git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/btree_journal_iter.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include "bcachefs.h"
   4 #include "bkey_buf.h"
   5 #include "bset.h"
   6 #include "btree_cache.h"
   7 #include "btree_journal_iter.h"
   8 #include "journal_io.h"
   9
  10 #include <linux/sort.h>
  11
  12 /*
  13  * For managing keys we read from the journal: until journal replay works normal
  14  * btree lookups need to be able to find and return keys from the journal where
  15  * they overwrite what's in the btree, so we have a special iterator and
  16  * operations for the regular btree iter code to use:
  17  */
  18
  19 static int __journal_key_cmp(enum btree_id      l_btree_id,
  20                              unsigned           l_level,
  21                              struct bpos        l_pos,
  22                              const struct journal_key *r)
  23 {
  24         return (cmp_int(l_btree_id,     r->btree_id) ?:
  25                 cmp_int(l_level,        r->level) ?:
  26                 bpos_cmp(l_pos, r->k->k.p));
  27 }
  28
  29 static int journal_key_cmp(const struct journal_key *l, const struct journal_key *r)
  30 {
  31         return __journal_key_cmp(l->btree_id, l->level, l->k->k.p, r);
  32 }
  33
  34 static inline size_t idx_to_pos(struct journal_keys *keys, size_t idx)
  35 {
  36         size_t gap_size = keys->size - keys->nr;
  37
  38         if (idx >= keys->gap)
  39                 idx += gap_size;
  40         return idx;
  41 }
  42
  43 static inline struct journal_key *idx_to_key(struct journal_keys *keys, size_t idx)
  44 {
  45         return keys->d + idx_to_pos(keys, idx);
  46 }
  47
  48 static size_t __bch2_journal_key_search(struct journal_keys *keys,
  49                                         enum btree_id id, unsigned level,
  50                                         struct bpos pos)
  51 {
  52         size_t l = 0, r = keys->nr, m;
  53
  54         while (l < r) {
  55                 m = l + ((r - l) >> 1);
  56                 if (__journal_key_cmp(id, level, pos, idx_to_key(keys, m)) > 0)
  57                         l = m + 1;
  58                 else
  59                         r = m;
  60         }
  61
  62         BUG_ON(l < keys->nr &&
  63                __journal_key_cmp(id, level, pos, idx_to_key(keys, l)) > 0);
  64
  65         BUG_ON(l &&
  66                __journal_key_cmp(id, level, pos, idx_to_key(keys, l - 1)) <= 0);
  67
  68         return l;
  69 }
  70
  71 static size_t bch2_journal_key_search(struct journal_keys *keys,
  72                                       enum btree_id id, unsigned level,
  73                                       struct bpos pos)
  74 {
  75         return idx_to_pos(keys, __bch2_journal_key_search(keys, id, level, pos));
  76 }
  77
  78 /* Returns first non-overwritten key >= search key: */
  79 struct bkey_i *bch2_journal_keys_peek_upto(struct bch_fs *c, enum btree_id btree_id,
  80                                            unsigned level, struct bpos pos,
  81                                            struct bpos end_pos, size_t *idx)
  82 {
  83         struct journal_keys *keys = &c->journal_keys;
  84         unsigned iters = 0;
  85         struct journal_key *k;
  86
  87         BUG_ON(*idx > keys->nr);
  88 search:
  89         if (!*idx)
  90                 *idx = __bch2_journal_key_search(keys, btree_id, level, pos);
  91
  92         while (*idx &&
  93                __journal_key_cmp(btree_id, level, end_pos, idx_to_key(keys, *idx - 1)) <= 0) {
  94                 --(*idx);
  95                 iters++;
  96                 if (iters == 10) {
  97                         *idx = 0;
  98                         goto search;
  99                 }
 100         }
 101
 102         while ((k = *idx < keys->nr ? idx_to_key(keys, *idx) : NULL)) {
 103                 if (__journal_key_cmp(btree_id, level, end_pos, k) < 0)
 104                         return NULL;
 105
 106                 if (k->overwritten) {
 107                         (*idx)++;
 108                         continue;
 109                 }
 110
 111                 if (__journal_key_cmp(btree_id, level, pos, k) <= 0)
 112                         return k->k;
 113
 114                 (*idx)++;
 115                 iters++;
 116                 if (iters == 10) {
 117                         *idx = 0;
 118                         goto search;
 119                 }
 120         }
 121
 122         return NULL;
 123 }
 124
 125 struct bkey_i *bch2_journal_keys_peek_slot(struct bch_fs *c, enum btree_id btree_id,
 126                                            unsigned level, struct bpos pos)
 127 {
 128         size_t idx = 0;
 129
 130         return bch2_journal_keys_peek_upto(c, btree_id, level, pos, pos, &idx);
 131 }
 132
 133 static void journal_iters_fix(struct bch_fs *c)
 134 {
 135         struct journal_keys *keys = &c->journal_keys;
 136         /* The key we just inserted is immediately before the gap: */
 137         size_t gap_end = keys->gap + (keys->size - keys->nr);
 138         struct btree_and_journal_iter *iter;
 139
 140         /*
 141          * If an iterator points one after the key we just inserted, decrement
 142          * the iterator so it points at the key we just inserted - if the
 143          * decrement was unnecessary, bch2_btree_and_journal_iter_peek() will
 144          * handle that:
 145          */
 146         list_for_each_entry(iter, &c->journal_iters, journal.list)
 147                 if (iter->journal.idx == gap_end)
 148                         iter->journal.idx = keys->gap - 1;
 149 }
 150
 151 static void journal_iters_move_gap(struct bch_fs *c, size_t old_gap, size_t new_gap)
 152 {
 153         struct journal_keys *keys = &c->journal_keys;
 154         struct journal_iter *iter;
 155         size_t gap_size = keys->size - keys->nr;
 156
 157         list_for_each_entry(iter, &c->journal_iters, list) {
 158                 if (iter->idx > old_gap)
 159                         iter->idx -= gap_size;
 160                 if (iter->idx >= new_gap)
 161                         iter->idx += gap_size;
 162         }
 163 }
 164
 165 int bch2_journal_key_insert_take(struct bch_fs *c, enum btree_id id,
 166                                  unsigned level, struct bkey_i *k)
 167 {
 168         struct journal_key n = {
 169                 .btree_id       = id,
 170                 .level          = level,
 171                 .k              = k,
 172                 .allocated      = true,
 173                 /*
 174                  * Ensure these keys are done last by journal replay, to unblock
 175                  * journal reclaim:
 176                  */
 177                 .journal_seq    = U32_MAX,
 178         };
 179         struct journal_keys *keys = &c->journal_keys;
 180         size_t idx = bch2_journal_key_search(keys, id, level, k->k.p);
 181
 182         BUG_ON(test_bit(BCH_FS_rw, &c->flags));
 183
 184         if (idx < keys->size &&
 185             journal_key_cmp(&n, &keys->d[idx]) == 0) {
 186                 if (keys->d[idx].allocated)
 187                         kfree(keys->d[idx].k);
 188                 keys->d[idx] = n;
 189                 return 0;
 190         }
 191
 192         if (idx > keys->gap)
 193                 idx -= keys->size - keys->nr;
 194
 195         if (keys->nr == keys->size) {
 196                 struct journal_keys new_keys = {
 197                         .nr                     = keys->nr,
 198                         .size                   = max_t(size_t, keys->size, 8) * 2,
 199                 };
 200
 201                 new_keys.d = kvmalloc_array(new_keys.size, sizeof(new_keys.d[0]), GFP_KERNEL);
 202                 if (!new_keys.d) {
 203                         bch_err(c, "%s: error allocating new key array (size %zu)",
 204                                 __func__, new_keys.size);
 205                         return -BCH_ERR_ENOMEM_journal_key_insert;
 206                 }
 207
 208                 /* Since @keys was full, there was no gap: */
 209                 memcpy(new_keys.d, keys->d, sizeof(keys->d[0]) * keys->nr);
 210                 kvfree(keys->d);
 211                 keys->d         = new_keys.d;
 212                 keys->nr        = new_keys.nr;
 213                 keys->size      = new_keys.size;
 214
 215                 /* And now the gap is at the end: */
 216                 keys->gap       = keys->nr;
 217         }
 218
 219         journal_iters_move_gap(c, keys->gap, idx);
 220
 221         move_gap(keys->d, keys->nr, keys->size, keys->gap, idx);
 222         keys->gap = idx;
 223
 224         keys->nr++;
 225         keys->d[keys->gap++] = n;
 226
 227         journal_iters_fix(c);
 228
 229         return 0;
 230 }
 231
 232 /*
 233  * Can only be used from the recovery thread while we're still RO - can't be
 234  * used once we've got RW, as journal_keys is at that point used by multiple
 235  * threads:
 236  */
 237 int bch2_journal_key_insert(struct bch_fs *c, enum btree_id id,
 238                             unsigned level, struct bkey_i *k)
 239 {
 240         struct bkey_i *n;
 241         int ret;
 242
 243         n = kmalloc(bkey_bytes(&k->k), GFP_KERNEL);
 244         if (!n)
 245                 return -BCH_ERR_ENOMEM_journal_key_insert;
 246
 247         bkey_copy(n, k);
 248         ret = bch2_journal_key_insert_take(c, id, level, n);
 249         if (ret)
 250                 kfree(n);
 251         return ret;
 252 }
 253
 254 int bch2_journal_key_delete(struct bch_fs *c, enum btree_id id,
 255                             unsigned level, struct bpos pos)
 256 {
 257         struct bkey_i whiteout;
 258
 259         bkey_init(&whiteout.k);
 260         whiteout.k.p = pos;
 261
 262         return bch2_journal_key_insert(c, id, level, &whiteout);
 263 }
 264
 265 void bch2_journal_key_overwritten(struct bch_fs *c, enum btree_id btree,
 266                                   unsigned level, struct bpos pos)
 267 {
 268         struct journal_keys *keys = &c->journal_keys;
 269         size_t idx = bch2_journal_key_search(keys, btree, level, pos);
 270
 271         if (idx < keys->size &&
 272             keys->d[idx].btree_id       == btree &&
 273             keys->d[idx].level          == level &&
 274             bpos_eq(keys->d[idx].k->k.p, pos))
 275                 keys->d[idx].overwritten = true;
 276 }
 277
 278 static void bch2_journal_iter_advance(struct journal_iter *iter)
 279 {
 280         if (iter->idx < iter->keys->size) {
 281                 iter->idx++;
 282                 if (iter->idx == iter->keys->gap)
 283                         iter->idx += iter->keys->size - iter->keys->nr;
 284         }
 285 }
 286
 287 static struct bkey_s_c bch2_journal_iter_peek(struct journal_iter *iter)
 288 {
 289         struct journal_key *k = iter->keys->d + iter->idx;
 290
 291         while (k < iter->keys->d + iter->keys->size &&
 292                k->btree_id      == iter->btree_id &&
 293                k->level         == iter->level) {
 294                 if (!k->overwritten)
 295                         return bkey_i_to_s_c(k->k);
 296
 297                 bch2_journal_iter_advance(iter);
 298                 k = iter->keys->d + iter->idx;
 299         }
 300
 301         return bkey_s_c_null;
 302 }
 303
 304 static void bch2_journal_iter_exit(struct journal_iter *iter)
 305 {
 306         list_del(&iter->list);
 307 }
 308
 309 static void bch2_journal_iter_init(struct bch_fs *c,
 310                                    struct journal_iter *iter,
 311                                    enum btree_id id, unsigned level,
 312                                    struct bpos pos)
 313 {
 314         iter->btree_id  = id;
 315         iter->level     = level;
 316         iter->keys      = &c->journal_keys;
 317         iter->idx       = bch2_journal_key_search(&c->journal_keys, id, level, pos);
 318 }
 319
 320 static struct bkey_s_c bch2_journal_iter_peek_btree(struct btree_and_journal_iter *iter)
 321 {
 322         return bch2_btree_node_iter_peek_unpack(&iter->node_iter,
 323                                                 iter->b, &iter->unpacked);
 324 }
 325
 326 static void bch2_journal_iter_advance_btree(struct btree_and_journal_iter *iter)
 327 {
 328         bch2_btree_node_iter_advance(&iter->node_iter, iter->b);
 329 }
 330
 331 void bch2_btree_and_journal_iter_advance(struct btree_and_journal_iter *iter)
 332 {
 333         if (bpos_eq(iter->pos, SPOS_MAX))
 334                 iter->at_end = true;
 335         else
 336                 iter->pos = bpos_successor(iter->pos);
 337 }
 338
 339 static void btree_and_journal_iter_prefetch(struct btree_and_journal_iter *_iter)
 340 {
 341         struct btree_and_journal_iter iter = *_iter;
 342         struct bch_fs *c = iter.trans->c;
 343         unsigned level = iter.journal.level;
 344         struct bkey_buf tmp;
 345         unsigned nr = test_bit(BCH_FS_started, &c->flags)
 346                 ? (level > 1 ? 0 :  2)
 347                 : (level > 1 ? 1 : 16);
 348
 349         iter.prefetch = false;
 350         bch2_bkey_buf_init(&tmp);
 351
 352         while (nr--) {
 353                 bch2_btree_and_journal_iter_advance(&iter);
 354                 struct bkey_s_c k = bch2_btree_and_journal_iter_peek(&iter);
 355                 if (!k.k)
 356                         break;
 357
 358                 bch2_bkey_buf_reassemble(&tmp, c, k);
 359                 bch2_btree_node_prefetch(iter.trans, NULL, tmp.k, iter.journal.btree_id, level - 1);
 360         }
 361
 362         bch2_bkey_buf_exit(&tmp, c);
 363 }
 364
 365 struct bkey_s_c bch2_btree_and_journal_iter_peek(struct btree_and_journal_iter *iter)
 366 {
 367         struct bkey_s_c btree_k, journal_k, ret;
 368
 369         if (iter->prefetch && iter->journal.level)
 370                 btree_and_journal_iter_prefetch(iter);
 371 again:
 372         if (iter->at_end)
 373                 return bkey_s_c_null;
 374
 375         while ((btree_k = bch2_journal_iter_peek_btree(iter)).k &&
 376                bpos_lt(btree_k.k->p, iter->pos))
 377                 bch2_journal_iter_advance_btree(iter);
 378
 379         while ((journal_k = bch2_journal_iter_peek(&iter->journal)).k &&
 380                bpos_lt(journal_k.k->p, iter->pos))
 381                 bch2_journal_iter_advance(&iter->journal);
 382
 383         ret = journal_k.k &&
 384                 (!btree_k.k || bpos_le(journal_k.k->p, btree_k.k->p))
 385                 ? journal_k
 386                 : btree_k;
 387
 388         if (ret.k && iter->b && bpos_gt(ret.k->p, iter->b->data->max_key))
 389                 ret = bkey_s_c_null;
 390
 391         if (ret.k) {
 392                 iter->pos = ret.k->p;
 393                 if (bkey_deleted(ret.k)) {
 394                         bch2_btree_and_journal_iter_advance(iter);
 395                         goto again;
 396                 }
 397         } else {
 398                 iter->pos = SPOS_MAX;
 399                 iter->at_end = true;
 400         }
 401
 402         return ret;
 403 }
 404
 405 void bch2_btree_and_journal_iter_exit(struct btree_and_journal_iter *iter)
 406 {
 407         bch2_journal_iter_exit(&iter->journal);
 408 }
 409
 410 void __bch2_btree_and_journal_iter_init_node_iter(struct btree_trans *trans,
 411                                                   struct btree_and_journal_iter *iter,
 412                                                   struct btree *b,
 413                                                   struct btree_node_iter node_iter,
 414                                                   struct bpos pos)
 415 {
 416         memset(iter, 0, sizeof(*iter));
 417
 418         iter->trans = trans;
 419         iter->b = b;
 420         iter->node_iter = node_iter;
 421         bch2_journal_iter_init(trans->c, &iter->journal, b->c.btree_id, b->c.level, pos);
 422         INIT_LIST_HEAD(&iter->journal.list);
 423         iter->pos = b->data->min_key;
 424         iter->at_end = false;
 425 }
 426
 427 /*
 428  * this version is used by btree_gc before filesystem has gone RW and
 429  * multithreaded, so uses the journal_iters list:
 430  */
 431 void bch2_btree_and_journal_iter_init_node_iter(struct btree_trans *trans,
 432                                                 struct btree_and_journal_iter *iter,
 433                                                 struct btree *b)
 434 {
 435         struct btree_node_iter node_iter;
 436
 437         bch2_btree_node_iter_init_from_start(&node_iter, b);
 438         __bch2_btree_and_journal_iter_init_node_iter(trans, iter, b, node_iter, b->data->min_key);
 439         list_add(&iter->journal.list, &trans->c->journal_iters);
 440 }
 441
 442 /* sort and dedup all keys in the journal: */
 443
 444 void bch2_journal_entries_free(struct bch_fs *c)
 445 {
 446         struct journal_replay **i;
 447         struct genradix_iter iter;
 448
 449         genradix_for_each(&c->journal_entries, iter, i)
 450                 kvfree(*i);
 451         genradix_free(&c->journal_entries);
 452 }
 453
 454 /*
 455  * When keys compare equal, oldest compares first:
 456  */
 457 static int journal_sort_key_cmp(const void *_l, const void *_r)
 458 {
 459         const struct journal_key *l = _l;
 460         const struct journal_key *r = _r;
 461
 462         return  journal_key_cmp(l, r) ?:
 463                 cmp_int(l->journal_seq, r->journal_seq) ?:
 464                 cmp_int(l->journal_offset, r->journal_offset);
 465 }
 466
 467 void bch2_journal_keys_put(struct bch_fs *c)
 468 {
 469         struct journal_keys *keys = &c->journal_keys;
 470         struct journal_key *i;
 471
 472         BUG_ON(atomic_read(&keys->ref) <= 0);
 473
 474         if (!atomic_dec_and_test(&keys->ref))
 475                 return;
 476
 477         move_gap(keys->d, keys->nr, keys->size, keys->gap, keys->nr);
 478         keys->gap = keys->nr;
 479
 480         for (i = keys->d; i < keys->d + keys->nr; i++)
 481                 if (i->allocated)
 482                         kfree(i->k);
 483
 484         kvfree(keys->d);
 485         keys->d = NULL;
 486         keys->nr = keys->gap = keys->size = 0;
 487
 488         bch2_journal_entries_free(c);
 489 }
 490
 491 static void __journal_keys_sort(struct journal_keys *keys)
 492 {
 493         struct journal_key *src, *dst;
 494
 495         sort(keys->d, keys->nr, sizeof(keys->d[0]), journal_sort_key_cmp, NULL);
 496
 497         src = dst = keys->d;
 498         while (src < keys->d + keys->nr) {
 499                 while (src + 1 < keys->d + keys->nr &&
 500                        !journal_key_cmp(src, src + 1))
 501                         src++;
 502
 503                 *dst++ = *src++;
 504         }
 505
 506         keys->nr = dst - keys->d;
 507 }
 508
 509 int bch2_journal_keys_sort(struct bch_fs *c)
 510 {
 511         struct genradix_iter iter;
 512         struct journal_replay *i, **_i;
 513         struct jset_entry *entry;
 514         struct bkey_i *k;
 515         struct journal_keys *keys = &c->journal_keys;
 516         size_t nr_keys = 0, nr_read = 0;
 517
 518         genradix_for_each(&c->journal_entries, iter, _i) {
 519                 i = *_i;
 520
 521                 if (!i || i->ignore)
 522                         continue;
 523
 524                 for_each_jset_key(k, entry, &i->j)
 525                         nr_keys++;
 526         }
 527
 528         if (!nr_keys)
 529                 return 0;
 530
 531         keys->size = roundup_pow_of_two(nr_keys);
 532
 533         keys->d = kvmalloc_array(keys->size, sizeof(keys->d[0]), GFP_KERNEL);
 534         if (!keys->d) {
 535                 bch_err(c, "Failed to allocate buffer for sorted journal keys (%zu keys); trying slowpath",
 536                         nr_keys);
 537
 538                 do {
 539                         keys->size >>= 1;
 540                         keys->d = kvmalloc_array(keys->size, sizeof(keys->d[0]), GFP_KERNEL);
 541                 } while (!keys->d && keys->size > nr_keys / 8);
 542
 543                 if (!keys->d) {
 544                         bch_err(c, "Failed to allocate %zu size buffer for sorted journal keys; exiting",
 545                                 keys->size);
 546                         return -BCH_ERR_ENOMEM_journal_keys_sort;
 547                 }
 548         }
 549
 550         genradix_for_each(&c->journal_entries, iter, _i) {
 551                 i = *_i;
 552
 553                 if (!i || i->ignore)
 554                         continue;
 555
 556                 cond_resched();
 557
 558                 for_each_jset_key(k, entry, &i->j) {
 559                         if (keys->nr == keys->size) {
 560                                 __journal_keys_sort(keys);
 561
 562                                 if (keys->nr > keys->size * 7 / 8) {
 563                                         bch_err(c, "Too many journal keys for slowpath; have %zu compacted, buf size %zu, processed %zu/%zu",
 564                                                 keys->nr, keys->size, nr_read, nr_keys);
 565                                         return -BCH_ERR_ENOMEM_journal_keys_sort;
 566                                 }
 567                         }
 568
 569                         keys->d[keys->nr++] = (struct journal_key) {
 570                                 .btree_id       = entry->btree_id,
 571                                 .level          = entry->level,
 572                                 .k              = k,
 573                                 .journal_seq    = le64_to_cpu(i->j.seq),
 574                                 .journal_offset = k->_data - i->j._data,
 575                         };
 576
 577                         nr_read++;
 578                 }
 579         }
 580
 581         __journal_keys_sort(keys);
 582         keys->gap = keys->nr;
 583
 584         bch_verbose(c, "Journal keys: %zu read, %zu after sorting and compacting", nr_keys, keys->nr);
 585         return 0;
 586 }