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 /* Directory contains encrypted data */ 380 #define BTRFS_FT_ENCRYPTED 0x80 381 382 static inline __u8 btrfs_dir_flags_to_ftype(__u8 flags) 383 { 384 return flags & ~BTRFS_FT_ENCRYPTED; 385 } 386 387 /* 388 * Inode flags 389 */ 390 #define BTRFS_INODE_NODATASUM (1U << 0) 391 #define BTRFS_INODE_NODATACOW (1U << 1) 392 #define BTRFS_INODE_READONLY (1U << 2) 393 #define BTRFS_INODE_NOCOMPRESS (1U << 3) 394 #define BTRFS_INODE_PREALLOC (1U << 4) 395 #define BTRFS_INODE_SYNC (1U << 5) 396 #define BTRFS_INODE_IMMUTABLE (1U << 6) 397 #define BTRFS_INODE_APPEND (1U << 7) 398 #define BTRFS_INODE_NODUMP (1U << 8) 399 #define BTRFS_INODE_NOATIME (1U << 9) 400 #define BTRFS_INODE_DIRSYNC (1U << 10) 401 #define BTRFS_INODE_COMPRESS (1U << 11) 402 403 #define BTRFS_INODE_ROOT_ITEM_INIT (1U << 31) 404 405 #define BTRFS_INODE_FLAG_MASK \ 406 (BTRFS_INODE_NODATASUM | \ 407 BTRFS_INODE_NODATACOW | \ 408 BTRFS_INODE_READONLY | \ 409 BTRFS_INODE_NOCOMPRESS | \ 410 BTRFS_INODE_PREALLOC | \ 411 BTRFS_INODE_SYNC | \ 412 BTRFS_INODE_IMMUTABLE | \ 413 BTRFS_INODE_APPEND | \ 414 BTRFS_INODE_NODUMP | \ 415 BTRFS_INODE_NOATIME | \ 416 BTRFS_INODE_DIRSYNC | \ 417 BTRFS_INODE_COMPRESS | \ 418 BTRFS_INODE_ROOT_ITEM_INIT) 419 420 #define BTRFS_INODE_RO_VERITY (1U << 0) 421 422 #define BTRFS_INODE_RO_FLAG_MASK (BTRFS_INODE_RO_VERITY) 423 424 /* 425 * The key defines the order in the tree, and so it also defines (optimal) 426 * block layout. 427 * 428 * objectid corresponds to the inode number. 429 * 430 * type tells us things about the object, and is a kind of stream selector. 431 * so for a given inode, keys with type of 1 might refer to the inode data, 432 * type of 2 may point to file data in the btree and type == 3 may point to 433 * extents. 434 * 435 * offset is the starting byte offset for this key in the stream. 436 * 437 * btrfs_disk_key is in disk byte order. struct btrfs_key is always 438 * in cpu native order. Otherwise they are identical and their sizes 439 * should be the same (ie both packed) 440 */ 441 struct btrfs_disk_key { 442 __le64 objectid; 443 __u8 type; 444 __le64 offset; 445 } __attribute__ ((__packed__)); 446 447 struct btrfs_key { 448 __u64 objectid; 449 __u8 type; 450 __u64 offset; 451 } __attribute__ ((__packed__)); 452 453 /* 454 * Every tree block (leaf or node) starts with this header. 455 */ 456 struct btrfs_header { 457 /* These first four must match the super block */ 458 __u8 csum[BTRFS_CSUM_SIZE]; 459 /* FS specific uuid */ 460 __u8 fsid[BTRFS_FSID_SIZE]; 461 /* Which block this node is supposed to live in */ 462 __le64 bytenr; 463 __le64 flags; 464 465 /* Allowed to be different from the super from here on down */ 466 __u8 chunk_tree_uuid[BTRFS_UUID_SIZE]; 467 __le64 generation; 468 __le64 owner; 469 __le32 nritems; 470 __u8 level; 471 } __attribute__ ((__packed__)); 472 473 /* 474 * This is a very generous portion of the super block, giving us room to 475 * translate 14 chunks with 3 stripes each. 476 */ 477 #define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048 478 479 /* 480 * Just in case we somehow lose the roots and are not able to mount, we store 481 * an array of the roots from previous transactions in the super. 482 */ 483 #define BTRFS_NUM_BACKUP_ROOTS 4 484 struct btrfs_root_backup { 485 __le64 tree_root; 486 __le64 tree_root_gen; 487 488 __le64 chunk_root; 489 __le64 chunk_root_gen; 490 491 __le64 extent_root; 492 __le64 extent_root_gen; 493 494 __le64 fs_root; 495 __le64 fs_root_gen; 496 497 __le64 dev_root; 498 __le64 dev_root_gen; 499 500 __le64 csum_root; 501 __le64 csum_root_gen; 502 503 __le64 total_bytes; 504 __le64 bytes_used; 505 __le64 num_devices; 506 /* future */ 507 __le64 unused_64[4]; 508 509 __u8 tree_root_level; 510 __u8 chunk_root_level; 511 __u8 extent_root_level; 512 __u8 fs_root_level; 513 __u8 dev_root_level; 514 __u8 csum_root_level; 515 /* future and to align */ 516 __u8 unused_8[10]; 517 } __attribute__ ((__packed__)); 518 519 /* 520 * A leaf is full of items. offset and size tell us where to find the item in 521 * the leaf (relative to the start of the data area) 522 */ 523 struct btrfs_item { 524 struct btrfs_disk_key key; 525 __le32 offset; 526 __le32 size; 527 } __attribute__ ((__packed__)); 528 529 /* 530 * Leaves have an item area and a data area: 531 * [item0, item1....itemN] [free space] [dataN...data1, data0] 532 * 533 * The data is separate from the items to get the keys closer together during 534 * searches. 535 */ 536 struct btrfs_leaf { 537 struct btrfs_header header; 538 struct btrfs_item items[]; 539 } __attribute__ ((__packed__)); 540 541 /* 542 * All non-leaf blocks are nodes, they hold only keys and pointers to other 543 * blocks. 544 */ 545 struct btrfs_key_ptr { 546 struct btrfs_disk_key key; 547 __le64 blockptr; 548 __le64 generation; 549 } __attribute__ ((__packed__)); 550 551 struct btrfs_node { 552 struct btrfs_header header; 553 struct btrfs_key_ptr ptrs[]; 554 } __attribute__ ((__packed__)); 555 556 struct btrfs_dev_item { 557 /* the internal btrfs device id */ 558 __le64 devid; 559 560 /* size of the device */ 561 __le64 total_bytes; 562 563 /* bytes used */ 564 __le64 bytes_used; 565 566 /* optimal io alignment for this device */ 567 __le32 io_align; 568 569 /* optimal io width for this device */ 570 __le32 io_width; 571 572 /* minimal io size for this device */ 573 __le32 sector_size; 574 575 /* type and info about this device */ 576 __le64 type; 577 578 /* expected generation for this device */ 579 __le64 generation; 580 581 /* 582 * starting byte of this partition on the device, 583 * to allow for stripe alignment in the future 584 */ 585 __le64 start_offset; 586 587 /* grouping information for allocation decisions */ 588 __le32 dev_group; 589 590 /* seek speed 0-100 where 100 is fastest */ 591 __u8 seek_speed; 592 593 /* bandwidth 0-100 where 100 is fastest */ 594 __u8 bandwidth; 595 596 /* btrfs generated uuid for this device */ 597 __u8 uuid[BTRFS_UUID_SIZE]; 598 599 /* uuid of FS who owns this device */ 600 __u8 fsid[BTRFS_UUID_SIZE]; 601 } __attribute__ ((__packed__)); 602 603 struct btrfs_stripe { 604 __le64 devid; 605 __le64 offset; 606 __u8 dev_uuid[BTRFS_UUID_SIZE]; 607 } __attribute__ ((__packed__)); 608 609 struct btrfs_chunk { 610 /* size of this chunk in bytes */ 611 __le64 length; 612 613 /* objectid of the root referencing this chunk */ 614 __le64 owner; 615 616 __le64 stripe_len; 617 __le64 type; 618 619 /* optimal io alignment for this chunk */ 620 __le32 io_align; 621 622 /* optimal io width for this chunk */ 623 __le32 io_width; 624 625 /* minimal io size for this chunk */ 626 __le32 sector_size; 627 628 /* 2^16 stripes is quite a lot, a second limit is the size of a single 629 * item in the btree 630 */ 631 __le16 num_stripes; 632 633 /* sub stripes only matter for raid10 */ 634 __le16 sub_stripes; 635 struct btrfs_stripe stripe; 636 /* additional stripes go here */ 637 } __attribute__ ((__packed__)); 638 639 /* 640 * The super block basically lists the main trees of the FS. 641 */ 642 struct btrfs_super_block { 643 /* The first 4 fields must match struct btrfs_header */ 644 __u8 csum[BTRFS_CSUM_SIZE]; 645 /* FS specific UUID, visible to user */ 646 __u8 fsid[BTRFS_FSID_SIZE]; 647 /* This block number */ 648 __le64 bytenr; 649 __le64 flags; 650 651 /* Allowed to be different from the btrfs_header from here own down */ 652 __le64 magic; 653 __le64 generation; 654 __le64 root; 655 __le64 chunk_root; 656 __le64 log_root; 657 658 /* 659 * This member has never been utilized since the very beginning, thus 660 * it's always 0 regardless of kernel version. We always use 661 * generation + 1 to read log tree root. So here we mark it deprecated. 662 */ 663 __le64 __unused_log_root_transid; 664 __le64 total_bytes; 665 __le64 bytes_used; 666 __le64 root_dir_objectid; 667 __le64 num_devices; 668 __le32 sectorsize; 669 __le32 nodesize; 670 __le32 __unused_leafsize; 671 __le32 stripesize; 672 __le32 sys_chunk_array_size; 673 __le64 chunk_root_generation; 674 __le64 compat_flags; 675 __le64 compat_ro_flags; 676 __le64 incompat_flags; 677 __le16 csum_type; 678 __u8 root_level; 679 __u8 chunk_root_level; 680 __u8 log_root_level; 681 struct btrfs_dev_item dev_item; 682 683 char label[BTRFS_LABEL_SIZE]; 684 685 __le64 cache_generation; 686 __le64 uuid_tree_generation; 687 688 /* The UUID written into btree blocks */ 689 __u8 metadata_uuid[BTRFS_FSID_SIZE]; 690 691 /* Future expansion */ 692 __u8 reserved8[8]; 693 __le64 reserved[27]; 694 __u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE]; 695 struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS]; 696 697 /* Padded to 4096 bytes */ 698 __u8 padding[565]; 699 } __attribute__ ((__packed__)); 700 701 #define BTRFS_FREE_SPACE_EXTENT 1 702 #define BTRFS_FREE_SPACE_BITMAP 2 703 704 struct btrfs_free_space_entry { 705 __le64 offset; 706 __le64 bytes; 707 __u8 type; 708 } __attribute__ ((__packed__)); 709 710 struct btrfs_free_space_header { 711 struct btrfs_disk_key location; 712 __le64 generation; 713 __le64 num_entries; 714 __le64 num_bitmaps; 715 } __attribute__ ((__packed__)); 716 717 #define BTRFS_HEADER_FLAG_WRITTEN (1ULL << 0) 718 #define BTRFS_HEADER_FLAG_RELOC (1ULL << 1) 719 720 /* Super block flags */ 721 /* Errors detected */ 722 #define BTRFS_SUPER_FLAG_ERROR (1ULL << 2) 723 724 #define BTRFS_SUPER_FLAG_SEEDING (1ULL << 32) 725 #define BTRFS_SUPER_FLAG_METADUMP (1ULL << 33) 726 #define BTRFS_SUPER_FLAG_METADUMP_V2 (1ULL << 34) 727 #define BTRFS_SUPER_FLAG_CHANGING_FSID (1ULL << 35) 728 #define BTRFS_SUPER_FLAG_CHANGING_FSID_V2 (1ULL << 36) 729 730 731 /* 732 * items in the extent btree are used to record the objectid of the 733 * owner of the block and the number of references 734 */ 735 736 struct btrfs_extent_item { 737 __le64 refs; 738 __le64 generation; 739 __le64 flags; 740 } __attribute__ ((__packed__)); 741 742 struct btrfs_extent_item_v0 { 743 __le32 refs; 744 } __attribute__ ((__packed__)); 745 746 747 #define BTRFS_EXTENT_FLAG_DATA (1ULL << 0) 748 #define BTRFS_EXTENT_FLAG_TREE_BLOCK (1ULL << 1) 749 750 /* following flags only apply to tree blocks */ 751 752 /* use full backrefs for extent pointers in the block */ 753 #define BTRFS_BLOCK_FLAG_FULL_BACKREF (1ULL << 8) 754 755 #define BTRFS_BACKREF_REV_MAX 256 756 #define BTRFS_BACKREF_REV_SHIFT 56 757 #define BTRFS_BACKREF_REV_MASK (((u64)BTRFS_BACKREF_REV_MAX - 1) << \ 758 BTRFS_BACKREF_REV_SHIFT) 759 760 #define BTRFS_OLD_BACKREF_REV 0 761 #define BTRFS_MIXED_BACKREF_REV 1 762 763 /* 764 * this flag is only used internally by scrub and may be changed at any time 765 * it is only declared here to avoid collisions 766 */ 767 #define BTRFS_EXTENT_FLAG_SUPER (1ULL << 48) 768 769 struct btrfs_tree_block_info { 770 struct btrfs_disk_key key; 771 __u8 level; 772 } __attribute__ ((__packed__)); 773 774 struct btrfs_extent_data_ref { 775 __le64 root; 776 __le64 objectid; 777 __le64 offset; 778 __le32 count; 779 } __attribute__ ((__packed__)); 780 781 struct btrfs_shared_data_ref { 782 __le32 count; 783 } __attribute__ ((__packed__)); 784 785 struct btrfs_extent_inline_ref { 786 __u8 type; 787 __le64 offset; 788 } __attribute__ ((__packed__)); 789 790 /* dev extents record free space on individual devices. The owner 791 * field points back to the chunk allocation mapping tree that allocated 792 * the extent. The chunk tree uuid field is a way to double check the owner 793 */ 794 struct btrfs_dev_extent { 795 __le64 chunk_tree; 796 __le64 chunk_objectid; 797 __le64 chunk_offset; 798 __le64 length; 799 __u8 chunk_tree_uuid[BTRFS_UUID_SIZE]; 800 } __attribute__ ((__packed__)); 801 802 struct btrfs_inode_ref { 803 __le64 index; 804 __le16 name_len; 805 /* name goes here */ 806 } __attribute__ ((__packed__)); 807 808 struct btrfs_inode_extref { 809 __le64 parent_objectid; 810 __le64 index; 811 __le16 name_len; 812 __u8 name[]; 813 /* name goes here */ 814 } __attribute__ ((__packed__)); 815 816 struct btrfs_timespec { 817 __le64 sec; 818 __le32 nsec; 819 } __attribute__ ((__packed__)); 820 821 struct btrfs_inode_item { 822 /* nfs style generation number */ 823 __le64 generation; 824 /* transid that last touched this inode */ 825 __le64 transid; 826 __le64 size; 827 __le64 nbytes; 828 __le64 block_group; 829 __le32 nlink; 830 __le32 uid; 831 __le32 gid; 832 __le32 mode; 833 __le64 rdev; 834 __le64 flags; 835 836 /* modification sequence number for NFS */ 837 __le64 sequence; 838 839 /* 840 * a little future expansion, for more than this we can 841 * just grow the inode item and version it 842 */ 843 __le64 reserved[4]; 844 struct btrfs_timespec atime; 845 struct btrfs_timespec ctime; 846 struct btrfs_timespec mtime; 847 struct btrfs_timespec otime; 848 } __attribute__ ((__packed__)); 849 850 struct btrfs_dir_log_item { 851 __le64 end; 852 } __attribute__ ((__packed__)); 853 854 struct btrfs_dir_item { 855 struct btrfs_disk_key location; 856 __le64 transid; 857 __le16 data_len; 858 __le16 name_len; 859 __u8 type; 860 } __attribute__ ((__packed__)); 861 862 #define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0) 863 864 /* 865 * Internal in-memory flag that a subvolume has been marked for deletion but 866 * still visible as a directory 867 */ 868 #define BTRFS_ROOT_SUBVOL_DEAD (1ULL << 48) 869 870 struct btrfs_root_item { 871 struct btrfs_inode_item inode; 872 __le64 generation; 873 __le64 root_dirid; 874 __le64 bytenr; 875 __le64 byte_limit; 876 __le64 bytes_used; 877 __le64 last_snapshot; 878 __le64 flags; 879 __le32 refs; 880 struct btrfs_disk_key drop_progress; 881 __u8 drop_level; 882 __u8 level; 883 884 /* 885 * The following fields appear after subvol_uuids+subvol_times 886 * were introduced. 887 */ 888 889 /* 890 * This generation number is used to test if the new fields are valid 891 * and up to date while reading the root item. Every time the root item 892 * is written out, the "generation" field is copied into this field. If 893 * anyone ever mounted the fs with an older kernel, we will have 894 * mismatching generation values here and thus must invalidate the 895 * new fields. See btrfs_update_root and btrfs_find_last_root for 896 * details. 897 * the offset of generation_v2 is also used as the start for the memset 898 * when invalidating the fields. 899 */ 900 __le64 generation_v2; 901 __u8 uuid[BTRFS_UUID_SIZE]; 902 __u8 parent_uuid[BTRFS_UUID_SIZE]; 903 __u8 received_uuid[BTRFS_UUID_SIZE]; 904 __le64 ctransid; /* updated when an inode changes */ 905 __le64 otransid; /* trans when created */ 906 __le64 stransid; /* trans when sent. non-zero for received subvol */ 907 __le64 rtransid; /* trans when received. non-zero for received subvol */ 908 struct btrfs_timespec ctime; 909 struct btrfs_timespec otime; 910 struct btrfs_timespec stime; 911 struct btrfs_timespec rtime; 912 __le64 reserved[8]; /* for future */ 913 } __attribute__ ((__packed__)); 914 915 /* 916 * Btrfs root item used to be smaller than current size. The old format ends 917 * at where member generation_v2 is. 918 */ 919 static inline __u32 btrfs_legacy_root_item_size(void) 920 { 921 return offsetof(struct btrfs_root_item, generation_v2); 922 } 923 924 /* 925 * this is used for both forward and backward root refs 926 */ 927 struct btrfs_root_ref { 928 __le64 dirid; 929 __le64 sequence; 930 __le16 name_len; 931 } __attribute__ ((__packed__)); 932 933 struct btrfs_disk_balance_args { 934 /* 935 * profiles to operate on, single is denoted by 936 * BTRFS_AVAIL_ALLOC_BIT_SINGLE 937 */ 938 __le64 profiles; 939 940 /* 941 * usage filter 942 * BTRFS_BALANCE_ARGS_USAGE with a single value means '0..N' 943 * BTRFS_BALANCE_ARGS_USAGE_RANGE - range syntax, min..max 944 */ 945 union { 946 __le64 usage; 947 struct { 948 __le32 usage_min; 949 __le32 usage_max; 950 }; 951 }; 952 953 /* devid filter */ 954 __le64 devid; 955 956 /* devid subset filter [pstart..pend) */ 957 __le64 pstart; 958 __le64 pend; 959 960 /* btrfs virtual address space subset filter [vstart..vend) */ 961 __le64 vstart; 962 __le64 vend; 963 964 /* 965 * profile to convert to, single is denoted by 966 * BTRFS_AVAIL_ALLOC_BIT_SINGLE 967 */ 968 __le64 target; 969 970 /* BTRFS_BALANCE_ARGS_* */ 971 __le64 flags; 972 973 /* 974 * BTRFS_BALANCE_ARGS_LIMIT with value 'limit' 975 * BTRFS_BALANCE_ARGS_LIMIT_RANGE - the extend version can use minimum 976 * and maximum 977 */ 978 union { 979 __le64 limit; 980 struct { 981 __le32 limit_min; 982 __le32 limit_max; 983 }; 984 }; 985 986 /* 987 * Process chunks that cross stripes_min..stripes_max devices, 988 * BTRFS_BALANCE_ARGS_STRIPES_RANGE 989 */ 990 __le32 stripes_min; 991 __le32 stripes_max; 992 993 __le64 unused[6]; 994 } __attribute__ ((__packed__)); 995 996 /* 997 * store balance parameters to disk so that balance can be properly 998 * resumed after crash or unmount 999 */ 1000 struct btrfs_balance_item { 1001 /* BTRFS_BALANCE_* */ 1002 __le64 flags; 1003 1004 struct btrfs_disk_balance_args data; 1005 struct btrfs_disk_balance_args meta; 1006 struct btrfs_disk_balance_args sys; 1007 1008 __le64 unused[4]; 1009 } __attribute__ ((__packed__)); 1010 1011 enum { 1012 BTRFS_FILE_EXTENT_INLINE = 0, 1013 BTRFS_FILE_EXTENT_REG = 1, 1014 BTRFS_FILE_EXTENT_PREALLOC = 2, 1015 BTRFS_NR_FILE_EXTENT_TYPES = 3, 1016 }; 1017 1018 struct btrfs_file_extent_item { 1019 /* 1020 * transaction id that created this extent 1021 */ 1022 __le64 generation; 1023 /* 1024 * max number of bytes to hold this extent in ram 1025 * when we split a compressed extent we can't know how big 1026 * each of the resulting pieces will be. So, this is 1027 * an upper limit on the size of the extent in ram instead of 1028 * an exact limit. 1029 */ 1030 __le64 ram_bytes; 1031 1032 /* 1033 * 32 bits for the various ways we might encode the data, 1034 * including compression and encryption. If any of these 1035 * are set to something a given disk format doesn't understand 1036 * it is treated like an incompat flag for reading and writing, 1037 * but not for stat. 1038 */ 1039 __u8 compression; 1040 __u8 encryption; 1041 __le16 other_encoding; /* spare for later use */ 1042 1043 /* are we inline data or a real extent? */ 1044 __u8 type; 1045 1046 /* 1047 * disk space consumed by the extent, checksum blocks are included 1048 * in these numbers 1049 * 1050 * At this offset in the structure, the inline extent data start. 1051 */ 1052 __le64 disk_bytenr; 1053 __le64 disk_num_bytes; 1054 /* 1055 * the logical offset in file blocks (no csums) 1056 * this extent record is for. This allows a file extent to point 1057 * into the middle of an existing extent on disk, sharing it 1058 * between two snapshots (useful if some bytes in the middle of the 1059 * extent have changed 1060 */ 1061 __le64 offset; 1062 /* 1063 * the logical number of file blocks (no csums included). This 1064 * always reflects the size uncompressed and without encoding. 1065 */ 1066 __le64 num_bytes; 1067 1068 } __attribute__ ((__packed__)); 1069 1070 struct btrfs_csum_item { 1071 __u8 csum; 1072 } __attribute__ ((__packed__)); 1073 1074 struct btrfs_dev_stats_item { 1075 /* 1076 * grow this item struct at the end for future enhancements and keep 1077 * the existing values unchanged 1078 */ 1079 __le64 values[BTRFS_DEV_STAT_VALUES_MAX]; 1080 } __attribute__ ((__packed__)); 1081 1082 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS 0 1083 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID 1 1084 1085 struct btrfs_dev_replace_item { 1086 /* 1087 * grow this item struct at the end for future enhancements and keep 1088 * the existing values unchanged 1089 */ 1090 __le64 src_devid; 1091 __le64 cursor_left; 1092 __le64 cursor_right; 1093 __le64 cont_reading_from_srcdev_mode; 1094 1095 __le64 replace_state; 1096 __le64 time_started; 1097 __le64 time_stopped; 1098 __le64 num_write_errors; 1099 __le64 num_uncorrectable_read_errors; 1100 } __attribute__ ((__packed__)); 1101 1102 /* different types of block groups (and chunks) */ 1103 #define BTRFS_BLOCK_GROUP_DATA (1ULL << 0) 1104 #define BTRFS_BLOCK_GROUP_SYSTEM (1ULL << 1) 1105 #define BTRFS_BLOCK_GROUP_METADATA (1ULL << 2) 1106 #define BTRFS_BLOCK_GROUP_RAID0 (1ULL << 3) 1107 #define BTRFS_BLOCK_GROUP_RAID1 (1ULL << 4) 1108 #define BTRFS_BLOCK_GROUP_DUP (1ULL << 5) 1109 #define BTRFS_BLOCK_GROUP_RAID10 (1ULL << 6) 1110 #define BTRFS_BLOCK_GROUP_RAID5 (1ULL << 7) 1111 #define BTRFS_BLOCK_GROUP_RAID6 (1ULL << 8) 1112 #define BTRFS_BLOCK_GROUP_RAID1C3 (1ULL << 9) 1113 #define BTRFS_BLOCK_GROUP_RAID1C4 (1ULL << 10) 1114 #define BTRFS_BLOCK_GROUP_RESERVED (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \ 1115 BTRFS_SPACE_INFO_GLOBAL_RSV) 1116 1117 #define BTRFS_BLOCK_GROUP_TYPE_MASK (BTRFS_BLOCK_GROUP_DATA | \ 1118 BTRFS_BLOCK_GROUP_SYSTEM | \ 1119 BTRFS_BLOCK_GROUP_METADATA) 1120 1121 #define BTRFS_BLOCK_GROUP_PROFILE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \ 1122 BTRFS_BLOCK_GROUP_RAID1 | \ 1123 BTRFS_BLOCK_GROUP_RAID1C3 | \ 1124 BTRFS_BLOCK_GROUP_RAID1C4 | \ 1125 BTRFS_BLOCK_GROUP_RAID5 | \ 1126 BTRFS_BLOCK_GROUP_RAID6 | \ 1127 BTRFS_BLOCK_GROUP_DUP | \ 1128 BTRFS_BLOCK_GROUP_RAID10) 1129 #define BTRFS_BLOCK_GROUP_RAID56_MASK (BTRFS_BLOCK_GROUP_RAID5 | \ 1130 BTRFS_BLOCK_GROUP_RAID6) 1131 1132 #define BTRFS_BLOCK_GROUP_RAID1_MASK (BTRFS_BLOCK_GROUP_RAID1 | \ 1133 BTRFS_BLOCK_GROUP_RAID1C3 | \ 1134 BTRFS_BLOCK_GROUP_RAID1C4) 1135 1136 /* 1137 * We need a bit for restriper to be able to tell when chunks of type 1138 * SINGLE are available. This "extended" profile format is used in 1139 * fs_info->avail_*_alloc_bits (in-memory) and balance item fields 1140 * (on-disk). The corresponding on-disk bit in chunk.type is reserved 1141 * to avoid remappings between two formats in future. 1142 */ 1143 #define BTRFS_AVAIL_ALLOC_BIT_SINGLE (1ULL << 48) 1144 1145 /* 1146 * A fake block group type that is used to communicate global block reserve 1147 * size to userspace via the SPACE_INFO ioctl. 1148 */ 1149 #define BTRFS_SPACE_INFO_GLOBAL_RSV (1ULL << 49) 1150 1151 #define BTRFS_EXTENDED_PROFILE_MASK (BTRFS_BLOCK_GROUP_PROFILE_MASK | \ 1152 BTRFS_AVAIL_ALLOC_BIT_SINGLE) 1153 1154 static inline __u64 chunk_to_extended(__u64 flags) 1155 { 1156 if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0) 1157 flags |= BTRFS_AVAIL_ALLOC_BIT_SINGLE; 1158 1159 return flags; 1160 } 1161 static inline __u64 extended_to_chunk(__u64 flags) 1162 { 1163 return flags & ~BTRFS_AVAIL_ALLOC_BIT_SINGLE; 1164 } 1165 1166 struct btrfs_block_group_item { 1167 __le64 used; 1168 __le64 chunk_objectid; 1169 __le64 flags; 1170 } __attribute__ ((__packed__)); 1171 1172 struct btrfs_free_space_info { 1173 __le32 extent_count; 1174 __le32 flags; 1175 } __attribute__ ((__packed__)); 1176 1177 #define BTRFS_FREE_SPACE_USING_BITMAPS (1ULL << 0) 1178 1179 #define BTRFS_QGROUP_LEVEL_SHIFT 48 1180 static inline __u16 btrfs_qgroup_level(__u64 qgroupid) 1181 { 1182 return (__u16)(qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT); 1183 } 1184 1185 /* 1186 * is subvolume quota turned on? 1187 */ 1188 #define BTRFS_QGROUP_STATUS_FLAG_ON (1ULL << 0) 1189 /* 1190 * RESCAN is set during the initialization phase 1191 */ 1192 #define BTRFS_QGROUP_STATUS_FLAG_RESCAN (1ULL << 1) 1193 /* 1194 * Some qgroup entries are known to be out of date, 1195 * either because the configuration has changed in a way that 1196 * makes a rescan necessary, or because the fs has been mounted 1197 * with a non-qgroup-aware version. 1198 * Turning qouta off and on again makes it inconsistent, too. 1199 */ 1200 #define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT (1ULL << 2) 1201 1202 #define BTRFS_QGROUP_STATUS_FLAGS_MASK (BTRFS_QGROUP_STATUS_FLAG_ON | \ 1203 BTRFS_QGROUP_STATUS_FLAG_RESCAN | \ 1204 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) 1205 1206 #define BTRFS_QGROUP_STATUS_VERSION 1 1207 1208 struct btrfs_qgroup_status_item { 1209 __le64 version; 1210 /* 1211 * the generation is updated during every commit. As older 1212 * versions of btrfs are not aware of qgroups, it will be 1213 * possible to detect inconsistencies by checking the 1214 * generation on mount time 1215 */ 1216 __le64 generation; 1217 1218 /* flag definitions see above */ 1219 __le64 flags; 1220 1221 /* 1222 * only used during scanning to record the progress 1223 * of the scan. It contains a logical address 1224 */ 1225 __le64 rescan; 1226 } __attribute__ ((__packed__)); 1227 1228 struct btrfs_qgroup_info_item { 1229 __le64 generation; 1230 __le64 rfer; 1231 __le64 rfer_cmpr; 1232 __le64 excl; 1233 __le64 excl_cmpr; 1234 } __attribute__ ((__packed__)); 1235 1236 struct btrfs_qgroup_limit_item { 1237 /* 1238 * only updated when any of the other values change 1239 */ 1240 __le64 flags; 1241 __le64 max_rfer; 1242 __le64 max_excl; 1243 __le64 rsv_rfer; 1244 __le64 rsv_excl; 1245 } __attribute__ ((__packed__)); 1246 1247 struct btrfs_verity_descriptor_item { 1248 /* Size of the verity descriptor in bytes */ 1249 __le64 size; 1250 /* 1251 * When we implement support for fscrypt, we will need to encrypt the 1252 * Merkle tree for encrypted verity files. These 128 bits are for the 1253 * eventual storage of an fscrypt initialization vector. 1254 */ 1255 __le64 reserved[2]; 1256 __u8 encryption; 1257 } __attribute__ ((__packed__)); 1258 1259 #endif /* _BTRFS_CTREE_H_ */ 1260