fs/btrfs/btrfs_tree.h

   1 /*
   2  * From linux/include/uapi/linux/btrfs_tree.h
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #ifndef __BTRFS_BTRFS_TREE_H__
   8 #define __BTRFS_BTRFS_TREE_H__
   9
  10 #include <common.h>
  11
  12 #define BTRFS_VOL_NAME_MAX 255
  13 #define BTRFS_NAME_MAX 255
  14 #define BTRFS_LABEL_SIZE 256
  15 #define BTRFS_FSID_SIZE 16
  16 #define BTRFS_UUID_SIZE 16
  17
  18 /*
  19  * This header contains the structure definitions and constants used
  20  * by file system objects that can be retrieved using
  21  * the BTRFS_IOC_SEARCH_TREE ioctl.  That means basically anything that
  22  * is needed to describe a leaf node's key or item contents.
  23  */
  24
  25 /* holds pointers to all of the tree roots */
  26 #define BTRFS_ROOT_TREE_OBJECTID 1ULL
  27
  28 /* stores information about which extents are in use, and reference counts */
  29 #define BTRFS_EXTENT_TREE_OBJECTID 2ULL
  30
  31 /*
  32  * chunk tree stores translations from logical -> physical block numbering
  33  * the super block points to the chunk tree
  34  */
  35 #define BTRFS_CHUNK_TREE_OBJECTID 3ULL
  36
  37 /*
  38  * stores information about which areas of a given device are in use.
  39  * one per device.  The tree of tree roots points to the device tree
  40  */
  41 #define BTRFS_DEV_TREE_OBJECTID 4ULL
  42
  43 /* one per subvolume, storing files and directories */
  44 #define BTRFS_FS_TREE_OBJECTID 5ULL
  45
  46 /* directory objectid inside the root tree */
  47 #define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
  48
  49 /* holds checksums of all the data extents */
  50 #define BTRFS_CSUM_TREE_OBJECTID 7ULL
  51
  52 /* holds quota configuration and tracking */
  53 #define BTRFS_QUOTA_TREE_OBJECTID 8ULL
  54
  55 /* for storing items that use the BTRFS_UUID_KEY* types */
  56 #define BTRFS_UUID_TREE_OBJECTID 9ULL
  57
  58 /* tracks free space in block groups. */
  59 #define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
  60
  61 /* device stats in the device tree */
  62 #define BTRFS_DEV_STATS_OBJECTID 0ULL
  63
  64 /* for storing balance parameters in the root tree */
  65 #define BTRFS_BALANCE_OBJECTID -4ULL
  66
  67 /* orhpan objectid for tracking unlinked/truncated files */
  68 #define BTRFS_ORPHAN_OBJECTID -5ULL
  69
  70 /* does write ahead logging to speed up fsyncs */
  71 #define BTRFS_TREE_LOG_OBJECTID -6ULL
  72 #define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
  73
  74 /* for space balancing */
  75 #define BTRFS_TREE_RELOC_OBJECTID -8ULL
  76 #define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
  77
  78 /*
  79  * extent checksums all have this objectid
  80  * this allows them to share the logging tree
  81  * for fsyncs
  82  */
  83 #define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
  84
  85 /* For storing free space cache */
  86 #define BTRFS_FREE_SPACE_OBJECTID -11ULL
  87
  88 /*
  89  * The inode number assigned to the special inode for storing
  90  * free ino cache
  91  */
  92 #define BTRFS_FREE_INO_OBJECTID -12ULL
  93
  94 /* dummy objectid represents multiple objectids */
  95 #define BTRFS_MULTIPLE_OBJECTIDS -255ULL
  96
  97 /*
  98  * All files have objectids in this range.
  99  */
 100 #define BTRFS_FIRST_FREE_OBJECTID 256ULL
 101 #define BTRFS_LAST_FREE_OBJECTID -256ULL
 102 #define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
 103
 104
 105 /*
 106  * the device items go into the chunk tree.  The key is in the form
 107  * [ 1 BTRFS_DEV_ITEM_KEY device_id ]
 108  */
 109 #define BTRFS_DEV_ITEMS_OBJECTID 1ULL
 110
 111 #define BTRFS_BTREE_INODE_OBJECTID 1
 112
 113 #define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2
 114
 115 #define BTRFS_DEV_REPLACE_DEVID 0ULL
 116
 117 /*
 118  * inode items have the data typically returned from stat and store other
 119  * info about object characteristics.  There is one for every file and dir in
 120  * the FS
 121  */
 122 #define BTRFS_INODE_ITEM_KEY            1
 123 #define BTRFS_INODE_REF_KEY             12
 124 #define BTRFS_INODE_EXTREF_KEY          13
 125 #define BTRFS_XATTR_ITEM_KEY            24
 126 #define BTRFS_ORPHAN_ITEM_KEY           48
 127 /* reserve 2-15 close to the inode for later flexibility */
 128
 129 /*
 130  * dir items are the name -> inode pointers in a directory.  There is one
 131  * for every name in a directory.
 132  */
 133 #define BTRFS_DIR_LOG_ITEM_KEY  60
 134 #define BTRFS_DIR_LOG_INDEX_KEY 72
 135 #define BTRFS_DIR_ITEM_KEY      84
 136 #define BTRFS_DIR_INDEX_KEY     96
 137 /*
 138  * extent data is for file data
 139  */
 140 #define BTRFS_EXTENT_DATA_KEY   108
 141
 142 /*
 143  * extent csums are stored in a separate tree and hold csums for
 144  * an entire extent on disk.
 145  */
 146 #define BTRFS_EXTENT_CSUM_KEY   128
 147
 148 /*
 149  * root items point to tree roots.  They are typically in the root
 150  * tree used by the super block to find all the other trees
 151  */
 152 #define BTRFS_ROOT_ITEM_KEY     132
 153
 154 /*
 155  * root backrefs tie subvols and snapshots to the directory entries that
 156  * reference them
 157  */
 158 #define BTRFS_ROOT_BACKREF_KEY  144
 159
 160 /*
 161  * root refs make a fast index for listing all of the snapshots and
 162  * subvolumes referenced by a given root.  They point directly to the
 163  * directory item in the root that references the subvol
 164  */
 165 #define BTRFS_ROOT_REF_KEY      156
 166
 167 /*
 168  * extent items are in the extent map tree.  These record which blocks
 169  * are used, and how many references there are to each block
 170  */
 171 #define BTRFS_EXTENT_ITEM_KEY   168
 172
 173 /*
 174  * The same as the BTRFS_EXTENT_ITEM_KEY, except it's metadata we already know
 175  * the length, so we save the level in key->offset instead of the length.
 176  */
 177 #define BTRFS_METADATA_ITEM_KEY 169
 178
 179 #define BTRFS_TREE_BLOCK_REF_KEY        176
 180
 181 #define BTRFS_EXTENT_DATA_REF_KEY       178
 182
 183 #define BTRFS_EXTENT_REF_V0_KEY         180
 184
 185 #define BTRFS_SHARED_BLOCK_REF_KEY      182
 186
 187 #define BTRFS_SHARED_DATA_REF_KEY       184
 188
 189 /*
 190  * block groups give us hints into the extent allocation trees.  Which
 191  * blocks are free etc etc
 192  */
 193 #define BTRFS_BLOCK_GROUP_ITEM_KEY 192
 194
 195 /*
 196  * Every block group is represented in the free space tree by a free space info
 197  * item, which stores some accounting information. It is keyed on
 198  * (block_group_start, FREE_SPACE_INFO, block_group_length).
 199  */
 200 #define BTRFS_FREE_SPACE_INFO_KEY 198
 201
 202 /*
 203  * A free space extent tracks an extent of space that is free in a block group.
 204  * It is keyed on (start, FREE_SPACE_EXTENT, length).
 205  */
 206 #define BTRFS_FREE_SPACE_EXTENT_KEY 199
 207
 208 /*
 209  * When a block group becomes very fragmented, we convert it to use bitmaps
 210  * instead of extents. A free space bitmap is keyed on
 211  * (start, FREE_SPACE_BITMAP, length); the corresponding item is a bitmap with
 212  * (length / sectorsize) bits.
 213  */
 214 #define BTRFS_FREE_SPACE_BITMAP_KEY 200
 215
 216 #define BTRFS_DEV_EXTENT_KEY    204
 217 #define BTRFS_DEV_ITEM_KEY      216
 218 #define BTRFS_CHUNK_ITEM_KEY    228
 219
 220 /*
 221  * Records the overall state of the qgroups.
 222  * There's only one instance of this key present,
 223  * (0, BTRFS_QGROUP_STATUS_KEY, 0)
 224  */
 225 #define BTRFS_QGROUP_STATUS_KEY         240
 226 /*
 227  * Records the currently used space of the qgroup.
 228  * One key per qgroup, (0, BTRFS_QGROUP_INFO_KEY, qgroupid).
 229  */
 230 #define BTRFS_QGROUP_INFO_KEY           242
 231 /*
 232  * Contains the user configured limits for the qgroup.
 233  * One key per qgroup, (0, BTRFS_QGROUP_LIMIT_KEY, qgroupid).
 234  */
 235 #define BTRFS_QGROUP_LIMIT_KEY          244
 236 /*
 237  * Records the child-parent relationship of qgroups. For
 238  * each relation, 2 keys are present:
 239  * (childid, BTRFS_QGROUP_RELATION_KEY, parentid)
 240  * (parentid, BTRFS_QGROUP_RELATION_KEY, childid)
 241  */
 242 #define BTRFS_QGROUP_RELATION_KEY       246
 243
 244 /*
 245  * Obsolete name, see BTRFS_TEMPORARY_ITEM_KEY.
 246  */
 247 #define BTRFS_BALANCE_ITEM_KEY  248
 248
 249 /*
 250  * The key type for tree items that are stored persistently, but do not need to
 251  * exist for extended period of time. The items can exist in any tree.
 252  *
 253  * [subtype, BTRFS_TEMPORARY_ITEM_KEY, data]
 254  *
 255  * Existing items:
 256  *
 257  * - balance status item
 258  *   (BTRFS_BALANCE_OBJECTID, BTRFS_TEMPORARY_ITEM_KEY, 0)
 259  */
 260 #define BTRFS_TEMPORARY_ITEM_KEY        248
 261
 262 /*
 263  * Obsolete name, see BTRFS_PERSISTENT_ITEM_KEY
 264  */
 265 #define BTRFS_DEV_STATS_KEY             249
 266
 267 /*
 268  * The key type for tree items that are stored persistently and usually exist
 269  * for a long period, eg. filesystem lifetime. The item kinds can be status
 270  * information, stats or preference values. The item can exist in any tree.
 271  *
 272  * [subtype, BTRFS_PERSISTENT_ITEM_KEY, data]
 273  *
 274  * Existing items:
 275  *
 276  * - device statistics, store IO stats in the device tree, one key for all
 277  *   stats
 278  *   (BTRFS_DEV_STATS_OBJECTID, BTRFS_DEV_STATS_KEY, 0)
 279  */
 280 #define BTRFS_PERSISTENT_ITEM_KEY       249
 281
 282 /*
 283  * Persistantly stores the device replace state in the device tree.
 284  * The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0).
 285  */
 286 #define BTRFS_DEV_REPLACE_KEY   250
 287
 288 /*
 289  * Stores items that allow to quickly map UUIDs to something else.
 290  * These items are part of the filesystem UUID tree.
 291  * The key is built like this:
 292  * (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits).
 293  */
 294 #if BTRFS_UUID_SIZE != 16
 295 #error "UUID items require BTRFS_UUID_SIZE == 16!"
 296 #endif
 297 #define BTRFS_UUID_KEY_SUBVOL   251     /* for UUIDs assigned to subvols */
 298 #define BTRFS_UUID_KEY_RECEIVED_SUBVOL  252     /* for UUIDs assigned to
 299                                                  * received subvols */
 300
 301 /*
 302  * string items are for debugging.  They just store a short string of
 303  * data in the FS
 304  */
 305 #define BTRFS_STRING_ITEM_KEY   253
 306
 307
 308
 309 /* 32 bytes in various csum fields */
 310 #define BTRFS_CSUM_SIZE 32
 311
 312 /* csum types */
 313 #define BTRFS_CSUM_TYPE_CRC32   0
 314
 315 /*
 316  * flags definitions for directory entry item type
 317  *
 318  * Used by:
 319  * struct btrfs_dir_item.type
 320  */
 321 #define BTRFS_FT_UNKNOWN        0
 322 #define BTRFS_FT_REG_FILE       1
 323 #define BTRFS_FT_DIR            2
 324 #define BTRFS_FT_CHRDEV         3
 325 #define BTRFS_FT_BLKDEV         4
 326 #define BTRFS_FT_FIFO           5
 327 #define BTRFS_FT_SOCK           6
 328 #define BTRFS_FT_SYMLINK        7
 329 #define BTRFS_FT_XATTR          8
 330 #define BTRFS_FT_MAX            9
 331
 332 /*
 333  * The key defines the order in the tree, and so it also defines (optimal)
 334  * block layout.
 335  *
 336  * objectid corresponds to the inode number.
 337  *
 338  * type tells us things about the object, and is a kind of stream selector.
 339  * so for a given inode, keys with type of 1 might refer to the inode data,
 340  * type of 2 may point to file data in the btree and type == 3 may point to
 341  * extents.
 342  *
 343  * offset is the starting byte offset for this key in the stream.
 344  */
 345
 346 struct btrfs_key {
 347         __u64 objectid;
 348         __u8 type;
 349         __u64 offset;
 350 } __attribute__ ((__packed__));
 351
 352 struct btrfs_dev_item {
 353         /* the internal btrfs device id */
 354         __u64 devid;
 355
 356         /* size of the device */
 357         __u64 total_bytes;
 358
 359         /* bytes used */
 360         __u64 bytes_used;
 361
 362         /* optimal io alignment for this device */
 363         __u32 io_align;
 364
 365         /* optimal io width for this device */
 366         __u32 io_width;
 367
 368         /* minimal io size for this device */
 369         __u32 sector_size;
 370
 371         /* type and info about this device */
 372         __u64 type;
 373
 374         /* expected generation for this device */
 375         __u64 generation;
 376
 377         /*
 378          * starting byte of this partition on the device,
 379          * to allow for stripe alignment in the future
 380          */
 381         __u64 start_offset;
 382
 383         /* grouping information for allocation decisions */
 384         __u32 dev_group;
 385
 386         /* seek speed 0-100 where 100 is fastest */
 387         __u8 seek_speed;
 388
 389         /* bandwidth 0-100 where 100 is fastest */
 390         __u8 bandwidth;
 391
 392         /* btrfs generated uuid for this device */
 393         __u8 uuid[BTRFS_UUID_SIZE];
 394
 395         /* uuid of FS who owns this device */
 396         __u8 fsid[BTRFS_UUID_SIZE];
 397 } __attribute__ ((__packed__));
 398
 399 struct btrfs_stripe {
 400         __u64 devid;
 401         __u64 offset;
 402         __u8 dev_uuid[BTRFS_UUID_SIZE];
 403 } __attribute__ ((__packed__));
 404
 405 struct btrfs_chunk {
 406         /* size of this chunk in bytes */
 407         __u64 length;
 408
 409         /* objectid of the root referencing this chunk */
 410         __u64 owner;
 411
 412         __u64 stripe_len;
 413         __u64 type;
 414
 415         /* optimal io alignment for this chunk */
 416         __u32 io_align;
 417
 418         /* optimal io width for this chunk */
 419         __u32 io_width;
 420
 421         /* minimal io size for this chunk */
 422         __u32 sector_size;
 423
 424         /* 2^16 stripes is quite a lot, a second limit is the size of a single
 425          * item in the btree
 426          */
 427         __u16 num_stripes;
 428
 429         /* sub stripes only matter for raid10 */
 430         __u16 sub_stripes;
 431         struct btrfs_stripe stripe;
 432         /* additional stripes go here */
 433 } __attribute__ ((__packed__));
 434
 435 #define BTRFS_FREE_SPACE_EXTENT 1
 436 #define BTRFS_FREE_SPACE_BITMAP 2
 437
 438 struct btrfs_free_space_entry {
 439         __u64 offset;
 440         __u64 bytes;
 441         __u8 type;
 442 } __attribute__ ((__packed__));
 443
 444 struct btrfs_free_space_header {
 445         struct btrfs_key location;
 446         __u64 generation;
 447         __u64 num_entries;
 448         __u64 num_bitmaps;
 449 } __attribute__ ((__packed__));
 450
 451 #define BTRFS_HEADER_FLAG_WRITTEN       (1ULL << 0)
 452 #define BTRFS_HEADER_FLAG_RELOC         (1ULL << 1)
 453
 454 /* Super block flags */
 455 /* Errors detected */
 456 #define BTRFS_SUPER_FLAG_ERROR          (1ULL << 2)
 457
 458 #define BTRFS_SUPER_FLAG_SEEDING        (1ULL << 32)
 459 #define BTRFS_SUPER_FLAG_METADUMP       (1ULL << 33)
 460
 461
 462 /*
 463  * items in the extent btree are used to record the objectid of the
 464  * owner of the block and the number of references
 465  */
 466
 467 struct btrfs_extent_item {
 468         __u64 refs;
 469         __u64 generation;
 470         __u64 flags;
 471 } __attribute__ ((__packed__));
 472
 473
 474 #define BTRFS_EXTENT_FLAG_DATA          (1ULL << 0)
 475 #define BTRFS_EXTENT_FLAG_TREE_BLOCK    (1ULL << 1)
 476
 477 /* following flags only apply to tree blocks */
 478
 479 /* use full backrefs for extent pointers in the block */
 480 #define BTRFS_BLOCK_FLAG_FULL_BACKREF   (1ULL << 8)
 481
 482 /*
 483  * this flag is only used internally by scrub and may be changed at any time
 484  * it is only declared here to avoid collisions
 485  */
 486 #define BTRFS_EXTENT_FLAG_SUPER         (1ULL << 48)
 487
 488 struct btrfs_tree_block_info {
 489         struct btrfs_key key;
 490         __u8 level;
 491 } __attribute__ ((__packed__));
 492
 493 struct btrfs_extent_data_ref {
 494         __u64 root;
 495         __u64 objectid;
 496         __u64 offset;
 497         __u32 count;
 498 } __attribute__ ((__packed__));
 499
 500 struct btrfs_shared_data_ref {
 501         __u32 count;
 502 } __attribute__ ((__packed__));
 503
 504 struct btrfs_extent_inline_ref {
 505         __u8 type;
 506         __u64 offset;
 507 } __attribute__ ((__packed__));
 508
 509 /* dev extents record free space on individual devices.  The owner
 510  * field points back to the chunk allocation mapping tree that allocated
 511  * the extent.  The chunk tree uuid field is a way to double check the owner
 512  */
 513 struct btrfs_dev_extent {
 514         __u64 chunk_tree;
 515         __u64 chunk_objectid;
 516         __u64 chunk_offset;
 517         __u64 length;
 518         __u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
 519 } __attribute__ ((__packed__));
 520
 521 struct btrfs_inode_ref {
 522         __u64 index;
 523         __u16 name_len;
 524         /* name goes here */
 525 } __attribute__ ((__packed__));
 526
 527 struct btrfs_inode_extref {
 528         __u64 parent_objectid;
 529         __u64 index;
 530         __u16 name_len;
 531         __u8   name[0];
 532         /* name goes here */
 533 } __attribute__ ((__packed__));
 534
 535 struct btrfs_timespec {
 536         __u64 sec;
 537         __u32 nsec;
 538 } __attribute__ ((__packed__));
 539
 540 struct btrfs_inode_item {
 541         /* nfs style generation number */
 542         __u64 generation;
 543         /* transid that last touched this inode */
 544         __u64 transid;
 545         __u64 size;
 546         __u64 nbytes;
 547         __u64 block_group;
 548         __u32 nlink;
 549         __u32 uid;
 550         __u32 gid;
 551         __u32 mode;
 552         __u64 rdev;
 553         __u64 flags;
 554
 555         /* modification sequence number for NFS */
 556         __u64 sequence;
 557
 558         /*
 559          * a little future expansion, for more than this we can
 560          * just grow the inode item and version it
 561          */
 562         __u64 reserved[4];
 563         struct btrfs_timespec atime;
 564         struct btrfs_timespec ctime;
 565         struct btrfs_timespec mtime;
 566         struct btrfs_timespec otime;
 567 } __attribute__ ((__packed__));
 568
 569 struct btrfs_dir_log_item {
 570         __u64 end;
 571 } __attribute__ ((__packed__));
 572
 573 struct btrfs_dir_item {
 574         struct btrfs_key location;
 575         __u64 transid;
 576         __u16 data_len;
 577         __u16 name_len;
 578         __u8 type;
 579 } __attribute__ ((__packed__));
 580
 581 #define BTRFS_ROOT_SUBVOL_RDONLY        (1ULL << 0)
 582
 583 /*
 584  * Internal in-memory flag that a subvolume has been marked for deletion but
 585  * still visible as a directory
 586  */
 587 #define BTRFS_ROOT_SUBVOL_DEAD          (1ULL << 48)
 588
 589 struct btrfs_root_item {
 590         struct btrfs_inode_item inode;
 591         __u64 generation;
 592         __u64 root_dirid;
 593         __u64 bytenr;
 594         __u64 byte_limit;
 595         __u64 bytes_used;
 596         __u64 last_snapshot;
 597         __u64 flags;
 598         __u32 refs;
 599         struct btrfs_key drop_progress;
 600         __u8 drop_level;
 601         __u8 level;
 602
 603         /*
 604          * The following fields appear after subvol_uuids+subvol_times
 605          * were introduced.
 606          */
 607
 608         /*
 609          * This generation number is used to test if the new fields are valid
 610          * and up to date while reading the root item. Every time the root item
 611          * is written out, the "generation" field is copied into this field. If
 612          * anyone ever mounted the fs with an older kernel, we will have
 613          * mismatching generation values here and thus must invalidate the
 614          * new fields. See btrfs_update_root and btrfs_find_last_root for
 615          * details.
 616          * the offset of generation_v2 is also used as the start for the memset
 617          * when invalidating the fields.
 618          */
 619         __u64 generation_v2;
 620         __u8 uuid[BTRFS_UUID_SIZE];
 621         __u8 parent_uuid[BTRFS_UUID_SIZE];
 622         __u8 received_uuid[BTRFS_UUID_SIZE];
 623         __u64 ctransid; /* updated when an inode changes */
 624         __u64 otransid; /* trans when created */
 625         __u64 stransid; /* trans when sent. non-zero for received subvol */
 626         __u64 rtransid; /* trans when received. non-zero for received subvol */
 627         struct btrfs_timespec ctime;
 628         struct btrfs_timespec otime;
 629         struct btrfs_timespec stime;
 630         struct btrfs_timespec rtime;
 631         __u64 reserved[8]; /* for future */
 632 } __attribute__ ((__packed__));
 633
 634 /*
 635  * this is used for both forward and backward root refs
 636  */
 637 struct btrfs_root_ref {
 638         __u64 dirid;
 639         __u64 sequence;
 640         __u16 name_len;
 641 } __attribute__ ((__packed__));
 642
 643 #define BTRFS_FILE_EXTENT_INLINE 0
 644 #define BTRFS_FILE_EXTENT_REG 1
 645 #define BTRFS_FILE_EXTENT_PREALLOC 2
 646
 647 enum btrfs_compression_type {
 648         BTRFS_COMPRESS_NONE  = 0,
 649         BTRFS_COMPRESS_ZLIB  = 1,
 650         BTRFS_COMPRESS_LZO   = 2,
 651         BTRFS_COMPRESS_TYPES = 2,
 652         BTRFS_COMPRESS_LAST  = 3,
 653 };
 654
 655 struct btrfs_file_extent_item {
 656         /*
 657          * transaction id that created this extent
 658          */
 659         __u64 generation;
 660         /*
 661          * max number of bytes to hold this extent in ram
 662          * when we split a compressed extent we can't know how big
 663          * each of the resulting pieces will be.  So, this is
 664          * an upper limit on the size of the extent in ram instead of
 665          * an exact limit.
 666          */
 667         __u64 ram_bytes;
 668
 669         /*
 670          * 32 bits for the various ways we might encode the data,
 671          * including compression and encryption.  If any of these
 672          * are set to something a given disk format doesn't understand
 673          * it is treated like an incompat flag for reading and writing,
 674          * but not for stat.
 675          */
 676         __u8 compression;
 677         __u8 encryption;
 678         __u16 other_encoding; /* spare for later use */
 679
 680         /* are we inline data or a real extent? */
 681         __u8 type;
 682
 683         /*
 684          * disk space consumed by the extent, checksum blocks are included
 685          * in these numbers
 686          *
 687          * At this offset in the structure, the inline extent data start.
 688          */
 689         __u64 disk_bytenr;
 690         __u64 disk_num_bytes;
 691         /*
 692          * the logical offset in file blocks (no csums)
 693          * this extent record is for.  This allows a file extent to point
 694          * into the middle of an existing extent on disk, sharing it
 695          * between two snapshots (useful if some bytes in the middle of the
 696          * extent have changed
 697          */
 698         __u64 offset;
 699         /*
 700          * the logical number of file blocks (no csums included).  This
 701          * always reflects the size uncompressed and without encoding.
 702          */
 703         __u64 num_bytes;
 704
 705 } __attribute__ ((__packed__));
 706
 707 struct btrfs_csum_item {
 708         __u8 csum;
 709 } __attribute__ ((__packed__));
 710
 711 /* different types of block groups (and chunks) */
 712 #define BTRFS_BLOCK_GROUP_DATA          (1ULL << 0)
 713 #define BTRFS_BLOCK_GROUP_SYSTEM        (1ULL << 1)
 714 #define BTRFS_BLOCK_GROUP_METADATA      (1ULL << 2)
 715 #define BTRFS_BLOCK_GROUP_RAID0         (1ULL << 3)
 716 #define BTRFS_BLOCK_GROUP_RAID1         (1ULL << 4)
 717 #define BTRFS_BLOCK_GROUP_DUP           (1ULL << 5)
 718 #define BTRFS_BLOCK_GROUP_RAID10        (1ULL << 6)
 719 #define BTRFS_BLOCK_GROUP_RAID5         (1ULL << 7)
 720 #define BTRFS_BLOCK_GROUP_RAID6         (1ULL << 8)
 721 #define BTRFS_BLOCK_GROUP_RESERVED      (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \
 722                                          BTRFS_SPACE_INFO_GLOBAL_RSV)
 723
 724 enum btrfs_raid_types {
 725         BTRFS_RAID_RAID10,
 726         BTRFS_RAID_RAID1,
 727         BTRFS_RAID_DUP,
 728         BTRFS_RAID_RAID0,
 729         BTRFS_RAID_SINGLE,
 730         BTRFS_RAID_RAID5,
 731         BTRFS_RAID_RAID6,
 732         BTRFS_NR_RAID_TYPES
 733 };
 734
 735 #define BTRFS_BLOCK_GROUP_TYPE_MASK     (BTRFS_BLOCK_GROUP_DATA |    \
 736                                          BTRFS_BLOCK_GROUP_SYSTEM |  \
 737                                          BTRFS_BLOCK_GROUP_METADATA)
 738
 739 #define BTRFS_BLOCK_GROUP_PROFILE_MASK  (BTRFS_BLOCK_GROUP_RAID0 |   \
 740                                          BTRFS_BLOCK_GROUP_RAID1 |   \
 741                                          BTRFS_BLOCK_GROUP_RAID5 |   \
 742                                          BTRFS_BLOCK_GROUP_RAID6 |   \
 743                                          BTRFS_BLOCK_GROUP_DUP |     \
 744                                          BTRFS_BLOCK_GROUP_RAID10)
 745 #define BTRFS_BLOCK_GROUP_RAID56_MASK   (BTRFS_BLOCK_GROUP_RAID5 |   \
 746                                          BTRFS_BLOCK_GROUP_RAID6)
 747
 748 /*
 749  * We need a bit for restriper to be able to tell when chunks of type
 750  * SINGLE are available.  This "extended" profile format is used in
 751  * fs_info->avail_*_alloc_bits (in-memory) and balance item fields
 752  * (on-disk).  The corresponding on-disk bit in chunk.type is reserved
 753  * to avoid remappings between two formats in future.
 754  */
 755 #define BTRFS_AVAIL_ALLOC_BIT_SINGLE    (1ULL << 48)
 756
 757 /*
 758  * A fake block group type that is used to communicate global block reserve
 759  * size to userspace via the SPACE_INFO ioctl.
 760  */
 761 #define BTRFS_SPACE_INFO_GLOBAL_RSV     (1ULL << 49)
 762
 763 #define BTRFS_EXTENDED_PROFILE_MASK     (BTRFS_BLOCK_GROUP_PROFILE_MASK | \
 764                                          BTRFS_AVAIL_ALLOC_BIT_SINGLE)
 765
 766 #endif /* __BTRFS_BTRFS_TREE_H__ */