* 958 * profile to convert to, single is denoted by 959 * BTRFS_AVAIL_ALLOC_BIT_SINGLE 960 */ 961 __le64 target; 962 963 /* BTRFS_BALANCE_ARGS_* */ 964 __le64 flags; 965 966 /* 967 * BTRFS_BALANCE_ARGS_LIMIT with value 'limit' 968 * BTRFS_BALANCE_ARGS_LIMIT_RANGE - the extend version can use minimum 969 * and maximum 970 */ 971 union { 972 __le64 limit; 973 struct { 974 __le32 limit_min; 975 __le32 limit_max; 976 }; 977 }; 978 979 /* 980 * Process chunks that cross stripes_min..stripes_max devices, 981 * BTRFS_BALANCE_ARGS_STRIPES_RANGE 982 */ 983 __le32 stripes_min; 984 __le32 stripes_max; 985 986 __le64 unused[6]; 987 } __attribute__ ((__packed__)); 988 989 /* 990 * store balance parameters to disk so that balance can be properly 991 * resumed after crash or unmount 992 */ 993 struct btrfs_balance_item { 994 /* BTRFS_BALANCE_* */ 995 __le64 flags; 996 997 struct btrfs_disk_balance_args data; 998 struct btrfs_disk_balance_args meta; 999 struct btrfs_disk_balance_args sys; 1000 1001 __le64 unused[4]; 1002 } __attribute__ ((__packed__)); 1003 1004 enum { 1005 BTRFS_FILE_EXTENT_INLINE = 0, 1006 BTRFS_FILE_EXTENT_REG = 1, 1007 BTRFS_FILE_EXTENT_PREALLOC = 2, 1008 BTRFS_NR_FILE_EXTENT_TYPES = 3, 1009 }; 1010 1011 struct btrfs_file_extent_item { 1012 /* 1013 * transaction id that created this extent 1014 */ 1015 __le64 generation; 1016 /* 1017 * max number of bytes to hold this extent in ram 1018 * when we split a compressed extent we can't know how big 1019 * each of the resulting pieces will be. So, this is 1020 * an upper limit on the size of the extent in ram instead of 1021 * an exact limit. 1022 */ 1023 __le64 ram_bytes; 1024 1025 /* 1026 * 32 bits for the various ways we might encode the data, 1027 * including compression and encryption. If any of these 1028 * are set to something a given disk format doesn't understand 1029 * it is treated like an incompat flag for reading and writing, 1030 * but not for stat. 1031 */ 1032 __u8 compression; 1033 __u8 encryption; 1034 __le16 other_encoding; /* spare for later use */ 1035 1036 /* are we inline data or a real extent? */ 1037 __u8 type; 1038 1039 /* 1040 * disk space consumed by the extent, checksum blocks are included 1041 * in these numbers 1042 * 1043 * At this offset in the structure, the inline extent data start. 1044 */ 1045 __le64 disk_bytenr; 1046 __le64 disk_num_bytes; 1047 /* 1048 * the logical offset in file blocks (no csums) 1049 * this extent record is for. This allows a file extent to point 1050 * into the middle of an existing extent on disk, sharing it 1051 * between two snapshots (useful if some bytes in the middle of the 1052 * extent have changed 1053 */ 1054 __le64 offset; 1055 /* 1056 * the logical number of file blocks (no csums included). This 1057 * always reflects the size uncompressed and without encoding. 1058 */ 1059 __le64 num_bytes; 1060 1061 } __attribute__ ((__packed__)); 1062 1063 struct btrfs_csum_item { 1064 __u8 csum; 1065 } __attribute__ ((__packed__)); 1066 1067 struct btrfs_dev_stats_item { 1068 /* 1069 * grow this item struct at the end for future enhancements and keep 1070 * the existing values unchanged 1071 */ 1072 __le64 values[BTRFS_DEV_STAT_VALUES_MAX]; 1073 } __attribute__ ((__packed__)); 1074 1075 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS 0 1076 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID 1 1077 1078 struct btrfs_dev_replace_item { 1079 /* 1080 * grow this item struct at the end for future enhancements and keep 1081 * the existing values unchanged 1082 */ 1083 __le64 src_devid; 1084 __le64 cursor_left; 1085 __le64 cursor_right; 1086 __le64 cont_reading_from_srcdev_mode; 1087 1088 __le64 replace_state; 1089 __le64 time_started; 1090 __le64 time_stopped; 1091 __le64 num_write_errors; 1092 __le64 num_uncorrectable_read_errors; 1093 } __attribute__ ((__packed__)); 1094 1095 /* different types of block groups (and chunks) */ 1096 #define BTRFS_BLOCK_GROUP_DATA (1ULL << 0) 1097 #define BTRFS_BLOCK_GROUP_SYSTEM (1ULL << 1) 1098 #define BTRFS_BLOCK_GROUP_METADATA (1ULL << 2) 1099 #define BTRFS_BLOCK_GROUP_RAID0 (1ULL << 3) 1100 #define BTRFS_BLOCK_GROUP_RAID1 (1ULL << 4) 1101 #define BTRFS_BLOCK_GROUP_DUP (1ULL << 5) 1102 #define BTRFS_BLOCK_GROUP_RAID10 (1ULL << 6) 1103 #define BTRFS_BLOCK_GROUP_RAID5 (1ULL << 7) 1104 #define BTRFS_BLOCK_GROUP_RAID6 (1ULL << 8) 1105 #define BTRFS_BLOCK_GROUP_RAID1C3 (1ULL << 9) 1106 #define BTRFS_BLOCK_GROUP_RAID1C4 (1ULL << 10) 1107 #define BTRFS_BLOCK_GROUP_RESERVED (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \ 1108 BTRFS_SPACE_INFO_GLOBAL_RSV) 1109 1110 #define BTRFS_BLOCK_GROUP_TYPE_MASK (BTRFS_BLOCK_GROUP_DATA | \ 1111 BTRFS_BLOCK_GROUP_SYSTEM | \ 1112 BTRFS_BLOCK_GROUP_METADATA) 1113 1114 #define BTRFS_BLOCK_GROUP_PROFILE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \ 1115 BTRFS_BLOCK_GROUP_RAID1 | \ 1116 BTRFS_BLOCK_GROUP_RAID1C3 | \ 1117 BTRFS_BLOCK_GROUP_RAID1C4 | \ 1118 BTRFS_BLOCK_GROUP_RAID5 | \ 1119 BTRFS_BLOCK_GROUP_RAID6 | \ 1120 BTRFS_BLOCK_GROUP_DUP | \ 1121 BTRFS_BLOCK_GROUP_RAID10) 1122 #define BTRFS_BLOCK_GROUP_RAID56_MASK (BTRFS_BLOCK_GROUP_RAID5 | \ 1123 BTRFS_BLOCK_GROUP_RAID6) 1124 1125 #define BTRFS_BLOCK_GROUP_RAID1_MASK (BTRFS_BLOCK_GROUP_RAID1 | \ 1126 BTRFS_BLOCK_GROUP_RAID1C3 | \ 1127 BTRFS_BLOCK_GROUP_RAID1C4) 1128 1129 /* 1130 * We need a bit for restriper to be able to tell when chunks of type 1131 * SINGLE are available. This "extended" profile format is used in 1132 * fs_info->avail_*_alloc_bits (in-memory) and balance item fields 1133 * (on-disk). The corresponding on-disk bit in chunk.type is reserved 1134 * to avoid remappings between two formats in future. 1135 */ 1136 #define BTRFS_AVAIL_ALLOC_BIT_SINGLE (1ULL << 48) 1137 1138 /* 1139 * A fake block group type that is used to communicate global block reserve 1140 * size to userspace via the SPACE_INFO ioctl. 1141 */ 1142 #define BTRFS_SPACE_INFO_GLOBAL_RSV (1ULL << 49) 1143 1144 #define BTRFS_EXTENDED_PROFILE_MASK (BTRFS_BLOCK_GROUP_PROFILE_MASK | \ 1145 BTRFS_AVAIL_ALLOC_BIT_SINGLE) 1146 1147 static inline __u64 chunk_to_extended(__u64 flags) 1148 { 1149 if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0) 1150 flags |= BTRFS_AVAIL_ALLOC_BIT_SINGLE; 1151 1152 return flags; 1153 } 1154 static inline __u64 extended_to_chunk(__u64 flags) 1155 { 1156 return flags & ~BTRFS_AVAIL_ALLOC_BIT_SINGLE; 1157 } 1158 1159 struct btrfs_block_group_item { 1160 __le64 used; 1161 __le64 chunk_objectid; 1162 __le64 flags; 1163 } __attribute__ ((__packed__)); 1164 1165 struct btrfs_free_space_info { 1166 __le32 extent_count; 1167 __le32 flags; 1168 } __attribute__ ((__packed__)); 1169 1170 #define BTRFS_FREE_SPACE_USING_BITMAPS (1ULL << 0) 1171 1172 #define BTRFS_QGROUP_LEVEL_SHIFT 48 1173 static inline __u16 btrfs_qgroup_level(__u64 qgroupid) 1174 { 1175 return (__u16)(qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT); 1176 } 1177 1178 /* 1179 * is subvolume quota turned on? 1180 */ 1181 #define BTRFS_QGROUP_STATUS_FLAG_ON (1ULL << 0) 1182 /* 1183 * RESCAN is set during the initialization phase 1184 */ 1185 #define BTRFS_QGROUP_STATUS_FLAG_RESCAN (1ULL << 1) 1186 /* 1187 * Some qgroup entries are known to be out of date, 1188 * either because the configuration has changed in a way that 1189 * makes a rescan necessary, or because the fs has been mounted 1190 * with a non-qgroup-aware version. 1191 * Turning qouta off and on again makes it inconsistent, too. 1192 */ 1193 #define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT (1ULL << 2) 1194 1195 #define BTRFS_QGROUP_STATUS_FLAGS_MASK (BTRFS_QGROUP_STATUS_FLAG_ON | \ 1196 BTRFS_QGROUP_STATUS_FLAG_RESCAN | \ 1197 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) 1198 1199 #define BTRFS_QGROUP_STATUS_VERSION 1 1200 1201 struct btrfs_qgroup_status_item { 1202 __le64 version; 1203 /* 1204 * the generation is updated during every commit. As older 1205 * versions of btrfs are not aware of qgroups, it will be 1206 * possible to detect inconsistencies by checking the 1207 * generation on mount time 1208 */ 1209 __le64 generation; 1210 1211 /* flag definitions see above */ 1212 __le64 flags; 1213 1214 /* 1215 * only used during scanning to record the progress 1216 * of the scan. It contains a logical address 1217 */ 1218 __le64 rescan; 1219 } __attribute__ ((__packed__)); 1220 1221 struct btrfs_qgroup_info_item { 1222 __le64 generation; 1223 __le64 rfer; 1224 __le64 rfer_cmpr; 1225 __le64 excl; 1226 __le64 excl_cmpr; 1227 } __attribute__ ((__packed__)); 1228 1229 struct btrfs_qgroup_limit_item { 1230 /* 1231 * only updated when any of the other values change 1232 */ 1233 __le64 flags; 1234 __le64 max_rfer; 1235 __le64 max_excl; 1236 __le64 rsv_rfer; 1237 __le64 rsv_excl; 1238 } __attribute__ ((__packed__)); 1239 1240 struct btrfs_verity_descriptor_item { 1241 /* Size of the verity descriptor in bytes */ 1242 __le64 size; 1243 /* 1244 * When we implement support for fscrypt, we will need to encrypt the 1245 * Merkle tree for encrypted verity files. These 128 bits are for the 1246 * eventual storage of an fscrypt initialization vector. 1247 */ 1248 __le64 reserved[2]; 1249 __u8 encryption; 1250 } __attribute__ ((__packed__)); 1251 1252 #endif /* _BTRFS_CTREE_H_ */ 1253