drivers/md/bcache/journal.c

   1 /*
   2  * bcache journalling code, for btree insertions
   3  *
   4  * Copyright 2012 Google, Inc.
   5  */
   6
   7 #include "bcache.h"
   8 #include "btree.h"
   9 #include "debug.h"
  10 #include "request.h"
  11
  12 #include <trace/events/bcache.h>
  13
  14 /*
  15  * Journal replay/recovery:
  16  *
  17  * This code is all driven from run_cache_set(); we first read the journal
  18  * entries, do some other stuff, then we mark all the keys in the journal
  19  * entries (same as garbage collection would), then we replay them - reinserting
  20  * them into the cache in precisely the same order as they appear in the
  21  * journal.
  22  *
  23  * We only journal keys that go in leaf nodes, which simplifies things quite a
  24  * bit.
  25  */
  26
  27 static void journal_read_endio(struct bio *bio, int error)
  28 {
  29         struct closure *cl = bio->bi_private;
  30         closure_put(cl);
  31 }
  32
  33 static int journal_read_bucket(struct cache *ca, struct list_head *list,
  34                                struct btree_op *op, unsigned bucket_index)
  35 {
  36         struct journal_device *ja = &ca->journal;
  37         struct bio *bio = &ja->bio;
  38
  39         struct journal_replay *i;
  40         struct jset *j, *data = ca->set->journal.w[0].data;
  41         unsigned len, left, offset = 0;
  42         int ret = 0;
  43         sector_t bucket = bucket_to_sector(ca->set, ca->sb.d[bucket_index]);
  44
  45         pr_debug("reading %llu", (uint64_t) bucket);
  46
  47         while (offset < ca->sb.bucket_size) {
  48 reread:         left = ca->sb.bucket_size - offset;
  49                 len = min_t(unsigned, left, PAGE_SECTORS * 8);
  50
  51                 bio_reset(bio);
  52                 bio->bi_sector  = bucket + offset;
  53                 bio->bi_bdev    = ca->bdev;
  54                 bio->bi_rw      = READ;
  55                 bio->bi_size    = len << 9;
  56
  57                 bio->bi_end_io  = journal_read_endio;
  58                 bio->bi_private = &op->cl;
  59                 bch_bio_map(bio, data);
  60
  61                 closure_bio_submit(bio, &op->cl, ca);
  62                 closure_sync(&op->cl);
  63
  64                 /* This function could be simpler now since we no longer write
  65                  * journal entries that overlap bucket boundaries; this means
  66                  * the start of a bucket will always have a valid journal entry
  67                  * if it has any journal entries at all.
  68                  */
  69
  70                 j = data;
  71                 while (len) {
  72                         struct list_head *where;
  73                         size_t blocks, bytes = set_bytes(j);
  74
  75                         if (j->magic != jset_magic(ca->set))
  76                                 return ret;
  77
  78                         if (bytes > left << 9)
  79                                 return ret;
  80
  81                         if (bytes > len << 9)
  82                                 goto reread;
  83
  84                         if (j->csum != csum_set(j))
  85                                 return ret;
  86
  87                         blocks = set_blocks(j, ca->set);
  88
  89                         while (!list_empty(list)) {
  90                                 i = list_first_entry(list,
  91                                         struct journal_replay, list);
  92                                 if (i->j.seq >= j->last_seq)
  93                                         break;
  94                                 list_del(&i->list);
  95                                 kfree(i);
  96                         }
  97
  98                         list_for_each_entry_reverse(i, list, list) {
  99                                 if (j->seq == i->j.seq)
 100                                         goto next_set;
 101
 102                                 if (j->seq < i->j.last_seq)
 103                                         goto next_set;
 104
 105                                 if (j->seq > i->j.seq) {
 106                                         where = &i->list;
 107                                         goto add;
 108                                 }
 109                         }
 110
 111                         where = list;
 112 add:
 113                         i = kmalloc(offsetof(struct journal_replay, j) +
 114                                     bytes, GFP_KERNEL);
 115                         if (!i)
 116                                 return -ENOMEM;
 117                         memcpy(&i->j, j, bytes);
 118                         list_add(&i->list, where);
 119                         ret = 1;
 120
 121                         ja->seq[bucket_index] = j->seq;
 122 next_set:
 123                         offset  += blocks * ca->sb.block_size;
 124                         len     -= blocks * ca->sb.block_size;
 125                         j = ((void *) j) + blocks * block_bytes(ca);
 126                 }
 127         }
 128
 129         return ret;
 130 }
 131
 132 int bch_journal_read(struct cache_set *c, struct list_head *list,
 133                         struct btree_op *op)
 134 {
 135 #define read_bucket(b)                                                  \
 136         ({                                                              \
 137                 int ret = journal_read_bucket(ca, list, op, b);         \
 138                 __set_bit(b, bitmap);                                   \
 139                 if (ret < 0)                                            \
 140                         return ret;                                     \
 141                 ret;                                                    \
 142         })
 143
 144         struct cache *ca;
 145         unsigned iter;
 146
 147         for_each_cache(ca, c, iter) {
 148                 struct journal_device *ja = &ca->journal;
 149                 unsigned long bitmap[SB_JOURNAL_BUCKETS / BITS_PER_LONG];
 150                 unsigned i, l, r, m;
 151                 uint64_t seq;
 152
 153                 bitmap_zero(bitmap, SB_JOURNAL_BUCKETS);
 154                 pr_debug("%u journal buckets", ca->sb.njournal_buckets);
 155
 156                 /* Read journal buckets ordered by golden ratio hash to quickly
 157                  * find a sequence of buckets with valid journal entries
 158                  */
 159                 for (i = 0; i < ca->sb.njournal_buckets; i++) {
 160                         l = (i * 2654435769U) % ca->sb.njournal_buckets;
 161
 162                         if (test_bit(l, bitmap))
 163                                 break;
 164
 165                         if (read_bucket(l))
 166                                 goto bsearch;
 167                 }
 168
 169                 /* If that fails, check all the buckets we haven't checked
 170                  * already
 171                  */
 172                 pr_debug("falling back to linear search");
 173
 174                 for (l = 0; l < ca->sb.njournal_buckets; l++) {
 175                         if (test_bit(l, bitmap))
 176                                 continue;
 177
 178                         if (read_bucket(l))
 179                                 goto bsearch;
 180                 }
 181 bsearch:
 182                 /* Binary search */
 183                 m = r = find_next_bit(bitmap, ca->sb.njournal_buckets, l + 1);
 184                 pr_debug("starting binary search, l %u r %u", l, r);
 185
 186                 while (l + 1 < r) {
 187                         seq = list_entry(list->prev, struct journal_replay,
 188                                          list)->j.seq;
 189
 190                         m = (l + r) >> 1;
 191                         read_bucket(m);
 192
 193                         if (seq != list_entry(list->prev, struct journal_replay,
 194                                               list)->j.seq)
 195                                 l = m;
 196                         else
 197                                 r = m;
 198                 }
 199
 200                 /* Read buckets in reverse order until we stop finding more
 201                  * journal entries
 202                  */
 203                 pr_debug("finishing up");
 204                 l = m;
 205
 206                 while (1) {
 207                         if (!l--)
 208                                 l = ca->sb.njournal_buckets - 1;
 209
 210                         if (l == m)
 211                                 break;
 212
 213                         if (test_bit(l, bitmap))
 214                                 continue;
 215
 216                         if (!read_bucket(l))
 217                                 break;
 218                 }
 219
 220                 seq = 0;
 221
 222                 for (i = 0; i < ca->sb.njournal_buckets; i++)
 223                         if (ja->seq[i] > seq) {
 224                                 seq = ja->seq[i];
 225                                 ja->cur_idx = ja->discard_idx =
 226                                         ja->last_idx = i;
 227
 228                         }
 229         }
 230
 231         c->journal.seq = list_entry(list->prev,
 232                                     struct journal_replay,
 233                                     list)->j.seq;
 234
 235         return 0;
 236 #undef read_bucket
 237 }
 238
 239 void bch_journal_mark(struct cache_set *c, struct list_head *list)
 240 {
 241         atomic_t p = { 0 };
 242         struct bkey *k;
 243         struct journal_replay *i;
 244         struct journal *j = &c->journal;
 245         uint64_t last = j->seq;
 246
 247         /*
 248          * journal.pin should never fill up - we never write a journal
 249          * entry when it would fill up. But if for some reason it does, we
 250          * iterate over the list in reverse order so that we can just skip that
 251          * refcount instead of bugging.
 252          */
 253
 254         list_for_each_entry_reverse(i, list, list) {
 255                 BUG_ON(last < i->j.seq);
 256                 i->pin = NULL;
 257
 258                 while (last-- != i->j.seq)
 259                         if (fifo_free(&j->pin) > 1) {
 260                                 fifo_push_front(&j->pin, p);
 261                                 atomic_set(&fifo_front(&j->pin), 0);
 262                         }
 263
 264                 if (fifo_free(&j->pin) > 1) {
 265                         fifo_push_front(&j->pin, p);
 266                         i->pin = &fifo_front(&j->pin);
 267                         atomic_set(i->pin, 1);
 268                 }
 269
 270                 for (k = i->j.start;
 271                      k < end(&i->j);
 272                      k = bkey_next(k)) {
 273                         unsigned j;
 274
 275                         for (j = 0; j < KEY_PTRS(k); j++) {
 276                                 struct bucket *g = PTR_BUCKET(c, k, j);
 277                                 atomic_inc(&g->pin);
 278
 279                                 if (g->prio == BTREE_PRIO &&
 280                                     !ptr_stale(c, k, j))
 281                                         g->prio = INITIAL_PRIO;
 282                         }
 283
 284                         __bch_btree_mark_key(c, 0, k);
 285                 }
 286         }
 287 }
 288
 289 int bch_journal_replay(struct cache_set *s, struct list_head *list,
 290                           struct btree_op *op)
 291 {
 292         int ret = 0, keys = 0, entries = 0;
 293         struct bkey *k;
 294         struct journal_replay *i =
 295                 list_entry(list->prev, struct journal_replay, list);
 296
 297         uint64_t start = i->j.last_seq, end = i->j.seq, n = start;
 298
 299         list_for_each_entry(i, list, list) {
 300                 BUG_ON(i->pin && atomic_read(i->pin) != 1);
 301
 302                 if (n != i->j.seq)
 303                         pr_err(
 304                 "journal entries %llu-%llu missing! (replaying %llu-%llu)\n",
 305                 n, i->j.seq - 1, start, end);
 306
 307                 for (k = i->j.start;
 308                      k < end(&i->j);
 309                      k = bkey_next(k)) {
 310                         trace_bcache_journal_replay_key(k);
 311
 312                         bkey_copy(op->keys.top, k);
 313                         bch_keylist_push(&op->keys);
 314
 315                         op->journal = i->pin;
 316                         atomic_inc(op->journal);
 317
 318                         ret = bch_btree_insert(op, s);
 319                         if (ret)
 320                                 goto err;
 321
 322                         BUG_ON(!bch_keylist_empty(&op->keys));
 323                         keys++;
 324
 325                         cond_resched();
 326                 }
 327
 328                 if (i->pin)
 329                         atomic_dec(i->pin);
 330                 n = i->j.seq + 1;
 331                 entries++;
 332         }
 333
 334         pr_info("journal replay done, %i keys in %i entries, seq %llu",
 335                 keys, entries, end);
 336
 337         while (!list_empty(list)) {
 338                 i = list_first_entry(list, struct journal_replay, list);
 339                 list_del(&i->list);
 340                 kfree(i);
 341         }
 342 err:
 343         closure_sync(&op->cl);
 344         return ret;
 345 }
 346
 347 /* Journalling */
 348
 349 static void btree_flush_write(struct cache_set *c)
 350 {
 351         /*
 352          * Try to find the btree node with that references the oldest journal
 353          * entry, best is our current candidate and is locked if non NULL:
 354          */
 355         struct btree *b, *best = NULL;
 356         unsigned iter;
 357
 358         for_each_cached_btree(b, c, iter) {
 359                 if (!down_write_trylock(&b->lock))
 360                         continue;
 361
 362                 if (!btree_node_dirty(b) ||
 363                     !btree_current_write(b)->journal) {
 364                         rw_unlock(true, b);
 365                         continue;
 366                 }
 367
 368                 if (!best)
 369                         best = b;
 370                 else if (journal_pin_cmp(c,
 371                                          btree_current_write(best),
 372                                          btree_current_write(b))) {
 373                         rw_unlock(true, best);
 374                         best = b;
 375                 } else
 376                         rw_unlock(true, b);
 377         }
 378
 379         if (best)
 380                 goto out;
 381
 382         /* We can't find the best btree node, just pick the first */
 383         list_for_each_entry(b, &c->btree_cache, list)
 384                 if (!b->level && btree_node_dirty(b)) {
 385                         best = b;
 386                         rw_lock(true, best, best->level);
 387                         goto found;
 388                 }
 389
 390 out:
 391         if (!best)
 392                 return;
 393 found:
 394         if (btree_node_dirty(best))
 395                 bch_btree_node_write(best, NULL);
 396         rw_unlock(true, best);
 397 }
 398
 399 #define last_seq(j)     ((j)->seq - fifo_used(&(j)->pin) + 1)
 400
 401 static void journal_discard_endio(struct bio *bio, int error)
 402 {
 403         struct journal_device *ja =
 404                 container_of(bio, struct journal_device, discard_bio);
 405         struct cache *ca = container_of(ja, struct cache, journal);
 406
 407         atomic_set(&ja->discard_in_flight, DISCARD_DONE);
 408
 409         closure_wake_up(&ca->set->journal.wait);
 410         closure_put(&ca->set->cl);
 411 }
 412
 413 static void journal_discard_work(struct work_struct *work)
 414 {
 415         struct journal_device *ja =
 416                 container_of(work, struct journal_device, discard_work);
 417
 418         submit_bio(0, &ja->discard_bio);
 419 }
 420
 421 static void do_journal_discard(struct cache *ca)
 422 {
 423         struct journal_device *ja = &ca->journal;
 424         struct bio *bio = &ja->discard_bio;
 425
 426         if (!ca->discard) {
 427                 ja->discard_idx = ja->last_idx;
 428                 return;
 429         }
 430
 431         switch (atomic_read(&ja->discard_in_flight) == DISCARD_IN_FLIGHT) {
 432         case DISCARD_IN_FLIGHT:
 433                 return;
 434
 435         case DISCARD_DONE:
 436                 ja->discard_idx = (ja->discard_idx + 1) %
 437                         ca->sb.njournal_buckets;
 438
 439                 atomic_set(&ja->discard_in_flight, DISCARD_READY);
 440                 /* fallthrough */
 441
 442         case DISCARD_READY:
 443                 if (ja->discard_idx == ja->last_idx)
 444                         return;
 445
 446                 atomic_set(&ja->discard_in_flight, DISCARD_IN_FLIGHT);
 447
 448                 bio_init(bio);
 449                 bio->bi_sector          = bucket_to_sector(ca->set,
 450                                                 ca->sb.d[ja->discard_idx]);
 451                 bio->bi_bdev            = ca->bdev;
 452                 bio->bi_rw              = REQ_WRITE|REQ_DISCARD;
 453                 bio->bi_max_vecs        = 1;
 454                 bio->bi_io_vec          = bio->bi_inline_vecs;
 455                 bio->bi_size            = bucket_bytes(ca);
 456                 bio->bi_end_io          = journal_discard_endio;
 457
 458                 closure_get(&ca->set->cl);
 459                 INIT_WORK(&ja->discard_work, journal_discard_work);
 460                 schedule_work(&ja->discard_work);
 461         }
 462 }
 463
 464 static void journal_reclaim(struct cache_set *c)
 465 {
 466         struct bkey *k = &c->journal.key;
 467         struct cache *ca;
 468         uint64_t last_seq;
 469         unsigned iter, n = 0;
 470         atomic_t p;
 471
 472         while (!atomic_read(&fifo_front(&c->journal.pin)))
 473                 fifo_pop(&c->journal.pin, p);
 474
 475         last_seq = last_seq(&c->journal);
 476
 477         /* Update last_idx */
 478
 479         for_each_cache(ca, c, iter) {
 480                 struct journal_device *ja = &ca->journal;
 481
 482                 while (ja->last_idx != ja->cur_idx &&
 483                        ja->seq[ja->last_idx] < last_seq)
 484                         ja->last_idx = (ja->last_idx + 1) %
 485                                 ca->sb.njournal_buckets;
 486         }
 487
 488         for_each_cache(ca, c, iter)
 489                 do_journal_discard(ca);
 490
 491         if (c->journal.blocks_free)
 492                 return;
 493
 494         /*
 495          * Allocate:
 496          * XXX: Sort by free journal space
 497          */
 498
 499         for_each_cache(ca, c, iter) {
 500                 struct journal_device *ja = &ca->journal;
 501                 unsigned next = (ja->cur_idx + 1) % ca->sb.njournal_buckets;
 502
 503                 /* No space available on this device */
 504                 if (next == ja->discard_idx)
 505                         continue;
 506
 507                 ja->cur_idx = next;
 508                 k->ptr[n++] = PTR(0,
 509                                   bucket_to_sector(c, ca->sb.d[ja->cur_idx]),
 510                                   ca->sb.nr_this_dev);
 511         }
 512
 513         bkey_init(k);
 514         SET_KEY_PTRS(k, n);
 515
 516         if (n)
 517                 c->journal.blocks_free = c->sb.bucket_size >> c->block_bits;
 518
 519         if (!journal_full(&c->journal))
 520                 __closure_wake_up(&c->journal.wait);
 521 }
 522
 523 void bch_journal_next(struct journal *j)
 524 {
 525         atomic_t p = { 1 };
 526
 527         j->cur = (j->cur == j->w)
 528                 ? &j->w[1]
 529                 : &j->w[0];
 530
 531         /*
 532          * The fifo_push() needs to happen at the same time as j->seq is
 533          * incremented for last_seq() to be calculated correctly
 534          */
 535         BUG_ON(!fifo_push(&j->pin, p));
 536         atomic_set(&fifo_back(&j->pin), 1);
 537
 538         j->cur->data->seq       = ++j->seq;
 539         j->cur->need_write      = false;
 540         j->cur->data->keys      = 0;
 541
 542         if (fifo_full(&j->pin))
 543                 pr_debug("journal_pin full (%zu)", fifo_used(&j->pin));
 544 }
 545
 546 static void journal_write_endio(struct bio *bio, int error)
 547 {
 548         struct journal_write *w = bio->bi_private;
 549
 550         cache_set_err_on(error, w->c, "journal io error");
 551         closure_put(&w->c->journal.io.cl);
 552 }
 553
 554 static void journal_write(struct closure *);
 555
 556 static void journal_write_done(struct closure *cl)
 557 {
 558         struct journal *j = container_of(cl, struct journal, io.cl);
 559         struct cache_set *c = container_of(j, struct cache_set, journal);
 560
 561         struct journal_write *w = (j->cur == j->w)
 562                 ? &j->w[1]
 563                 : &j->w[0];
 564
 565         __closure_wake_up(&w->wait);
 566
 567         if (c->journal_delay_ms)
 568                 closure_delay(&j->io, msecs_to_jiffies(c->journal_delay_ms));
 569
 570         continue_at(cl, journal_write, system_wq);
 571 }
 572
 573 static void journal_write_unlocked(struct closure *cl)
 574         __releases(c->journal.lock)
 575 {
 576         struct cache_set *c = container_of(cl, struct cache_set, journal.io.cl);
 577         struct cache *ca;
 578         struct journal_write *w = c->journal.cur;
 579         struct bkey *k = &c->journal.key;
 580         unsigned i, sectors = set_blocks(w->data, c) * c->sb.block_size;
 581
 582         struct bio *bio;
 583         struct bio_list list;
 584         bio_list_init(&list);
 585
 586         if (!w->need_write) {
 587                 /*
 588                  * XXX: have to unlock closure before we unlock journal lock,
 589                  * else we race with bch_journal(). But this way we race
 590                  * against cache set unregister. Doh.
 591                  */
 592                 set_closure_fn(cl, NULL, NULL);
 593                 closure_sub(cl, CLOSURE_RUNNING + 1);
 594                 spin_unlock(&c->journal.lock);
 595                 return;
 596         } else if (journal_full(&c->journal)) {
 597                 journal_reclaim(c);
 598                 spin_unlock(&c->journal.lock);
 599
 600                 btree_flush_write(c);
 601                 continue_at(cl, journal_write, system_wq);
 602         }
 603
 604         c->journal.blocks_free -= set_blocks(w->data, c);
 605
 606         w->data->btree_level = c->root->level;
 607
 608         bkey_copy(&w->data->btree_root, &c->root->key);
 609         bkey_copy(&w->data->uuid_bucket, &c->uuid_bucket);
 610
 611         for_each_cache(ca, c, i)
 612                 w->data->prio_bucket[ca->sb.nr_this_dev] = ca->prio_buckets[0];
 613
 614         w->data->magic          = jset_magic(c);
 615         w->data->version        = BCACHE_JSET_VERSION;
 616         w->data->last_seq       = last_seq(&c->journal);
 617         w->data->csum           = csum_set(w->data);
 618
 619         for (i = 0; i < KEY_PTRS(k); i++) {
 620                 ca = PTR_CACHE(c, k, i);
 621                 bio = &ca->journal.bio;
 622
 623                 atomic_long_add(sectors, &ca->meta_sectors_written);
 624
 625                 bio_reset(bio);
 626                 bio->bi_sector  = PTR_OFFSET(k, i);
 627                 bio->bi_bdev    = ca->bdev;
 628                 bio->bi_rw      = REQ_WRITE|REQ_SYNC|REQ_META|REQ_FLUSH|REQ_FUA;
 629                 bio->bi_size    = sectors << 9;
 630
 631                 bio->bi_end_io  = journal_write_endio;
 632                 bio->bi_private = w;
 633                 bch_bio_map(bio, w->data);
 634
 635                 trace_bcache_journal_write(bio);
 636                 bio_list_add(&list, bio);
 637
 638                 SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + sectors);
 639
 640                 ca->journal.seq[ca->journal.cur_idx] = w->data->seq;
 641         }
 642
 643         atomic_dec_bug(&fifo_back(&c->journal.pin));
 644         bch_journal_next(&c->journal);
 645         journal_reclaim(c);
 646
 647         spin_unlock(&c->journal.lock);
 648
 649         while ((bio = bio_list_pop(&list)))
 650                 closure_bio_submit(bio, cl, c->cache[0]);
 651
 652         continue_at(cl, journal_write_done, NULL);
 653 }
 654
 655 static void journal_write(struct closure *cl)
 656 {
 657         struct cache_set *c = container_of(cl, struct cache_set, journal.io.cl);
 658
 659         spin_lock(&c->journal.lock);
 660         journal_write_unlocked(cl);
 661 }
 662
 663 static void __journal_try_write(struct cache_set *c, bool noflush)
 664         __releases(c->journal.lock)
 665 {
 666         struct closure *cl = &c->journal.io.cl;
 667
 668         if (!closure_trylock(cl, &c->cl))
 669                 spin_unlock(&c->journal.lock);
 670         else if (noflush && journal_full(&c->journal)) {
 671                 spin_unlock(&c->journal.lock);
 672                 continue_at(cl, journal_write, system_wq);
 673         } else
 674                 journal_write_unlocked(cl);
 675 }
 676
 677 #define journal_try_write(c)    __journal_try_write(c, false)
 678
 679 void bch_journal_meta(struct cache_set *c, struct closure *cl)
 680 {
 681         struct journal_write *w;
 682
 683         if (CACHE_SYNC(&c->sb)) {
 684                 spin_lock(&c->journal.lock);
 685
 686                 w = c->journal.cur;
 687                 w->need_write = true;
 688
 689                 if (cl)
 690                         BUG_ON(!closure_wait(&w->wait, cl));
 691
 692                 __journal_try_write(c, true);
 693         }
 694 }
 695
 696 /*
 697  * Entry point to the journalling code - bio_insert() and btree_invalidate()
 698  * pass bch_journal() a list of keys to be journalled, and then
 699  * bch_journal() hands those same keys off to btree_insert_async()
 700  */
 701
 702 void bch_journal(struct closure *cl)
 703 {
 704         struct btree_op *op = container_of(cl, struct btree_op, cl);
 705         struct cache_set *c = op->c;
 706         struct journal_write *w;
 707         size_t b, n = ((uint64_t *) op->keys.top) - op->keys.list;
 708
 709         if (op->type != BTREE_INSERT ||
 710             !CACHE_SYNC(&c->sb))
 711                 goto out;
 712
 713         /*
 714          * If we're looping because we errored, might already be waiting on
 715          * another journal write:
 716          */
 717         while (atomic_read(&cl->parent->remaining) & CLOSURE_WAITING)
 718                 closure_sync(cl->parent);
 719
 720         spin_lock(&c->journal.lock);
 721
 722         if (journal_full(&c->journal)) {
 723                 trace_bcache_journal_full(c);
 724
 725                 closure_wait(&c->journal.wait, cl);
 726
 727                 journal_reclaim(c);
 728                 spin_unlock(&c->journal.lock);
 729
 730                 btree_flush_write(c);
 731                 continue_at(cl, bch_journal, bcache_wq);
 732         }
 733
 734         w = c->journal.cur;
 735         w->need_write = true;
 736         b = __set_blocks(w->data, w->data->keys + n, c);
 737
 738         if (b * c->sb.block_size > PAGE_SECTORS << JSET_BITS ||
 739             b > c->journal.blocks_free) {
 740                 trace_bcache_journal_entry_full(c);
 741
 742                 /*
 743                  * XXX: If we were inserting so many keys that they won't fit in
 744                  * an _empty_ journal write, we'll deadlock. For now, handle
 745                  * this in bch_keylist_realloc() - but something to think about.
 746                  */
 747                 BUG_ON(!w->data->keys);
 748
 749                 BUG_ON(!closure_wait(&w->wait, cl));
 750
 751                 closure_flush(&c->journal.io);
 752
 753                 journal_try_write(c);
 754                 continue_at(cl, bch_journal, bcache_wq);
 755         }
 756
 757         memcpy(end(w->data), op->keys.list, n * sizeof(uint64_t));
 758         w->data->keys += n;
 759
 760         op->journal = &fifo_back(&c->journal.pin);
 761         atomic_inc(op->journal);
 762
 763         if (op->flush_journal) {
 764                 closure_flush(&c->journal.io);
 765                 closure_wait(&w->wait, cl->parent);
 766         }
 767
 768         journal_try_write(c);
 769 out:
 770         bch_btree_insert_async(cl);
 771 }
 772
 773 void bch_journal_free(struct cache_set *c)
 774 {
 775         free_pages((unsigned long) c->journal.w[1].data, JSET_BITS);
 776         free_pages((unsigned long) c->journal.w[0].data, JSET_BITS);
 777         free_fifo(&c->journal.pin);
 778 }
 779
 780 int bch_journal_alloc(struct cache_set *c)
 781 {
 782         struct journal *j = &c->journal;
 783
 784         closure_init_unlocked(&j->io);
 785         spin_lock_init(&j->lock);
 786
 787         c->journal_delay_ms = 100;
 788
 789         j->w[0].c = c;
 790         j->w[1].c = c;
 791
 792         if (!(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)) ||
 793             !(j->w[0].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS)) ||
 794             !(j->w[1].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS)))
 795                 return -ENOMEM;
 796
 797         return 0;
 798 }