fs/bcachefs/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 <uapi/linux/magic.h>
  80 #include "vstructs.h"
  81
  82 #ifdef __KERNEL__
  83 typedef uuid_t __uuid_t;
  84 #endif
  85
  86 #define BITMASK(name, type, field, offset, end)                         \
  87 static const __maybe_unused unsigned    name##_OFFSET = offset;         \
  88 static const __maybe_unused unsigned    name##_BITS = (end - offset);   \
  89                                                                         \
  90 static inline __u64 name(const type *k)                                 \
  91 {                                                                       \
  92         return (k->field >> offset) & ~(~0ULL << (end - offset));       \
  93 }                                                                       \
  94                                                                         \
  95 static inline void SET_##name(type *k, __u64 v)                         \
  96 {                                                                       \
  97         k->field &= ~(~(~0ULL << (end - offset)) << offset);            \
  98         k->field |= (v & ~(~0ULL << (end - offset))) << offset;         \
  99 }
 100
 101 #define LE_BITMASK(_bits, name, type, field, offset, end)               \
 102 static const __maybe_unused unsigned    name##_OFFSET = offset;         \
 103 static const __maybe_unused unsigned    name##_BITS = (end - offset);   \
 104 static const __maybe_unused __u##_bits  name##_MAX = (1ULL << (end - offset)) - 1;\
 105                                                                         \
 106 static inline __u64 name(const type *k)                                 \
 107 {                                                                       \
 108         return (__le##_bits##_to_cpu(k->field) >> offset) &             \
 109                 ~(~0ULL << (end - offset));                             \
 110 }                                                                       \
 111                                                                         \
 112 static inline void SET_##name(type *k, __u64 v)                         \
 113 {                                                                       \
 114         __u##_bits new = __le##_bits##_to_cpu(k->field);                \
 115                                                                         \
 116         new &= ~(~(~0ULL << (end - offset)) << offset);                 \
 117         new |= (v & ~(~0ULL << (end - offset))) << offset;              \
 118         k->field = __cpu_to_le##_bits(new);                             \
 119 }
 120
 121 #define LE16_BITMASK(n, t, f, o, e)     LE_BITMASK(16, n, t, f, o, e)
 122 #define LE32_BITMASK(n, t, f, o, e)     LE_BITMASK(32, n, t, f, o, e)
 123 #define LE64_BITMASK(n, t, f, o, e)     LE_BITMASK(64, n, t, f, o, e)
 124
 125 struct bkey_format {
 126         __u8            key_u64s;
 127         __u8            nr_fields;
 128         /* One unused slot for now: */
 129         __u8            bits_per_field[6];
 130         __le64          field_offset[6];
 131 };
 132
 133 /* Btree keys - all units are in sectors */
 134
 135 struct bpos {
 136         /*
 137          * Word order matches machine byte order - btree code treats a bpos as a
 138          * single large integer, for search/comparison purposes
 139          *
 140          * Note that wherever a bpos is embedded in another on disk data
 141          * structure, it has to be byte swabbed when reading in metadata that
 142          * wasn't written in native endian order:
 143          */
 144 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 145         __u32           snapshot;
 146         __u64           offset;
 147         __u64           inode;
 148 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 149         __u64           inode;
 150         __u64           offset;         /* Points to end of extent - sectors */
 151         __u32           snapshot;
 152 #else
 153 #error edit for your odd byteorder.
 154 #endif
 155 } __packed
 156 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 157 __aligned(4)
 158 #endif
 159 ;
 160
 161 #define KEY_INODE_MAX                   ((__u64)~0ULL)
 162 #define KEY_OFFSET_MAX                  ((__u64)~0ULL)
 163 #define KEY_SNAPSHOT_MAX                ((__u32)~0U)
 164 #define KEY_SIZE_MAX                    ((__u32)~0U)
 165
 166 static inline struct bpos SPOS(__u64 inode, __u64 offset, __u32 snapshot)
 167 {
 168         return (struct bpos) {
 169                 .inode          = inode,
 170                 .offset         = offset,
 171                 .snapshot       = snapshot,
 172         };
 173 }
 174
 175 #define POS_MIN                         SPOS(0, 0, 0)
 176 #define POS_MAX                         SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, 0)
 177 #define SPOS_MAX                        SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, KEY_SNAPSHOT_MAX)
 178 #define POS(_inode, _offset)            SPOS(_inode, _offset, 0)
 179
 180 /* Empty placeholder struct, for container_of() */
 181 struct bch_val {
 182         __u64           __nothing[0];
 183 };
 184
 185 struct bversion {
 186 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 187         __u64           lo;
 188         __u32           hi;
 189 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 190         __u32           hi;
 191         __u64           lo;
 192 #endif
 193 } __packed
 194 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 195 __aligned(4)
 196 #endif
 197 ;
 198
 199 struct bkey {
 200         /* Size of combined key and value, in u64s */
 201         __u8            u64s;
 202
 203         /* Format of key (0 for format local to btree node) */
 204 #if defined(__LITTLE_ENDIAN_BITFIELD)
 205         __u8            format:7,
 206                         needs_whiteout:1;
 207 #elif defined (__BIG_ENDIAN_BITFIELD)
 208         __u8            needs_whiteout:1,
 209                         format:7;
 210 #else
 211 #error edit for your odd byteorder.
 212 #endif
 213
 214         /* Type of the value */
 215         __u8            type;
 216
 217 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 218         __u8            pad[1];
 219
 220         struct bversion bversion;
 221         __u32           size;           /* extent size, in sectors */
 222         struct bpos     p;
 223 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 224         struct bpos     p;
 225         __u32           size;           /* extent size, in sectors */
 226         struct bversion version;
 227
 228         __u8            pad[1];
 229 #endif
 230 } __packed
 231 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 232 /*
 233  * The big-endian version of bkey can't be compiled by rustc with the "aligned"
 234  * attr since it doesn't allow types to have both "packed" and "aligned" attrs.
 235  * So for Rust compatibility, don't include this. It can be included in the LE
 236  * version because the "packed" attr is redundant in that case.
 237  *
 238  * History: (quoting Kent)
 239  *
 240  * Specifically, when i was designing bkey, I wanted the header to be no
 241  * bigger than necessary so that bkey_packed could use the rest. That means that
 242  * decently offten extent keys will fit into only 8 bytes, instead of spilling over
 243  * to 16.
 244  *
 245  * But packed_bkey treats the part after the header - the packed section -
 246  * as a single multi word, variable length integer. And bkey, the unpacked
 247  * version, is just a special case version of a bkey_packed; all the packed
 248  * bkey code will work on keys in any packed format, the in-memory
 249  * representation of an unpacked key also is just one type of packed key...
 250  *
 251  * So that constrains the key part of a bkig endian bkey to start right
 252  * after the header.
 253  *
 254  * If we ever do a bkey_v2 and need to expand the hedaer by another byte for
 255  * some reason - that will clean up this wart.
 256  */
 257 __aligned(8)
 258 #endif
 259 ;
 260
 261 struct bkey_packed {
 262         __u64           _data[0];
 263
 264         /* Size of combined key and value, in u64s */
 265         __u8            u64s;
 266
 267         /* Format of key (0 for format local to btree node) */
 268
 269         /*
 270          * XXX: next incompat on disk format change, switch format and
 271          * needs_whiteout - bkey_packed() will be cheaper if format is the high
 272          * bits of the bitfield
 273          */
 274 #if defined(__LITTLE_ENDIAN_BITFIELD)
 275         __u8            format:7,
 276                         needs_whiteout:1;
 277 #elif defined (__BIG_ENDIAN_BITFIELD)
 278         __u8            needs_whiteout:1,
 279                         format:7;
 280 #endif
 281
 282         /* Type of the value */
 283         __u8            type;
 284         __u8            key_start[0];
 285
 286         /*
 287          * We copy bkeys with struct assignment in various places, and while
 288          * that shouldn't be done with packed bkeys we can't disallow it in C,
 289          * and it's legal to cast a bkey to a bkey_packed  - so padding it out
 290          * to the same size as struct bkey should hopefully be safest.
 291          */
 292         __u8            pad[sizeof(struct bkey) - 3];
 293 } __packed __aligned(8);
 294
 295 typedef struct {
 296         __le64                  lo;
 297         __le64                  hi;
 298 } bch_le128;
 299
 300 #define BKEY_U64s                       (sizeof(struct bkey) / sizeof(__u64))
 301 #define BKEY_U64s_MAX                   U8_MAX
 302 #define BKEY_VAL_U64s_MAX               (BKEY_U64s_MAX - BKEY_U64s)
 303
 304 #define KEY_PACKED_BITS_START           24
 305
 306 #define KEY_FORMAT_LOCAL_BTREE          0
 307 #define KEY_FORMAT_CURRENT              1
 308
 309 enum bch_bkey_fields {
 310         BKEY_FIELD_INODE,
 311         BKEY_FIELD_OFFSET,
 312         BKEY_FIELD_SNAPSHOT,
 313         BKEY_FIELD_SIZE,
 314         BKEY_FIELD_VERSION_HI,
 315         BKEY_FIELD_VERSION_LO,
 316         BKEY_NR_FIELDS,
 317 };
 318
 319 #define bkey_format_field(name, field)                                  \
 320         [BKEY_FIELD_##name] = (sizeof(((struct bkey *) NULL)->field) * 8)
 321
 322 #define BKEY_FORMAT_CURRENT                                             \
 323 ((struct bkey_format) {                                                 \
 324         .key_u64s       = BKEY_U64s,                                    \
 325         .nr_fields      = BKEY_NR_FIELDS,                               \
 326         .bits_per_field = {                                             \
 327                 bkey_format_field(INODE,        p.inode),               \
 328                 bkey_format_field(OFFSET,       p.offset),              \
 329                 bkey_format_field(SNAPSHOT,     p.snapshot),            \
 330                 bkey_format_field(SIZE,         size),                  \
 331                 bkey_format_field(VERSION_HI,   bversion.hi),           \
 332                 bkey_format_field(VERSION_LO,   bversion.lo),           \
 333         },                                                              \
 334 })
 335
 336 /* bkey with inline value */
 337 struct bkey_i {
 338         __u64                   _data[0];
 339
 340         struct bkey     k;
 341         struct bch_val  v;
 342 };
 343
 344 #define POS_KEY(_pos)                                                   \
 345 ((struct bkey) {                                                        \
 346         .u64s           = BKEY_U64s,                                    \
 347         .format         = KEY_FORMAT_CURRENT,                           \
 348         .p              = _pos,                                         \
 349 })
 350
 351 #define KEY(_inode, _offset, _size)                                     \
 352 ((struct bkey) {                                                        \
 353         .u64s           = BKEY_U64s,                                    \
 354         .format         = KEY_FORMAT_CURRENT,                           \
 355         .p              = POS(_inode, _offset),                         \
 356         .size           = _size,                                        \
 357 })
 358
 359 static inline void bkey_init(struct bkey *k)
 360 {
 361         *k = KEY(0, 0, 0);
 362 }
 363
 364 #define bkey_bytes(_k)          ((_k)->u64s * sizeof(__u64))
 365
 366 #define __BKEY_PADDED(key, pad)                                 \
 367         struct bkey_i key; __u64 key ## _pad[pad]
 368
 369 /*
 370  * - DELETED keys are used internally to mark keys that should be ignored but
 371  *   override keys in composition order.  Their version number is ignored.
 372  *
 373  * - DISCARDED keys indicate that the data is all 0s because it has been
 374  *   discarded. DISCARDs may have a version; if the version is nonzero the key
 375  *   will be persistent, otherwise the key will be dropped whenever the btree
 376  *   node is rewritten (like DELETED keys).
 377  *
 378  * - ERROR: any read of the data returns a read error, as the data was lost due
 379  *   to a failing device. Like DISCARDED keys, they can be removed (overridden)
 380  *   by new writes or cluster-wide GC. Node repair can also overwrite them with
 381  *   the same or a more recent version number, but not with an older version
 382  *   number.
 383  *
 384  * - WHITEOUT: for hash table btrees
 385  */
 386 #define BCH_BKEY_TYPES()                                \
 387         x(deleted,              0)                      \
 388         x(whiteout,             1)                      \
 389         x(error,                2)                      \
 390         x(cookie,               3)                      \
 391         x(hash_whiteout,        4)                      \
 392         x(btree_ptr,            5)                      \
 393         x(extent,               6)                      \
 394         x(reservation,          7)                      \
 395         x(inode,                8)                      \
 396         x(inode_generation,     9)                      \
 397         x(dirent,               10)                     \
 398         x(xattr,                11)                     \
 399         x(alloc,                12)                     \
 400         x(quota,                13)                     \
 401         x(stripe,               14)                     \
 402         x(reflink_p,            15)                     \
 403         x(reflink_v,            16)                     \
 404         x(inline_data,          17)                     \
 405         x(btree_ptr_v2,         18)                     \
 406         x(indirect_inline_data, 19)                     \
 407         x(alloc_v2,             20)                     \
 408         x(subvolume,            21)                     \
 409         x(snapshot,             22)                     \
 410         x(inode_v2,             23)                     \
 411         x(alloc_v3,             24)                     \
 412         x(set,                  25)                     \
 413         x(lru,                  26)                     \
 414         x(alloc_v4,             27)                     \
 415         x(backpointer,          28)                     \
 416         x(inode_v3,             29)                     \
 417         x(bucket_gens,          30)                     \
 418         x(snapshot_tree,        31)                     \
 419         x(logged_op_truncate,   32)                     \
 420         x(logged_op_finsert,    33)                     \
 421         x(accounting,           34)
 422
 423 enum bch_bkey_type {
 424 #define x(name, nr) KEY_TYPE_##name     = nr,
 425         BCH_BKEY_TYPES()
 426 #undef x
 427         KEY_TYPE_MAX,
 428 };
 429
 430 struct bch_deleted {
 431         struct bch_val          v;
 432 };
 433
 434 struct bch_whiteout {
 435         struct bch_val          v;
 436 };
 437
 438 struct bch_error {
 439         struct bch_val          v;
 440 };
 441
 442 struct bch_cookie {
 443         struct bch_val          v;
 444         __le64                  cookie;
 445 };
 446
 447 struct bch_hash_whiteout {
 448         struct bch_val          v;
 449 };
 450
 451 struct bch_set {
 452         struct bch_val          v;
 453 };
 454
 455 /* 128 bits, sufficient for cryptographic MACs: */
 456 struct bch_csum {
 457         __le64                  lo;
 458         __le64                  hi;
 459 } __packed __aligned(8);
 460
 461 struct bch_backpointer {
 462         struct bch_val          v;
 463         __u8                    btree_id;
 464         __u8                    level;
 465         __u8                    data_type;
 466         __u64                   bucket_offset:40;
 467         __u32                   bucket_len;
 468         struct bpos             pos;
 469 } __packed __aligned(8);
 470
 471 /* Optional/variable size superblock sections: */
 472
 473 struct bch_sb_field {
 474         __u64                   _data[0];
 475         __le32                  u64s;
 476         __le32                  type;
 477 };
 478
 479 #define BCH_SB_FIELDS()                         \
 480         x(journal,                      0)      \
 481         x(members_v1,                   1)      \
 482         x(crypt,                        2)      \
 483         x(replicas_v0,                  3)      \
 484         x(quota,                        4)      \
 485         x(disk_groups,                  5)      \
 486         x(clean,                        6)      \
 487         x(replicas,                     7)      \
 488         x(journal_seq_blacklist,        8)      \
 489         x(journal_v2,                   9)      \
 490         x(counters,                     10)     \
 491         x(members_v2,                   11)     \
 492         x(errors,                       12)     \
 493         x(ext,                          13)     \
 494         x(downgrade,                    14)
 495
 496 #include "alloc_background_format.h"
 497 #include "dirent_format.h"
 498 #include "disk_accounting_format.h"
 499 #include "disk_groups_format.h"
 500 #include "extents_format.h"
 501 #include "ec_format.h"
 502 #include "dirent_format.h"
 503 #include "disk_groups_format.h"
 504 #include "inode_format.h"
 505 #include "journal_seq_blacklist_format.h"
 506 #include "logged_ops_format.h"
 507 #include "lru_format.h"
 508 #include "quota_format.h"
 509 #include "reflink_format.h"
 510 #include "replicas_format.h"
 511 #include "snapshot_format.h"
 512 #include "subvolume_format.h"
 513 #include "sb-counters_format.h"
 514 #include "sb-downgrade_format.h"
 515 #include "sb-errors_format.h"
 516 #include "sb-members_format.h"
 517 #include "xattr_format.h"
 518
 519 enum bch_sb_field_type {
 520 #define x(f, nr)        BCH_SB_FIELD_##f = nr,
 521         BCH_SB_FIELDS()
 522 #undef x
 523         BCH_SB_FIELD_NR
 524 };
 525
 526 /*
 527  * Most superblock fields are replicated in all device's superblocks - a few are
 528  * not:
 529  */
 530 #define BCH_SINGLE_DEVICE_SB_FIELDS             \
 531         ((1U << BCH_SB_FIELD_journal)|          \
 532          (1U << BCH_SB_FIELD_journal_v2))
 533
 534 /* BCH_SB_FIELD_journal: */
 535
 536 struct bch_sb_field_journal {
 537         struct bch_sb_field     field;
 538         __le64                  buckets[];
 539 };
 540
 541 struct bch_sb_field_journal_v2 {
 542         struct bch_sb_field     field;
 543
 544         struct bch_sb_field_journal_v2_entry {
 545                 __le64          start;
 546                 __le64          nr;
 547         }                       d[];
 548 };
 549
 550 /* BCH_SB_FIELD_crypt: */
 551
 552 struct nonce {
 553         __le32                  d[4];
 554 };
 555
 556 struct bch_key {
 557         __le64                  key[4];
 558 };
 559
 560 #define BCH_KEY_MAGIC                                   \
 561         (((__u64) 'b' <<  0)|((__u64) 'c' <<  8)|               \
 562          ((__u64) 'h' << 16)|((__u64) '*' << 24)|               \
 563          ((__u64) '*' << 32)|((__u64) 'k' << 40)|               \
 564          ((__u64) 'e' << 48)|((__u64) 'y' << 56))
 565
 566 struct bch_encrypted_key {
 567         __le64                  magic;
 568         struct bch_key          key;
 569 };
 570
 571 /*
 572  * If this field is present in the superblock, it stores an encryption key which
 573  * is used encrypt all other data/metadata. The key will normally be encrypted
 574  * with the key userspace provides, but if encryption has been turned off we'll
 575  * just store the master key unencrypted in the superblock so we can access the
 576  * previously encrypted data.
 577  */
 578 struct bch_sb_field_crypt {
 579         struct bch_sb_field     field;
 580
 581         __le64                  flags;
 582         __le64                  kdf_flags;
 583         struct bch_encrypted_key key;
 584 };
 585
 586 LE64_BITMASK(BCH_CRYPT_KDF_TYPE,        struct bch_sb_field_crypt, flags, 0, 4);
 587
 588 enum bch_kdf_types {
 589         BCH_KDF_SCRYPT          = 0,
 590         BCH_KDF_NR              = 1,
 591 };
 592
 593 /* stored as base 2 log of scrypt params: */
 594 LE64_BITMASK(BCH_KDF_SCRYPT_N,  struct bch_sb_field_crypt, kdf_flags,  0, 16);
 595 LE64_BITMASK(BCH_KDF_SCRYPT_R,  struct bch_sb_field_crypt, kdf_flags, 16, 32);
 596 LE64_BITMASK(BCH_KDF_SCRYPT_P,  struct bch_sb_field_crypt, kdf_flags, 32, 48);
 597
 598 /*
 599  * On clean shutdown, store btree roots and current journal sequence number in
 600  * the superblock:
 601  */
 602 struct jset_entry {
 603         __le16                  u64s;
 604         __u8                    btree_id;
 605         __u8                    level;
 606         __u8                    type; /* designates what this jset holds */
 607         __u8                    pad[3];
 608
 609         struct bkey_i           start[0];
 610         __u64                   _data[];
 611 };
 612
 613 struct bch_sb_field_clean {
 614         struct bch_sb_field     field;
 615
 616         __le32                  flags;
 617         __le16                  _read_clock; /* no longer used */
 618         __le16                  _write_clock;
 619         __le64                  journal_seq;
 620
 621         struct jset_entry       start[0];
 622         __u64                   _data[];
 623 };
 624
 625 struct bch_sb_field_ext {
 626         struct bch_sb_field     field;
 627         __le64                  recovery_passes_required[2];
 628         __le64                  errors_silent[8];
 629         __le64                  btrees_lost_data;
 630 };
 631
 632 /* Superblock: */
 633
 634 /*
 635  * New versioning scheme:
 636  * One common version number for all on disk data structures - superblock, btree
 637  * nodes, journal entries
 638  */
 639 #define BCH_VERSION_MAJOR(_v)           ((__u16) ((_v) >> 10))
 640 #define BCH_VERSION_MINOR(_v)           ((__u16) ((_v) & ~(~0U << 10)))
 641 #define BCH_VERSION(_major, _minor)     (((_major) << 10)|(_minor) << 0)
 642
 643 /*
 644  * field 1:             version name
 645  * field 2:             BCH_VERSION(major, minor)
 646  * field 3:             recovery passess required on upgrade
 647  */
 648 #define BCH_METADATA_VERSIONS()                                         \
 649         x(bkey_renumber,                BCH_VERSION(0, 10))             \
 650         x(inode_btree_change,           BCH_VERSION(0, 11))             \
 651         x(snapshot,                     BCH_VERSION(0, 12))             \
 652         x(inode_backpointers,           BCH_VERSION(0, 13))             \
 653         x(btree_ptr_sectors_written,    BCH_VERSION(0, 14))             \
 654         x(snapshot_2,                   BCH_VERSION(0, 15))             \
 655         x(reflink_p_fix,                BCH_VERSION(0, 16))             \
 656         x(subvol_dirent,                BCH_VERSION(0, 17))             \
 657         x(inode_v2,                     BCH_VERSION(0, 18))             \
 658         x(freespace,                    BCH_VERSION(0, 19))             \
 659         x(alloc_v4,                     BCH_VERSION(0, 20))             \
 660         x(new_data_types,               BCH_VERSION(0, 21))             \
 661         x(backpointers,                 BCH_VERSION(0, 22))             \
 662         x(inode_v3,                     BCH_VERSION(0, 23))             \
 663         x(unwritten_extents,            BCH_VERSION(0, 24))             \
 664         x(bucket_gens,                  BCH_VERSION(0, 25))             \
 665         x(lru_v2,                       BCH_VERSION(0, 26))             \
 666         x(fragmentation_lru,            BCH_VERSION(0, 27))             \
 667         x(no_bps_in_alloc_keys,         BCH_VERSION(0, 28))             \
 668         x(snapshot_trees,               BCH_VERSION(0, 29))             \
 669         x(major_minor,                  BCH_VERSION(1,  0))             \
 670         x(snapshot_skiplists,           BCH_VERSION(1,  1))             \
 671         x(deleted_inodes,               BCH_VERSION(1,  2))             \
 672         x(rebalance_work,               BCH_VERSION(1,  3))             \
 673         x(member_seq,                   BCH_VERSION(1,  4))             \
 674         x(subvolume_fs_parent,          BCH_VERSION(1,  5))             \
 675         x(btree_subvolume_children,     BCH_VERSION(1,  6))             \
 676         x(mi_btree_bitmap,              BCH_VERSION(1,  7))             \
 677         x(bucket_stripe_sectors,        BCH_VERSION(1,  8))             \
 678         x(disk_accounting_v2,           BCH_VERSION(1,  9))             \
 679         x(disk_accounting_v3,           BCH_VERSION(1, 10))             \
 680         x(disk_accounting_inum,         BCH_VERSION(1, 11))             \
 681         x(rebalance_work_acct_fix,      BCH_VERSION(1, 12))
 682
 683 enum bcachefs_metadata_version {
 684         bcachefs_metadata_version_min = 9,
 685 #define x(t, n) bcachefs_metadata_version_##t = n,
 686         BCH_METADATA_VERSIONS()
 687 #undef x
 688         bcachefs_metadata_version_max
 689 };
 690
 691 static const __maybe_unused
 692 unsigned bcachefs_metadata_required_upgrade_below = bcachefs_metadata_version_rebalance_work;
 693
 694 #define bcachefs_metadata_version_current       (bcachefs_metadata_version_max - 1)
 695
 696 #define BCH_SB_SECTOR                   8
 697
 698 #define BCH_SB_LAYOUT_SIZE_BITS_MAX     16 /* 32 MB */
 699
 700 struct bch_sb_layout {
 701         __uuid_t                magic;  /* bcachefs superblock UUID */
 702         __u8                    layout_type;
 703         __u8                    sb_max_size_bits; /* base 2 of 512 byte sectors */
 704         __u8                    nr_superblocks;
 705         __u8                    pad[5];
 706         __le64                  sb_offset[61];
 707 } __packed __aligned(8);
 708
 709 #define BCH_SB_LAYOUT_SECTOR    7
 710
 711 /*
 712  * @offset      - sector where this sb was written
 713  * @version     - on disk format version
 714  * @version_min - Oldest metadata version this filesystem contains; so we can
 715  *                safely drop compatibility code and refuse to mount filesystems
 716  *                we'd need it for
 717  * @magic       - identifies as a bcachefs superblock (BCHFS_MAGIC)
 718  * @seq         - incremented each time superblock is written
 719  * @uuid        - used for generating various magic numbers and identifying
 720  *                member devices, never changes
 721  * @user_uuid   - user visible UUID, may be changed
 722  * @label       - filesystem label
 723  * @seq         - identifies most recent superblock, incremented each time
 724  *                superblock is written
 725  * @features    - enabled incompatible features
 726  */
 727 struct bch_sb {
 728         struct bch_csum         csum;
 729         __le16                  version;
 730         __le16                  version_min;
 731         __le16                  pad[2];
 732         __uuid_t                magic;
 733         __uuid_t                uuid;
 734         __uuid_t                user_uuid;
 735         __u8                    label[BCH_SB_LABEL_SIZE];
 736         __le64                  offset;
 737         __le64                  seq;
 738
 739         __le16                  block_size;
 740         __u8                    dev_idx;
 741         __u8                    nr_devices;
 742         __le32                  u64s;
 743
 744         __le64                  time_base_lo;
 745         __le32                  time_base_hi;
 746         __le32                  time_precision;
 747
 748         __le64                  flags[7];
 749         __le64                  write_time;
 750         __le64                  features[2];
 751         __le64                  compat[2];
 752
 753         struct bch_sb_layout    layout;
 754
 755         struct bch_sb_field     start[0];
 756         __le64                  _data[];
 757 } __packed __aligned(8);
 758
 759 /*
 760  * Flags:
 761  * BCH_SB_INITALIZED    - set on first mount
 762  * BCH_SB_CLEAN         - did we shut down cleanly? Just a hint, doesn't affect
 763  *                        behaviour of mount/recovery path:
 764  * BCH_SB_INODE_32BIT   - limit inode numbers to 32 bits
 765  * BCH_SB_128_BIT_MACS  - 128 bit macs instead of 80
 766  * BCH_SB_ENCRYPTION_TYPE - if nonzero encryption is enabled; overrides
 767  *                         DATA/META_CSUM_TYPE. Also indicates encryption
 768  *                         algorithm in use, if/when we get more than one
 769  */
 770
 771 LE16_BITMASK(BCH_SB_BLOCK_SIZE,         struct bch_sb, block_size, 0, 16);
 772
 773 LE64_BITMASK(BCH_SB_INITIALIZED,        struct bch_sb, flags[0],  0,  1);
 774 LE64_BITMASK(BCH_SB_CLEAN,              struct bch_sb, flags[0],  1,  2);
 775 LE64_BITMASK(BCH_SB_CSUM_TYPE,          struct bch_sb, flags[0],  2,  8);
 776 LE64_BITMASK(BCH_SB_ERROR_ACTION,       struct bch_sb, flags[0],  8, 12);
 777
 778 LE64_BITMASK(BCH_SB_BTREE_NODE_SIZE,    struct bch_sb, flags[0], 12, 28);
 779
 780 LE64_BITMASK(BCH_SB_GC_RESERVE,         struct bch_sb, flags[0], 28, 33);
 781 LE64_BITMASK(BCH_SB_ROOT_RESERVE,       struct bch_sb, flags[0], 33, 40);
 782
 783 LE64_BITMASK(BCH_SB_META_CSUM_TYPE,     struct bch_sb, flags[0], 40, 44);
 784 LE64_BITMASK(BCH_SB_DATA_CSUM_TYPE,     struct bch_sb, flags[0], 44, 48);
 785
 786 LE64_BITMASK(BCH_SB_META_REPLICAS_WANT, struct bch_sb, flags[0], 48, 52);
 787 LE64_BITMASK(BCH_SB_DATA_REPLICAS_WANT, struct bch_sb, flags[0], 52, 56);
 788
 789 LE64_BITMASK(BCH_SB_POSIX_ACL,          struct bch_sb, flags[0], 56, 57);
 790 LE64_BITMASK(BCH_SB_USRQUOTA,           struct bch_sb, flags[0], 57, 58);
 791 LE64_BITMASK(BCH_SB_GRPQUOTA,           struct bch_sb, flags[0], 58, 59);
 792 LE64_BITMASK(BCH_SB_PRJQUOTA,           struct bch_sb, flags[0], 59, 60);
 793
 794 LE64_BITMASK(BCH_SB_HAS_ERRORS,         struct bch_sb, flags[0], 60, 61);
 795 LE64_BITMASK(BCH_SB_HAS_TOPOLOGY_ERRORS,struct bch_sb, flags[0], 61, 62);
 796
 797 LE64_BITMASK(BCH_SB_BIG_ENDIAN,         struct bch_sb, flags[0], 62, 63);
 798 LE64_BITMASK(BCH_SB_PROMOTE_WHOLE_EXTENTS,
 799                                         struct bch_sb, flags[0], 63, 64);
 800
 801 LE64_BITMASK(BCH_SB_STR_HASH_TYPE,      struct bch_sb, flags[1],  0,  4);
 802 LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_LO,struct bch_sb, flags[1],  4,  8);
 803 LE64_BITMASK(BCH_SB_INODE_32BIT,        struct bch_sb, flags[1],  8,  9);
 804
 805 LE64_BITMASK(BCH_SB_128_BIT_MACS,       struct bch_sb, flags[1],  9, 10);
 806 LE64_BITMASK(BCH_SB_ENCRYPTION_TYPE,    struct bch_sb, flags[1], 10, 14);
 807
 808 /*
 809  * Max size of an extent that may require bouncing to read or write
 810  * (checksummed, compressed): 64k
 811  */
 812 LE64_BITMASK(BCH_SB_ENCODED_EXTENT_MAX_BITS,
 813                                         struct bch_sb, flags[1], 14, 20);
 814
 815 LE64_BITMASK(BCH_SB_META_REPLICAS_REQ,  struct bch_sb, flags[1], 20, 24);
 816 LE64_BITMASK(BCH_SB_DATA_REPLICAS_REQ,  struct bch_sb, flags[1], 24, 28);
 817
 818 LE64_BITMASK(BCH_SB_PROMOTE_TARGET,     struct bch_sb, flags[1], 28, 40);
 819 LE64_BITMASK(BCH_SB_FOREGROUND_TARGET,  struct bch_sb, flags[1], 40, 52);
 820 LE64_BITMASK(BCH_SB_BACKGROUND_TARGET,  struct bch_sb, flags[1], 52, 64);
 821
 822 LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO,
 823                                         struct bch_sb, flags[2],  0,  4);
 824 LE64_BITMASK(BCH_SB_GC_RESERVE_BYTES,   struct bch_sb, flags[2],  4, 64);
 825
 826 LE64_BITMASK(BCH_SB_ERASURE_CODE,       struct bch_sb, flags[3],  0, 16);
 827 LE64_BITMASK(BCH_SB_METADATA_TARGET,    struct bch_sb, flags[3], 16, 28);
 828 LE64_BITMASK(BCH_SB_SHARD_INUMS,        struct bch_sb, flags[3], 28, 29);
 829 LE64_BITMASK(BCH_SB_INODES_USE_KEY_CACHE,struct bch_sb, flags[3], 29, 30);
 830 LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DELAY,struct bch_sb, flags[3], 30, 62);
 831 LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DISABLED,struct bch_sb, flags[3], 62, 63);
 832 LE64_BITMASK(BCH_SB_JOURNAL_RECLAIM_DELAY,struct bch_sb, flags[4], 0, 32);
 833 LE64_BITMASK(BCH_SB_JOURNAL_TRANSACTION_NAMES,struct bch_sb, flags[4], 32, 33);
 834 LE64_BITMASK(BCH_SB_NOCOW,              struct bch_sb, flags[4], 33, 34);
 835 LE64_BITMASK(BCH_SB_WRITE_BUFFER_SIZE,  struct bch_sb, flags[4], 34, 54);
 836 LE64_BITMASK(BCH_SB_VERSION_UPGRADE,    struct bch_sb, flags[4], 54, 56);
 837
 838 LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_HI,struct bch_sb, flags[4], 56, 60);
 839 LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI,
 840                                         struct bch_sb, flags[4], 60, 64);
 841
 842 LE64_BITMASK(BCH_SB_VERSION_UPGRADE_COMPLETE,
 843                                         struct bch_sb, flags[5],  0, 16);
 844 LE64_BITMASK(BCH_SB_ALLOCATOR_STUCK_TIMEOUT,
 845                                         struct bch_sb, flags[5], 16, 32);
 846
 847 static inline __u64 BCH_SB_COMPRESSION_TYPE(const struct bch_sb *sb)
 848 {
 849         return BCH_SB_COMPRESSION_TYPE_LO(sb) | (BCH_SB_COMPRESSION_TYPE_HI(sb) << 4);
 850 }
 851
 852 static inline void SET_BCH_SB_COMPRESSION_TYPE(struct bch_sb *sb, __u64 v)
 853 {
 854         SET_BCH_SB_COMPRESSION_TYPE_LO(sb, v);
 855         SET_BCH_SB_COMPRESSION_TYPE_HI(sb, v >> 4);
 856 }
 857
 858 static inline __u64 BCH_SB_BACKGROUND_COMPRESSION_TYPE(const struct bch_sb *sb)
 859 {
 860         return BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO(sb) |
 861                 (BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI(sb) << 4);
 862 }
 863
 864 static inline void SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE(struct bch_sb *sb, __u64 v)
 865 {
 866         SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO(sb, v);
 867         SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI(sb, v >> 4);
 868 }
 869
 870 /*
 871  * Features:
 872  *
 873  * journal_seq_blacklist_v3:    gates BCH_SB_FIELD_journal_seq_blacklist
 874  * reflink:                     gates KEY_TYPE_reflink
 875  * inline_data:                 gates KEY_TYPE_inline_data
 876  * new_siphash:                 gates BCH_STR_HASH_siphash
 877  * new_extent_overwrite:        gates BTREE_NODE_NEW_EXTENT_OVERWRITE
 878  */
 879 #define BCH_SB_FEATURES()                       \
 880         x(lz4,                          0)      \
 881         x(gzip,                         1)      \
 882         x(zstd,                         2)      \
 883         x(atomic_nlink,                 3)      \
 884         x(ec,                           4)      \
 885         x(journal_seq_blacklist_v3,     5)      \
 886         x(reflink,                      6)      \
 887         x(new_siphash,                  7)      \
 888         x(inline_data,                  8)      \
 889         x(new_extent_overwrite,         9)      \
 890         x(incompressible,               10)     \
 891         x(btree_ptr_v2,                 11)     \
 892         x(extents_above_btree_updates,  12)     \
 893         x(btree_updates_journalled,     13)     \
 894         x(reflink_inline_data,          14)     \
 895         x(new_varint,                   15)     \
 896         x(journal_no_flush,             16)     \
 897         x(alloc_v2,                     17)     \
 898         x(extents_across_btree_nodes,   18)
 899
 900 #define BCH_SB_FEATURES_ALWAYS                          \
 901         ((1ULL << BCH_FEATURE_new_extent_overwrite)|    \
 902          (1ULL << BCH_FEATURE_extents_above_btree_updates)|\
 903          (1ULL << BCH_FEATURE_btree_updates_journalled)|\
 904          (1ULL << BCH_FEATURE_alloc_v2)|\
 905          (1ULL << BCH_FEATURE_extents_across_btree_nodes))
 906
 907 #define BCH_SB_FEATURES_ALL                             \
 908         (BCH_SB_FEATURES_ALWAYS|                        \
 909          (1ULL << BCH_FEATURE_new_siphash)|             \
 910          (1ULL << BCH_FEATURE_btree_ptr_v2)|            \
 911          (1ULL << BCH_FEATURE_new_varint)|              \
 912          (1ULL << BCH_FEATURE_journal_no_flush))
 913
 914 enum bch_sb_feature {
 915 #define x(f, n) BCH_FEATURE_##f,
 916         BCH_SB_FEATURES()
 917 #undef x
 918         BCH_FEATURE_NR,
 919 };
 920
 921 #define BCH_SB_COMPAT()                                 \
 922         x(alloc_info,                           0)      \
 923         x(alloc_metadata,                       1)      \
 924         x(extents_above_btree_updates_done,     2)      \
 925         x(bformat_overflow_done,                3)
 926
 927 enum bch_sb_compat {
 928 #define x(f, n) BCH_COMPAT_##f,
 929         BCH_SB_COMPAT()
 930 #undef x
 931         BCH_COMPAT_NR,
 932 };
 933
 934 /* options: */
 935
 936 #define BCH_VERSION_UPGRADE_OPTS()      \
 937         x(compatible,           0)      \
 938         x(incompatible,         1)      \
 939         x(none,                 2)
 940
 941 enum bch_version_upgrade_opts {
 942 #define x(t, n) BCH_VERSION_UPGRADE_##t = n,
 943         BCH_VERSION_UPGRADE_OPTS()
 944 #undef x
 945 };
 946
 947 #define BCH_REPLICAS_MAX                4U
 948
 949 #define BCH_BKEY_PTRS_MAX               16U
 950
 951 #define BCH_ERROR_ACTIONS()             \
 952         x(continue,             0)      \
 953         x(fix_safe,             1)      \
 954         x(panic,                2)      \
 955         x(ro,                   3)
 956
 957 enum bch_error_actions {
 958 #define x(t, n) BCH_ON_ERROR_##t = n,
 959         BCH_ERROR_ACTIONS()
 960 #undef x
 961         BCH_ON_ERROR_NR
 962 };
 963
 964 #define BCH_STR_HASH_TYPES()            \
 965         x(crc32c,               0)      \
 966         x(crc64,                1)      \
 967         x(siphash_old,          2)      \
 968         x(siphash,              3)
 969
 970 enum bch_str_hash_type {
 971 #define x(t, n) BCH_STR_HASH_##t = n,
 972         BCH_STR_HASH_TYPES()
 973 #undef x
 974         BCH_STR_HASH_NR
 975 };
 976
 977 #define BCH_STR_HASH_OPTS()             \
 978         x(crc32c,               0)      \
 979         x(crc64,                1)      \
 980         x(siphash,              2)
 981
 982 enum bch_str_hash_opts {
 983 #define x(t, n) BCH_STR_HASH_OPT_##t = n,
 984         BCH_STR_HASH_OPTS()
 985 #undef x
 986         BCH_STR_HASH_OPT_NR
 987 };
 988
 989 #define BCH_CSUM_TYPES()                        \
 990         x(none,                         0)      \
 991         x(crc32c_nonzero,               1)      \
 992         x(crc64_nonzero,                2)      \
 993         x(chacha20_poly1305_80,         3)      \
 994         x(chacha20_poly1305_128,        4)      \
 995         x(crc32c,                       5)      \
 996         x(crc64,                        6)      \
 997         x(xxhash,                       7)
 998
 999 enum bch_csum_type {
1000 #define x(t, n) BCH_CSUM_##t = n,
1001         BCH_CSUM_TYPES()
1002 #undef x
1003         BCH_CSUM_NR
1004 };
1005
1006 static const __maybe_unused unsigned bch_crc_bytes[] = {
1007         [BCH_CSUM_none]                         = 0,
1008         [BCH_CSUM_crc32c_nonzero]               = 4,
1009         [BCH_CSUM_crc32c]                       = 4,
1010         [BCH_CSUM_crc64_nonzero]                = 8,
1011         [BCH_CSUM_crc64]                        = 8,
1012         [BCH_CSUM_xxhash]                       = 8,
1013         [BCH_CSUM_chacha20_poly1305_80]         = 10,
1014         [BCH_CSUM_chacha20_poly1305_128]        = 16,
1015 };
1016
1017 static inline _Bool bch2_csum_type_is_encryption(enum bch_csum_type type)
1018 {
1019         switch (type) {
1020         case BCH_CSUM_chacha20_poly1305_80:
1021         case BCH_CSUM_chacha20_poly1305_128:
1022                 return true;
1023         default:
1024                 return false;
1025         }
1026 }
1027
1028 #define BCH_CSUM_OPTS()                 \
1029         x(none,                 0)      \
1030         x(crc32c,               1)      \
1031         x(crc64,                2)      \
1032         x(xxhash,               3)
1033
1034 enum bch_csum_opts {
1035 #define x(t, n) BCH_CSUM_OPT_##t = n,
1036         BCH_CSUM_OPTS()
1037 #undef x
1038         BCH_CSUM_OPT_NR
1039 };
1040
1041 #define BCH_COMPRESSION_TYPES()         \
1042         x(none,                 0)      \
1043         x(lz4_old,              1)      \
1044         x(gzip,                 2)      \
1045         x(lz4,                  3)      \
1046         x(zstd,                 4)      \
1047         x(incompressible,       5)
1048
1049 enum bch_compression_type {
1050 #define x(t, n) BCH_COMPRESSION_TYPE_##t = n,
1051         BCH_COMPRESSION_TYPES()
1052 #undef x
1053         BCH_COMPRESSION_TYPE_NR
1054 };
1055
1056 #define BCH_COMPRESSION_OPTS()          \
1057         x(none,         0)              \
1058         x(lz4,          1)              \
1059         x(gzip,         2)              \
1060         x(zstd,         3)
1061
1062 enum bch_compression_opts {
1063 #define x(t, n) BCH_COMPRESSION_OPT_##t = n,
1064         BCH_COMPRESSION_OPTS()
1065 #undef x
1066         BCH_COMPRESSION_OPT_NR
1067 };
1068
1069 /*
1070  * Magic numbers
1071  *
1072  * The various other data structures have their own magic numbers, which are
1073  * xored with the first part of the cache set's UUID
1074  */
1075
1076 #define BCACHE_MAGIC                                                    \
1077         UUID_INIT(0xc68573f6, 0x4e1a, 0x45ca,                           \
1078                   0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81)
1079 #define BCHFS_MAGIC                                                     \
1080         UUID_INIT(0xc68573f6, 0x66ce, 0x90a9,                           \
1081                   0xd9, 0x6a, 0x60, 0xcf, 0x80, 0x3d, 0xf7, 0xef)
1082
1083 #define BCACHEFS_STATFS_MAGIC           BCACHEFS_SUPER_MAGIC
1084
1085 #define JSET_MAGIC              __cpu_to_le64(0x245235c1a3625032ULL)
1086 #define BSET_MAGIC              __cpu_to_le64(0x90135c78b99e07f5ULL)
1087
1088 static inline __le64 __bch2_sb_magic(struct bch_sb *sb)
1089 {
1090         __le64 ret;
1091
1092         memcpy(&ret, &sb->uuid, sizeof(ret));
1093         return ret;
1094 }
1095
1096 static inline __u64 __jset_magic(struct bch_sb *sb)
1097 {
1098         return __le64_to_cpu(__bch2_sb_magic(sb) ^ JSET_MAGIC);
1099 }
1100
1101 static inline __u64 __bset_magic(struct bch_sb *sb)
1102 {
1103         return __le64_to_cpu(__bch2_sb_magic(sb) ^ BSET_MAGIC);
1104 }
1105
1106 /* Journal */
1107
1108 #define JSET_KEYS_U64s  (sizeof(struct jset_entry) / sizeof(__u64))
1109
1110 #define BCH_JSET_ENTRY_TYPES()                  \
1111         x(btree_keys,           0)              \
1112         x(btree_root,           1)              \
1113         x(prio_ptrs,            2)              \
1114         x(blacklist,            3)              \
1115         x(blacklist_v2,         4)              \
1116         x(usage,                5)              \
1117         x(data_usage,           6)              \
1118         x(clock,                7)              \
1119         x(dev_usage,            8)              \
1120         x(log,                  9)              \
1121         x(overwrite,            10)             \
1122         x(write_buffer_keys,    11)             \
1123         x(datetime,             12)
1124
1125 enum bch_jset_entry_type {
1126 #define x(f, nr)        BCH_JSET_ENTRY_##f      = nr,
1127         BCH_JSET_ENTRY_TYPES()
1128 #undef x
1129         BCH_JSET_ENTRY_NR
1130 };
1131
1132 static inline bool jset_entry_is_key(struct jset_entry *e)
1133 {
1134         switch (e->type) {
1135         case BCH_JSET_ENTRY_btree_keys:
1136         case BCH_JSET_ENTRY_btree_root:
1137         case BCH_JSET_ENTRY_write_buffer_keys:
1138                 return true;
1139         }
1140
1141         return false;
1142 }
1143
1144 /*
1145  * Journal sequence numbers can be blacklisted: bsets record the max sequence
1146  * number of all the journal entries they contain updates for, so that on
1147  * recovery we can ignore those bsets that contain index updates newer that what
1148  * made it into the journal.
1149  *
1150  * This means that we can't reuse that journal_seq - we have to skip it, and
1151  * then record that we skipped it so that the next time we crash and recover we
1152  * don't think there was a missing journal entry.
1153  */
1154 struct jset_entry_blacklist {
1155         struct jset_entry       entry;
1156         __le64                  seq;
1157 };
1158
1159 struct jset_entry_blacklist_v2 {
1160         struct jset_entry       entry;
1161         __le64                  start;
1162         __le64                  end;
1163 };
1164
1165 #define BCH_FS_USAGE_TYPES()                    \
1166         x(reserved,             0)              \
1167         x(inodes,               1)              \
1168         x(key_version,          2)
1169
1170 enum bch_fs_usage_type {
1171 #define x(f, nr)        BCH_FS_USAGE_##f        = nr,
1172         BCH_FS_USAGE_TYPES()
1173 #undef x
1174         BCH_FS_USAGE_NR
1175 };
1176
1177 struct jset_entry_usage {
1178         struct jset_entry       entry;
1179         __le64                  v;
1180 } __packed;
1181
1182 struct jset_entry_data_usage {
1183         struct jset_entry       entry;
1184         __le64                  v;
1185         struct bch_replicas_entry_v1 r;
1186 } __packed;
1187
1188 struct jset_entry_clock {
1189         struct jset_entry       entry;
1190         __u8                    rw;
1191         __u8                    pad[7];
1192         __le64                  time;
1193 } __packed;
1194
1195 struct jset_entry_dev_usage_type {
1196         __le64                  buckets;
1197         __le64                  sectors;
1198         __le64                  fragmented;
1199 } __packed;
1200
1201 struct jset_entry_dev_usage {
1202         struct jset_entry       entry;
1203         __le32                  dev;
1204         __u32                   pad;
1205
1206         __le64                  _buckets_ec;            /* No longer used */
1207         __le64                  _buckets_unavailable;   /* No longer used */
1208
1209         struct jset_entry_dev_usage_type d[];
1210 };
1211
1212 static inline unsigned jset_entry_dev_usage_nr_types(struct jset_entry_dev_usage *u)
1213 {
1214         return (vstruct_bytes(&u->entry) - sizeof(struct jset_entry_dev_usage)) /
1215                 sizeof(struct jset_entry_dev_usage_type);
1216 }
1217
1218 struct jset_entry_log {
1219         struct jset_entry       entry;
1220         u8                      d[];
1221 } __packed __aligned(8);
1222
1223 struct jset_entry_datetime {
1224         struct jset_entry       entry;
1225         __le64                  seconds;
1226 } __packed __aligned(8);
1227
1228 /*
1229  * On disk format for a journal entry:
1230  * seq is monotonically increasing; every journal entry has its own unique
1231  * sequence number.
1232  *
1233  * last_seq is the oldest journal entry that still has keys the btree hasn't
1234  * flushed to disk yet.
1235  *
1236  * version is for on disk format changes.
1237  */
1238 struct jset {
1239         struct bch_csum         csum;
1240
1241         __le64                  magic;
1242         __le64                  seq;
1243         __le32                  version;
1244         __le32                  flags;
1245
1246         __le32                  u64s; /* size of d[] in u64s */
1247
1248         __u8                    encrypted_start[0];
1249
1250         __le16                  _read_clock; /* no longer used */
1251         __le16                  _write_clock;
1252
1253         /* Sequence number of oldest dirty journal entry */
1254         __le64                  last_seq;
1255
1256
1257         struct jset_entry       start[0];
1258         __u64                   _data[];
1259 } __packed __aligned(8);
1260
1261 LE32_BITMASK(JSET_CSUM_TYPE,    struct jset, flags, 0, 4);
1262 LE32_BITMASK(JSET_BIG_ENDIAN,   struct jset, flags, 4, 5);
1263 LE32_BITMASK(JSET_NO_FLUSH,     struct jset, flags, 5, 6);
1264
1265 #define BCH_JOURNAL_BUCKETS_MIN         8
1266
1267 /* Btree: */
1268
1269 enum btree_id_flags {
1270         BTREE_ID_EXTENTS        = BIT(0),
1271         BTREE_ID_SNAPSHOTS      = BIT(1),
1272         BTREE_ID_SNAPSHOT_FIELD = BIT(2),
1273         BTREE_ID_DATA           = BIT(3),
1274 };
1275
1276 #define BCH_BTREE_IDS()                                                         \
1277         x(extents,              0,      BTREE_ID_EXTENTS|BTREE_ID_SNAPSHOTS|BTREE_ID_DATA,\
1278           BIT_ULL(KEY_TYPE_whiteout)|                                           \
1279           BIT_ULL(KEY_TYPE_error)|                                              \
1280           BIT_ULL(KEY_TYPE_cookie)|                                             \
1281           BIT_ULL(KEY_TYPE_extent)|                                             \
1282           BIT_ULL(KEY_TYPE_reservation)|                                        \
1283           BIT_ULL(KEY_TYPE_reflink_p)|                                          \
1284           BIT_ULL(KEY_TYPE_inline_data))                                        \
1285         x(inodes,               1,      BTREE_ID_SNAPSHOTS,                     \
1286           BIT_ULL(KEY_TYPE_whiteout)|                                           \
1287           BIT_ULL(KEY_TYPE_inode)|                                              \
1288           BIT_ULL(KEY_TYPE_inode_v2)|                                           \
1289           BIT_ULL(KEY_TYPE_inode_v3)|                                           \
1290           BIT_ULL(KEY_TYPE_inode_generation))                                   \
1291         x(dirents,              2,      BTREE_ID_SNAPSHOTS,                     \
1292           BIT_ULL(KEY_TYPE_whiteout)|                                           \
1293           BIT_ULL(KEY_TYPE_hash_whiteout)|                                      \
1294           BIT_ULL(KEY_TYPE_dirent))                                             \
1295         x(xattrs,               3,      BTREE_ID_SNAPSHOTS,                     \
1296           BIT_ULL(KEY_TYPE_whiteout)|                                           \
1297           BIT_ULL(KEY_TYPE_cookie)|                                             \
1298           BIT_ULL(KEY_TYPE_hash_whiteout)|                                      \
1299           BIT_ULL(KEY_TYPE_xattr))                                              \
1300         x(alloc,                4,      0,                                      \
1301           BIT_ULL(KEY_TYPE_alloc)|                                              \
1302           BIT_ULL(KEY_TYPE_alloc_v2)|                                           \
1303           BIT_ULL(KEY_TYPE_alloc_v3)|                                           \
1304           BIT_ULL(KEY_TYPE_alloc_v4))                                           \
1305         x(quotas,               5,      0,                                      \
1306           BIT_ULL(KEY_TYPE_quota))                                              \
1307         x(stripes,              6,      0,                                      \
1308           BIT_ULL(KEY_TYPE_stripe))                                             \
1309         x(reflink,              7,      BTREE_ID_EXTENTS|BTREE_ID_DATA,         \
1310           BIT_ULL(KEY_TYPE_reflink_v)|                                          \
1311           BIT_ULL(KEY_TYPE_indirect_inline_data)|                               \
1312           BIT_ULL(KEY_TYPE_error))                                              \
1313         x(subvolumes,           8,      0,                                      \
1314           BIT_ULL(KEY_TYPE_subvolume))                                          \
1315         x(snapshots,            9,      0,                                      \
1316           BIT_ULL(KEY_TYPE_snapshot))                                           \
1317         x(lru,                  10,     0,                                      \
1318           BIT_ULL(KEY_TYPE_set))                                                \
1319         x(freespace,            11,     BTREE_ID_EXTENTS,                       \
1320           BIT_ULL(KEY_TYPE_set))                                                \
1321         x(need_discard,         12,     0,                                      \
1322           BIT_ULL(KEY_TYPE_set))                                                \
1323         x(backpointers,         13,     0,                                      \
1324           BIT_ULL(KEY_TYPE_backpointer))                                        \
1325         x(bucket_gens,          14,     0,                                      \
1326           BIT_ULL(KEY_TYPE_bucket_gens))                                        \
1327         x(snapshot_trees,       15,     0,                                      \
1328           BIT_ULL(KEY_TYPE_snapshot_tree))                                      \
1329         x(deleted_inodes,       16,     BTREE_ID_SNAPSHOT_FIELD,                \
1330           BIT_ULL(KEY_TYPE_set))                                                \
1331         x(logged_ops,           17,     0,                                      \
1332           BIT_ULL(KEY_TYPE_logged_op_truncate)|                                 \
1333           BIT_ULL(KEY_TYPE_logged_op_finsert))                                  \
1334         x(rebalance_work,       18,     BTREE_ID_SNAPSHOT_FIELD,                \
1335           BIT_ULL(KEY_TYPE_set)|BIT_ULL(KEY_TYPE_cookie))                       \
1336         x(subvolume_children,   19,     0,                                      \
1337           BIT_ULL(KEY_TYPE_set))                                                \
1338         x(accounting,           20,     BTREE_ID_SNAPSHOT_FIELD,                \
1339           BIT_ULL(KEY_TYPE_accounting))                                         \
1340
1341 enum btree_id {
1342 #define x(name, nr, ...) BTREE_ID_##name = nr,
1343         BCH_BTREE_IDS()
1344 #undef x
1345         BTREE_ID_NR
1346 };
1347
1348 /*
1349  * Maximum number of btrees that we will _ever_ have under the current scheme,
1350  * where we refer to them with 64 bit bitfields - and we also need a bit for
1351  * the interior btree node type:
1352  */
1353 #define BTREE_ID_NR_MAX         63
1354
1355 static inline bool btree_id_is_alloc(enum btree_id id)
1356 {
1357         switch (id) {
1358         case BTREE_ID_alloc:
1359         case BTREE_ID_backpointers:
1360         case BTREE_ID_need_discard:
1361         case BTREE_ID_freespace:
1362         case BTREE_ID_bucket_gens:
1363                 return true;
1364         default:
1365                 return false;
1366         }
1367 }
1368
1369 #define BTREE_MAX_DEPTH         4U
1370
1371 /* Btree nodes */
1372
1373 /*
1374  * Btree nodes
1375  *
1376  * On disk a btree node is a list/log of these; within each set the keys are
1377  * sorted
1378  */
1379 struct bset {
1380         __le64                  seq;
1381
1382         /*
1383          * Highest journal entry this bset contains keys for.
1384          * If on recovery we don't see that journal entry, this bset is ignored:
1385          * this allows us to preserve the order of all index updates after a
1386          * crash, since the journal records a total order of all index updates
1387          * and anything that didn't make it to the journal doesn't get used.
1388          */
1389         __le64                  journal_seq;
1390
1391         __le32                  flags;
1392         __le16                  version;
1393         __le16                  u64s; /* count of d[] in u64s */
1394
1395         struct bkey_packed      start[0];
1396         __u64                   _data[];
1397 } __packed __aligned(8);
1398
1399 LE32_BITMASK(BSET_CSUM_TYPE,    struct bset, flags, 0, 4);
1400
1401 LE32_BITMASK(BSET_BIG_ENDIAN,   struct bset, flags, 4, 5);
1402 LE32_BITMASK(BSET_SEPARATE_WHITEOUTS,
1403                                 struct bset, flags, 5, 6);
1404
1405 /* Sector offset within the btree node: */
1406 LE32_BITMASK(BSET_OFFSET,       struct bset, flags, 16, 32);
1407
1408 struct btree_node {
1409         struct bch_csum         csum;
1410         __le64                  magic;
1411
1412         /* this flags field is encrypted, unlike bset->flags: */
1413         __le64                  flags;
1414
1415         /* Closed interval: */
1416         struct bpos             min_key;
1417         struct bpos             max_key;
1418         struct bch_extent_ptr   _ptr; /* not used anymore */
1419         struct bkey_format      format;
1420
1421         union {
1422         struct bset             keys;
1423         struct {
1424                 __u8            pad[22];
1425                 __le16          u64s;
1426                 __u64           _data[0];
1427
1428         };
1429         };
1430 } __packed __aligned(8);
1431
1432 LE64_BITMASK(BTREE_NODE_ID_LO,  struct btree_node, flags,  0,  4);
1433 LE64_BITMASK(BTREE_NODE_LEVEL,  struct btree_node, flags,  4,  8);
1434 LE64_BITMASK(BTREE_NODE_NEW_EXTENT_OVERWRITE,
1435                                 struct btree_node, flags,  8,  9);
1436 LE64_BITMASK(BTREE_NODE_ID_HI,  struct btree_node, flags,  9, 25);
1437 /* 25-32 unused */
1438 LE64_BITMASK(BTREE_NODE_SEQ,    struct btree_node, flags, 32, 64);
1439
1440 static inline __u64 BTREE_NODE_ID(struct btree_node *n)
1441 {
1442         return BTREE_NODE_ID_LO(n) | (BTREE_NODE_ID_HI(n) << 4);
1443 }
1444
1445 static inline void SET_BTREE_NODE_ID(struct btree_node *n, __u64 v)
1446 {
1447         SET_BTREE_NODE_ID_LO(n, v);
1448         SET_BTREE_NODE_ID_HI(n, v >> 4);
1449 }
1450
1451 struct btree_node_entry {
1452         struct bch_csum         csum;
1453
1454         union {
1455         struct bset             keys;
1456         struct {
1457                 __u8            pad[22];
1458                 __le16          u64s;
1459                 __u64           _data[0];
1460         };
1461         };
1462 } __packed __aligned(8);
1463
1464 #endif /* _BCACHEFS_FORMAT_H */