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 #define BITMASK(name, type, field, offset, end)                         \
  82 static const unsigned   name##_OFFSET = offset;                         \
  83 static const unsigned   name##_BITS = (end - offset);                   \
  84                                                                         \
  85 static inline __u64 name(const type *k)                                 \
  86 {                                                                       \
  87         return (k->field >> offset) & ~(~0ULL << (end - offset));       \
  88 }                                                                       \
  89                                                                         \
  90 static inline void SET_##name(type *k, __u64 v)                         \
  91 {                                                                       \
  92         k->field &= ~(~(~0ULL << (end - offset)) << offset);            \
  93         k->field |= (v & ~(~0ULL << (end - offset))) << offset;         \
  94 }
  95
  96 #define LE_BITMASK(_bits, name, type, field, offset, end)               \
  97 static const unsigned   name##_OFFSET = offset;                         \
  98 static const unsigned   name##_BITS = (end - offset);                   \
  99 static const __u##_bits name##_MAX = (1ULL << (end - offset)) - 1;      \
 100                                                                         \
 101 static inline __u64 name(const type *k)                                 \
 102 {                                                                       \
 103         return (__le##_bits##_to_cpu(k->field) >> offset) &             \
 104                 ~(~0ULL << (end - offset));                             \
 105 }                                                                       \
 106                                                                         \
 107 static inline void SET_##name(type *k, __u64 v)                         \
 108 {                                                                       \
 109         __u##_bits new = __le##_bits##_to_cpu(k->field);                \
 110                                                                         \
 111         new &= ~(~(~0ULL << (end - offset)) << offset);                 \
 112         new |= (v & ~(~0ULL << (end - offset))) << offset;              \
 113         k->field = __cpu_to_le##_bits(new);                             \
 114 }
 115
 116 #define LE16_BITMASK(n, t, f, o, e)     LE_BITMASK(16, n, t, f, o, e)
 117 #define LE32_BITMASK(n, t, f, o, e)     LE_BITMASK(32, n, t, f, o, e)
 118 #define LE64_BITMASK(n, t, f, o, e)     LE_BITMASK(64, n, t, f, o, e)
 119
 120 struct bkey_format {
 121         __u8            key_u64s;
 122         __u8            nr_fields;
 123         /* One unused slot for now: */
 124         __u8            bits_per_field[6];
 125         __le64          field_offset[6];
 126 };
 127
 128 /* Btree keys - all units are in sectors */
 129
 130 struct bpos {
 131         /*
 132          * Word order matches machine byte order - btree code treats a bpos as a
 133          * single large integer, for search/comparison purposes
 134          *
 135          * Note that wherever a bpos is embedded in another on disk data
 136          * structure, it has to be byte swabbed when reading in metadata that
 137          * wasn't written in native endian order:
 138          */
 139 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 140         __u32           snapshot;
 141         __u64           offset;
 142         __u64           inode;
 143 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 144         __u64           inode;
 145         __u64           offset;         /* Points to end of extent - sectors */
 146         __u32           snapshot;
 147 #else
 148 #error edit for your odd byteorder.
 149 #endif
 150 } __packed __aligned(4);
 151
 152 #define KEY_INODE_MAX                   ((__u64)~0ULL)
 153 #define KEY_OFFSET_MAX                  ((__u64)~0ULL)
 154 #define KEY_SNAPSHOT_MAX                ((__u32)~0U)
 155 #define KEY_SIZE_MAX                    ((__u32)~0U)
 156
 157 static inline struct bpos SPOS(__u64 inode, __u64 offset, __u32 snapshot)
 158 {
 159         return (struct bpos) {
 160                 .inode          = inode,
 161                 .offset         = offset,
 162                 .snapshot       = snapshot,
 163         };
 164 }
 165
 166 #define POS_MIN                         SPOS(0, 0, 0)
 167 #define POS_MAX                         SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, 0)
 168 #define SPOS_MAX                        SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, KEY_SNAPSHOT_MAX)
 169 #define POS(_inode, _offset)            SPOS(_inode, _offset, 0)
 170
 171 /* Empty placeholder struct, for container_of() */
 172 struct bch_val {
 173         __u64           __nothing[0];
 174 };
 175
 176 struct bversion {
 177 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 178         __u64           lo;
 179         __u32           hi;
 180 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 181         __u32           hi;
 182         __u64           lo;
 183 #endif
 184 } __packed __aligned(4);
 185
 186 struct bkey {
 187         /* Size of combined key and value, in u64s */
 188         __u8            u64s;
 189
 190         /* Format of key (0 for format local to btree node) */
 191 #if defined(__LITTLE_ENDIAN_BITFIELD)
 192         __u8            format:7,
 193                         needs_whiteout:1;
 194 #elif defined (__BIG_ENDIAN_BITFIELD)
 195         __u8            needs_whiteout:1,
 196                         format:7;
 197 #else
 198 #error edit for your odd byteorder.
 199 #endif
 200
 201         /* Type of the value */
 202         __u8            type;
 203
 204 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 205         __u8            pad[1];
 206
 207         struct bversion version;
 208         __u32           size;           /* extent size, in sectors */
 209         struct bpos     p;
 210 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 211         struct bpos     p;
 212         __u32           size;           /* extent size, in sectors */
 213         struct bversion version;
 214
 215         __u8            pad[1];
 216 #endif
 217 } __packed __aligned(8);
 218
 219 struct bkey_packed {
 220         __u64           _data[0];
 221
 222         /* Size of combined key and value, in u64s */
 223         __u8            u64s;
 224
 225         /* Format of key (0 for format local to btree node) */
 226
 227         /*
 228          * XXX: next incompat on disk format change, switch format and
 229          * needs_whiteout - bkey_packed() will be cheaper if format is the high
 230          * bits of the bitfield
 231          */
 232 #if defined(__LITTLE_ENDIAN_BITFIELD)
 233         __u8            format:7,
 234                         needs_whiteout:1;
 235 #elif defined (__BIG_ENDIAN_BITFIELD)
 236         __u8            needs_whiteout:1,
 237                         format:7;
 238 #endif
 239
 240         /* Type of the value */
 241         __u8            type;
 242         __u8            key_start[0];
 243
 244         /*
 245          * We copy bkeys with struct assignment in various places, and while
 246          * that shouldn't be done with packed bkeys we can't disallow it in C,
 247          * and it's legal to cast a bkey to a bkey_packed  - so padding it out
 248          * to the same size as struct bkey should hopefully be safest.
 249          */
 250         __u8            pad[sizeof(struct bkey) - 3];
 251 } __packed __aligned(8);
 252
 253 typedef struct {
 254         __le64                  lo;
 255         __le64                  hi;
 256 } bch_le128;
 257
 258 #define BKEY_U64s                       (sizeof(struct bkey) / sizeof(__u64))
 259 #define BKEY_U64s_MAX                   U8_MAX
 260 #define BKEY_VAL_U64s_MAX               (BKEY_U64s_MAX - BKEY_U64s)
 261
 262 #define KEY_PACKED_BITS_START           24
 263
 264 #define KEY_FORMAT_LOCAL_BTREE          0
 265 #define KEY_FORMAT_CURRENT              1
 266
 267 enum bch_bkey_fields {
 268         BKEY_FIELD_INODE,
 269         BKEY_FIELD_OFFSET,
 270         BKEY_FIELD_SNAPSHOT,
 271         BKEY_FIELD_SIZE,
 272         BKEY_FIELD_VERSION_HI,
 273         BKEY_FIELD_VERSION_LO,
 274         BKEY_NR_FIELDS,
 275 };
 276
 277 #define bkey_format_field(name, field)                                  \
 278         [BKEY_FIELD_##name] = (sizeof(((struct bkey *) NULL)->field) * 8)
 279
 280 #define BKEY_FORMAT_CURRENT                                             \
 281 ((struct bkey_format) {                                                 \
 282         .key_u64s       = BKEY_U64s,                                    \
 283         .nr_fields      = BKEY_NR_FIELDS,                               \
 284         .bits_per_field = {                                             \
 285                 bkey_format_field(INODE,        p.inode),               \
 286                 bkey_format_field(OFFSET,       p.offset),              \
 287                 bkey_format_field(SNAPSHOT,     p.snapshot),            \
 288                 bkey_format_field(SIZE,         size),                  \
 289                 bkey_format_field(VERSION_HI,   version.hi),            \
 290                 bkey_format_field(VERSION_LO,   version.lo),            \
 291         },                                                              \
 292 })
 293
 294 /* bkey with inline value */
 295 struct bkey_i {
 296         __u64                   _data[0];
 297
 298         struct bkey     k;
 299         struct bch_val  v;
 300 };
 301
 302 #define KEY(_inode, _offset, _size)                                     \
 303 ((struct bkey) {                                                        \
 304         .u64s           = BKEY_U64s,                                    \
 305         .format         = KEY_FORMAT_CURRENT,                           \
 306         .p              = POS(_inode, _offset),                         \
 307         .size           = _size,                                        \
 308 })
 309
 310 static inline void bkey_init(struct bkey *k)
 311 {
 312         *k = KEY(0, 0, 0);
 313 }
 314
 315 #define bkey_bytes(_k)          ((_k)->u64s * sizeof(__u64))
 316
 317 #define __BKEY_PADDED(key, pad)                                 \
 318         struct bkey_i key; __u64 key ## _pad[pad]
 319
 320 /*
 321  * - DELETED keys are used internally to mark keys that should be ignored but
 322  *   override keys in composition order.  Their version number is ignored.
 323  *
 324  * - DISCARDED keys indicate that the data is all 0s because it has been
 325  *   discarded. DISCARDs may have a version; if the version is nonzero the key
 326  *   will be persistent, otherwise the key will be dropped whenever the btree
 327  *   node is rewritten (like DELETED keys).
 328  *
 329  * - ERROR: any read of the data returns a read error, as the data was lost due
 330  *   to a failing device. Like DISCARDED keys, they can be removed (overridden)
 331  *   by new writes or cluster-wide GC. Node repair can also overwrite them with
 332  *   the same or a more recent version number, but not with an older version
 333  *   number.
 334  *
 335  * - WHITEOUT: for hash table btrees
 336  */
 337 #define BCH_BKEY_TYPES()                                \
 338         x(deleted,              0)                      \
 339         x(whiteout,             1)                      \
 340         x(error,                2)                      \
 341         x(cookie,               3)                      \
 342         x(hash_whiteout,        4)                      \
 343         x(btree_ptr,            5)                      \
 344         x(extent,               6)                      \
 345         x(reservation,          7)                      \
 346         x(inode,                8)                      \
 347         x(inode_generation,     9)                      \
 348         x(dirent,               10)                     \
 349         x(xattr,                11)                     \
 350         x(alloc,                12)                     \
 351         x(quota,                13)                     \
 352         x(stripe,               14)                     \
 353         x(reflink_p,            15)                     \
 354         x(reflink_v,            16)                     \
 355         x(inline_data,          17)                     \
 356         x(btree_ptr_v2,         18)                     \
 357         x(indirect_inline_data, 19)                     \
 358         x(alloc_v2,             20)                     \
 359         x(subvolume,            21)                     \
 360         x(snapshot,             22)                     \
 361         x(inode_v2,             23)                     \
 362         x(alloc_v3,             24)                     \
 363         x(set,                  25)                     \
 364         x(lru,                  26)                     \
 365         x(alloc_v4,             27)                     \
 366         x(backpointer,          28)                     \
 367         x(inode_v3,             29)                     \
 368         x(bucket_gens,          30)                     \
 369         x(snapshot_tree,        31)
 370
 371 enum bch_bkey_type {
 372 #define x(name, nr) KEY_TYPE_##name     = nr,
 373         BCH_BKEY_TYPES()
 374 #undef x
 375         KEY_TYPE_MAX,
 376 };
 377
 378 struct bch_deleted {
 379         struct bch_val          v;
 380 };
 381
 382 struct bch_whiteout {
 383         struct bch_val          v;
 384 };
 385
 386 struct bch_error {
 387         struct bch_val          v;
 388 };
 389
 390 struct bch_cookie {
 391         struct bch_val          v;
 392         __le64                  cookie;
 393 };
 394
 395 struct bch_hash_whiteout {
 396         struct bch_val          v;
 397 };
 398
 399 struct bch_set {
 400         struct bch_val          v;
 401 };
 402
 403 /* Extents */
 404
 405 /*
 406  * In extent bkeys, the value is a list of pointers (bch_extent_ptr), optionally
 407  * preceded by checksum/compression information (bch_extent_crc32 or
 408  * bch_extent_crc64).
 409  *
 410  * One major determining factor in the format of extents is how we handle and
 411  * represent extents that have been partially overwritten and thus trimmed:
 412  *
 413  * If an extent is not checksummed or compressed, when the extent is trimmed we
 414  * don't have to remember the extent we originally allocated and wrote: we can
 415  * merely adjust ptr->offset to point to the start of the data that is currently
 416  * live. The size field in struct bkey records the current (live) size of the
 417  * extent, and is also used to mean "size of region on disk that we point to" in
 418  * this case.
 419  *
 420  * Thus an extent that is not checksummed or compressed will consist only of a
 421  * list of bch_extent_ptrs, with none of the fields in
 422  * bch_extent_crc32/bch_extent_crc64.
 423  *
 424  * When an extent is checksummed or compressed, it's not possible to read only
 425  * the data that is currently live: we have to read the entire extent that was
 426  * originally written, and then return only the part of the extent that is
 427  * currently live.
 428  *
 429  * Thus, in addition to the current size of the extent in struct bkey, we need
 430  * to store the size of the originally allocated space - this is the
 431  * compressed_size and uncompressed_size fields in bch_extent_crc32/64. Also,
 432  * when the extent is trimmed, instead of modifying the offset field of the
 433  * pointer, we keep a second smaller offset field - "offset into the original
 434  * extent of the currently live region".
 435  *
 436  * The other major determining factor is replication and data migration:
 437  *
 438  * Each pointer may have its own bch_extent_crc32/64. When doing a replicated
 439  * write, we will initially write all the replicas in the same format, with the
 440  * same checksum type and compression format - however, when copygc runs later (or
 441  * tiering/cache promotion, anything that moves data), it is not in general
 442  * going to rewrite all the pointers at once - one of the replicas may be in a
 443  * bucket on one device that has very little fragmentation while another lives
 444  * in a bucket that has become heavily fragmented, and thus is being rewritten
 445  * sooner than the rest.
 446  *
 447  * Thus it will only move a subset of the pointers (or in the case of
 448  * tiering/cache promotion perhaps add a single pointer without dropping any
 449  * current pointers), and if the extent has been partially overwritten it must
 450  * write only the currently live portion (or copygc would not be able to reduce
 451  * fragmentation!) - which necessitates a different bch_extent_crc format for
 452  * the new pointer.
 453  *
 454  * But in the interests of space efficiency, we don't want to store one
 455  * bch_extent_crc for each pointer if we don't have to.
 456  *
 457  * Thus, a bch_extent consists of bch_extent_crc32s, bch_extent_crc64s, and
 458  * bch_extent_ptrs appended arbitrarily one after the other. We determine the
 459  * type of a given entry with a scheme similar to utf8 (except we're encoding a
 460  * type, not a size), encoding the type in the position of the first set bit:
 461  *
 462  * bch_extent_crc32     - 0b1
 463  * bch_extent_ptr       - 0b10
 464  * bch_extent_crc64     - 0b100
 465  *
 466  * We do it this way because bch_extent_crc32 is _very_ constrained on bits (and
 467  * bch_extent_crc64 is the least constrained).
 468  *
 469  * Then, each bch_extent_crc32/64 applies to the pointers that follow after it,
 470  * until the next bch_extent_crc32/64.
 471  *
 472  * If there are no bch_extent_crcs preceding a bch_extent_ptr, then that pointer
 473  * is neither checksummed nor compressed.
 474  */
 475
 476 /* 128 bits, sufficient for cryptographic MACs: */
 477 struct bch_csum {
 478         __le64                  lo;
 479         __le64                  hi;
 480 } __packed __aligned(8);
 481
 482 #define BCH_EXTENT_ENTRY_TYPES()                \
 483         x(ptr,                  0)              \
 484         x(crc32,                1)              \
 485         x(crc64,                2)              \
 486         x(crc128,               3)              \
 487         x(stripe_ptr,           4)
 488 #define BCH_EXTENT_ENTRY_MAX    5
 489
 490 enum bch_extent_entry_type {
 491 #define x(f, n) BCH_EXTENT_ENTRY_##f = n,
 492         BCH_EXTENT_ENTRY_TYPES()
 493 #undef x
 494 };
 495
 496 /* Compressed/uncompressed size are stored biased by 1: */
 497 struct bch_extent_crc32 {
 498 #if defined(__LITTLE_ENDIAN_BITFIELD)
 499         __u32                   type:2,
 500                                 _compressed_size:7,
 501                                 _uncompressed_size:7,
 502                                 offset:7,
 503                                 _unused:1,
 504                                 csum_type:4,
 505                                 compression_type:4;
 506         __u32                   csum;
 507 #elif defined (__BIG_ENDIAN_BITFIELD)
 508         __u32                   csum;
 509         __u32                   compression_type:4,
 510                                 csum_type:4,
 511                                 _unused:1,
 512                                 offset:7,
 513                                 _uncompressed_size:7,
 514                                 _compressed_size:7,
 515                                 type:2;
 516 #endif
 517 } __packed __aligned(8);
 518
 519 #define CRC32_SIZE_MAX          (1U << 7)
 520 #define CRC32_NONCE_MAX         0
 521
 522 struct bch_extent_crc64 {
 523 #if defined(__LITTLE_ENDIAN_BITFIELD)
 524         __u64                   type:3,
 525                                 _compressed_size:9,
 526                                 _uncompressed_size:9,
 527                                 offset:9,
 528                                 nonce:10,
 529                                 csum_type:4,
 530                                 compression_type:4,
 531                                 csum_hi:16;
 532 #elif defined (__BIG_ENDIAN_BITFIELD)
 533         __u64                   csum_hi:16,
 534                                 compression_type:4,
 535                                 csum_type:4,
 536                                 nonce:10,
 537                                 offset:9,
 538                                 _uncompressed_size:9,
 539                                 _compressed_size:9,
 540                                 type:3;
 541 #endif
 542         __u64                   csum_lo;
 543 } __packed __aligned(8);
 544
 545 #define CRC64_SIZE_MAX          (1U << 9)
 546 #define CRC64_NONCE_MAX         ((1U << 10) - 1)
 547
 548 struct bch_extent_crc128 {
 549 #if defined(__LITTLE_ENDIAN_BITFIELD)
 550         __u64                   type:4,
 551                                 _compressed_size:13,
 552                                 _uncompressed_size:13,
 553                                 offset:13,
 554                                 nonce:13,
 555                                 csum_type:4,
 556                                 compression_type:4;
 557 #elif defined (__BIG_ENDIAN_BITFIELD)
 558         __u64                   compression_type:4,
 559                                 csum_type:4,
 560                                 nonce:13,
 561                                 offset:13,
 562                                 _uncompressed_size:13,
 563                                 _compressed_size:13,
 564                                 type:4;
 565 #endif
 566         struct bch_csum         csum;
 567 } __packed __aligned(8);
 568
 569 #define CRC128_SIZE_MAX         (1U << 13)
 570 #define CRC128_NONCE_MAX        ((1U << 13) - 1)
 571
 572 /*
 573  * @reservation - pointer hasn't been written to, just reserved
 574  */
 575 struct bch_extent_ptr {
 576 #if defined(__LITTLE_ENDIAN_BITFIELD)
 577         __u64                   type:1,
 578                                 cached:1,
 579                                 unused:1,
 580                                 unwritten:1,
 581                                 offset:44, /* 8 petabytes */
 582                                 dev:8,
 583                                 gen:8;
 584 #elif defined (__BIG_ENDIAN_BITFIELD)
 585         __u64                   gen:8,
 586                                 dev:8,
 587                                 offset:44,
 588                                 unwritten:1,
 589                                 unused:1,
 590                                 cached:1,
 591                                 type:1;
 592 #endif
 593 } __packed __aligned(8);
 594
 595 struct bch_extent_stripe_ptr {
 596 #if defined(__LITTLE_ENDIAN_BITFIELD)
 597         __u64                   type:5,
 598                                 block:8,
 599                                 redundancy:4,
 600                                 idx:47;
 601 #elif defined (__BIG_ENDIAN_BITFIELD)
 602         __u64                   idx:47,
 603                                 redundancy:4,
 604                                 block:8,
 605                                 type:5;
 606 #endif
 607 };
 608
 609 struct bch_extent_reservation {
 610 #if defined(__LITTLE_ENDIAN_BITFIELD)
 611         __u64                   type:6,
 612                                 unused:22,
 613                                 replicas:4,
 614                                 generation:32;
 615 #elif defined (__BIG_ENDIAN_BITFIELD)
 616         __u64                   generation:32,
 617                                 replicas:4,
 618                                 unused:22,
 619                                 type:6;
 620 #endif
 621 };
 622
 623 union bch_extent_entry {
 624 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ ||  __BITS_PER_LONG == 64
 625         unsigned long                   type;
 626 #elif __BITS_PER_LONG == 32
 627         struct {
 628                 unsigned long           pad;
 629                 unsigned long           type;
 630         };
 631 #else
 632 #error edit for your odd byteorder.
 633 #endif
 634
 635 #define x(f, n) struct bch_extent_##f   f;
 636         BCH_EXTENT_ENTRY_TYPES()
 637 #undef x
 638 };
 639
 640 struct bch_btree_ptr {
 641         struct bch_val          v;
 642
 643         __u64                   _data[0];
 644         struct bch_extent_ptr   start[];
 645 } __packed __aligned(8);
 646
 647 struct bch_btree_ptr_v2 {
 648         struct bch_val          v;
 649
 650         __u64                   mem_ptr;
 651         __le64                  seq;
 652         __le16                  sectors_written;
 653         __le16                  flags;
 654         struct bpos             min_key;
 655         __u64                   _data[0];
 656         struct bch_extent_ptr   start[];
 657 } __packed __aligned(8);
 658
 659 LE16_BITMASK(BTREE_PTR_RANGE_UPDATED,   struct bch_btree_ptr_v2, flags, 0, 1);
 660
 661 struct bch_extent {
 662         struct bch_val          v;
 663
 664         __u64                   _data[0];
 665         union bch_extent_entry  start[];
 666 } __packed __aligned(8);
 667
 668 struct bch_reservation {
 669         struct bch_val          v;
 670
 671         __le32                  generation;
 672         __u8                    nr_replicas;
 673         __u8                    pad[3];
 674 } __packed __aligned(8);
 675
 676 /* Maximum size (in u64s) a single pointer could be: */
 677 #define BKEY_EXTENT_PTR_U64s_MAX\
 678         ((sizeof(struct bch_extent_crc128) +                    \
 679           sizeof(struct bch_extent_ptr)) / sizeof(u64))
 680
 681 /* Maximum possible size of an entire extent value: */
 682 #define BKEY_EXTENT_VAL_U64s_MAX                                \
 683         (1 + BKEY_EXTENT_PTR_U64s_MAX * (BCH_REPLICAS_MAX + 1))
 684
 685 /* * Maximum possible size of an entire extent, key + value: */
 686 #define BKEY_EXTENT_U64s_MAX            (BKEY_U64s + BKEY_EXTENT_VAL_U64s_MAX)
 687
 688 /* Btree pointers don't carry around checksums: */
 689 #define BKEY_BTREE_PTR_VAL_U64s_MAX                             \
 690         ((sizeof(struct bch_btree_ptr_v2) +                     \
 691           sizeof(struct bch_extent_ptr) * BCH_REPLICAS_MAX) / sizeof(u64))
 692 #define BKEY_BTREE_PTR_U64s_MAX                                 \
 693         (BKEY_U64s + BKEY_BTREE_PTR_VAL_U64s_MAX)
 694
 695 /* Inodes */
 696
 697 #define BLOCKDEV_INODE_MAX      4096
 698
 699 #define BCACHEFS_ROOT_INO       4096
 700
 701 struct bch_inode {
 702         struct bch_val          v;
 703
 704         __le64                  bi_hash_seed;
 705         __le32                  bi_flags;
 706         __le16                  bi_mode;
 707         __u8                    fields[0];
 708 } __packed __aligned(8);
 709
 710 struct bch_inode_v2 {
 711         struct bch_val          v;
 712
 713         __le64                  bi_journal_seq;
 714         __le64                  bi_hash_seed;
 715         __le64                  bi_flags;
 716         __le16                  bi_mode;
 717         __u8                    fields[0];
 718 } __packed __aligned(8);
 719
 720 struct bch_inode_v3 {
 721         struct bch_val          v;
 722
 723         __le64                  bi_journal_seq;
 724         __le64                  bi_hash_seed;
 725         __le64                  bi_flags;
 726         __le64                  bi_sectors;
 727         __le64                  bi_size;
 728         __le64                  bi_version;
 729         __u8                    fields[0];
 730 } __packed __aligned(8);
 731
 732 #define INODEv3_FIELDS_START_INITIAL    6
 733 #define INODEv3_FIELDS_START_CUR        (offsetof(struct bch_inode_v3, fields) / sizeof(u64))
 734
 735 struct bch_inode_generation {
 736         struct bch_val          v;
 737
 738         __le32                  bi_generation;
 739         __le32                  pad;
 740 } __packed __aligned(8);
 741
 742 /*
 743  * bi_subvol and bi_parent_subvol are only set for subvolume roots:
 744  */
 745
 746 #define BCH_INODE_FIELDS_v2()                   \
 747         x(bi_atime,                     96)     \
 748         x(bi_ctime,                     96)     \
 749         x(bi_mtime,                     96)     \
 750         x(bi_otime,                     96)     \
 751         x(bi_size,                      64)     \
 752         x(bi_sectors,                   64)     \
 753         x(bi_uid,                       32)     \
 754         x(bi_gid,                       32)     \
 755         x(bi_nlink,                     32)     \
 756         x(bi_generation,                32)     \
 757         x(bi_dev,                       32)     \
 758         x(bi_data_checksum,             8)      \
 759         x(bi_compression,               8)      \
 760         x(bi_project,                   32)     \
 761         x(bi_background_compression,    8)      \
 762         x(bi_data_replicas,             8)      \
 763         x(bi_promote_target,            16)     \
 764         x(bi_foreground_target,         16)     \
 765         x(bi_background_target,         16)     \
 766         x(bi_erasure_code,              16)     \
 767         x(bi_fields_set,                16)     \
 768         x(bi_dir,                       64)     \
 769         x(bi_dir_offset,                64)     \
 770         x(bi_subvol,                    32)     \
 771         x(bi_parent_subvol,             32)
 772
 773 #define BCH_INODE_FIELDS_v3()                   \
 774         x(bi_atime,                     96)     \
 775         x(bi_ctime,                     96)     \
 776         x(bi_mtime,                     96)     \
 777         x(bi_otime,                     96)     \
 778         x(bi_uid,                       32)     \
 779         x(bi_gid,                       32)     \
 780         x(bi_nlink,                     32)     \
 781         x(bi_generation,                32)     \
 782         x(bi_dev,                       32)     \
 783         x(bi_data_checksum,             8)      \
 784         x(bi_compression,               8)      \
 785         x(bi_project,                   32)     \
 786         x(bi_background_compression,    8)      \
 787         x(bi_data_replicas,             8)      \
 788         x(bi_promote_target,            16)     \
 789         x(bi_foreground_target,         16)     \
 790         x(bi_background_target,         16)     \
 791         x(bi_erasure_code,              16)     \
 792         x(bi_fields_set,                16)     \
 793         x(bi_dir,                       64)     \
 794         x(bi_dir_offset,                64)     \
 795         x(bi_subvol,                    32)     \
 796         x(bi_parent_subvol,             32)     \
 797         x(bi_nocow,                     8)
 798
 799 /* subset of BCH_INODE_FIELDS */
 800 #define BCH_INODE_OPTS()                        \
 801         x(data_checksum,                8)      \
 802         x(compression,                  8)      \
 803         x(project,                      32)     \
 804         x(background_compression,       8)      \
 805         x(data_replicas,                8)      \
 806         x(promote_target,               16)     \
 807         x(foreground_target,            16)     \
 808         x(background_target,            16)     \
 809         x(erasure_code,                 16)     \
 810         x(nocow,                        8)
 811
 812 enum inode_opt_id {
 813 #define x(name, ...)                            \
 814         Inode_opt_##name,
 815         BCH_INODE_OPTS()
 816 #undef  x
 817         Inode_opt_nr,
 818 };
 819
 820 enum {
 821         /*
 822          * User flags (get/settable with FS_IOC_*FLAGS, correspond to FS_*_FL
 823          * flags)
 824          */
 825         __BCH_INODE_SYNC                = 0,
 826         __BCH_INODE_IMMUTABLE           = 1,
 827         __BCH_INODE_APPEND              = 2,
 828         __BCH_INODE_NODUMP              = 3,
 829         __BCH_INODE_NOATIME             = 4,
 830
 831         __BCH_INODE_I_SIZE_DIRTY        = 5,
 832         __BCH_INODE_I_SECTORS_DIRTY     = 6,
 833         __BCH_INODE_UNLINKED            = 7,
 834         __BCH_INODE_BACKPTR_UNTRUSTED   = 8,
 835
 836         /* bits 20+ reserved for packed fields below: */
 837 };
 838
 839 #define BCH_INODE_SYNC          (1 << __BCH_INODE_SYNC)
 840 #define BCH_INODE_IMMUTABLE     (1 << __BCH_INODE_IMMUTABLE)
 841 #define BCH_INODE_APPEND        (1 << __BCH_INODE_APPEND)
 842 #define BCH_INODE_NODUMP        (1 << __BCH_INODE_NODUMP)
 843 #define BCH_INODE_NOATIME       (1 << __BCH_INODE_NOATIME)
 844 #define BCH_INODE_I_SIZE_DIRTY  (1 << __BCH_INODE_I_SIZE_DIRTY)
 845 #define BCH_INODE_I_SECTORS_DIRTY (1 << __BCH_INODE_I_SECTORS_DIRTY)
 846 #define BCH_INODE_UNLINKED      (1 << __BCH_INODE_UNLINKED)
 847 #define BCH_INODE_BACKPTR_UNTRUSTED (1 << __BCH_INODE_BACKPTR_UNTRUSTED)
 848
 849 LE32_BITMASK(INODE_STR_HASH,    struct bch_inode, bi_flags, 20, 24);
 850 LE32_BITMASK(INODE_NR_FIELDS,   struct bch_inode, bi_flags, 24, 31);
 851 LE32_BITMASK(INODE_NEW_VARINT,  struct bch_inode, bi_flags, 31, 32);
 852
 853 LE64_BITMASK(INODEv2_STR_HASH,  struct bch_inode_v2, bi_flags, 20, 24);
 854 LE64_BITMASK(INODEv2_NR_FIELDS, struct bch_inode_v2, bi_flags, 24, 31);
 855
 856 LE64_BITMASK(INODEv3_STR_HASH,  struct bch_inode_v3, bi_flags, 20, 24);
 857 LE64_BITMASK(INODEv3_NR_FIELDS, struct bch_inode_v3, bi_flags, 24, 31);
 858
 859 LE64_BITMASK(INODEv3_FIELDS_START,
 860                                 struct bch_inode_v3, bi_flags, 31, 36);
 861 LE64_BITMASK(INODEv3_MODE,      struct bch_inode_v3, bi_flags, 36, 52);
 862
 863 /* Dirents */
 864
 865 /*
 866  * Dirents (and xattrs) have to implement string lookups; since our b-tree
 867  * doesn't support arbitrary length strings for the key, we instead index by a
 868  * 64 bit hash (currently truncated sha1) of the string, stored in the offset
 869  * field of the key - using linear probing to resolve hash collisions. This also
 870  * provides us with the readdir cookie posix requires.
 871  *
 872  * Linear probing requires us to use whiteouts for deletions, in the event of a
 873  * collision:
 874  */
 875
 876 struct bch_dirent {
 877         struct bch_val          v;
 878
 879         /* Target inode number: */
 880         union {
 881         __le64                  d_inum;
 882         struct {                /* DT_SUBVOL */
 883         __le32                  d_child_subvol;
 884         __le32                  d_parent_subvol;
 885         };
 886         };
 887
 888         /*
 889          * Copy of mode bits 12-15 from the target inode - so userspace can get
 890          * the filetype without having to do a stat()
 891          */
 892         __u8                    d_type;
 893
 894         __u8                    d_name[];
 895 } __packed __aligned(8);
 896
 897 #define DT_SUBVOL       16
 898 #define BCH_DT_MAX      17
 899
 900 #define BCH_NAME_MAX    ((unsigned) (U8_MAX * sizeof(u64) -             \
 901                          sizeof(struct bkey) -                          \
 902                          offsetof(struct bch_dirent, d_name)))
 903
 904 /* Xattrs */
 905
 906 #define KEY_TYPE_XATTR_INDEX_USER                       0
 907 #define KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS   1
 908 #define KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT  2
 909 #define KEY_TYPE_XATTR_INDEX_TRUSTED                    3
 910 #define KEY_TYPE_XATTR_INDEX_SECURITY           4
 911
 912 struct bch_xattr {
 913         struct bch_val          v;
 914         __u8                    x_type;
 915         __u8                    x_name_len;
 916         __le16                  x_val_len;
 917         __u8                    x_name[];
 918 } __packed __aligned(8);
 919
 920 /* Bucket/allocation information: */
 921
 922 struct bch_alloc {
 923         struct bch_val          v;
 924         __u8                    fields;
 925         __u8                    gen;
 926         __u8                    data[];
 927 } __packed __aligned(8);
 928
 929 #define BCH_ALLOC_FIELDS_V1()                   \
 930         x(read_time,            16)             \
 931         x(write_time,           16)             \
 932         x(data_type,            8)              \
 933         x(dirty_sectors,        16)             \
 934         x(cached_sectors,       16)             \
 935         x(oldest_gen,           8)              \
 936         x(stripe,               32)             \
 937         x(stripe_redundancy,    8)
 938
 939 enum {
 940 #define x(name, _bits) BCH_ALLOC_FIELD_V1_##name,
 941         BCH_ALLOC_FIELDS_V1()
 942 #undef x
 943 };
 944
 945 struct bch_alloc_v2 {
 946         struct bch_val          v;
 947         __u8                    nr_fields;
 948         __u8                    gen;
 949         __u8                    oldest_gen;
 950         __u8                    data_type;
 951         __u8                    data[];
 952 } __packed __aligned(8);
 953
 954 #define BCH_ALLOC_FIELDS_V2()                   \
 955         x(read_time,            64)             \
 956         x(write_time,           64)             \
 957         x(dirty_sectors,        32)             \
 958         x(cached_sectors,       32)             \
 959         x(stripe,               32)             \
 960         x(stripe_redundancy,    8)
 961
 962 struct bch_alloc_v3 {
 963         struct bch_val          v;
 964         __le64                  journal_seq;
 965         __le32                  flags;
 966         __u8                    nr_fields;
 967         __u8                    gen;
 968         __u8                    oldest_gen;
 969         __u8                    data_type;
 970         __u8                    data[];
 971 } __packed __aligned(8);
 972
 973 LE32_BITMASK(BCH_ALLOC_V3_NEED_DISCARD,struct bch_alloc_v3, flags,  0,  1)
 974 LE32_BITMASK(BCH_ALLOC_V3_NEED_INC_GEN,struct bch_alloc_v3, flags,  1,  2)
 975
 976 struct bch_alloc_v4 {
 977         struct bch_val          v;
 978         __u64                   journal_seq;
 979         __u32                   flags;
 980         __u8                    gen;
 981         __u8                    oldest_gen;
 982         __u8                    data_type;
 983         __u8                    stripe_redundancy;
 984         __u32                   dirty_sectors;
 985         __u32                   cached_sectors;
 986         __u64                   io_time[2];
 987         __u32                   stripe;
 988         __u32                   nr_external_backpointers;
 989         __u64                   fragmentation_lru;
 990 } __packed __aligned(8);
 991
 992 #define BCH_ALLOC_V4_U64s_V0    6
 993 #define BCH_ALLOC_V4_U64s       (sizeof(struct bch_alloc_v4) / sizeof(u64))
 994
 995 BITMASK(BCH_ALLOC_V4_NEED_DISCARD,      struct bch_alloc_v4, flags,  0,  1)
 996 BITMASK(BCH_ALLOC_V4_NEED_INC_GEN,      struct bch_alloc_v4, flags,  1,  2)
 997 BITMASK(BCH_ALLOC_V4_BACKPOINTERS_START,struct bch_alloc_v4, flags,  2,  8)
 998 BITMASK(BCH_ALLOC_V4_NR_BACKPOINTERS,   struct bch_alloc_v4, flags,  8,  14)
 999
1000 #define BCH_ALLOC_V4_NR_BACKPOINTERS_MAX        40
1001
1002 struct bch_backpointer {
1003         struct bch_val          v;
1004         __u8                    btree_id;
1005         __u8                    level;
1006         __u8                    data_type;
1007         __u64                   bucket_offset:40;
1008         __u32                   bucket_len;
1009         struct bpos             pos;
1010 } __packed __aligned(8);
1011
1012 #define KEY_TYPE_BUCKET_GENS_BITS       8
1013 #define KEY_TYPE_BUCKET_GENS_NR         (1U << KEY_TYPE_BUCKET_GENS_BITS)
1014 #define KEY_TYPE_BUCKET_GENS_MASK       (KEY_TYPE_BUCKET_GENS_NR - 1)
1015
1016 struct bch_bucket_gens {
1017         struct bch_val          v;
1018         u8                      gens[KEY_TYPE_BUCKET_GENS_NR];
1019 } __packed __aligned(8);
1020
1021 /* Quotas: */
1022
1023 enum quota_types {
1024         QTYP_USR                = 0,
1025         QTYP_GRP                = 1,
1026         QTYP_PRJ                = 2,
1027         QTYP_NR                 = 3,
1028 };
1029
1030 enum quota_counters {
1031         Q_SPC                   = 0,
1032         Q_INO                   = 1,
1033         Q_COUNTERS              = 2,
1034 };
1035
1036 struct bch_quota_counter {
1037         __le64                  hardlimit;
1038         __le64                  softlimit;
1039 };
1040
1041 struct bch_quota {
1042         struct bch_val          v;
1043         struct bch_quota_counter c[Q_COUNTERS];
1044 } __packed __aligned(8);
1045
1046 /* Erasure coding */
1047
1048 struct bch_stripe {
1049         struct bch_val          v;
1050         __le16                  sectors;
1051         __u8                    algorithm;
1052         __u8                    nr_blocks;
1053         __u8                    nr_redundant;
1054
1055         __u8                    csum_granularity_bits;
1056         __u8                    csum_type;
1057         __u8                    pad;
1058
1059         struct bch_extent_ptr   ptrs[];
1060 } __packed __aligned(8);
1061
1062 /* Reflink: */
1063
1064 struct bch_reflink_p {
1065         struct bch_val          v;
1066         __le64                  idx;
1067         /*
1068          * A reflink pointer might point to an indirect extent which is then
1069          * later split (by copygc or rebalance). If we only pointed to part of
1070          * the original indirect extent, and then one of the fragments is
1071          * outside the range we point to, we'd leak a refcount: so when creating
1072          * reflink pointers, we need to store pad values to remember the full
1073          * range we were taking a reference on.
1074          */
1075         __le32                  front_pad;
1076         __le32                  back_pad;
1077 } __packed __aligned(8);
1078
1079 struct bch_reflink_v {
1080         struct bch_val          v;
1081         __le64                  refcount;
1082         union bch_extent_entry  start[0];
1083         __u64                   _data[0];
1084 } __packed __aligned(8);
1085
1086 struct bch_indirect_inline_data {
1087         struct bch_val          v;
1088         __le64                  refcount;
1089         u8                      data[0];
1090 };
1091
1092 /* Inline data */
1093
1094 struct bch_inline_data {
1095         struct bch_val          v;
1096         u8                      data[0];
1097 };
1098
1099 /* Subvolumes: */
1100
1101 #define SUBVOL_POS_MIN          POS(0, 1)
1102 #define SUBVOL_POS_MAX          POS(0, S32_MAX)
1103 #define BCACHEFS_ROOT_SUBVOL    1
1104
1105 struct bch_subvolume {
1106         struct bch_val          v;
1107         __le32                  flags;
1108         __le32                  snapshot;
1109         __le64                  inode;
1110         __le32                  parent;
1111         __le32                  pad;
1112         bch_le128               otime;
1113 };
1114
1115 LE32_BITMASK(BCH_SUBVOLUME_RO,          struct bch_subvolume, flags,  0,  1)
1116 /*
1117  * We need to know whether a subvolume is a snapshot so we can know whether we
1118  * can delete it (or whether it should just be rm -rf'd)
1119  */
1120 LE32_BITMASK(BCH_SUBVOLUME_SNAP,        struct bch_subvolume, flags,  1,  2)
1121 LE32_BITMASK(BCH_SUBVOLUME_UNLINKED,    struct bch_subvolume, flags,  2,  3)
1122
1123 /* Snapshots */
1124
1125 struct bch_snapshot {
1126         struct bch_val          v;
1127         __le32                  flags;
1128         __le32                  parent;
1129         __le32                  children[2];
1130         __le32                  subvol;
1131         __le32                  tree;
1132 };
1133
1134 LE32_BITMASK(BCH_SNAPSHOT_DELETED,      struct bch_snapshot, flags,  0,  1)
1135
1136 /* True if a subvolume points to this snapshot node: */
1137 LE32_BITMASK(BCH_SNAPSHOT_SUBVOL,       struct bch_snapshot, flags,  1,  2)
1138
1139 /*
1140  * Snapshot trees:
1141  *
1142  * The snapshot_trees btree gives us persistent indentifier for each tree of
1143  * bch_snapshot nodes, and allow us to record and easily find the root/master
1144  * subvolume that other snapshots were created from:
1145  */
1146 struct bch_snapshot_tree {
1147         struct bch_val          v;
1148         __le32                  master_subvol;
1149         __le32                  root_snapshot;
1150 };
1151
1152 /* LRU btree: */
1153
1154 struct bch_lru {
1155         struct bch_val          v;
1156         __le64                  idx;
1157 } __packed __aligned(8);
1158
1159 #define LRU_ID_STRIPES          (1U << 16)
1160
1161 /* Optional/variable size superblock sections: */
1162
1163 struct bch_sb_field {
1164         __u64                   _data[0];
1165         __le32                  u64s;
1166         __le32                  type;
1167 };
1168
1169 #define BCH_SB_FIELDS()                         \
1170         x(journal,      0)                      \
1171         x(members,      1)                      \
1172         x(crypt,        2)                      \
1173         x(replicas_v0,  3)                      \
1174         x(quota,        4)                      \
1175         x(disk_groups,  5)                      \
1176         x(clean,        6)                      \
1177         x(replicas,     7)                      \
1178         x(journal_seq_blacklist, 8)             \
1179         x(journal_v2,   9)                      \
1180         x(counters,     10)
1181
1182 enum bch_sb_field_type {
1183 #define x(f, nr)        BCH_SB_FIELD_##f = nr,
1184         BCH_SB_FIELDS()
1185 #undef x
1186         BCH_SB_FIELD_NR
1187 };
1188
1189 /*
1190  * Most superblock fields are replicated in all device's superblocks - a few are
1191  * not:
1192  */
1193 #define BCH_SINGLE_DEVICE_SB_FIELDS             \
1194         ((1U << BCH_SB_FIELD_journal)|          \
1195          (1U << BCH_SB_FIELD_journal_v2))
1196
1197 /* BCH_SB_FIELD_journal: */
1198
1199 struct bch_sb_field_journal {
1200         struct bch_sb_field     field;
1201         __le64                  buckets[0];
1202 };
1203
1204 struct bch_sb_field_journal_v2 {
1205         struct bch_sb_field     field;
1206
1207         struct bch_sb_field_journal_v2_entry {
1208                 __le64          start;
1209                 __le64          nr;
1210         }                       d[0];
1211 };
1212
1213 /* BCH_SB_FIELD_members: */
1214
1215 #define BCH_MIN_NR_NBUCKETS     (1 << 6)
1216
1217 struct bch_member {
1218         uuid_le                 uuid;
1219         __le64                  nbuckets;       /* device size */
1220         __le16                  first_bucket;   /* index of first bucket used */
1221         __le16                  bucket_size;    /* sectors */
1222         __le32                  pad;
1223         __le64                  last_mount;     /* time_t */
1224
1225         __le64                  flags[2];
1226 };
1227
1228 LE64_BITMASK(BCH_MEMBER_STATE,          struct bch_member, flags[0],  0,  4)
1229 /* 4-14 unused, was TIER, HAS_(META)DATA, REPLACEMENT */
1230 LE64_BITMASK(BCH_MEMBER_DISCARD,        struct bch_member, flags[0], 14, 15)
1231 LE64_BITMASK(BCH_MEMBER_DATA_ALLOWED,   struct bch_member, flags[0], 15, 20)
1232 LE64_BITMASK(BCH_MEMBER_GROUP,          struct bch_member, flags[0], 20, 28)
1233 LE64_BITMASK(BCH_MEMBER_DURABILITY,     struct bch_member, flags[0], 28, 30)
1234 LE64_BITMASK(BCH_MEMBER_FREESPACE_INITIALIZED,
1235                                         struct bch_member, flags[0], 30, 31)
1236
1237 #if 0
1238 LE64_BITMASK(BCH_MEMBER_NR_READ_ERRORS, struct bch_member, flags[1], 0,  20);
1239 LE64_BITMASK(BCH_MEMBER_NR_WRITE_ERRORS,struct bch_member, flags[1], 20, 40);
1240 #endif
1241
1242 #define BCH_MEMBER_STATES()                     \
1243         x(rw,           0)                      \
1244         x(ro,           1)                      \
1245         x(failed,       2)                      \
1246         x(spare,        3)
1247
1248 enum bch_member_state {
1249 #define x(t, n) BCH_MEMBER_STATE_##t = n,
1250         BCH_MEMBER_STATES()
1251 #undef x
1252         BCH_MEMBER_STATE_NR
1253 };
1254
1255 struct bch_sb_field_members {
1256         struct bch_sb_field     field;
1257         struct bch_member       members[0];
1258 };
1259
1260 /* BCH_SB_FIELD_crypt: */
1261
1262 struct nonce {
1263         __le32                  d[4];
1264 };
1265
1266 struct bch_key {
1267         __le64                  key[4];
1268 };
1269
1270 #define BCH_KEY_MAGIC                                   \
1271         (((u64) 'b' <<  0)|((u64) 'c' <<  8)|           \
1272          ((u64) 'h' << 16)|((u64) '*' << 24)|           \
1273          ((u64) '*' << 32)|((u64) 'k' << 40)|           \
1274          ((u64) 'e' << 48)|((u64) 'y' << 56))
1275
1276 struct bch_encrypted_key {
1277         __le64                  magic;
1278         struct bch_key          key;
1279 };
1280
1281 /*
1282  * If this field is present in the superblock, it stores an encryption key which
1283  * is used encrypt all other data/metadata. The key will normally be encrypted
1284  * with the key userspace provides, but if encryption has been turned off we'll
1285  * just store the master key unencrypted in the superblock so we can access the
1286  * previously encrypted data.
1287  */
1288 struct bch_sb_field_crypt {
1289         struct bch_sb_field     field;
1290
1291         __le64                  flags;
1292         __le64                  kdf_flags;
1293         struct bch_encrypted_key key;
1294 };
1295
1296 LE64_BITMASK(BCH_CRYPT_KDF_TYPE,        struct bch_sb_field_crypt, flags, 0, 4);
1297
1298 enum bch_kdf_types {
1299         BCH_KDF_SCRYPT          = 0,
1300         BCH_KDF_NR              = 1,
1301 };
1302
1303 /* stored as base 2 log of scrypt params: */
1304 LE64_BITMASK(BCH_KDF_SCRYPT_N,  struct bch_sb_field_crypt, kdf_flags,  0, 16);
1305 LE64_BITMASK(BCH_KDF_SCRYPT_R,  struct bch_sb_field_crypt, kdf_flags, 16, 32);
1306 LE64_BITMASK(BCH_KDF_SCRYPT_P,  struct bch_sb_field_crypt, kdf_flags, 32, 48);
1307
1308 /* BCH_SB_FIELD_replicas: */
1309
1310 #define BCH_DATA_TYPES()                \
1311         x(free,         0)              \
1312         x(sb,           1)              \
1313         x(journal,      2)              \
1314         x(btree,        3)              \
1315         x(user,         4)              \
1316         x(cached,       5)              \
1317         x(parity,       6)              \
1318         x(stripe,       7)              \
1319         x(need_gc_gens, 8)              \
1320         x(need_discard, 9)
1321
1322 enum bch_data_type {
1323 #define x(t, n) BCH_DATA_##t,
1324         BCH_DATA_TYPES()
1325 #undef x
1326         BCH_DATA_NR
1327 };
1328
1329 static inline bool data_type_is_empty(enum bch_data_type type)
1330 {
1331         switch (type) {
1332         case BCH_DATA_free:
1333         case BCH_DATA_need_gc_gens:
1334         case BCH_DATA_need_discard:
1335                 return true;
1336         default:
1337                 return false;
1338         }
1339 }
1340
1341 static inline bool data_type_is_hidden(enum bch_data_type type)
1342 {
1343         switch (type) {
1344         case BCH_DATA_sb:
1345         case BCH_DATA_journal:
1346                 return true;
1347         default:
1348                 return false;
1349         }
1350 }
1351
1352 struct bch_replicas_entry_v0 {
1353         __u8                    data_type;
1354         __u8                    nr_devs;
1355         __u8                    devs[];
1356 } __packed;
1357
1358 struct bch_sb_field_replicas_v0 {
1359         struct bch_sb_field     field;
1360         struct bch_replicas_entry_v0 entries[];
1361 } __packed __aligned(8);
1362
1363 struct bch_replicas_entry {
1364         __u8                    data_type;
1365         __u8                    nr_devs;
1366         __u8                    nr_required;
1367         __u8                    devs[];
1368 } __packed;
1369
1370 #define replicas_entry_bytes(_i)                                        \
1371         (offsetof(typeof(*(_i)), devs) + (_i)->nr_devs)
1372
1373 struct bch_sb_field_replicas {
1374         struct bch_sb_field     field;
1375         struct bch_replicas_entry entries[];
1376 } __packed __aligned(8);
1377
1378 /* BCH_SB_FIELD_quota: */
1379
1380 struct bch_sb_quota_counter {
1381         __le32                          timelimit;
1382         __le32                          warnlimit;
1383 };
1384
1385 struct bch_sb_quota_type {
1386         __le64                          flags;
1387         struct bch_sb_quota_counter     c[Q_COUNTERS];
1388 };
1389
1390 struct bch_sb_field_quota {
1391         struct bch_sb_field             field;
1392         struct bch_sb_quota_type        q[QTYP_NR];
1393 } __packed __aligned(8);
1394
1395 /* BCH_SB_FIELD_disk_groups: */
1396
1397 #define BCH_SB_LABEL_SIZE               32
1398
1399 struct bch_disk_group {
1400         __u8                    label[BCH_SB_LABEL_SIZE];
1401         __le64                  flags[2];
1402 } __packed __aligned(8);
1403
1404 LE64_BITMASK(BCH_GROUP_DELETED,         struct bch_disk_group, flags[0], 0,  1)
1405 LE64_BITMASK(BCH_GROUP_DATA_ALLOWED,    struct bch_disk_group, flags[0], 1,  6)
1406 LE64_BITMASK(BCH_GROUP_PARENT,          struct bch_disk_group, flags[0], 6, 24)
1407
1408 struct bch_sb_field_disk_groups {
1409         struct bch_sb_field     field;
1410         struct bch_disk_group   entries[0];
1411 } __packed __aligned(8);
1412
1413 /* BCH_SB_FIELD_counters */
1414
1415 #define BCH_PERSISTENT_COUNTERS()                               \
1416         x(io_read,                                      0)      \
1417         x(io_write,                                     1)      \
1418         x(io_move,                                      2)      \
1419         x(bucket_invalidate,                            3)      \
1420         x(bucket_discard,                               4)      \
1421         x(bucket_alloc,                                 5)      \
1422         x(bucket_alloc_fail,                            6)      \
1423         x(btree_cache_scan,                             7)      \
1424         x(btree_cache_reap,                             8)      \
1425         x(btree_cache_cannibalize,                      9)      \
1426         x(btree_cache_cannibalize_lock,                 10)     \
1427         x(btree_cache_cannibalize_lock_fail,            11)     \
1428         x(btree_cache_cannibalize_unlock,               12)     \
1429         x(btree_node_write,                             13)     \
1430         x(btree_node_read,                              14)     \
1431         x(btree_node_compact,                           15)     \
1432         x(btree_node_merge,                             16)     \
1433         x(btree_node_split,                             17)     \
1434         x(btree_node_rewrite,                           18)     \
1435         x(btree_node_alloc,                             19)     \
1436         x(btree_node_free,                              20)     \
1437         x(btree_node_set_root,                          21)     \
1438         x(btree_path_relock_fail,                       22)     \
1439         x(btree_path_upgrade_fail,                      23)     \
1440         x(btree_reserve_get_fail,                       24)     \
1441         x(journal_entry_full,                           25)     \
1442         x(journal_full,                                 26)     \
1443         x(journal_reclaim_finish,                       27)     \
1444         x(journal_reclaim_start,                        28)     \
1445         x(journal_write,                                29)     \
1446         x(read_promote,                                 30)     \
1447         x(read_bounce,                                  31)     \
1448         x(read_split,                                   33)     \
1449         x(read_retry,                                   32)     \
1450         x(read_reuse_race,                              34)     \
1451         x(move_extent_read,                             35)     \
1452         x(move_extent_write,                            36)     \
1453         x(move_extent_finish,                           37)     \
1454         x(move_extent_fail,                             38)     \
1455         x(move_extent_alloc_mem_fail,                   39)     \
1456         x(copygc,                                       40)     \
1457         x(copygc_wait,                                  41)     \
1458         x(gc_gens_end,                                  42)     \
1459         x(gc_gens_start,                                43)     \
1460         x(trans_blocked_journal_reclaim,                44)     \
1461         x(trans_restart_btree_node_reused,              45)     \
1462         x(trans_restart_btree_node_split,               46)     \
1463         x(trans_restart_fault_inject,                   47)     \
1464         x(trans_restart_iter_upgrade,                   48)     \
1465         x(trans_restart_journal_preres_get,             49)     \
1466         x(trans_restart_journal_reclaim,                50)     \
1467         x(trans_restart_journal_res_get,                51)     \
1468         x(trans_restart_key_cache_key_realloced,        52)     \
1469         x(trans_restart_key_cache_raced,                53)     \
1470         x(trans_restart_mark_replicas,                  54)     \
1471         x(trans_restart_mem_realloced,                  55)     \
1472         x(trans_restart_memory_allocation_failure,      56)     \
1473         x(trans_restart_relock,                         57)     \
1474         x(trans_restart_relock_after_fill,              58)     \
1475         x(trans_restart_relock_key_cache_fill,          59)     \
1476         x(trans_restart_relock_next_node,               60)     \
1477         x(trans_restart_relock_parent_for_fill,         61)     \
1478         x(trans_restart_relock_path,                    62)     \
1479         x(trans_restart_relock_path_intent,             63)     \
1480         x(trans_restart_too_many_iters,                 64)     \
1481         x(trans_restart_traverse,                       65)     \
1482         x(trans_restart_upgrade,                        66)     \
1483         x(trans_restart_would_deadlock,                 67)     \
1484         x(trans_restart_would_deadlock_write,           68)     \
1485         x(trans_restart_injected,                       69)     \
1486         x(trans_restart_key_cache_upgrade,              70)     \
1487         x(trans_traverse_all,                           71)     \
1488         x(transaction_commit,                           72)     \
1489         x(write_super,                                  73)     \
1490         x(trans_restart_would_deadlock_recursion_limit, 74)     \
1491         x(trans_restart_write_buffer_flush,             75)     \
1492         x(trans_restart_split_race,                     76)
1493
1494 enum bch_persistent_counters {
1495 #define x(t, n, ...) BCH_COUNTER_##t,
1496         BCH_PERSISTENT_COUNTERS()
1497 #undef x
1498         BCH_COUNTER_NR
1499 };
1500
1501 struct bch_sb_field_counters {
1502         struct bch_sb_field     field;
1503         __le64                  d[0];
1504 };
1505
1506 /*
1507  * On clean shutdown, store btree roots and current journal sequence number in
1508  * the superblock:
1509  */
1510 struct jset_entry {
1511         __le16                  u64s;
1512         __u8                    btree_id;
1513         __u8                    level;
1514         __u8                    type; /* designates what this jset holds */
1515         __u8                    pad[3];
1516
1517         union {
1518                 struct bkey_i   start[0];
1519                 __u64           _data[0];
1520         };
1521 };
1522
1523 struct bch_sb_field_clean {
1524         struct bch_sb_field     field;
1525
1526         __le32                  flags;
1527         __le16                  _read_clock; /* no longer used */
1528         __le16                  _write_clock;
1529         __le64                  journal_seq;
1530
1531         union {
1532                 struct jset_entry start[0];
1533                 __u64           _data[0];
1534         };
1535 };
1536
1537 struct journal_seq_blacklist_entry {
1538         __le64                  start;
1539         __le64                  end;
1540 };
1541
1542 struct bch_sb_field_journal_seq_blacklist {
1543         struct bch_sb_field     field;
1544
1545         union {
1546                 struct journal_seq_blacklist_entry start[0];
1547                 __u64           _data[0];
1548         };
1549 };
1550
1551 /* Superblock: */
1552
1553 /*
1554  * New versioning scheme:
1555  * One common version number for all on disk data structures - superblock, btree
1556  * nodes, journal entries
1557  */
1558 #define BCH_JSET_VERSION_OLD                    2
1559 #define BCH_BSET_VERSION_OLD                    3
1560
1561 #define BCH_METADATA_VERSIONS()                         \
1562         x(bkey_renumber,                10)             \
1563         x(inode_btree_change,           11)             \
1564         x(snapshot,                     12)             \
1565         x(inode_backpointers,           13)             \
1566         x(btree_ptr_sectors_written,    14)             \
1567         x(snapshot_2,                   15)             \
1568         x(reflink_p_fix,                16)             \
1569         x(subvol_dirent,                17)             \
1570         x(inode_v2,                     18)             \
1571         x(freespace,                    19)             \
1572         x(alloc_v4,                     20)             \
1573         x(new_data_types,               21)             \
1574         x(backpointers,                 22)             \
1575         x(inode_v3,                     23)             \
1576         x(unwritten_extents,            24)             \
1577         x(bucket_gens,                  25)             \
1578         x(lru_v2,                       26)             \
1579         x(fragmentation_lru,            27)             \
1580         x(no_bps_in_alloc_keys,         28)             \
1581         x(snapshot_trees,               29)
1582
1583 enum bcachefs_metadata_version {
1584         bcachefs_metadata_version_min = 9,
1585 #define x(t, n) bcachefs_metadata_version_##t = n,
1586         BCH_METADATA_VERSIONS()
1587 #undef x
1588         bcachefs_metadata_version_max
1589 };
1590
1591 static const unsigned bcachefs_metadata_required_upgrade_below = bcachefs_metadata_version_snapshot_trees;
1592
1593 #define bcachefs_metadata_version_current       (bcachefs_metadata_version_max - 1)
1594
1595 #define BCH_SB_SECTOR                   8
1596 #define BCH_SB_MEMBERS_MAX              64 /* XXX kill */
1597
1598 struct bch_sb_layout {
1599         uuid_le                 magic;  /* bcachefs superblock UUID */
1600         __u8                    layout_type;
1601         __u8                    sb_max_size_bits; /* base 2 of 512 byte sectors */
1602         __u8                    nr_superblocks;
1603         __u8                    pad[5];
1604         __le64                  sb_offset[61];
1605 } __packed __aligned(8);
1606
1607 #define BCH_SB_LAYOUT_SECTOR    7
1608
1609 /*
1610  * @offset      - sector where this sb was written
1611  * @version     - on disk format version
1612  * @version_min - Oldest metadata version this filesystem contains; so we can
1613  *                safely drop compatibility code and refuse to mount filesystems
1614  *                we'd need it for
1615  * @magic       - identifies as a bcachefs superblock (BCHFS_MAGIC)
1616  * @seq         - incremented each time superblock is written
1617  * @uuid        - used for generating various magic numbers and identifying
1618  *                member devices, never changes
1619  * @user_uuid   - user visible UUID, may be changed
1620  * @label       - filesystem label
1621  * @seq         - identifies most recent superblock, incremented each time
1622  *                superblock is written
1623  * @features    - enabled incompatible features
1624  */
1625 struct bch_sb {
1626         struct bch_csum         csum;
1627         __le16                  version;
1628         __le16                  version_min;
1629         __le16                  pad[2];
1630         uuid_le                 magic;
1631         uuid_le                 uuid;
1632         uuid_le                 user_uuid;
1633         __u8                    label[BCH_SB_LABEL_SIZE];
1634         __le64                  offset;
1635         __le64                  seq;
1636
1637         __le16                  block_size;
1638         __u8                    dev_idx;
1639         __u8                    nr_devices;
1640         __le32                  u64s;
1641
1642         __le64                  time_base_lo;
1643         __le32                  time_base_hi;
1644         __le32                  time_precision;
1645
1646         __le64                  flags[8];
1647         __le64                  features[2];
1648         __le64                  compat[2];
1649
1650         struct bch_sb_layout    layout;
1651
1652         union {
1653                 struct bch_sb_field start[0];
1654                 __le64          _data[0];
1655         };
1656 } __packed __aligned(8);
1657
1658 /*
1659  * Flags:
1660  * BCH_SB_INITALIZED    - set on first mount
1661  * BCH_SB_CLEAN         - did we shut down cleanly? Just a hint, doesn't affect
1662  *                        behaviour of mount/recovery path:
1663  * BCH_SB_INODE_32BIT   - limit inode numbers to 32 bits
1664  * BCH_SB_128_BIT_MACS  - 128 bit macs instead of 80
1665  * BCH_SB_ENCRYPTION_TYPE - if nonzero encryption is enabled; overrides
1666  *                         DATA/META_CSUM_TYPE. Also indicates encryption
1667  *                         algorithm in use, if/when we get more than one
1668  */
1669
1670 LE16_BITMASK(BCH_SB_BLOCK_SIZE,         struct bch_sb, block_size, 0, 16);
1671
1672 LE64_BITMASK(BCH_SB_INITIALIZED,        struct bch_sb, flags[0],  0,  1);
1673 LE64_BITMASK(BCH_SB_CLEAN,              struct bch_sb, flags[0],  1,  2);
1674 LE64_BITMASK(BCH_SB_CSUM_TYPE,          struct bch_sb, flags[0],  2,  8);
1675 LE64_BITMASK(BCH_SB_ERROR_ACTION,       struct bch_sb, flags[0],  8, 12);
1676
1677 LE64_BITMASK(BCH_SB_BTREE_NODE_SIZE,    struct bch_sb, flags[0], 12, 28);
1678
1679 LE64_BITMASK(BCH_SB_GC_RESERVE,         struct bch_sb, flags[0], 28, 33);
1680 LE64_BITMASK(BCH_SB_ROOT_RESERVE,       struct bch_sb, flags[0], 33, 40);
1681
1682 LE64_BITMASK(BCH_SB_META_CSUM_TYPE,     struct bch_sb, flags[0], 40, 44);
1683 LE64_BITMASK(BCH_SB_DATA_CSUM_TYPE,     struct bch_sb, flags[0], 44, 48);
1684
1685 LE64_BITMASK(BCH_SB_META_REPLICAS_WANT, struct bch_sb, flags[0], 48, 52);
1686 LE64_BITMASK(BCH_SB_DATA_REPLICAS_WANT, struct bch_sb, flags[0], 52, 56);
1687
1688 LE64_BITMASK(BCH_SB_POSIX_ACL,          struct bch_sb, flags[0], 56, 57);
1689 LE64_BITMASK(BCH_SB_USRQUOTA,           struct bch_sb, flags[0], 57, 58);
1690 LE64_BITMASK(BCH_SB_GRPQUOTA,           struct bch_sb, flags[0], 58, 59);
1691 LE64_BITMASK(BCH_SB_PRJQUOTA,           struct bch_sb, flags[0], 59, 60);
1692
1693 LE64_BITMASK(BCH_SB_HAS_ERRORS,         struct bch_sb, flags[0], 60, 61);
1694 LE64_BITMASK(BCH_SB_HAS_TOPOLOGY_ERRORS,struct bch_sb, flags[0], 61, 62);
1695
1696 LE64_BITMASK(BCH_SB_BIG_ENDIAN,         struct bch_sb, flags[0], 62, 63);
1697
1698 LE64_BITMASK(BCH_SB_STR_HASH_TYPE,      struct bch_sb, flags[1],  0,  4);
1699 LE64_BITMASK(BCH_SB_COMPRESSION_TYPE,   struct bch_sb, flags[1],  4,  8);
1700 LE64_BITMASK(BCH_SB_INODE_32BIT,        struct bch_sb, flags[1],  8,  9);
1701
1702 LE64_BITMASK(BCH_SB_128_BIT_MACS,       struct bch_sb, flags[1],  9, 10);
1703 LE64_BITMASK(BCH_SB_ENCRYPTION_TYPE,    struct bch_sb, flags[1], 10, 14);
1704
1705 /*
1706  * Max size of an extent that may require bouncing to read or write
1707  * (checksummed, compressed): 64k
1708  */
1709 LE64_BITMASK(BCH_SB_ENCODED_EXTENT_MAX_BITS,
1710                                         struct bch_sb, flags[1], 14, 20);
1711
1712 LE64_BITMASK(BCH_SB_META_REPLICAS_REQ,  struct bch_sb, flags[1], 20, 24);
1713 LE64_BITMASK(BCH_SB_DATA_REPLICAS_REQ,  struct bch_sb, flags[1], 24, 28);
1714
1715 LE64_BITMASK(BCH_SB_PROMOTE_TARGET,     struct bch_sb, flags[1], 28, 40);
1716 LE64_BITMASK(BCH_SB_FOREGROUND_TARGET,  struct bch_sb, flags[1], 40, 52);
1717 LE64_BITMASK(BCH_SB_BACKGROUND_TARGET,  struct bch_sb, flags[1], 52, 64);
1718
1719 LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE,
1720                                         struct bch_sb, flags[2],  0,  4);
1721 LE64_BITMASK(BCH_SB_GC_RESERVE_BYTES,   struct bch_sb, flags[2],  4, 64);
1722
1723 LE64_BITMASK(BCH_SB_ERASURE_CODE,       struct bch_sb, flags[3],  0, 16);
1724 LE64_BITMASK(BCH_SB_METADATA_TARGET,    struct bch_sb, flags[3], 16, 28);
1725 LE64_BITMASK(BCH_SB_SHARD_INUMS,        struct bch_sb, flags[3], 28, 29);
1726 LE64_BITMASK(BCH_SB_INODES_USE_KEY_CACHE,struct bch_sb, flags[3], 29, 30);
1727 LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DELAY,struct bch_sb, flags[3], 30, 62);
1728 LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DISABLED,struct bch_sb, flags[3], 62, 63);
1729 LE64_BITMASK(BCH_SB_JOURNAL_RECLAIM_DELAY,struct bch_sb, flags[4], 0, 32);
1730 LE64_BITMASK(BCH_SB_JOURNAL_TRANSACTION_NAMES,struct bch_sb, flags[4], 32, 33);
1731 LE64_BITMASK(BCH_SB_NOCOW,              struct bch_sb, flags[4], 33, 34);
1732 LE64_BITMASK(BCH_SB_WRITE_BUFFER_SIZE,  struct bch_sb, flags[4], 34, 54);
1733
1734 /*
1735  * Features:
1736  *
1737  * journal_seq_blacklist_v3:    gates BCH_SB_FIELD_journal_seq_blacklist
1738  * reflink:                     gates KEY_TYPE_reflink
1739  * inline_data:                 gates KEY_TYPE_inline_data
1740  * new_siphash:                 gates BCH_STR_HASH_siphash
1741  * new_extent_overwrite:        gates BTREE_NODE_NEW_EXTENT_OVERWRITE
1742  */
1743 #define BCH_SB_FEATURES()                       \
1744         x(lz4,                          0)      \
1745         x(gzip,                         1)      \
1746         x(zstd,                         2)      \
1747         x(atomic_nlink,                 3)      \
1748         x(ec,                           4)      \
1749         x(journal_seq_blacklist_v3,     5)      \
1750         x(reflink,                      6)      \
1751         x(new_siphash,                  7)      \
1752         x(inline_data,                  8)      \
1753         x(new_extent_overwrite,         9)      \
1754         x(incompressible,               10)     \
1755         x(btree_ptr_v2,                 11)     \
1756         x(extents_above_btree_updates,  12)     \
1757         x(btree_updates_journalled,     13)     \
1758         x(reflink_inline_data,          14)     \
1759         x(new_varint,                   15)     \
1760         x(journal_no_flush,             16)     \
1761         x(alloc_v2,                     17)     \
1762         x(extents_across_btree_nodes,   18)
1763
1764 #define BCH_SB_FEATURES_ALWAYS                          \
1765         ((1ULL << BCH_FEATURE_new_extent_overwrite)|    \
1766          (1ULL << BCH_FEATURE_extents_above_btree_updates)|\
1767          (1ULL << BCH_FEATURE_btree_updates_journalled)|\
1768          (1ULL << BCH_FEATURE_alloc_v2)|\
1769          (1ULL << BCH_FEATURE_extents_across_btree_nodes))
1770
1771 #define BCH_SB_FEATURES_ALL                             \
1772         (BCH_SB_FEATURES_ALWAYS|                        \
1773          (1ULL << BCH_FEATURE_new_siphash)|             \
1774          (1ULL << BCH_FEATURE_btree_ptr_v2)|            \
1775          (1ULL << BCH_FEATURE_new_varint)|              \
1776          (1ULL << BCH_FEATURE_journal_no_flush))
1777
1778 enum bch_sb_feature {
1779 #define x(f, n) BCH_FEATURE_##f,
1780         BCH_SB_FEATURES()
1781 #undef x
1782         BCH_FEATURE_NR,
1783 };
1784
1785 #define BCH_SB_COMPAT()                                 \
1786         x(alloc_info,                           0)      \
1787         x(alloc_metadata,                       1)      \
1788         x(extents_above_btree_updates_done,     2)      \
1789         x(bformat_overflow_done,                3)
1790
1791 enum bch_sb_compat {
1792 #define x(f, n) BCH_COMPAT_##f,
1793         BCH_SB_COMPAT()
1794 #undef x
1795         BCH_COMPAT_NR,
1796 };
1797
1798 /* options: */
1799
1800 #define BCH_REPLICAS_MAX                4U
1801
1802 #define BCH_BKEY_PTRS_MAX               16U
1803
1804 #define BCH_ERROR_ACTIONS()             \
1805         x(continue,             0)      \
1806         x(ro,                   1)      \
1807         x(panic,                2)
1808
1809 enum bch_error_actions {
1810 #define x(t, n) BCH_ON_ERROR_##t = n,
1811         BCH_ERROR_ACTIONS()
1812 #undef x
1813         BCH_ON_ERROR_NR
1814 };
1815
1816 #define BCH_STR_HASH_TYPES()            \
1817         x(crc32c,               0)      \
1818         x(crc64,                1)      \
1819         x(siphash_old,          2)      \
1820         x(siphash,              3)
1821
1822 enum bch_str_hash_type {
1823 #define x(t, n) BCH_STR_HASH_##t = n,
1824         BCH_STR_HASH_TYPES()
1825 #undef x
1826         BCH_STR_HASH_NR
1827 };
1828
1829 #define BCH_STR_HASH_OPTS()             \
1830         x(crc32c,               0)      \
1831         x(crc64,                1)      \
1832         x(siphash,              2)
1833
1834 enum bch_str_hash_opts {
1835 #define x(t, n) BCH_STR_HASH_OPT_##t = n,
1836         BCH_STR_HASH_OPTS()
1837 #undef x
1838         BCH_STR_HASH_OPT_NR
1839 };
1840
1841 #define BCH_CSUM_TYPES()                        \
1842         x(none,                         0)      \
1843         x(crc32c_nonzero,               1)      \
1844         x(crc64_nonzero,                2)      \
1845         x(chacha20_poly1305_80,         3)      \
1846         x(chacha20_poly1305_128,        4)      \
1847         x(crc32c,                       5)      \
1848         x(crc64,                        6)      \
1849         x(xxhash,                       7)
1850
1851 enum bch_csum_type {
1852 #define x(t, n) BCH_CSUM_##t = n,
1853         BCH_CSUM_TYPES()
1854 #undef x
1855         BCH_CSUM_NR
1856 };
1857
1858 static const unsigned bch_crc_bytes[] = {
1859         [BCH_CSUM_none]                         = 0,
1860         [BCH_CSUM_crc32c_nonzero]               = 4,
1861         [BCH_CSUM_crc32c]                       = 4,
1862         [BCH_CSUM_crc64_nonzero]                = 8,
1863         [BCH_CSUM_crc64]                        = 8,
1864         [BCH_CSUM_xxhash]                       = 8,
1865         [BCH_CSUM_chacha20_poly1305_80]         = 10,
1866         [BCH_CSUM_chacha20_poly1305_128]        = 16,
1867 };
1868
1869 static inline _Bool bch2_csum_type_is_encryption(enum bch_csum_type type)
1870 {
1871         switch (type) {
1872         case BCH_CSUM_chacha20_poly1305_80:
1873         case BCH_CSUM_chacha20_poly1305_128:
1874                 return true;
1875         default:
1876                 return false;
1877         }
1878 }
1879
1880 #define BCH_CSUM_OPTS()                 \
1881         x(none,                 0)      \
1882         x(crc32c,               1)      \
1883         x(crc64,                2)      \
1884         x(xxhash,               3)
1885
1886 enum bch_csum_opts {
1887 #define x(t, n) BCH_CSUM_OPT_##t = n,
1888         BCH_CSUM_OPTS()
1889 #undef x
1890         BCH_CSUM_OPT_NR
1891 };
1892
1893 #define BCH_COMPRESSION_TYPES()         \
1894         x(none,                 0)      \
1895         x(lz4_old,              1)      \
1896         x(gzip,                 2)      \
1897         x(lz4,                  3)      \
1898         x(zstd,                 4)      \
1899         x(incompressible,       5)
1900
1901 enum bch_compression_type {
1902 #define x(t, n) BCH_COMPRESSION_TYPE_##t = n,
1903         BCH_COMPRESSION_TYPES()
1904 #undef x
1905         BCH_COMPRESSION_TYPE_NR
1906 };
1907
1908 #define BCH_COMPRESSION_OPTS()          \
1909         x(none,         0)              \
1910         x(lz4,          1)              \
1911         x(gzip,         2)              \
1912         x(zstd,         3)
1913
1914 enum bch_compression_opts {
1915 #define x(t, n) BCH_COMPRESSION_OPT_##t = n,
1916         BCH_COMPRESSION_OPTS()
1917 #undef x
1918         BCH_COMPRESSION_OPT_NR
1919 };
1920
1921 /*
1922  * Magic numbers
1923  *
1924  * The various other data structures have their own magic numbers, which are
1925  * xored with the first part of the cache set's UUID
1926  */
1927
1928 #define BCACHE_MAGIC                                                    \
1929         UUID_LE(0xf67385c6, 0x1a4e, 0xca45,                             \
1930                 0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81)
1931 #define BCHFS_MAGIC                                                     \
1932         UUID_LE(0xf67385c6, 0xce66, 0xa990,                             \
1933                 0xd9, 0x6a, 0x60, 0xcf, 0x80, 0x3d, 0xf7, 0xef)
1934
1935 #define BCACHEFS_STATFS_MAGIC           0xca451a4e
1936
1937 #define JSET_MAGIC              __cpu_to_le64(0x245235c1a3625032ULL)
1938 #define BSET_MAGIC              __cpu_to_le64(0x90135c78b99e07f5ULL)
1939
1940 static inline __le64 __bch2_sb_magic(struct bch_sb *sb)
1941 {
1942         __le64 ret;
1943
1944         memcpy(&ret, &sb->uuid, sizeof(ret));
1945         return ret;
1946 }
1947
1948 static inline __u64 __jset_magic(struct bch_sb *sb)
1949 {
1950         return __le64_to_cpu(__bch2_sb_magic(sb) ^ JSET_MAGIC);
1951 }
1952
1953 static inline __u64 __bset_magic(struct bch_sb *sb)
1954 {
1955         return __le64_to_cpu(__bch2_sb_magic(sb) ^ BSET_MAGIC);
1956 }
1957
1958 /* Journal */
1959
1960 #define JSET_KEYS_U64s  (sizeof(struct jset_entry) / sizeof(__u64))
1961
1962 #define BCH_JSET_ENTRY_TYPES()                  \
1963         x(btree_keys,           0)              \
1964         x(btree_root,           1)              \
1965         x(prio_ptrs,            2)              \
1966         x(blacklist,            3)              \
1967         x(blacklist_v2,         4)              \
1968         x(usage,                5)              \
1969         x(data_usage,           6)              \
1970         x(clock,                7)              \
1971         x(dev_usage,            8)              \
1972         x(log,                  9)              \
1973         x(overwrite,            10)
1974
1975 enum {
1976 #define x(f, nr)        BCH_JSET_ENTRY_##f      = nr,
1977         BCH_JSET_ENTRY_TYPES()
1978 #undef x
1979         BCH_JSET_ENTRY_NR
1980 };
1981
1982 /*
1983  * Journal sequence numbers can be blacklisted: bsets record the max sequence
1984  * number of all the journal entries they contain updates for, so that on
1985  * recovery we can ignore those bsets that contain index updates newer that what
1986  * made it into the journal.
1987  *
1988  * This means that we can't reuse that journal_seq - we have to skip it, and
1989  * then record that we skipped it so that the next time we crash and recover we
1990  * don't think there was a missing journal entry.
1991  */
1992 struct jset_entry_blacklist {
1993         struct jset_entry       entry;
1994         __le64                  seq;
1995 };
1996
1997 struct jset_entry_blacklist_v2 {
1998         struct jset_entry       entry;
1999         __le64                  start;
2000         __le64                  end;
2001 };
2002
2003 #define BCH_FS_USAGE_TYPES()                    \
2004         x(reserved,             0)              \
2005         x(inodes,               1)              \
2006         x(key_version,          2)
2007
2008 enum {
2009 #define x(f, nr)        BCH_FS_USAGE_##f        = nr,
2010         BCH_FS_USAGE_TYPES()
2011 #undef x
2012         BCH_FS_USAGE_NR
2013 };
2014
2015 struct jset_entry_usage {
2016         struct jset_entry       entry;
2017         __le64                  v;
2018 } __packed;
2019
2020 struct jset_entry_data_usage {
2021         struct jset_entry       entry;
2022         __le64                  v;
2023         struct bch_replicas_entry r;
2024 } __packed;
2025
2026 struct jset_entry_clock {
2027         struct jset_entry       entry;
2028         __u8                    rw;
2029         __u8                    pad[7];
2030         __le64                  time;
2031 } __packed;
2032
2033 struct jset_entry_dev_usage_type {
2034         __le64                  buckets;
2035         __le64                  sectors;
2036         __le64                  fragmented;
2037 } __packed;
2038
2039 struct jset_entry_dev_usage {
2040         struct jset_entry       entry;
2041         __le32                  dev;
2042         __u32                   pad;
2043
2044         __le64                  buckets_ec;
2045         __le64                  _buckets_unavailable; /* No longer used */
2046
2047         struct jset_entry_dev_usage_type d[];
2048 } __packed;
2049
2050 static inline unsigned jset_entry_dev_usage_nr_types(struct jset_entry_dev_usage *u)
2051 {
2052         return (vstruct_bytes(&u->entry) - sizeof(struct jset_entry_dev_usage)) /
2053                 sizeof(struct jset_entry_dev_usage_type);
2054 }
2055
2056 struct jset_entry_log {
2057         struct jset_entry       entry;
2058         u8                      d[];
2059 } __packed;
2060
2061 /*
2062  * On disk format for a journal entry:
2063  * seq is monotonically increasing; every journal entry has its own unique
2064  * sequence number.
2065  *
2066  * last_seq is the oldest journal entry that still has keys the btree hasn't
2067  * flushed to disk yet.
2068  *
2069  * version is for on disk format changes.
2070  */
2071 struct jset {
2072         struct bch_csum         csum;
2073
2074         __le64                  magic;
2075         __le64                  seq;
2076         __le32                  version;
2077         __le32                  flags;
2078
2079         __le32                  u64s; /* size of d[] in u64s */
2080
2081         __u8                    encrypted_start[0];
2082
2083         __le16                  _read_clock; /* no longer used */
2084         __le16                  _write_clock;
2085
2086         /* Sequence number of oldest dirty journal entry */
2087         __le64                  last_seq;
2088
2089
2090         union {
2091                 struct jset_entry start[0];
2092                 __u64           _data[0];
2093         };
2094 } __packed __aligned(8);
2095
2096 LE32_BITMASK(JSET_CSUM_TYPE,    struct jset, flags, 0, 4);
2097 LE32_BITMASK(JSET_BIG_ENDIAN,   struct jset, flags, 4, 5);
2098 LE32_BITMASK(JSET_NO_FLUSH,     struct jset, flags, 5, 6);
2099
2100 #define BCH_JOURNAL_BUCKETS_MIN         8
2101
2102 /* Btree: */
2103
2104 #define BCH_BTREE_IDS()                         \
2105         x(extents,              0)              \
2106         x(inodes,               1)              \
2107         x(dirents,              2)              \
2108         x(xattrs,               3)              \
2109         x(alloc,                4)              \
2110         x(quotas,               5)              \
2111         x(stripes,              6)              \
2112         x(reflink,              7)              \
2113         x(subvolumes,           8)              \
2114         x(snapshots,            9)              \
2115         x(lru,                  10)             \
2116         x(freespace,            11)             \
2117         x(need_discard,         12)             \
2118         x(backpointers,         13)             \
2119         x(bucket_gens,          14)             \
2120         x(snapshot_trees,       15)
2121
2122 enum btree_id {
2123 #define x(kwd, val) BTREE_ID_##kwd = val,
2124         BCH_BTREE_IDS()
2125 #undef x
2126         BTREE_ID_NR
2127 };
2128
2129 #define BTREE_MAX_DEPTH         4U
2130
2131 /* Btree nodes */
2132
2133 /*
2134  * Btree nodes
2135  *
2136  * On disk a btree node is a list/log of these; within each set the keys are
2137  * sorted
2138  */
2139 struct bset {
2140         __le64                  seq;
2141
2142         /*
2143          * Highest journal entry this bset contains keys for.
2144          * If on recovery we don't see that journal entry, this bset is ignored:
2145          * this allows us to preserve the order of all index updates after a
2146          * crash, since the journal records a total order of all index updates
2147          * and anything that didn't make it to the journal doesn't get used.
2148          */
2149         __le64                  journal_seq;
2150
2151         __le32                  flags;
2152         __le16                  version;
2153         __le16                  u64s; /* count of d[] in u64s */
2154
2155         union {
2156                 struct bkey_packed start[0];
2157                 __u64           _data[0];
2158         };
2159 } __packed __aligned(8);
2160
2161 LE32_BITMASK(BSET_CSUM_TYPE,    struct bset, flags, 0, 4);
2162
2163 LE32_BITMASK(BSET_BIG_ENDIAN,   struct bset, flags, 4, 5);
2164 LE32_BITMASK(BSET_SEPARATE_WHITEOUTS,
2165                                 struct bset, flags, 5, 6);
2166
2167 /* Sector offset within the btree node: */
2168 LE32_BITMASK(BSET_OFFSET,       struct bset, flags, 16, 32);
2169
2170 struct btree_node {
2171         struct bch_csum         csum;
2172         __le64                  magic;
2173
2174         /* this flags field is encrypted, unlike bset->flags: */
2175         __le64                  flags;
2176
2177         /* Closed interval: */
2178         struct bpos             min_key;
2179         struct bpos             max_key;
2180         struct bch_extent_ptr   _ptr; /* not used anymore */
2181         struct bkey_format      format;
2182
2183         union {
2184         struct bset             keys;
2185         struct {
2186                 __u8            pad[22];
2187                 __le16          u64s;
2188                 __u64           _data[0];
2189
2190         };
2191         };
2192 } __packed __aligned(8);
2193
2194 LE64_BITMASK(BTREE_NODE_ID,     struct btree_node, flags,  0,  4);
2195 LE64_BITMASK(BTREE_NODE_LEVEL,  struct btree_node, flags,  4,  8);
2196 LE64_BITMASK(BTREE_NODE_NEW_EXTENT_OVERWRITE,
2197                                 struct btree_node, flags,  8,  9);
2198 /* 9-32 unused */
2199 LE64_BITMASK(BTREE_NODE_SEQ,    struct btree_node, flags, 32, 64);
2200
2201 struct btree_node_entry {
2202         struct bch_csum         csum;
2203
2204         union {
2205         struct bset             keys;
2206         struct {
2207                 __u8            pad[22];
2208                 __le16          u64s;
2209                 __u64           _data[0];
2210
2211         };
2212         };
2213 } __packed __aligned(8);
2214
2215 #endif /* _BCACHEFS_FORMAT_H */