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 /* 224 * Obsolete key. Defintion removed in 6.6, value may be reused in the future. 225 * 226 * #define BTRFS_EXTENT_REF_V0_KEY 180 227 */ 228 229 #define BTRFS_SHARED_BLOCK_REF_KEY 182 230 231 #define BTRFS_SHARED_DATA_REF_KEY 184 232 233 /* 234 * block groups give us hints into the extent allocation trees. Which 235 * blocks are free etc etc 236 */ 237 #define BTRFS_BLOCK_GROUP_ITEM_KEY 192 238 239 /* 240 * Every block group is represented in the free space tree by a free space info 241 * item, which stores some accounting information. It is keyed on 242 * (block_group_start, FREE_SPACE_INFO, block_group_length). 243 */ 244 #define BTRFS_FREE_SPACE_INFO_KEY 198 245 246 /* 247 * A free space extent tracks an extent of space that is free in a block group. 248 * It is keyed on (start, FREE_SPACE_EXTENT, length). 249 */ 250 #define BTRFS_FREE_SPACE_EXTENT_KEY 199 251 252 /* 253 * When a block group becomes very fragmented, we convert it to use bitmaps 254 * instead of extents. A free space bitmap is keyed on 255 * (start, FREE_SPACE_BITMAP, length); the corresponding item is a bitmap with 256 * (length / sectorsize) bits. 257 */ 258 #define BTRFS_FREE_SPACE_BITMAP_KEY 200 259 260 #define BTRFS_DEV_EXTENT_KEY 204 261 #define BTRFS_DEV_ITEM_KEY 216 262 #define BTRFS_CHUNK_ITEM_KEY 228 263 264 /* 265 * Records the overall state of the qgroups. 266 * There's only one instance of this key present, 267 * (0, BTRFS_QGROUP_STATUS_KEY, 0) 268 */ 269 #define BTRFS_QGROUP_STATUS_KEY 240 270 /* 271 * Records the currently used space of the qgroup. 272 * One key per qgroup, (0, BTRFS_QGROUP_INFO_KEY, qgroupid). 273 */ 274 #define BTRFS_QGROUP_INFO_KEY 242 275 /* 276 * Contains the user configured limits for the qgroup. 277 * One key per qgroup, (0, BTRFS_QGROUP_LIMIT_KEY, qgroupid). 278 */ 279 #define BTRFS_QGROUP_LIMIT_KEY 244 280 /* 281 * Records the child-parent relationship of qgroups. For 282 * each relation, 2 keys are present: 283 * (childid, BTRFS_QGROUP_RELATION_KEY, parentid) 284 * (parentid, BTRFS_QGROUP_RELATION_KEY, childid) 285 */ 286 #define BTRFS_QGROUP_RELATION_KEY 246 287 288 /* 289 * Obsolete name, see BTRFS_TEMPORARY_ITEM_KEY. 290 */ 291 #define BTRFS_BALANCE_ITEM_KEY 248 292 293 /* 294 * The key type for tree items that are stored persistently, but do not need to 295 * exist for extended period of time. The items can exist in any tree. 296 * 297 * [subtype, BTRFS_TEMPORARY_ITEM_KEY, data] 298 * 299 * Existing items: 300 * 301 * - balance status item 302 * (BTRFS_BALANCE_OBJECTID, BTRFS_TEMPORARY_ITEM_KEY, 0) 303 */ 304 #define BTRFS_TEMPORARY_ITEM_KEY 248 305 306 /* 307 * Obsolete name, see BTRFS_PERSISTENT_ITEM_KEY 308 */ 309 #define BTRFS_DEV_STATS_KEY 249 310 311 /* 312 * The key type for tree items that are stored persistently and usually exist 313 * for a long period, eg. filesystem lifetime. The item kinds can be status 314 * information, stats or preference values. The item can exist in any tree. 315 * 316 * [subtype, BTRFS_PERSISTENT_ITEM_KEY, data] 317 * 318 * Existing items: 319 * 320 * - device statistics, store IO stats in the device tree, one key for all 321 * stats 322 * (BTRFS_DEV_STATS_OBJECTID, BTRFS_DEV_STATS_KEY, 0) 323 */ 324 #define BTRFS_PERSISTENT_ITEM_KEY 249 325 326 /* 327 * Persistently stores the device replace state in the device tree. 328 * The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0). 329 */ 330 #define BTRFS_DEV_REPLACE_KEY 250 331 332 /* 333 * Stores items that allow to quickly map UUIDs to something else. 334 * These items are part of the filesystem UUID tree. 335 * The key is built like this: 336 * (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits). 337 */ 338 #if BTRFS_UUID_SIZE != 16 339 #error "UUID items require BTRFS_UUID_SIZE == 16!" 340 #endif 341 #define BTRFS_UUID_KEY_SUBVOL 251 /* for UUIDs assigned to subvols */ 342 #define BTRFS_UUID_KEY_RECEIVED_SUBVOL 252 /* for UUIDs assigned to 343 * received subvols */ 344 345 /* 346 * string items are for debugging. They just store a short string of 347 * data in the FS 348 */ 349 #define BTRFS_STRING_ITEM_KEY 253 350 351 /* Maximum metadata block size (nodesize) */ 352 #define BTRFS_MAX_METADATA_BLOCKSIZE 65536 353 354 /* 32 bytes in various csum fields */ 355 #define BTRFS_CSUM_SIZE 32 356 357 /* csum types */ 358 enum btrfs_csum_type { 359 BTRFS_CSUM_TYPE_CRC32 = 0, 360 BTRFS_CSUM_TYPE_XXHASH = 1, 361 BTRFS_CSUM_TYPE_SHA256 = 2, 362 BTRFS_CSUM_TYPE_BLAKE2 = 3, 363 }; 364 365 /* 366 * flags definitions for directory entry item type 367 * 368 * Used by: 369 * struct btrfs_dir_item.type 370 * 371 * Values 0..7 must match common file type values in fs_types.h. 372 */ 373 #define BTRFS_FT_UNKNOWN 0 374 #define BTRFS_FT_REG_FILE 1 375 #define BTRFS_FT_DIR 2 376 #define BTRFS_FT_CHRDEV 3 377 #define BTRFS_FT_BLKDEV 4 378 #define BTRFS_FT_FIFO 5 379 #define BTRFS_FT_SOCK 6 380 #define BTRFS_FT_SYMLINK 7 381 #define BTRFS_FT_XATTR 8 382 #define BTRFS_FT_MAX 9 383 /* Directory contains encrypted data */ 384 #define BTRFS_FT_ENCRYPTED 0x80 385 386 static inline __u8 btrfs_dir_flags_to_ftype(__u8 flags) 387 { 388 return flags & ~BTRFS_FT_ENCRYPTED; 389 } 390 391 /* 392 * Inode flags 393 */ 394 #define BTRFS_INODE_NODATASUM (1U << 0) 395 #define BTRFS_INODE_NODATACOW (1U << 1) 396 #define BTRFS_INODE_READONLY (1U << 2) 397 #define BTRFS_INODE_NOCOMPRESS (1U << 3) 398 #define BTRFS_INODE_PREALLOC (1U << 4) 399 #define BTRFS_INODE_SYNC (1U << 5) 400 #define BTRFS_INODE_IMMUTABLE (1U << 6) 401 #define BTRFS_INODE_APPEND (1U << 7) 402 #define BTRFS_INODE_NODUMP (1U << 8) 403 #define BTRFS_INODE_NOATIME (1U << 9) 404 #define BTRFS_INODE_DIRSYNC (1U << 10) 405 #define BTRFS_INODE_COMPRESS (1U << 11) 406 407 #define BTRFS_INODE_ROOT_ITEM_INIT (1U << 31) 408 409 #define BTRFS_INODE_FLAG_MASK \ 410 (BTRFS_INODE_NODATASUM | \ 411 BTRFS_INODE_NODATACOW | \ 412 BTRFS_INODE_READONLY | \ 413 BTRFS_INODE_NOCOMPRESS | \ 414 BTRFS_INODE_PREALLOC | \ 415 BTRFS_INODE_SYNC | \ 416 BTRFS_INODE_IMMUTABLE | \ 417 BTRFS_INODE_APPEND | \ 418 BTRFS_INODE_NODUMP | \ 419 BTRFS_INODE_NOATIME | \ 420 BTRFS_INODE_DIRSYNC | \ 421 BTRFS_INODE_COMPRESS | \ 422 BTRFS_INODE_ROOT_ITEM_INIT) 423 424 #define BTRFS_INODE_RO_VERITY (1U << 0) 425 426 #define BTRFS_INODE_RO_FLAG_MASK (BTRFS_INODE_RO_VERITY) 427 428 /* 429 * The key defines the order in the tree, and so it also defines (optimal) 430 * block layout. 431 * 432 * objectid corresponds to the inode number. 433 * 434 * type tells us things about the object, and is a kind of stream selector. 435 * so for a given inode, keys with type of 1 might refer to the inode data, 436 * type of 2 may point to file data in the btree and type == 3 may point to 437 * extents. 438 * 439 * offset is the starting byte offset for this key in the stream. 440 * 441 * btrfs_disk_key is in disk byte order. struct btrfs_key is always 442 * in cpu native order. Otherwise they are identical and their sizes 443 * should be the same (ie both packed) 444 */ 445 struct btrfs_disk_key { 446 __le64 objectid; 447 __u8 type; 448 __le64 offset; 449 } __attribute__ ((__packed__)); 450 451 struct btrfs_key { 452 __u64 objectid; 453 __u8 type; 454 __u64 offset; 455 } __attribute__ ((__packed__)); 456 457 /* 458 * Every tree block (leaf or node) starts with this header. 459 */ 460 struct btrfs_header { 461 /* These first four must match the super block */ 462 __u8 csum[BTRFS_CSUM_SIZE]; 463 /* FS specific uuid */ 464 __u8 fsid[BTRFS_FSID_SIZE]; 465 /* Which block this node is supposed to live in */ 466 __le64 bytenr; 467 __le64 flags; 468 469 /* Allowed to be different from the super from here on down */ 470 __u8 chunk_tree_uuid[BTRFS_UUID_SIZE]; 471 __le64 generation; 472 __le64 owner; 473 __le32 nritems; 474 __u8 level; 475 } __attribute__ ((__packed__)); 476 477 /* 478 * This is a very generous portion of the super block, giving us room to 479 * translate 14 chunks with 3 stripes each. 480 */ 481 #define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048 482 483 /* 484 * Just in case we somehow lose the roots and are not able to mount, we store 485 * an array of the roots from previous transactions in the super. 486 */ 487 #define BTRFS_NUM_BACKUP_ROOTS 4 488 struct btrfs_root_backup { 489 __le64 tree_root; 490 __le64 tree_root_gen; 491 492 __le64 chunk_root; 493 __le64 chunk_root_gen; 494 495 __le64 extent_root; 496 __le64 extent_root_gen; 497 498 __le64 fs_root; 499 __le64 fs_root_gen; 500 501 __le64 dev_root; 502 __le64 dev_root_gen; 503 504 __le64 csum_root; 505 __le64 csum_root_gen; 506 507 __le64 total_bytes; 508 __le64 bytes_used; 509 __le64 num_devices; 510 /* future */ 511 __le64 unused_64[4]; 512 513 __u8 tree_root_level; 514 __u8 chunk_root_level; 515 __u8 extent_root_level; 516 __u8 fs_root_level; 517 __u8 dev_root_level; 518 __u8 csum_root_level; 519 /* future and to align */ 520 __u8 unused_8[10]; 521 } __attribute__ ((__packed__)); 522 523 /* 524 * A leaf is full of items. offset and size tell us where to find the item in 525 * the leaf (relative to the start of the data area) 526 */ 527 struct btrfs_item { 528 struct btrfs_disk_key key; 529 __le32 offset; 530 __le32 size; 531 } __attribute__ ((__packed__)); 532 533 /* 534 * Leaves have an item area and a data area: 535 * [item0, item1....itemN] [free space] [dataN...data1, data0] 536 * 537 * The data is separate from the items to get the keys closer together during 538 * searches. 539 */ 540 struct btrfs_leaf { 541 struct btrfs_header header; 542 struct btrfs_item items[]; 543 } __attribute__ ((__packed__)); 544 545 /* 546 * All non-leaf blocks are nodes, they hold only keys and pointers to other 547 * blocks. 548 */ 549 struct btrfs_key_ptr { 550 struct btrfs_disk_key key; 551 __le64 blockptr; 552 __le64 generation; 553 } __attribute__ ((__packed__)); 554 555 struct btrfs_node { 556 struct btrfs_header header; 557 struct btrfs_key_ptr ptrs[]; 558 } __attribute__ ((__packed__)); 559 560 struct btrfs_dev_item { 561 /* the internal btrfs device id */ 562 __le64 devid; 563 564 /* size of the device */ 565 __le64 total_bytes; 566 567 /* bytes used */ 568 __le64 bytes_used; 569 570 /* optimal io alignment for this device */ 571 __le32 io_align; 572 573 /* optimal io width for this device */ 574 __le32 io_width; 575 576 /* minimal io size for this device */ 577 __le32 sector_size; 578 579 /* type and info about this device */ 580 __le64 type; 581 582 /* expected generation for this device */ 583 __le64 generation; 584 585 /* 586 * starting byte of this partition on the device, 587 * to allow for stripe alignment in the future 588 */ 589 __le64 start_offset; 590 591 /* grouping information for allocation decisions */ 592 __le32 dev_group; 593 594 /* seek speed 0-100 where 100 is fastest */ 595 __u8 seek_speed; 596 597 /* bandwidth 0-100 where 100 is fastest */ 598 __u8 bandwidth; 599 600 /* btrfs generated uuid for this device */ 601 __u8 uuid[BTRFS_UUID_SIZE]; 602 603 /* uuid of FS who owns this device */ 604 __u8 fsid[BTRFS_UUID_SIZE]; 605 } __attribute__ ((__packed__)); 606 607 struct btrfs_stripe { 608 __le64 devid; 609 __le64 offset; 610 __u8 dev_uuid[BTRFS_UUID_SIZE]; 611 } __attribute__ ((__packed__)); 612 613 struct btrfs_chunk { 614 /* size of this chunk in bytes */ 615 __le64 length; 616 617 /* objectid of the root referencing this chunk */ 618 __le64 owner; 619 620 __le64 stripe_len; 621 __le64 type; 622 623 /* optimal io alignment for this chunk */ 624 __le32 io_align; 625 626 /* optimal io width for this chunk */ 627 __le32 io_width; 628 629 /* minimal io size for this chunk */ 630 __le32 sector_size; 631 632 /* 2^16 stripes is quite a lot, a second limit is the size of a single 633 * item in the btree 634 */ 635 __le16 num_stripes; 636 637 /* sub stripes only matter for raid10 */ 638 __le16 sub_stripes; 639 struct btrfs_stripe stripe; 640 /* additional stripes go here */ 641 } __attribute__ ((__packed__)); 642 643 /* 644 * The super block basically lists the main trees of the FS. 645 */ 646 struct btrfs_super_block { 647 /* The first 4 fields must match struct btrfs_header */ 648 __u8 csum[BTRFS_CSUM_SIZE]; 649 /* FS specific UUID, visible to user */ 650 __u8 fsid[BTRFS_FSID_SIZE]; 651 /* This block number */ 652 __le64 bytenr; 653 __le64 flags; 654 655 /* Allowed to be different from the btrfs_header from here own down */ 656 __le64 magic; 657 __le64 generation; 658 __le64 root; 659 __le64 chunk_root; 660 __le64 log_root; 661 662 /* 663 * This member has never been utilized since the very beginning, thus 664 * it's always 0 regardless of kernel version. We always use 665 * generation + 1 to read log tree root. So here we mark it deprecated. 666 */ 667 __le64 __unused_log_root_transid; 668 __le64 total_bytes; 669 __le64 bytes_used; 670 __le64 root_dir_objectid; 671 __le64 num_devices; 672 __le32 sectorsize; 673 __le32 nodesize; 674 __le32 __unused_leafsize; 675 __le32 stripesize; 676 __le32 sys_chunk_array_size; 677 __le64 chunk_root_generation; 678 __le64 compat_flags; 679 __le64 compat_ro_flags; 680 __le64 incompat_flags; 681 __le16 csum_type; 682 __u8 root_level; 683 __u8 chunk_root_level; 684 __u8 log_root_level; 685 struct btrfs_dev_item dev_item; 686 687 char label[BTRFS_LABEL_SIZE]; 688 689 __le64 cache_generation; 690 __le64 uuid_tree_generation; 691 692 /* The UUID written into btree blocks */ 693 __u8 metadata_uuid[BTRFS_FSID_SIZE]; 694 695 __u64 nr_global_roots; 696 697 /* Future expansion */ 698 __le64 reserved[27]; 699 __u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE]; 700 struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS]; 701 702 /* Padded to 4096 bytes */ 703 __u8 padding[565]; 704 } __attribute__ ((__packed__)); 705 706 #define BTRFS_FREE_SPACE_EXTENT 1 707 #define BTRFS_FREE_SPACE_BITMAP 2 708 709 struct btrfs_free_space_entry { 710 __le64 offset; 711 __le64 bytes; 712 __u8 type; 713 } __attribute__ ((__packed__)); 714 715 struct btrfs_free_space_header { 716 struct btrfs_disk_key location; 717 __le64 generation; 718 __le64 num_entries; 719 __le64 num_bitmaps; 720 } __attribute__ ((__packed__)); 721 722 #define BTRFS_HEADER_FLAG_WRITTEN (1ULL << 0) 723 #define BTRFS_HEADER_FLAG_RELOC (1ULL << 1) 724 725 /* Super block flags */ 726 /* Errors detected */ 727 #define BTRFS_SUPER_FLAG_ERROR (1ULL << 2) 728 729 #define BTRFS_SUPER_FLAG_SEEDING (1ULL << 32) 730 #define BTRFS_SUPER_FLAG_METADUMP (1ULL << 33) 731 #define BTRFS_SUPER_FLAG_METADUMP_V2 (1ULL << 34) 732 #define BTRFS_SUPER_FLAG_CHANGING_FSID (1ULL << 35) 733 #define BTRFS_SUPER_FLAG_CHANGING_FSID_V2 (1ULL << 36) 734 735 736 /* 737 * items in the extent btree are used to record the objectid of the 738 * owner of the block and the number of references 739 */ 740 741 struct btrfs_extent_item { 742 __le64 refs; 743 __le64 generation; 744 __le64 flags; 745 } __attribute__ ((__packed__)); 746 747 struct btrfs_extent_item_v0 { 748 __le32 refs; 749 } __attribute__ ((__packed__)); 750 751 752 #define BTRFS_EXTENT_FLAG_DATA (1ULL << 0) 753 #define BTRFS_EXTENT_FLAG_TREE_BLOCK (1ULL << 1) 754 755 /* following flags only apply to tree blocks */ 756 757 /* use full backrefs for extent pointers in the block */ 758 #define BTRFS_BLOCK_FLAG_FULL_BACKREF (1ULL << 8) 759 760 #define BTRFS_BACKREF_REV_MAX 256 761 #define BTRFS_BACKREF_REV_SHIFT 56 762 #define BTRFS_BACKREF_REV_MASK (((u64)BTRFS_BACKREF_REV_MAX - 1) << \ 763 BTRFS_BACKREF_REV_SHIFT) 764 765 #define BTRFS_OLD_BACKREF_REV 0 766 #define BTRFS_MIXED_BACKREF_REV 1 767 768 /* 769 * this flag is only used internally by scrub and may be changed at any time 770 * it is only declared here to avoid collisions 771 */ 772 #define BTRFS_EXTENT_FLAG_SUPER (1ULL << 48) 773 774 struct btrfs_tree_block_info { 775 struct btrfs_disk_key key; 776 __u8 level; 777 } __attribute__ ((__packed__)); 778 779 struct btrfs_extent_data_ref { 780 __le64 root; 781 __le64 objectid; 782 __le64 offset; 783 __le32 count; 784 } __attribute__ ((__packed__)); 785 786 struct btrfs_shared_data_ref { 787 __le32 count; 788 } __attribute__ ((__packed__)); 789 790 struct btrfs_extent_inline_ref { 791 __u8 type; 792 __le64 offset; 793 } __attribute__ ((__packed__)); 794 795 /* dev extents record free space on individual devices. The owner 796 * field points back to the chunk allocation mapping tree that allocated 797 * the extent. The chunk tree uuid field is a way to double check the owner 798 */ 799 struct btrfs_dev_extent { 800 __le64 chunk_tree; 801 __le64 chunk_objectid; 802 __le64 chunk_offset; 803 __le64 length; 804 __u8 chunk_tree_uuid[BTRFS_UUID_SIZE]; 805 } __attribute__ ((__packed__)); 806 807 struct btrfs_inode_ref { 808 __le64 index; 809 __le16 name_len; 810 /* name goes here */ 811 } __attribute__ ((__packed__)); 812 813 struct btrfs_inode_extref { 814 __le64 parent_objectid; 815 __le64 index; 816 __le16 name_len; 817 __u8 name[]; 818 /* name goes here */ 819 } __attribute__ ((__packed__)); 820 821 struct btrfs_timespec { 822 __le64 sec; 823 __le32 nsec; 824 } __attribute__ ((__packed__)); 825 826 struct btrfs_inode_item { 827 /* nfs style generation number */ 828 __le64 generation; 829 /* transid that last touched this inode */ 830 __le64 transid; 831 __le64 size; 832 __le64 nbytes; 833 __le64 block_group; 834 __le32 nlink; 835 __le32 uid; 836 __le32 gid; 837 __le32 mode; 838 __le64 rdev; 839 __le64 flags; 840 841 /* modification sequence number for NFS */ 842 __le64 sequence; 843 844 /* 845 * a little future expansion, for more than this we can 846 * just grow the inode item and version it 847 */ 848 __le64 reserved[4]; 849 struct btrfs_timespec atime; 850 struct btrfs_timespec ctime; 851 struct btrfs_timespec mtime; 852 struct btrfs_timespec otime; 853 } __attribute__ ((__packed__)); 854 855 struct btrfs_dir_log_item { 856 __le64 end; 857 } __attribute__ ((__packed__)); 858 859 struct btrfs_dir_item { 860 struct btrfs_disk_key location; 861 __le64 transid; 862 __le16 data_len; 863 __le16 name_len; 864 __u8 type; 865 } __attribute__ ((__packed__)); 866 867 #define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0) 868 869 /* 870 * Internal in-memory flag that a subvolume has been marked for deletion but 871 * still visible as a directory 872 */ 873 #define BTRFS_ROOT_SUBVOL_DEAD (1ULL << 48) 874 875 struct btrfs_root_item { 876 struct btrfs_inode_item inode; 877 __le64 generation; 878 __le64 root_dirid; 879 __le64 bytenr; 880 __le64 byte_limit; 881 __le64 bytes_used; 882 __le64 last_snapshot; 883 __le64 flags; 884 __le32 refs; 885 struct btrfs_disk_key drop_progress; 886 __u8 drop_level; 887 __u8 level; 888 889 /* 890 * The following fields appear after subvol_uuids+subvol_times 891 * were introduced. 892 */ 893 894 /* 895 * This generation number is used to test if the new fields are valid 896 * and up to date while reading the root item. Every time the root item 897 * is written out, the "generation" field is copied into this field. If 898 * anyone ever mounted the fs with an older kernel, we will have 899 * mismatching generation values here and thus must invalidate the 900 * new fields. See btrfs_update_root and btrfs_find_last_root for 901 * details. 902 * the offset of generation_v2 is also used as the start for the memset 903 * when invalidating the fields. 904 */ 905 __le64 generation_v2; 906 __u8 uuid[BTRFS_UUID_SIZE]; 907 __u8 parent_uuid[BTRFS_UUID_SIZE]; 908 __u8 received_uuid[BTRFS_UUID_SIZE]; 909 __le64 ctransid; /* updated when an inode changes */ 910 __le64 otransid; /* trans when created */ 911 __le64 stransid; /* trans when sent. non-zero for received subvol */ 912 __le64 rtransid; /* trans when received. non-zero for received subvol */ 913 struct btrfs_timespec ctime; 914 struct btrfs_timespec otime; 915 struct btrfs_timespec stime; 916 struct btrfs_timespec rtime; 917 __le64 reserved[8]; /* for future */ 918 } __attribute__ ((__packed__)); 919 920 /* 921 * Btrfs root item used to be smaller than current size. The old format ends 922 * at where member generation_v2 is. 923 */ 924 static inline __u32 btrfs_legacy_root_item_size(void) 925 { 926 return offsetof(struct btrfs_root_item, generation_v2); 927 } 928 929 /* 930 * this is used for both forward and backward root refs 931 */ 932 struct btrfs_root_ref { 933 __le64 dirid; 934 __le64 sequence; 935 __le16 name_len; 936 } __attribute__ ((__packed__)); 937 938 struct btrfs_disk_balance_args { 939 /* 940 * profiles to operate on, single is denoted by 941 * BTRFS_AVAIL_ALLOC_BIT_SINGLE 942 */ 943 __le64 profiles; 944 945 /* 946 * usage filter 947 * BTRFS_BALANCE_ARGS_USAGE with a single value means '0..N' 948 * BTRFS_BALANCE_ARGS_USAGE_RANGE - range syntax, min..max 949 */ 950 union { 951 __le64 usage; 952 struct { 953 __le32 usage_min; 954 __le32 usage_max; 955 }; 956 }; 957 958 /* devid filter */ 959 __le64 devid; 960 961 /* devid subset filter [pstart..pend) */ 962 __le64 pstart; 963 __le64 pend; 964 965 /* btrfs virtual address space subset filter [vstart..vend) */ 966 __le64 vstart; 967 __le64 vend; 968 969 /* 970 * profile to convert to, single is denoted by 971 * BTRFS_AVAIL_ALLOC_BIT_SINGLE 972 */ 973 __le64 target; 974 975 /* BTRFS_BALANCE_ARGS_* */ 976 __le64 flags; 977 978 /* 979 * BTRFS_BALANCE_ARGS_LIMIT with value 'limit' 980 * BTRFS_BALANCE_ARGS_LIMIT_RANGE - the extend version can use minimum 981 * and maximum 982 */ 983 union { 984 __le64 limit; 985 struct { 986 __le32 limit_min; 987 __le32 limit_max; 988 }; 989 }; 990 991 /* 992 * Process chunks that cross stripes_min..stripes_max devices, 993 * BTRFS_BALANCE_ARGS_STRIPES_RANGE 994 */ 995 __le32 stripes_min; 996 __le32 stripes_max; 997 998 __le64 unused[6]; 999 } __attribute__ ((__packed__)); 1000 1001 /* 1002 * store balance parameters to disk so that balance can be properly 1003 * resumed after crash or unmount 1004 */ 1005 struct btrfs_balance_item { 1006 /* BTRFS_BALANCE_* */ 1007 __le64 flags; 1008 1009 struct btrfs_disk_balance_args data; 1010 struct btrfs_disk_balance_args meta; 1011 struct btrfs_disk_balance_args sys; 1012 1013 __le64 unused[4]; 1014 } __attribute__ ((__packed__)); 1015 1016 enum { 1017 BTRFS_FILE_EXTENT_INLINE = 0, 1018 BTRFS_FILE_EXTENT_REG = 1, 1019 BTRFS_FILE_EXTENT_PREALLOC = 2, 1020 BTRFS_NR_FILE_EXTENT_TYPES = 3, 1021 }; 1022 1023 struct btrfs_file_extent_item { 1024 /* 1025 * transaction id that created this extent 1026 */ 1027 __le64 generation; 1028 /* 1029 * max number of bytes to hold this extent in ram 1030 * when we split a compressed extent we can't know how big 1031 * each of the resulting pieces will be. So, this is 1032 * an upper limit on the size of the extent in ram instead of 1033 * an exact limit. 1034 */ 1035 __le64 ram_bytes; 1036 1037 /* 1038 * 32 bits for the various ways we might encode the data, 1039 * including compression and encryption. If any of these 1040 * are set to something a given disk format doesn't understand 1041 * it is treated like an incompat flag for reading and writing, 1042 * but not for stat. 1043 */ 1044 __u8 compression; 1045 __u8 encryption; 1046 __le16 other_encoding; /* spare for later use */ 1047 1048 /* are we inline data or a real extent? */ 1049 __u8 type; 1050 1051 /* 1052 * disk space consumed by the extent, checksum blocks are included 1053 * in these numbers 1054 * 1055 * At this offset in the structure, the inline extent data start. 1056 */ 1057 __le64 disk_bytenr; 1058 __le64 disk_num_bytes; 1059 /* 1060 * the logical offset in file blocks (no csums) 1061 * this extent record is for. This allows a file extent to point 1062 * into the middle of an existing extent on disk, sharing it 1063 * between two snapshots (useful if some bytes in the middle of the 1064 * extent have changed 1065 */ 1066 __le64 offset; 1067 /* 1068 * the logical number of file blocks (no csums included). This 1069 * always reflects the size uncompressed and without encoding. 1070 */ 1071 __le64 num_bytes; 1072 1073 } __attribute__ ((__packed__)); 1074 1075 struct btrfs_csum_item { 1076 __u8 csum; 1077 } __attribute__ ((__packed__)); 1078 1079 struct btrfs_dev_stats_item { 1080 /* 1081 * grow this item struct at the end for future enhancements and keep 1082 * the existing values unchanged 1083 */ 1084 __le64 values[BTRFS_DEV_STAT_VALUES_MAX]; 1085 } __attribute__ ((__packed__)); 1086 1087 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS 0 1088 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID 1 1089 1090 struct btrfs_dev_replace_item { 1091 /* 1092 * grow this item struct at the end for future enhancements and keep 1093 * the existing values unchanged 1094 */ 1095 __le64 src_devid; 1096 __le64 cursor_left; 1097 __le64 cursor_right; 1098 __le64 cont_reading_from_srcdev_mode; 1099 1100 __le64 replace_state; 1101 __le64 time_started; 1102 __le64 time_stopped; 1103 __le64 num_write_errors; 1104 __le64 num_uncorrectable_read_errors; 1105 } __attribute__ ((__packed__)); 1106 1107 /* different types of block groups (and chunks) */ 1108 #define BTRFS_BLOCK_GROUP_DATA (1ULL << 0) 1109 #define BTRFS_BLOCK_GROUP_SYSTEM (1ULL << 1) 1110 #define BTRFS_BLOCK_GROUP_METADATA (1ULL << 2) 1111 #define BTRFS_BLOCK_GROUP_RAID0 (1ULL << 3) 1112 #define BTRFS_BLOCK_GROUP_RAID1 (1ULL << 4) 1113 #define BTRFS_BLOCK_GROUP_DUP (1ULL << 5) 1114 #define BTRFS_BLOCK_GROUP_RAID10 (1ULL << 6) 1115 #define BTRFS_BLOCK_GROUP_RAID5 (1ULL << 7) 1116 #define BTRFS_BLOCK_GROUP_RAID6 (1ULL << 8) 1117 #define BTRFS_BLOCK_GROUP_RAID1C3 (1ULL << 9) 1118 #define BTRFS_BLOCK_GROUP_RAID1C4 (1ULL << 10) 1119 #define BTRFS_BLOCK_GROUP_RESERVED (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \ 1120 BTRFS_SPACE_INFO_GLOBAL_RSV) 1121 1122 #define BTRFS_BLOCK_GROUP_TYPE_MASK (BTRFS_BLOCK_GROUP_DATA | \ 1123 BTRFS_BLOCK_GROUP_SYSTEM | \ 1124 BTRFS_BLOCK_GROUP_METADATA) 1125 1126 #define BTRFS_BLOCK_GROUP_PROFILE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \ 1127 BTRFS_BLOCK_GROUP_RAID1 | \ 1128 BTRFS_BLOCK_GROUP_RAID1C3 | \ 1129 BTRFS_BLOCK_GROUP_RAID1C4 | \ 1130 BTRFS_BLOCK_GROUP_RAID5 | \ 1131 BTRFS_BLOCK_GROUP_RAID6 | \ 1132 BTRFS_BLOCK_GROUP_DUP | \ 1133 BTRFS_BLOCK_GROUP_RAID10) 1134 #define BTRFS_BLOCK_GROUP_RAID56_MASK (BTRFS_BLOCK_GROUP_RAID5 | \ 1135 BTRFS_BLOCK_GROUP_RAID6) 1136 1137 #define BTRFS_BLOCK_GROUP_RAID1_MASK (BTRFS_BLOCK_GROUP_RAID1 | \ 1138 BTRFS_BLOCK_GROUP_RAID1C3 | \ 1139 BTRFS_BLOCK_GROUP_RAID1C4) 1140 1141 /* 1142 * We need a bit for restriper to be able to tell when chunks of type 1143 * SINGLE are available. This "extended" profile format is used in 1144 * fs_info->avail_*_alloc_bits (in-memory) and balance item fields 1145 * (on-disk). The corresponding on-disk bit in chunk.type is reserved 1146 * to avoid remappings between two formats in future. 1147 */ 1148 #define BTRFS_AVAIL_ALLOC_BIT_SINGLE (1ULL << 48) 1149 1150 /* 1151 * A fake block group type that is used to communicate global block reserve 1152 * size to userspace via the SPACE_INFO ioctl. 1153 */ 1154 #define BTRFS_SPACE_INFO_GLOBAL_RSV (1ULL << 49) 1155 1156 #define BTRFS_EXTENDED_PROFILE_MASK (BTRFS_BLOCK_GROUP_PROFILE_MASK | \ 1157 BTRFS_AVAIL_ALLOC_BIT_SINGLE) 1158 1159 static inline __u64 chunk_to_extended(__u64 flags) 1160 { 1161 if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0) 1162 flags |= BTRFS_AVAIL_ALLOC_BIT_SINGLE; 1163 1164 return flags; 1165 } 1166 static inline __u64 extended_to_chunk(__u64 flags) 1167 { 1168 return flags & ~BTRFS_AVAIL_ALLOC_BIT_SINGLE; 1169 } 1170 1171 struct btrfs_block_group_item { 1172 __le64 used; 1173 __le64 chunk_objectid; 1174 __le64 flags; 1175 } __attribute__ ((__packed__)); 1176 1177 struct btrfs_free_space_info { 1178 __le32 extent_count; 1179 __le32 flags; 1180 } __attribute__ ((__packed__)); 1181 1182 #define BTRFS_FREE_SPACE_USING_BITMAPS (1ULL << 0) 1183 1184 #define BTRFS_QGROUP_LEVEL_SHIFT 48 1185 static inline __u16 btrfs_qgroup_level(__u64 qgroupid) 1186 { 1187 return (__u16)(qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT); 1188 } 1189 1190 /* 1191 * is subvolume quota turned on? 1192 */ 1193 #define BTRFS_QGROUP_STATUS_FLAG_ON (1ULL << 0) 1194 /* 1195 * RESCAN is set during the initialization phase 1196 */ 1197 #define BTRFS_QGROUP_STATUS_FLAG_RESCAN (1ULL << 1) 1198 /* 1199 * Some qgroup entries are known to be out of date, 1200 * either because the configuration has changed in a way that 1201 * makes a rescan necessary, or because the fs has been mounted 1202 * with a non-qgroup-aware version. 1203 * Turning qouta off and on again makes it inconsistent, too. 1204 */ 1205 #define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT (1ULL << 2) 1206 1207 #define BTRFS_QGROUP_STATUS_FLAGS_MASK (BTRFS_QGROUP_STATUS_FLAG_ON | \ 1208 BTRFS_QGROUP_STATUS_FLAG_RESCAN | \ 1209 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) 1210 1211 #define BTRFS_QGROUP_STATUS_VERSION 1 1212 1213 struct btrfs_qgroup_status_item { 1214 __le64 version; 1215 /* 1216 * the generation is updated during every commit. As older 1217 * versions of btrfs are not aware of qgroups, it will be 1218 * possible to detect inconsistencies by checking the 1219 * generation on mount time 1220 */ 1221 __le64 generation; 1222 1223 /* flag definitions see above */ 1224 __le64 flags; 1225 1226 /* 1227 * only used during scanning to record the progress 1228 * of the scan. It contains a logical address 1229 */ 1230 __le64 rescan; 1231 } __attribute__ ((__packed__)); 1232 1233 struct btrfs_qgroup_info_item { 1234 __le64 generation; 1235 __le64 rfer; 1236 __le64 rfer_cmpr; 1237 __le64 excl; 1238 __le64 excl_cmpr; 1239 } __attribute__ ((__packed__)); 1240 1241 struct btrfs_qgroup_limit_item { 1242 /* 1243 * only updated when any of the other values change 1244 */ 1245 __le64 flags; 1246 __le64 max_rfer; 1247 __le64 max_excl; 1248 __le64 rsv_rfer; 1249 __le64 rsv_excl; 1250 } __attribute__ ((__packed__)); 1251 1252 struct btrfs_verity_descriptor_item { 1253 /* Size of the verity descriptor in bytes */ 1254 __le64 size; 1255 /* 1256 * When we implement support for fscrypt, we will need to encrypt the 1257 * Merkle tree for encrypted verity files. These 128 bits are for the 1258 * eventual storage of an fscrypt initialization vector. 1259 */ 1260 __le64 reserved[2]; 1261 __u8 encryption; 1262 } __attribute__ ((__packed__)); 1263 1264 #endif /* _BTRFS_CTREE_H_ */ 1265