git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/bcachefs_format.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _BCACHEFS_FORMAT_H
   3 #define _BCACHEFS_FORMAT_H
   4
   5 /*
   6  * bcachefs on disk data structures
   7  *
   8  * OVERVIEW:
   9  *
  10  * There are three main types of on disk data structures in bcachefs (this is
  11  * reduced from 5 in bcache)
  12  *
  13  *  - superblock
  14  *  - journal
  15  *  - btree
  16  *
  17  * The btree is the primary structure; most metadata exists as keys in the
  18  * various btrees. There are only a small number of btrees, they're not
  19  * sharded - we have one btree for extents, another for inodes, et cetera.
  20  *
  21  * SUPERBLOCK:
  22  *
  23  * The superblock contains the location of the journal, the list of devices in
  24  * the filesystem, and in general any metadata we need in order to decide
  25  * whether we can start a filesystem or prior to reading the journal/btree
  26  * roots.
  27  *
  28  * The superblock is extensible, and most of the contents of the superblock are
  29  * in variable length, type tagged fields; see struct bch_sb_field.
  30  *
  31  * Backup superblocks do not reside in a fixed location; also, superblocks do
  32  * not have a fixed size. To locate backup superblocks we have struct
  33  * bch_sb_layout; we store a copy of this inside every superblock, and also
  34  * before the first superblock.
  35  *
  36  * JOURNAL:
  37  *
  38  * The journal primarily records btree updates in the order they occurred;
  39  * journal replay consists of just iterating over all the keys in the open
  40  * journal entries and re-inserting them into the btrees.
  41  *
  42  * The journal also contains entry types for the btree roots, and blacklisted
  43  * journal sequence numbers (see journal_seq_blacklist.c).
  44  *
  45  * BTREE:
  46  *
  47  * bcachefs btrees are copy on write b+ trees, where nodes are big (typically
  48  * 128k-256k) and log structured. We use struct btree_node for writing the first
  49  * entry in a given node (offset 0), and struct btree_node_entry for all
  50  * subsequent writes.
  51  *
  52  * After the header, btree node entries contain a list of keys in sorted order.
  53  * Values are stored inline with the keys; since values are variable length (and
  54  * keys effectively are variable length too, due to packing) we can't do random
  55  * access without building up additional in memory tables in the btree node read
  56  * path.
  57  *
  58  * BTREE KEYS (struct bkey):
  59  *
  60  * The various btrees share a common format for the key - so as to avoid
  61  * switching in fastpath lookup/comparison code - but define their own
  62  * structures for the key values.
  63  *
  64  * The size of a key/value pair is stored as a u8 in units of u64s, so the max
  65  * size is just under 2k. The common part also contains a type tag for the
  66  * value, and a format field indicating whether the key is packed or not (and
  67  * also meant to allow adding new key fields in the future, if desired).
  68  *
  69  * bkeys, when stored within a btree node, may also be packed. In that case, the
  70  * bkey_format in that node is used to unpack it. Packed bkeys mean that we can
  71  * be generous with field sizes in the common part of the key format (64 bit
  72  * inode number, 64 bit offset, 96 bit version field, etc.) for negligible cost.
  73  */
  74
  75 #include <asm/types.h>
  76 #include <asm/byteorder.h>
  77 #include <linux/kernel.h>
  78 #include <linux/uuid.h>
  79 #include "vstructs.h"
  80
  81 #ifdef __KERNEL__
  82 typedef uuid_t __uuid_t;
  83 #endif
  84
  85 #define BITMASK(name, type, field, offset, end)                         \
  86 static const __maybe_unused unsigned    name##_OFFSET = offset;         \
  87 static const __maybe_unused unsigned    name##_BITS = (end - offset);   \
  88                                                                         \
  89 static inline __u64 name(const type *k)                                 \
  90 {                                                                       \
  91         return (k->field >> offset) & ~(~0ULL << (end - offset));       \
  92 }                                                                       \
  93                                                                         \
  94 static inline void SET_##name(type *k, __u64 v)                         \
  95 {                                                                       \
  96         k->field &= ~(~(~0ULL << (end - offset)) << offset);            \
  97         k->field |= (v & ~(~0ULL << (end - offset))) << offset;         \
  98 }
  99
 100 #define LE_BITMASK(_bits, name, type, field, offset, end)               \
 101 static const __maybe_unused unsigned    name##_OFFSET = offset;         \
 102 static const __maybe_unused unsigned    name##_BITS = (end - offset);   \
 103 static const __maybe_unused __u##_bits  name##_MAX = (1ULL << (end - offset)) - 1;\
 104                                                                         \
 105 static inline __u64 name(const type *k)                                 \
 106 {                                                                       \
 107         return (__le##_bits##_to_cpu(k->field) >> offset) &             \
 108                 ~(~0ULL << (end - offset));                             \
 109 }                                                                       \
 110                                                                         \
 111 static inline void SET_##name(type *k, __u64 v)                         \
 112 {                                                                       \
 113         __u##_bits new = __le##_bits##_to_cpu(k->field);                \
 114                                                                         \
 115         new &= ~(~(~0ULL << (end - offset)) << offset);                 \
 116         new |= (v & ~(~0ULL << (end - offset))) << offset;              \
 117         k->field = __cpu_to_le##_bits(new);                             \
 118 }
 119
 120 #define LE16_BITMASK(n, t, f, o, e)     LE_BITMASK(16, n, t, f, o, e)
 121 #define LE32_BITMASK(n, t, f, o, e)     LE_BITMASK(32, n, t, f, o, e)
 122 #define LE64_BITMASK(n, t, f, o, e)     LE_BITMASK(64, n, t, f, o, e)
 123
 124 struct bkey_format {
 125         __u8            key_u64s;
 126         __u8            nr_fields;
 127         /* One unused slot for now: */
 128         __u8            bits_per_field[6];
 129         __le64          field_offset[6];
 130 };
 131
 132 /* Btree keys - all units are in sectors */
 133
 134 struct bpos {
 135         /*
 136          * Word order matches machine byte order - btree code treats a bpos as a
 137          * single large integer, for search/comparison purposes
 138          *
 139          * Note that wherever a bpos is embedded in another on disk data
 140          * structure, it has to be byte swabbed when reading in metadata that
 141          * wasn't written in native endian order:
 142          */
 143 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 144         __u32           snapshot;
 145         __u64           offset;
 146         __u64           inode;
 147 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 148         __u64           inode;
 149         __u64           offset;         /* Points to end of extent - sectors */
 150         __u32           snapshot;
 151 #else
 152 #error edit for your odd byteorder.
 153 #endif
 154 } __packed
 155 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 156 __aligned(4)
 157 #endif
 158 ;
 159
 160 #define KEY_INODE_MAX                   ((__u64)~0ULL)
 161 #define KEY_OFFSET_MAX                  ((__u64)~0ULL)
 162 #define KEY_SNAPSHOT_MAX                ((__u32)~0U)
 163 #define KEY_SIZE_MAX                    ((__u32)~0U)
 164
 165 static inline struct bpos SPOS(__u64 inode, __u64 offset, __u32 snapshot)
 166 {
 167         return (struct bpos) {
 168                 .inode          = inode,
 169                 .offset         = offset,
 170                 .snapshot       = snapshot,
 171         };
 172 }
 173
 174 #define POS_MIN                         SPOS(0, 0, 0)
 175 #define POS_MAX                         SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, 0)
 176 #define SPOS_MAX                        SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, KEY_SNAPSHOT_MAX)
 177 #define POS(_inode, _offset)            SPOS(_inode, _offset, 0)
 178
 179 /* Empty placeholder struct, for container_of() */
 180 struct bch_val {
 181         __u64           __nothing[0];
 182 };
 183
 184 struct bversion {
 185 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 186         __u64           lo;
 187         __u32           hi;
 188 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 189         __u32           hi;
 190         __u64           lo;
 191 #endif
 192 } __packed
 193 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 194 __aligned(4)
 195 #endif
 196 ;
 197
 198 struct bkey {
 199         /* Size of combined key and value, in u64s */
 200         __u8            u64s;
 201
 202         /* Format of key (0 for format local to btree node) */
 203 #if defined(__LITTLE_ENDIAN_BITFIELD)
 204         __u8            format:7,
 205                         needs_whiteout:1;
 206 #elif defined (__BIG_ENDIAN_BITFIELD)
 207         __u8            needs_whiteout:1,
 208                         format:7;
 209 #else
 210 #error edit for your odd byteorder.
 211 #endif
 212
 213         /* Type of the value */
 214         __u8            type;
 215
 216 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 217         __u8            pad[1];
 218
 219         struct bversion version;
 220         __u32           size;           /* extent size, in sectors */
 221         struct bpos     p;
 222 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 223         struct bpos     p;
 224         __u32           size;           /* extent size, in sectors */
 225         struct bversion version;
 226
 227         __u8            pad[1];
 228 #endif
 229 } __packed
 230 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 231 /*
 232  * The big-endian version of bkey can't be compiled by rustc with the "aligned"
 233  * attr since it doesn't allow types to have both "packed" and "aligned" attrs.
 234  * So for Rust compatibility, don't include this. It can be included in the LE
 235  * version because the "packed" attr is redundant in that case.
 236  *
 237  * History: (quoting Kent)
 238  *
 239  * Specifically, when i was designing bkey, I wanted the header to be no
 240  * bigger than necessary so that bkey_packed could use the rest. That means that
 241  * decently offten extent keys will fit into only 8 bytes, instead of spilling over
 242  * to 16.
 243  *
 244  * But packed_bkey treats the part after the header - the packed section -
 245  * as a single multi word, variable length integer. And bkey, the unpacked
 246  * version, is just a special case version of a bkey_packed; all the packed
 247  * bkey code will work on keys in any packed format, the in-memory
 248  * representation of an unpacked key also is just one type of packed key...
 249  *
 250  * So that constrains the key part of a bkig endian bkey to start right
 251  * after the header.
 252  *
 253  * If we ever do a bkey_v2 and need to expand the hedaer by another byte for
 254  * some reason - that will clean up this wart.
 255  */
 256 __aligned(8)
 257 #endif
 258 ;
 259
 260 struct bkey_packed {
 261         __u64           _data[0];
 262
 263         /* Size of combined key and value, in u64s */
 264         __u8            u64s;
 265
 266         /* Format of key (0 for format local to btree node) */
 267
 268         /*
 269          * XXX: next incompat on disk format change, switch format and
 270          * needs_whiteout - bkey_packed() will be cheaper if format is the high
 271          * bits of the bitfield
 272          */
 273 #if defined(__LITTLE_ENDIAN_BITFIELD)
 274         __u8            format:7,
 275                         needs_whiteout:1;
 276 #elif defined (__BIG_ENDIAN_BITFIELD)
 277         __u8            needs_whiteout:1,
 278                         format:7;
 279 #endif
 280
 281         /* Type of the value */
 282         __u8            type;
 283         __u8            key_start[0];
 284
 285         /*
 286          * We copy bkeys with struct assignment in various places, and while
 287          * that shouldn't be done with packed bkeys we can't disallow it in C,
 288          * and it's legal to cast a bkey to a bkey_packed  - so padding it out
 289          * to the same size as struct bkey should hopefully be safest.
 290          */
 291         __u8            pad[sizeof(struct bkey) - 3];
 292 } __packed __aligned(8);
 293
 294 typedef struct {
 295         __le64                  lo;
 296         __le64                  hi;
 297 } bch_le128;
 298
 299 #define BKEY_U64s                       (sizeof(struct bkey) / sizeof(__u64))
 300 #define BKEY_U64s_MAX                   U8_MAX
 301 #define BKEY_VAL_U64s_MAX               (BKEY_U64s_MAX - BKEY_U64s)
 302
 303 #define KEY_PACKED_BITS_START           24
 304
 305 #define KEY_FORMAT_LOCAL_BTREE          0
 306 #define KEY_FORMAT_CURRENT              1
 307
 308 enum bch_bkey_fields {
 309         BKEY_FIELD_INODE,
 310         BKEY_FIELD_OFFSET,
 311         BKEY_FIELD_SNAPSHOT,
 312         BKEY_FIELD_SIZE,
 313         BKEY_FIELD_VERSION_HI,
 314         BKEY_FIELD_VERSION_LO,
 315         BKEY_NR_FIELDS,
 316 };
 317
 318 #define bkey_format_field(name, field)                                  \
 319         [BKEY_FIELD_##name] = (sizeof(((struct bkey *) NULL)->field) * 8)
 320
 321 #define BKEY_FORMAT_CURRENT                                             \
 322 ((struct bkey_format) {                                                 \
 323         .key_u64s       = BKEY_U64s,                                    \
 324         .nr_fields      = BKEY_NR_FIELDS,                               \
 325         .bits_per_field = {                                             \
 326                 bkey_format_field(INODE,        p.inode),               \
 327                 bkey_format_field(OFFSET,       p.offset),              \
 328                 bkey_format_field(SNAPSHOT,     p.snapshot),            \
 329                 bkey_format_field(SIZE,         size),                  \
 330                 bkey_format_field(VERSION_HI,   version.hi),            \
 331                 bkey_format_field(VERSION_LO,   version.lo),            \
 332         },                                                              \
 333 })
 334
 335 /* bkey with inline value */
 336 struct bkey_i {
 337         __u64                   _data[0];
 338
 339         struct bkey     k;
 340         struct bch_val  v;
 341 };
 342
 343 #define POS_KEY(_pos)                                                   \
 344 ((struct bkey) {                                                        \
 345         .u64s           = BKEY_U64s,                                    \
 346         .format         = KEY_FORMAT_CURRENT,                           \
 347         .p              = _pos,                                         \
 348 })
 349
 350 #define KEY(_inode, _offset, _size)                                     \
 351 ((struct bkey) {                                                        \
 352         .u64s           = BKEY_U64s,                                    \
 353         .format         = KEY_FORMAT_CURRENT,                           \
 354         .p              = POS(_inode, _offset),                         \
 355         .size           = _size,                                        \
 356 })
 357
 358 static inline void bkey_init(struct bkey *k)
 359 {
 360         *k = KEY(0, 0, 0);
 361 }
 362
 363 #define bkey_bytes(_k)          ((_k)->u64s * sizeof(__u64))
 364
 365 #define __BKEY_PADDED(key, pad)                                 \
 366         struct bkey_i key; __u64 key ## _pad[pad]
 367
 368 /*
 369  * - DELETED keys are used internally to mark keys that should be ignored but
 370  *   override keys in composition order.  Their version number is ignored.
 371  *
 372  * - DISCARDED keys indicate that the data is all 0s because it has been
 373  *   discarded. DISCARDs may have a version; if the version is nonzero the key
 374  *   will be persistent, otherwise the key will be dropped whenever the btree
 375  *   node is rewritten (like DELETED keys).
 376  *
 377  * - ERROR: any read of the data returns a read error, as the data was lost due
 378  *   to a failing device. Like DISCARDED keys, they can be removed (overridden)
 379  *   by new writes or cluster-wide GC. Node repair can also overwrite them with
 380  *   the same or a more recent version number, but not with an older version
 381  *   number.
 382  *
 383  * - WHITEOUT: for hash table btrees
 384  */
 385 #define BCH_BKEY_TYPES()                                \
 386         x(deleted,              0)                      \
 387         x(whiteout,             1)                      \
 388         x(error,                2)                      \
 389         x(cookie,               3)                      \
 390         x(hash_whiteout,        4)                      \
 391         x(btree_ptr,            5)                      \
 392         x(extent,               6)                      \
 393         x(reservation,          7)                      \
 394         x(inode,                8)                      \
 395         x(inode_generation,     9)                      \
 396         x(dirent,               10)                     \
 397         x(xattr,                11)                     \
 398         x(alloc,                12)                     \
 399         x(quota,                13)                     \
 400         x(stripe,               14)                     \
 401         x(reflink_p,            15)                     \
 402         x(reflink_v,            16)                     \
 403         x(inline_data,          17)                     \
 404         x(btree_ptr_v2,         18)                     \
 405         x(indirect_inline_data, 19)                     \
 406         x(alloc_v2,             20)                     \
 407         x(subvolume,            21)                     \
 408         x(snapshot,             22)                     \
 409         x(inode_v2,             23)                     \
 410         x(alloc_v3,             24)                     \
 411         x(set,                  25)                     \
 412         x(lru,                  26)                     \
 413         x(alloc_v4,             27)                     \
 414         x(backpointer,          28)                     \
 415         x(inode_v3,             29)                     \
 416         x(bucket_gens,          30)                     \
 417         x(snapshot_tree,        31)                     \
 418         x(logged_op_truncate,   32)                     \
 419         x(logged_op_finsert,    33)
 420
 421 enum bch_bkey_type {
 422 #define x(name, nr) KEY_TYPE_##name     = nr,
 423         BCH_BKEY_TYPES()
 424 #undef x
 425         KEY_TYPE_MAX,
 426 };
 427
 428 struct bch_deleted {
 429         struct bch_val          v;
 430 };
 431
 432 struct bch_whiteout {
 433         struct bch_val          v;
 434 };
 435
 436 struct bch_error {
 437         struct bch_val          v;
 438 };
 439
 440 struct bch_cookie {
 441         struct bch_val          v;
 442         __le64                  cookie;
 443 };
 444
 445 struct bch_hash_whiteout {
 446         struct bch_val          v;
 447 };
 448
 449 struct bch_set {
 450         struct bch_val          v;
 451 };
 452
 453 /* 128 bits, sufficient for cryptographic MACs: */
 454 struct bch_csum {
 455         __le64                  lo;
 456         __le64                  hi;
 457 } __packed __aligned(8);
 458
 459 struct bch_backpointer {
 460         struct bch_val          v;
 461         __u8                    btree_id;
 462         __u8                    level;
 463         __u8                    data_type;
 464         __u64                   bucket_offset:40;
 465         __u32                   bucket_len;
 466         struct bpos             pos;
 467 } __packed __aligned(8);
 468
 469 /* LRU btree: */
 470
 471 struct bch_lru {
 472         struct bch_val          v;
 473         __le64                  idx;
 474 } __packed __aligned(8);
 475
 476 #define LRU_ID_STRIPES          (1U << 16)
 477
 478 /* Optional/variable size superblock sections: */
 479
 480 struct bch_sb_field {
 481         __u64                   _data[0];
 482         __le32                  u64s;
 483         __le32                  type;
 484 };
 485
 486 #define BCH_SB_FIELDS()                         \
 487         x(journal,                      0)      \
 488         x(members_v1,                   1)      \
 489         x(crypt,                        2)      \
 490         x(replicas_v0,                  3)      \
 491         x(quota,                        4)      \
 492         x(disk_groups,                  5)      \
 493         x(clean,                        6)      \
 494         x(replicas,                     7)      \
 495         x(journal_seq_blacklist,        8)      \
 496         x(journal_v2,                   9)      \
 497         x(counters,                     10)     \
 498         x(members_v2,                   11)     \
 499         x(errors,                       12)     \
 500         x(ext,                          13)     \
 501         x(downgrade,                    14)
 502
 503 #include "alloc_background_format.h"
 504 #include "extents_format.h"
 505 #include "reflink_format.h"
 506 #include "ec_format.h"
 507 #include "inode_format.h"
 508 #include "dirent_format.h"
 509 #include "xattr_format.h"
 510 #include "quota_format.h"
 511 #include "logged_ops_format.h"
 512 #include "snapshot_format.h"
 513 #include "subvolume_format.h"
 514 #include "sb-counters_format.h"
 515
 516 enum bch_sb_field_type {
 517 #define x(f, nr)        BCH_SB_FIELD_##f = nr,
 518         BCH_SB_FIELDS()
 519 #undef x
 520         BCH_SB_FIELD_NR
 521 };
 522
 523 /*
 524  * Most superblock fields are replicated in all device's superblocks - a few are
 525  * not:
 526  */
 527 #define BCH_SINGLE_DEVICE_SB_FIELDS             \
 528         ((1U << BCH_SB_FIELD_journal)|          \
 529          (1U << BCH_SB_FIELD_journal_v2))
 530
 531 /* BCH_SB_FIELD_journal: */
 532
 533 struct bch_sb_field_journal {
 534         struct bch_sb_field     field;
 535         __le64                  buckets[];
 536 };
 537
 538 struct bch_sb_field_journal_v2 {
 539         struct bch_sb_field     field;
 540
 541         struct bch_sb_field_journal_v2_entry {
 542                 __le64          start;
 543                 __le64          nr;
 544         }                       d[];
 545 };
 546
 547 /* BCH_SB_FIELD_members_v1: */
 548
 549 #define BCH_MIN_NR_NBUCKETS     (1 << 6)
 550
 551 #define BCH_IOPS_MEASUREMENTS()                 \
 552         x(seqread,      0)                      \
 553         x(seqwrite,     1)                      \
 554         x(randread,     2)                      \
 555         x(randwrite,    3)
 556
 557 enum bch_iops_measurement {
 558 #define x(t, n) BCH_IOPS_##t = n,
 559         BCH_IOPS_MEASUREMENTS()
 560 #undef x
 561         BCH_IOPS_NR
 562 };
 563
 564 #define BCH_MEMBER_ERROR_TYPES()                \
 565         x(read,         0)                      \
 566         x(write,        1)                      \
 567         x(checksum,     2)
 568
 569 enum bch_member_error_type {
 570 #define x(t, n) BCH_MEMBER_ERROR_##t = n,
 571         BCH_MEMBER_ERROR_TYPES()
 572 #undef x
 573         BCH_MEMBER_ERROR_NR
 574 };
 575
 576 struct bch_member {
 577         __uuid_t                uuid;
 578         __le64                  nbuckets;       /* device size */
 579         __le16                  first_bucket;   /* index of first bucket used */
 580         __le16                  bucket_size;    /* sectors */
 581         __le32                  pad;
 582         __le64                  last_mount;     /* time_t */
 583
 584         __le64                  flags;
 585         __le32                  iops[4];
 586         __le64                  errors[BCH_MEMBER_ERROR_NR];
 587         __le64                  errors_at_reset[BCH_MEMBER_ERROR_NR];
 588         __le64                  errors_reset_time;
 589         __le64                  seq;
 590 };
 591
 592 #define BCH_MEMBER_V1_BYTES     56
 593
 594 LE64_BITMASK(BCH_MEMBER_STATE,          struct bch_member, flags,  0,  4)
 595 /* 4-14 unused, was TIER, HAS_(META)DATA, REPLACEMENT */
 596 LE64_BITMASK(BCH_MEMBER_DISCARD,        struct bch_member, flags, 14, 15)
 597 LE64_BITMASK(BCH_MEMBER_DATA_ALLOWED,   struct bch_member, flags, 15, 20)
 598 LE64_BITMASK(BCH_MEMBER_GROUP,          struct bch_member, flags, 20, 28)
 599 LE64_BITMASK(BCH_MEMBER_DURABILITY,     struct bch_member, flags, 28, 30)
 600 LE64_BITMASK(BCH_MEMBER_FREESPACE_INITIALIZED,
 601                                         struct bch_member, flags, 30, 31)
 602
 603 #if 0
 604 LE64_BITMASK(BCH_MEMBER_NR_READ_ERRORS, struct bch_member, flags[1], 0,  20);
 605 LE64_BITMASK(BCH_MEMBER_NR_WRITE_ERRORS,struct bch_member, flags[1], 20, 40);
 606 #endif
 607
 608 #define BCH_MEMBER_STATES()                     \
 609         x(rw,           0)                      \
 610         x(ro,           1)                      \
 611         x(failed,       2)                      \
 612         x(spare,        3)
 613
 614 enum bch_member_state {
 615 #define x(t, n) BCH_MEMBER_STATE_##t = n,
 616         BCH_MEMBER_STATES()
 617 #undef x
 618         BCH_MEMBER_STATE_NR
 619 };
 620
 621 struct bch_sb_field_members_v1 {
 622         struct bch_sb_field     field;
 623         struct bch_member       _members[]; //Members are now variable size
 624 };
 625
 626 struct bch_sb_field_members_v2 {
 627         struct bch_sb_field     field;
 628         __le16                  member_bytes; //size of single member entry
 629         u8                      pad[6];
 630         struct bch_member       _members[];
 631 };
 632
 633 /* BCH_SB_FIELD_crypt: */
 634
 635 struct nonce {
 636         __le32                  d[4];
 637 };
 638
 639 struct bch_key {
 640         __le64                  key[4];
 641 };
 642
 643 #define BCH_KEY_MAGIC                                   \
 644         (((__u64) 'b' <<  0)|((__u64) 'c' <<  8)|               \
 645          ((__u64) 'h' << 16)|((__u64) '*' << 24)|               \
 646          ((__u64) '*' << 32)|((__u64) 'k' << 40)|               \
 647          ((__u64) 'e' << 48)|((__u64) 'y' << 56))
 648
 649 struct bch_encrypted_key {
 650         __le64                  magic;
 651         struct bch_key          key;
 652 };
 653
 654 /*
 655  * If this field is present in the superblock, it stores an encryption key which
 656  * is used encrypt all other data/metadata. The key will normally be encrypted
 657  * with the key userspace provides, but if encryption has been turned off we'll
 658  * just store the master key unencrypted in the superblock so we can access the
 659  * previously encrypted data.
 660  */
 661 struct bch_sb_field_crypt {
 662         struct bch_sb_field     field;
 663
 664         __le64                  flags;
 665         __le64                  kdf_flags;
 666         struct bch_encrypted_key key;
 667 };
 668
 669 LE64_BITMASK(BCH_CRYPT_KDF_TYPE,        struct bch_sb_field_crypt, flags, 0, 4);
 670
 671 enum bch_kdf_types {
 672         BCH_KDF_SCRYPT          = 0,
 673         BCH_KDF_NR              = 1,
 674 };
 675
 676 /* stored as base 2 log of scrypt params: */
 677 LE64_BITMASK(BCH_KDF_SCRYPT_N,  struct bch_sb_field_crypt, kdf_flags,  0, 16);
 678 LE64_BITMASK(BCH_KDF_SCRYPT_R,  struct bch_sb_field_crypt, kdf_flags, 16, 32);
 679 LE64_BITMASK(BCH_KDF_SCRYPT_P,  struct bch_sb_field_crypt, kdf_flags, 32, 48);
 680
 681 /* BCH_SB_FIELD_replicas: */
 682
 683 #define BCH_DATA_TYPES()                \
 684         x(free,         0)              \
 685         x(sb,           1)              \
 686         x(journal,      2)              \
 687         x(btree,        3)              \
 688         x(user,         4)              \
 689         x(cached,       5)              \
 690         x(parity,       6)              \
 691         x(stripe,       7)              \
 692         x(need_gc_gens, 8)              \
 693         x(need_discard, 9)
 694
 695 enum bch_data_type {
 696 #define x(t, n) BCH_DATA_##t,
 697         BCH_DATA_TYPES()
 698 #undef x
 699         BCH_DATA_NR
 700 };
 701
 702 static inline bool data_type_is_empty(enum bch_data_type type)
 703 {
 704         switch (type) {
 705         case BCH_DATA_free:
 706         case BCH_DATA_need_gc_gens:
 707         case BCH_DATA_need_discard:
 708                 return true;
 709         default:
 710                 return false;
 711         }
 712 }
 713
 714 static inline bool data_type_is_hidden(enum bch_data_type type)
 715 {
 716         switch (type) {
 717         case BCH_DATA_sb:
 718         case BCH_DATA_journal:
 719                 return true;
 720         default:
 721                 return false;
 722         }
 723 }
 724
 725 struct bch_replicas_entry_v0 {
 726         __u8                    data_type;
 727         __u8                    nr_devs;
 728         __u8                    devs[];
 729 } __packed;
 730
 731 struct bch_sb_field_replicas_v0 {
 732         struct bch_sb_field     field;
 733         struct bch_replicas_entry_v0 entries[];
 734 } __packed __aligned(8);
 735
 736 struct bch_replicas_entry_v1 {
 737         __u8                    data_type;
 738         __u8                    nr_devs;
 739         __u8                    nr_required;
 740         __u8                    devs[];
 741 } __packed;
 742
 743 #define replicas_entry_bytes(_i)                                        \
 744         (offsetof(typeof(*(_i)), devs) + (_i)->nr_devs)
 745
 746 struct bch_sb_field_replicas {
 747         struct bch_sb_field     field;
 748         struct bch_replicas_entry_v1 entries[];
 749 } __packed __aligned(8);
 750
 751 /* BCH_SB_FIELD_disk_groups: */
 752
 753 #define BCH_SB_LABEL_SIZE               32
 754
 755 struct bch_disk_group {
 756         __u8                    label[BCH_SB_LABEL_SIZE];
 757         __le64                  flags[2];
 758 } __packed __aligned(8);
 759
 760 LE64_BITMASK(BCH_GROUP_DELETED,         struct bch_disk_group, flags[0], 0,  1)
 761 LE64_BITMASK(BCH_GROUP_DATA_ALLOWED,    struct bch_disk_group, flags[0], 1,  6)
 762 LE64_BITMASK(BCH_GROUP_PARENT,          struct bch_disk_group, flags[0], 6, 24)
 763
 764 struct bch_sb_field_disk_groups {
 765         struct bch_sb_field     field;
 766         struct bch_disk_group   entries[];
 767 } __packed __aligned(8);
 768
 769 /*
 770  * On clean shutdown, store btree roots and current journal sequence number in
 771  * the superblock:
 772  */
 773 struct jset_entry {
 774         __le16                  u64s;
 775         __u8                    btree_id;
 776         __u8                    level;
 777         __u8                    type; /* designates what this jset holds */
 778         __u8                    pad[3];
 779
 780         struct bkey_i           start[0];
 781         __u64                   _data[];
 782 };
 783
 784 struct bch_sb_field_clean {
 785         struct bch_sb_field     field;
 786
 787         __le32                  flags;
 788         __le16                  _read_clock; /* no longer used */
 789         __le16                  _write_clock;
 790         __le64                  journal_seq;
 791
 792         struct jset_entry       start[0];
 793         __u64                   _data[];
 794 };
 795
 796 struct journal_seq_blacklist_entry {
 797         __le64                  start;
 798         __le64                  end;
 799 };
 800
 801 struct bch_sb_field_journal_seq_blacklist {
 802         struct bch_sb_field     field;
 803         struct journal_seq_blacklist_entry start[];
 804 };
 805
 806 struct bch_sb_field_errors {
 807         struct bch_sb_field     field;
 808         struct bch_sb_field_error_entry {
 809                 __le64          v;
 810                 __le64          last_error_time;
 811         }                       entries[];
 812 };
 813
 814 LE64_BITMASK(BCH_SB_ERROR_ENTRY_ID,     struct bch_sb_field_error_entry, v,  0, 16);
 815 LE64_BITMASK(BCH_SB_ERROR_ENTRY_NR,     struct bch_sb_field_error_entry, v, 16, 64);
 816
 817 struct bch_sb_field_ext {
 818         struct bch_sb_field     field;
 819         __le64                  recovery_passes_required[2];
 820         __le64                  errors_silent[8];
 821 };
 822
 823 struct bch_sb_field_downgrade_entry {
 824         __le16                  version;
 825         __le64                  recovery_passes[2];
 826         __le16                  nr_errors;
 827         __le16                  errors[] __counted_by(nr_errors);
 828 } __packed __aligned(2);
 829
 830 struct bch_sb_field_downgrade {
 831         struct bch_sb_field     field;
 832         struct bch_sb_field_downgrade_entry entries[];
 833 };
 834
 835 /* Superblock: */
 836
 837 /*
 838  * New versioning scheme:
 839  * One common version number for all on disk data structures - superblock, btree
 840  * nodes, journal entries
 841  */
 842 #define BCH_VERSION_MAJOR(_v)           ((__u16) ((_v) >> 10))
 843 #define BCH_VERSION_MINOR(_v)           ((__u16) ((_v) & ~(~0U << 10)))
 844 #define BCH_VERSION(_major, _minor)     (((_major) << 10)|(_minor) << 0)
 845
 846 /*
 847  * field 1:             version name
 848  * field 2:             BCH_VERSION(major, minor)
 849  * field 3:             recovery passess required on upgrade
 850  */
 851 #define BCH_METADATA_VERSIONS()                                         \
 852         x(bkey_renumber,                BCH_VERSION(0, 10))             \
 853         x(inode_btree_change,           BCH_VERSION(0, 11))             \
 854         x(snapshot,                     BCH_VERSION(0, 12))             \
 855         x(inode_backpointers,           BCH_VERSION(0, 13))             \
 856         x(btree_ptr_sectors_written,    BCH_VERSION(0, 14))             \
 857         x(snapshot_2,                   BCH_VERSION(0, 15))             \
 858         x(reflink_p_fix,                BCH_VERSION(0, 16))             \
 859         x(subvol_dirent,                BCH_VERSION(0, 17))             \
 860         x(inode_v2,                     BCH_VERSION(0, 18))             \
 861         x(freespace,                    BCH_VERSION(0, 19))             \
 862         x(alloc_v4,                     BCH_VERSION(0, 20))             \
 863         x(new_data_types,               BCH_VERSION(0, 21))             \
 864         x(backpointers,                 BCH_VERSION(0, 22))             \
 865         x(inode_v3,                     BCH_VERSION(0, 23))             \
 866         x(unwritten_extents,            BCH_VERSION(0, 24))             \
 867         x(bucket_gens,                  BCH_VERSION(0, 25))             \
 868         x(lru_v2,                       BCH_VERSION(0, 26))             \
 869         x(fragmentation_lru,            BCH_VERSION(0, 27))             \
 870         x(no_bps_in_alloc_keys,         BCH_VERSION(0, 28))             \
 871         x(snapshot_trees,               BCH_VERSION(0, 29))             \
 872         x(major_minor,                  BCH_VERSION(1,  0))             \
 873         x(snapshot_skiplists,           BCH_VERSION(1,  1))             \
 874         x(deleted_inodes,               BCH_VERSION(1,  2))             \
 875         x(rebalance_work,               BCH_VERSION(1,  3))             \
 876         x(member_seq,                   BCH_VERSION(1,  4))             \
 877         x(subvolume_fs_parent,          BCH_VERSION(1,  5))             \
 878         x(btree_subvolume_children,     BCH_VERSION(1,  6))
 879
 880 enum bcachefs_metadata_version {
 881         bcachefs_metadata_version_min = 9,
 882 #define x(t, n) bcachefs_metadata_version_##t = n,
 883         BCH_METADATA_VERSIONS()
 884 #undef x
 885         bcachefs_metadata_version_max
 886 };
 887
 888 static const __maybe_unused
 889 unsigned bcachefs_metadata_required_upgrade_below = bcachefs_metadata_version_rebalance_work;
 890
 891 #define bcachefs_metadata_version_current       (bcachefs_metadata_version_max - 1)
 892
 893 #define BCH_SB_SECTOR                   8
 894 #define BCH_SB_MEMBERS_MAX              64 /* XXX kill */
 895
 896 struct bch_sb_layout {
 897         __uuid_t                magic;  /* bcachefs superblock UUID */
 898         __u8                    layout_type;
 899         __u8                    sb_max_size_bits; /* base 2 of 512 byte sectors */
 900         __u8                    nr_superblocks;
 901         __u8                    pad[5];
 902         __le64                  sb_offset[61];
 903 } __packed __aligned(8);
 904
 905 #define BCH_SB_LAYOUT_SECTOR    7
 906
 907 /*
 908  * @offset      - sector where this sb was written
 909  * @version     - on disk format version
 910  * @version_min - Oldest metadata version this filesystem contains; so we can
 911  *                safely drop compatibility code and refuse to mount filesystems
 912  *                we'd need it for
 913  * @magic       - identifies as a bcachefs superblock (BCHFS_MAGIC)
 914  * @seq         - incremented each time superblock is written
 915  * @uuid        - used for generating various magic numbers and identifying
 916  *                member devices, never changes
 917  * @user_uuid   - user visible UUID, may be changed
 918  * @label       - filesystem label
 919  * @seq         - identifies most recent superblock, incremented each time
 920  *                superblock is written
 921  * @features    - enabled incompatible features
 922  */
 923 struct bch_sb {
 924         struct bch_csum         csum;
 925         __le16                  version;
 926         __le16                  version_min;
 927         __le16                  pad[2];
 928         __uuid_t                magic;
 929         __uuid_t                uuid;
 930         __uuid_t                user_uuid;
 931         __u8                    label[BCH_SB_LABEL_SIZE];
 932         __le64                  offset;
 933         __le64                  seq;
 934
 935         __le16                  block_size;
 936         __u8                    dev_idx;
 937         __u8                    nr_devices;
 938         __le32                  u64s;
 939
 940         __le64                  time_base_lo;
 941         __le32                  time_base_hi;
 942         __le32                  time_precision;
 943
 944         __le64                  flags[7];
 945         __le64                  write_time;
 946         __le64                  features[2];
 947         __le64                  compat[2];
 948
 949         struct bch_sb_layout    layout;
 950
 951         struct bch_sb_field     start[0];
 952         __le64                  _data[];
 953 } __packed __aligned(8);
 954
 955 /*
 956  * Flags:
 957  * BCH_SB_INITALIZED    - set on first mount
 958  * BCH_SB_CLEAN         - did we shut down cleanly? Just a hint, doesn't affect
 959  *                        behaviour of mount/recovery path:
 960  * BCH_SB_INODE_32BIT   - limit inode numbers to 32 bits
 961  * BCH_SB_128_BIT_MACS  - 128 bit macs instead of 80
 962  * BCH_SB_ENCRYPTION_TYPE - if nonzero encryption is enabled; overrides
 963  *                         DATA/META_CSUM_TYPE. Also indicates encryption
 964  *                         algorithm in use, if/when we get more than one
 965  */
 966
 967 LE16_BITMASK(BCH_SB_BLOCK_SIZE,         struct bch_sb, block_size, 0, 16);
 968
 969 LE64_BITMASK(BCH_SB_INITIALIZED,        struct bch_sb, flags[0],  0,  1);
 970 LE64_BITMASK(BCH_SB_CLEAN,              struct bch_sb, flags[0],  1,  2);
 971 LE64_BITMASK(BCH_SB_CSUM_TYPE,          struct bch_sb, flags[0],  2,  8);
 972 LE64_BITMASK(BCH_SB_ERROR_ACTION,       struct bch_sb, flags[0],  8, 12);
 973
 974 LE64_BITMASK(BCH_SB_BTREE_NODE_SIZE,    struct bch_sb, flags[0], 12, 28);
 975
 976 LE64_BITMASK(BCH_SB_GC_RESERVE,         struct bch_sb, flags[0], 28, 33);
 977 LE64_BITMASK(BCH_SB_ROOT_RESERVE,       struct bch_sb, flags[0], 33, 40);
 978
 979 LE64_BITMASK(BCH_SB_META_CSUM_TYPE,     struct bch_sb, flags[0], 40, 44);
 980 LE64_BITMASK(BCH_SB_DATA_CSUM_TYPE,     struct bch_sb, flags[0], 44, 48);
 981
 982 LE64_BITMASK(BCH_SB_META_REPLICAS_WANT, struct bch_sb, flags[0], 48, 52);
 983 LE64_BITMASK(BCH_SB_DATA_REPLICAS_WANT, struct bch_sb, flags[0], 52, 56);
 984
 985 LE64_BITMASK(BCH_SB_POSIX_ACL,          struct bch_sb, flags[0], 56, 57);
 986 LE64_BITMASK(BCH_SB_USRQUOTA,           struct bch_sb, flags[0], 57, 58);
 987 LE64_BITMASK(BCH_SB_GRPQUOTA,           struct bch_sb, flags[0], 58, 59);
 988 LE64_BITMASK(BCH_SB_PRJQUOTA,           struct bch_sb, flags[0], 59, 60);
 989
 990 LE64_BITMASK(BCH_SB_HAS_ERRORS,         struct bch_sb, flags[0], 60, 61);
 991 LE64_BITMASK(BCH_SB_HAS_TOPOLOGY_ERRORS,struct bch_sb, flags[0], 61, 62);
 992
 993 LE64_BITMASK(BCH_SB_BIG_ENDIAN,         struct bch_sb, flags[0], 62, 63);
 994
 995 LE64_BITMASK(BCH_SB_STR_HASH_TYPE,      struct bch_sb, flags[1],  0,  4);
 996 LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_LO,struct bch_sb, flags[1],  4,  8);
 997 LE64_BITMASK(BCH_SB_INODE_32BIT,        struct bch_sb, flags[1],  8,  9);
 998
 999 LE64_BITMASK(BCH_SB_128_BIT_MACS,       struct bch_sb, flags[1],  9, 10);
1000 LE64_BITMASK(BCH_SB_ENCRYPTION_TYPE,    struct bch_sb, flags[1], 10, 14);
1001
1002 /*
1003  * Max size of an extent that may require bouncing to read or write
1004  * (checksummed, compressed): 64k
1005  */
1006 LE64_BITMASK(BCH_SB_ENCODED_EXTENT_MAX_BITS,
1007                                         struct bch_sb, flags[1], 14, 20);
1008
1009 LE64_BITMASK(BCH_SB_META_REPLICAS_REQ,  struct bch_sb, flags[1], 20, 24);
1010 LE64_BITMASK(BCH_SB_DATA_REPLICAS_REQ,  struct bch_sb, flags[1], 24, 28);
1011
1012 LE64_BITMASK(BCH_SB_PROMOTE_TARGET,     struct bch_sb, flags[1], 28, 40);
1013 LE64_BITMASK(BCH_SB_FOREGROUND_TARGET,  struct bch_sb, flags[1], 40, 52);
1014 LE64_BITMASK(BCH_SB_BACKGROUND_TARGET,  struct bch_sb, flags[1], 52, 64);
1015
1016 LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO,
1017                                         struct bch_sb, flags[2],  0,  4);
1018 LE64_BITMASK(BCH_SB_GC_RESERVE_BYTES,   struct bch_sb, flags[2],  4, 64);
1019
1020 LE64_BITMASK(BCH_SB_ERASURE_CODE,       struct bch_sb, flags[3],  0, 16);
1021 LE64_BITMASK(BCH_SB_METADATA_TARGET,    struct bch_sb, flags[3], 16, 28);
1022 LE64_BITMASK(BCH_SB_SHARD_INUMS,        struct bch_sb, flags[3], 28, 29);
1023 LE64_BITMASK(BCH_SB_INODES_USE_KEY_CACHE,struct bch_sb, flags[3], 29, 30);
1024 LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DELAY,struct bch_sb, flags[3], 30, 62);
1025 LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DISABLED,struct bch_sb, flags[3], 62, 63);
1026 LE64_BITMASK(BCH_SB_JOURNAL_RECLAIM_DELAY,struct bch_sb, flags[4], 0, 32);
1027 LE64_BITMASK(BCH_SB_JOURNAL_TRANSACTION_NAMES,struct bch_sb, flags[4], 32, 33);
1028 LE64_BITMASK(BCH_SB_NOCOW,              struct bch_sb, flags[4], 33, 34);
1029 LE64_BITMASK(BCH_SB_WRITE_BUFFER_SIZE,  struct bch_sb, flags[4], 34, 54);
1030 LE64_BITMASK(BCH_SB_VERSION_UPGRADE,    struct bch_sb, flags[4], 54, 56);
1031
1032 LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_HI,struct bch_sb, flags[4], 56, 60);
1033 LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI,
1034                                         struct bch_sb, flags[4], 60, 64);
1035
1036 LE64_BITMASK(BCH_SB_VERSION_UPGRADE_COMPLETE,
1037                                         struct bch_sb, flags[5],  0, 16);
1038
1039 static inline __u64 BCH_SB_COMPRESSION_TYPE(const struct bch_sb *sb)
1040 {
1041         return BCH_SB_COMPRESSION_TYPE_LO(sb) | (BCH_SB_COMPRESSION_TYPE_HI(sb) << 4);
1042 }
1043
1044 static inline void SET_BCH_SB_COMPRESSION_TYPE(struct bch_sb *sb, __u64 v)
1045 {
1046         SET_BCH_SB_COMPRESSION_TYPE_LO(sb, v);
1047         SET_BCH_SB_COMPRESSION_TYPE_HI(sb, v >> 4);
1048 }
1049
1050 static inline __u64 BCH_SB_BACKGROUND_COMPRESSION_TYPE(const struct bch_sb *sb)
1051 {
1052         return BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO(sb) |
1053                 (BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI(sb) << 4);
1054 }
1055
1056 static inline void SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE(struct bch_sb *sb, __u64 v)
1057 {
1058         SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO(sb, v);
1059         SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI(sb, v >> 4);
1060 }
1061
1062 /*
1063  * Features:
1064  *
1065  * journal_seq_blacklist_v3:    gates BCH_SB_FIELD_journal_seq_blacklist
1066  * reflink:                     gates KEY_TYPE_reflink
1067  * inline_data:                 gates KEY_TYPE_inline_data
1068  * new_siphash:                 gates BCH_STR_HASH_siphash
1069  * new_extent_overwrite:        gates BTREE_NODE_NEW_EXTENT_OVERWRITE
1070  */
1071 #define BCH_SB_FEATURES()                       \
1072         x(lz4,                          0)      \
1073         x(gzip,                         1)      \
1074         x(zstd,                         2)      \
1075         x(atomic_nlink,                 3)      \
1076         x(ec,                           4)      \
1077         x(journal_seq_blacklist_v3,     5)      \
1078         x(reflink,                      6)      \
1079         x(new_siphash,                  7)      \
1080         x(inline_data,                  8)      \
1081         x(new_extent_overwrite,         9)      \
1082         x(incompressible,               10)     \
1083         x(btree_ptr_v2,                 11)     \
1084         x(extents_above_btree_updates,  12)     \
1085         x(btree_updates_journalled,     13)     \
1086         x(reflink_inline_data,          14)     \
1087         x(new_varint,                   15)     \
1088         x(journal_no_flush,             16)     \
1089         x(alloc_v2,                     17)     \
1090         x(extents_across_btree_nodes,   18)
1091
1092 #define BCH_SB_FEATURES_ALWAYS                          \
1093         ((1ULL << BCH_FEATURE_new_extent_overwrite)|    \
1094          (1ULL << BCH_FEATURE_extents_above_btree_updates)|\
1095          (1ULL << BCH_FEATURE_btree_updates_journalled)|\
1096          (1ULL << BCH_FEATURE_alloc_v2)|\
1097          (1ULL << BCH_FEATURE_extents_across_btree_nodes))
1098
1099 #define BCH_SB_FEATURES_ALL                             \
1100         (BCH_SB_FEATURES_ALWAYS|                        \
1101          (1ULL << BCH_FEATURE_new_siphash)|             \
1102          (1ULL << BCH_FEATURE_btree_ptr_v2)|            \
1103          (1ULL << BCH_FEATURE_new_varint)|              \
1104          (1ULL << BCH_FEATURE_journal_no_flush))
1105
1106 enum bch_sb_feature {
1107 #define x(f, n) BCH_FEATURE_##f,
1108         BCH_SB_FEATURES()
1109 #undef x
1110         BCH_FEATURE_NR,
1111 };
1112
1113 #define BCH_SB_COMPAT()                                 \
1114         x(alloc_info,                           0)      \
1115         x(alloc_metadata,                       1)      \
1116         x(extents_above_btree_updates_done,     2)      \
1117         x(bformat_overflow_done,                3)
1118
1119 enum bch_sb_compat {
1120 #define x(f, n) BCH_COMPAT_##f,
1121         BCH_SB_COMPAT()
1122 #undef x
1123         BCH_COMPAT_NR,
1124 };
1125
1126 /* options: */
1127
1128 #define BCH_VERSION_UPGRADE_OPTS()      \
1129         x(compatible,           0)      \
1130         x(incompatible,         1)      \
1131         x(none,                 2)
1132
1133 enum bch_version_upgrade_opts {
1134 #define x(t, n) BCH_VERSION_UPGRADE_##t = n,
1135         BCH_VERSION_UPGRADE_OPTS()
1136 #undef x
1137 };
1138
1139 #define BCH_REPLICAS_MAX                4U
1140
1141 #define BCH_BKEY_PTRS_MAX               16U
1142
1143 #define BCH_ERROR_ACTIONS()             \
1144         x(continue,             0)      \
1145         x(ro,                   1)      \
1146         x(panic,                2)
1147
1148 enum bch_error_actions {
1149 #define x(t, n) BCH_ON_ERROR_##t = n,
1150         BCH_ERROR_ACTIONS()
1151 #undef x
1152         BCH_ON_ERROR_NR
1153 };
1154
1155 #define BCH_STR_HASH_TYPES()            \
1156         x(crc32c,               0)      \
1157         x(crc64,                1)      \
1158         x(siphash_old,          2)      \
1159         x(siphash,              3)
1160
1161 enum bch_str_hash_type {
1162 #define x(t, n) BCH_STR_HASH_##t = n,
1163         BCH_STR_HASH_TYPES()
1164 #undef x
1165         BCH_STR_HASH_NR
1166 };
1167
1168 #define BCH_STR_HASH_OPTS()             \
1169         x(crc32c,               0)      \
1170         x(crc64,                1)      \
1171         x(siphash,              2)
1172
1173 enum bch_str_hash_opts {
1174 #define x(t, n) BCH_STR_HASH_OPT_##t = n,
1175         BCH_STR_HASH_OPTS()
1176 #undef x
1177         BCH_STR_HASH_OPT_NR
1178 };
1179
1180 #define BCH_CSUM_TYPES()                        \
1181         x(none,                         0)      \
1182         x(crc32c_nonzero,               1)      \
1183         x(crc64_nonzero,                2)      \
1184         x(chacha20_poly1305_80,         3)      \
1185         x(chacha20_poly1305_128,        4)      \
1186         x(crc32c,                       5)      \
1187         x(crc64,                        6)      \
1188         x(xxhash,                       7)
1189
1190 enum bch_csum_type {
1191 #define x(t, n) BCH_CSUM_##t = n,
1192         BCH_CSUM_TYPES()
1193 #undef x
1194         BCH_CSUM_NR
1195 };
1196
1197 static const __maybe_unused unsigned bch_crc_bytes[] = {
1198         [BCH_CSUM_none]                         = 0,
1199         [BCH_CSUM_crc32c_nonzero]               = 4,
1200         [BCH_CSUM_crc32c]                       = 4,
1201         [BCH_CSUM_crc64_nonzero]                = 8,
1202         [BCH_CSUM_crc64]                        = 8,
1203         [BCH_CSUM_xxhash]                       = 8,
1204         [BCH_CSUM_chacha20_poly1305_80]         = 10,
1205         [BCH_CSUM_chacha20_poly1305_128]        = 16,
1206 };
1207
1208 static inline _Bool bch2_csum_type_is_encryption(enum bch_csum_type type)
1209 {
1210         switch (type) {
1211         case BCH_CSUM_chacha20_poly1305_80:
1212         case BCH_CSUM_chacha20_poly1305_128:
1213                 return true;
1214         default:
1215                 return false;
1216         }
1217 }
1218
1219 #define BCH_CSUM_OPTS()                 \
1220         x(none,                 0)      \
1221         x(crc32c,               1)      \
1222         x(crc64,                2)      \
1223         x(xxhash,               3)
1224
1225 enum bch_csum_opts {
1226 #define x(t, n) BCH_CSUM_OPT_##t = n,
1227         BCH_CSUM_OPTS()
1228 #undef x
1229         BCH_CSUM_OPT_NR
1230 };
1231
1232 #define BCH_COMPRESSION_TYPES()         \
1233         x(none,                 0)      \
1234         x(lz4_old,              1)      \
1235         x(gzip,                 2)      \
1236         x(lz4,                  3)      \
1237         x(zstd,                 4)      \
1238         x(incompressible,       5)
1239
1240 enum bch_compression_type {
1241 #define x(t, n) BCH_COMPRESSION_TYPE_##t = n,
1242         BCH_COMPRESSION_TYPES()
1243 #undef x
1244         BCH_COMPRESSION_TYPE_NR
1245 };
1246
1247 #define BCH_COMPRESSION_OPTS()          \
1248         x(none,         0)              \
1249         x(lz4,          1)              \
1250         x(gzip,         2)              \
1251         x(zstd,         3)
1252
1253 enum bch_compression_opts {
1254 #define x(t, n) BCH_COMPRESSION_OPT_##t = n,
1255         BCH_COMPRESSION_OPTS()
1256 #undef x
1257         BCH_COMPRESSION_OPT_NR
1258 };
1259
1260 /*
1261  * Magic numbers
1262  *
1263  * The various other data structures have their own magic numbers, which are
1264  * xored with the first part of the cache set's UUID
1265  */
1266
1267 #define BCACHE_MAGIC                                                    \
1268         UUID_INIT(0xc68573f6, 0x4e1a, 0x45ca,                           \
1269                   0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81)
1270 #define BCHFS_MAGIC                                                     \
1271         UUID_INIT(0xc68573f6, 0x66ce, 0x90a9,                           \
1272                   0xd9, 0x6a, 0x60, 0xcf, 0x80, 0x3d, 0xf7, 0xef)
1273
1274 #define BCACHEFS_STATFS_MAGIC           0xca451a4e
1275
1276 #define JSET_MAGIC              __cpu_to_le64(0x245235c1a3625032ULL)
1277 #define BSET_MAGIC              __cpu_to_le64(0x90135c78b99e07f5ULL)
1278
1279 static inline __le64 __bch2_sb_magic(struct bch_sb *sb)
1280 {
1281         __le64 ret;
1282
1283         memcpy(&ret, &sb->uuid, sizeof(ret));
1284         return ret;
1285 }
1286
1287 static inline __u64 __jset_magic(struct bch_sb *sb)
1288 {
1289         return __le64_to_cpu(__bch2_sb_magic(sb) ^ JSET_MAGIC);
1290 }
1291
1292 static inline __u64 __bset_magic(struct bch_sb *sb)
1293 {
1294         return __le64_to_cpu(__bch2_sb_magic(sb) ^ BSET_MAGIC);
1295 }
1296
1297 /* Journal */
1298
1299 #define JSET_KEYS_U64s  (sizeof(struct jset_entry) / sizeof(__u64))
1300
1301 #define BCH_JSET_ENTRY_TYPES()                  \
1302         x(btree_keys,           0)              \
1303         x(btree_root,           1)              \
1304         x(prio_ptrs,            2)              \
1305         x(blacklist,            3)              \
1306         x(blacklist_v2,         4)              \
1307         x(usage,                5)              \
1308         x(data_usage,           6)              \
1309         x(clock,                7)              \
1310         x(dev_usage,            8)              \
1311         x(log,                  9)              \
1312         x(overwrite,            10)             \
1313         x(write_buffer_keys,    11)             \
1314         x(datetime,             12)
1315
1316 enum {
1317 #define x(f, nr)        BCH_JSET_ENTRY_##f      = nr,
1318         BCH_JSET_ENTRY_TYPES()
1319 #undef x
1320         BCH_JSET_ENTRY_NR
1321 };
1322
1323 static inline bool jset_entry_is_key(struct jset_entry *e)
1324 {
1325         switch (e->type) {
1326         case BCH_JSET_ENTRY_btree_keys:
1327         case BCH_JSET_ENTRY_btree_root:
1328         case BCH_JSET_ENTRY_overwrite:
1329         case BCH_JSET_ENTRY_write_buffer_keys:
1330                 return true;
1331         }
1332
1333         return false;
1334 }
1335
1336 /*
1337  * Journal sequence numbers can be blacklisted: bsets record the max sequence
1338  * number of all the journal entries they contain updates for, so that on
1339  * recovery we can ignore those bsets that contain index updates newer that what
1340  * made it into the journal.
1341  *
1342  * This means that we can't reuse that journal_seq - we have to skip it, and
1343  * then record that we skipped it so that the next time we crash and recover we
1344  * don't think there was a missing journal entry.
1345  */
1346 struct jset_entry_blacklist {
1347         struct jset_entry       entry;
1348         __le64                  seq;
1349 };
1350
1351 struct jset_entry_blacklist_v2 {
1352         struct jset_entry       entry;
1353         __le64                  start;
1354         __le64                  end;
1355 };
1356
1357 #define BCH_FS_USAGE_TYPES()                    \
1358         x(reserved,             0)              \
1359         x(inodes,               1)              \
1360         x(key_version,          2)
1361
1362 enum {
1363 #define x(f, nr)        BCH_FS_USAGE_##f        = nr,
1364         BCH_FS_USAGE_TYPES()
1365 #undef x
1366         BCH_FS_USAGE_NR
1367 };
1368
1369 struct jset_entry_usage {
1370         struct jset_entry       entry;
1371         __le64                  v;
1372 } __packed;
1373
1374 struct jset_entry_data_usage {
1375         struct jset_entry       entry;
1376         __le64                  v;
1377         struct bch_replicas_entry_v1 r;
1378 } __packed;
1379
1380 struct jset_entry_clock {
1381         struct jset_entry       entry;
1382         __u8                    rw;
1383         __u8                    pad[7];
1384         __le64                  time;
1385 } __packed;
1386
1387 struct jset_entry_dev_usage_type {
1388         __le64                  buckets;
1389         __le64                  sectors;
1390         __le64                  fragmented;
1391 } __packed;
1392
1393 struct jset_entry_dev_usage {
1394         struct jset_entry       entry;
1395         __le32                  dev;
1396         __u32                   pad;
1397
1398         __le64                  _buckets_ec;            /* No longer used */
1399         __le64                  _buckets_unavailable;   /* No longer used */
1400
1401         struct jset_entry_dev_usage_type d[];
1402 };
1403
1404 static inline unsigned jset_entry_dev_usage_nr_types(struct jset_entry_dev_usage *u)
1405 {
1406         return (vstruct_bytes(&u->entry) - sizeof(struct jset_entry_dev_usage)) /
1407                 sizeof(struct jset_entry_dev_usage_type);
1408 }
1409
1410 struct jset_entry_log {
1411         struct jset_entry       entry;
1412         u8                      d[];
1413 } __packed __aligned(8);
1414
1415 struct jset_entry_datetime {
1416         struct jset_entry       entry;
1417         __le64                  seconds;
1418 } __packed __aligned(8);
1419
1420 /*
1421  * On disk format for a journal entry:
1422  * seq is monotonically increasing; every journal entry has its own unique
1423  * sequence number.
1424  *
1425  * last_seq is the oldest journal entry that still has keys the btree hasn't
1426  * flushed to disk yet.
1427  *
1428  * version is for on disk format changes.
1429  */
1430 struct jset {
1431         struct bch_csum         csum;
1432
1433         __le64                  magic;
1434         __le64                  seq;
1435         __le32                  version;
1436         __le32                  flags;
1437
1438         __le32                  u64s; /* size of d[] in u64s */
1439
1440         __u8                    encrypted_start[0];
1441
1442         __le16                  _read_clock; /* no longer used */
1443         __le16                  _write_clock;
1444
1445         /* Sequence number of oldest dirty journal entry */
1446         __le64                  last_seq;
1447
1448
1449         struct jset_entry       start[0];
1450         __u64                   _data[];
1451 } __packed __aligned(8);
1452
1453 LE32_BITMASK(JSET_CSUM_TYPE,    struct jset, flags, 0, 4);
1454 LE32_BITMASK(JSET_BIG_ENDIAN,   struct jset, flags, 4, 5);
1455 LE32_BITMASK(JSET_NO_FLUSH,     struct jset, flags, 5, 6);
1456
1457 #define BCH_JOURNAL_BUCKETS_MIN         8
1458
1459 /* Btree: */
1460
1461 enum btree_id_flags {
1462         BTREE_ID_EXTENTS        = BIT(0),
1463         BTREE_ID_SNAPSHOTS      = BIT(1),
1464         BTREE_ID_SNAPSHOT_FIELD = BIT(2),
1465         BTREE_ID_DATA           = BIT(3),
1466 };
1467
1468 #define BCH_BTREE_IDS()                                                         \
1469         x(extents,              0,      BTREE_ID_EXTENTS|BTREE_ID_SNAPSHOTS|BTREE_ID_DATA,\
1470           BIT_ULL(KEY_TYPE_whiteout)|                                           \
1471           BIT_ULL(KEY_TYPE_error)|                                              \
1472           BIT_ULL(KEY_TYPE_cookie)|                                             \
1473           BIT_ULL(KEY_TYPE_extent)|                                             \
1474           BIT_ULL(KEY_TYPE_reservation)|                                        \
1475           BIT_ULL(KEY_TYPE_reflink_p)|                                          \
1476           BIT_ULL(KEY_TYPE_inline_data))                                        \
1477         x(inodes,               1,      BTREE_ID_SNAPSHOTS,                     \
1478           BIT_ULL(KEY_TYPE_whiteout)|                                           \
1479           BIT_ULL(KEY_TYPE_inode)|                                              \
1480           BIT_ULL(KEY_TYPE_inode_v2)|                                           \
1481           BIT_ULL(KEY_TYPE_inode_v3)|                                           \
1482           BIT_ULL(KEY_TYPE_inode_generation))                                   \
1483         x(dirents,              2,      BTREE_ID_SNAPSHOTS,                     \
1484           BIT_ULL(KEY_TYPE_whiteout)|                                           \
1485           BIT_ULL(KEY_TYPE_hash_whiteout)|                                      \
1486           BIT_ULL(KEY_TYPE_dirent))                                             \
1487         x(xattrs,               3,      BTREE_ID_SNAPSHOTS,                     \
1488           BIT_ULL(KEY_TYPE_whiteout)|                                           \
1489           BIT_ULL(KEY_TYPE_cookie)|                                             \
1490           BIT_ULL(KEY_TYPE_hash_whiteout)|                                      \
1491           BIT_ULL(KEY_TYPE_xattr))                                              \
1492         x(alloc,                4,      0,                                      \
1493           BIT_ULL(KEY_TYPE_alloc)|                                              \
1494           BIT_ULL(KEY_TYPE_alloc_v2)|                                           \
1495           BIT_ULL(KEY_TYPE_alloc_v3)|                                           \
1496           BIT_ULL(KEY_TYPE_alloc_v4))                                           \
1497         x(quotas,               5,      0,                                      \
1498           BIT_ULL(KEY_TYPE_quota))                                              \
1499         x(stripes,              6,      0,                                      \
1500           BIT_ULL(KEY_TYPE_stripe))                                             \
1501         x(reflink,              7,      BTREE_ID_EXTENTS|BTREE_ID_DATA,         \
1502           BIT_ULL(KEY_TYPE_reflink_v)|                                          \
1503           BIT_ULL(KEY_TYPE_indirect_inline_data))                               \
1504         x(subvolumes,           8,      0,                                      \
1505           BIT_ULL(KEY_TYPE_subvolume))                                          \
1506         x(snapshots,            9,      0,                                      \
1507           BIT_ULL(KEY_TYPE_snapshot))                                           \
1508         x(lru,                  10,     0,                                      \
1509           BIT_ULL(KEY_TYPE_set))                                                \
1510         x(freespace,            11,     BTREE_ID_EXTENTS,                       \
1511           BIT_ULL(KEY_TYPE_set))                                                \
1512         x(need_discard,         12,     0,                                      \
1513           BIT_ULL(KEY_TYPE_set))                                                \
1514         x(backpointers,         13,     0,                                      \
1515           BIT_ULL(KEY_TYPE_backpointer))                                        \
1516         x(bucket_gens,          14,     0,                                      \
1517           BIT_ULL(KEY_TYPE_bucket_gens))                                        \
1518         x(snapshot_trees,       15,     0,                                      \
1519           BIT_ULL(KEY_TYPE_snapshot_tree))                                      \
1520         x(deleted_inodes,       16,     BTREE_ID_SNAPSHOT_FIELD,                \
1521           BIT_ULL(KEY_TYPE_set))                                                \
1522         x(logged_ops,           17,     0,                                      \
1523           BIT_ULL(KEY_TYPE_logged_op_truncate)|                                 \
1524           BIT_ULL(KEY_TYPE_logged_op_finsert))                                  \
1525         x(rebalance_work,       18,     BTREE_ID_SNAPSHOT_FIELD,                \
1526           BIT_ULL(KEY_TYPE_set)|BIT_ULL(KEY_TYPE_cookie))                       \
1527         x(subvolume_children,   19,     0,                                      \
1528           BIT_ULL(KEY_TYPE_set))
1529
1530 enum btree_id {
1531 #define x(name, nr, ...) BTREE_ID_##name = nr,
1532         BCH_BTREE_IDS()
1533 #undef x
1534         BTREE_ID_NR
1535 };
1536
1537 #define BTREE_MAX_DEPTH         4U
1538
1539 /* Btree nodes */
1540
1541 /*
1542  * Btree nodes
1543  *
1544  * On disk a btree node is a list/log of these; within each set the keys are
1545  * sorted
1546  */
1547 struct bset {
1548         __le64                  seq;
1549
1550         /*
1551          * Highest journal entry this bset contains keys for.
1552          * If on recovery we don't see that journal entry, this bset is ignored:
1553          * this allows us to preserve the order of all index updates after a
1554          * crash, since the journal records a total order of all index updates
1555          * and anything that didn't make it to the journal doesn't get used.
1556          */
1557         __le64                  journal_seq;
1558
1559         __le32                  flags;
1560         __le16                  version;
1561         __le16                  u64s; /* count of d[] in u64s */
1562
1563         struct bkey_packed      start[0];
1564         __u64                   _data[];
1565 } __packed __aligned(8);
1566
1567 LE32_BITMASK(BSET_CSUM_TYPE,    struct bset, flags, 0, 4);
1568
1569 LE32_BITMASK(BSET_BIG_ENDIAN,   struct bset, flags, 4, 5);
1570 LE32_BITMASK(BSET_SEPARATE_WHITEOUTS,
1571                                 struct bset, flags, 5, 6);
1572
1573 /* Sector offset within the btree node: */
1574 LE32_BITMASK(BSET_OFFSET,       struct bset, flags, 16, 32);
1575
1576 struct btree_node {
1577         struct bch_csum         csum;
1578         __le64                  magic;
1579
1580         /* this flags field is encrypted, unlike bset->flags: */
1581         __le64                  flags;
1582
1583         /* Closed interval: */
1584         struct bpos             min_key;
1585         struct bpos             max_key;
1586         struct bch_extent_ptr   _ptr; /* not used anymore */
1587         struct bkey_format      format;
1588
1589         union {
1590         struct bset             keys;
1591         struct {
1592                 __u8            pad[22];
1593                 __le16          u64s;
1594                 __u64           _data[0];
1595
1596         };
1597         };
1598 } __packed __aligned(8);
1599
1600 LE64_BITMASK(BTREE_NODE_ID_LO,  struct btree_node, flags,  0,  4);
1601 LE64_BITMASK(BTREE_NODE_LEVEL,  struct btree_node, flags,  4,  8);
1602 LE64_BITMASK(BTREE_NODE_NEW_EXTENT_OVERWRITE,
1603                                 struct btree_node, flags,  8,  9);
1604 LE64_BITMASK(BTREE_NODE_ID_HI,  struct btree_node, flags,  9, 25);
1605 /* 25-32 unused */
1606 LE64_BITMASK(BTREE_NODE_SEQ,    struct btree_node, flags, 32, 64);
1607
1608 static inline __u64 BTREE_NODE_ID(struct btree_node *n)
1609 {
1610         return BTREE_NODE_ID_LO(n) | (BTREE_NODE_ID_HI(n) << 4);
1611 }
1612
1613 static inline void SET_BTREE_NODE_ID(struct btree_node *n, __u64 v)
1614 {
1615         SET_BTREE_NODE_ID_LO(n, v);
1616         SET_BTREE_NODE_ID_HI(n, v >> 4);
1617 }
1618
1619 struct btree_node_entry {
1620         struct bch_csum         csum;
1621
1622         union {
1623         struct bset             keys;
1624         struct {
1625                 __u8            pad[22];
1626                 __le16          u64s;
1627                 __u64           _data[0];
1628         };
1629         };
1630 } __packed __aligned(8);
1631
1632 #endif /* _BCACHEFS_FORMAT_H */