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

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include "bcachefs.h"
   4 #include "btree_key_cache.h"
   5 #include "errcode.h"
   6 #include "error.h"
   7 #include "journal.h"
   8 #include "journal_io.h"
   9 #include "journal_reclaim.h"
  10 #include "replicas.h"
  11 #include "super.h"
  12
  13 #include <linux/kthread.h>
  14 #include <linux/sched/mm.h>
  15 #include <trace/events/bcachefs.h>
  16
  17 /* Free space calculations: */
  18
  19 static unsigned journal_space_from(struct journal_device *ja,
  20                                    enum journal_space_from from)
  21 {
  22         switch (from) {
  23         case journal_space_discarded:
  24                 return ja->discard_idx;
  25         case journal_space_clean_ondisk:
  26                 return ja->dirty_idx_ondisk;
  27         case journal_space_clean:
  28                 return ja->dirty_idx;
  29         default:
  30                 BUG();
  31         }
  32 }
  33
  34 unsigned bch2_journal_dev_buckets_available(struct journal *j,
  35                                             struct journal_device *ja,
  36                                             enum journal_space_from from)
  37 {
  38         unsigned available = (journal_space_from(ja, from) -
  39                               ja->cur_idx - 1 + ja->nr) % ja->nr;
  40
  41         /*
  42          * Don't use the last bucket unless writing the new last_seq
  43          * will make another bucket available:
  44          */
  45         if (available && ja->dirty_idx_ondisk == ja->dirty_idx)
  46                 --available;
  47
  48         return available;
  49 }
  50
  51 static void journal_set_remaining(struct journal *j, unsigned u64s_remaining)
  52 {
  53         union journal_preres_state old, new;
  54         u64 v = atomic64_read(&j->prereserved.counter);
  55
  56         do {
  57                 old.v = new.v = v;
  58                 new.remaining = u64s_remaining;
  59         } while ((v = atomic64_cmpxchg(&j->prereserved.counter,
  60                                        old.v, new.v)) != old.v);
  61 }
  62
  63 static struct journal_space
  64 journal_dev_space_available(struct journal *j, struct bch_dev *ca,
  65                             enum journal_space_from from)
  66 {
  67         struct journal_device *ja = &ca->journal;
  68         unsigned sectors, buckets, unwritten;
  69         u64 seq;
  70
  71         if (from == journal_space_total)
  72                 return (struct journal_space) {
  73                         .next_entry     = ca->mi.bucket_size,
  74                         .total          = ca->mi.bucket_size * ja->nr,
  75                 };
  76
  77         buckets = bch2_journal_dev_buckets_available(j, ja, from);
  78         sectors = ja->sectors_free;
  79
  80         /*
  81          * We that we don't allocate the space for a journal entry
  82          * until we write it out - thus, account for it here:
  83          */
  84         for (seq = journal_last_unwritten_seq(j);
  85              seq <= journal_cur_seq(j);
  86              seq++) {
  87                 unwritten = j->buf[seq & JOURNAL_BUF_MASK].sectors;
  88
  89                 if (!unwritten)
  90                         continue;
  91
  92                 /* entry won't fit on this device, skip: */
  93                 if (unwritten > ca->mi.bucket_size)
  94                         continue;
  95
  96                 if (unwritten >= sectors) {
  97                         if (!buckets) {
  98                                 sectors = 0;
  99                                 break;
 100                         }
 101
 102                         buckets--;
 103                         sectors = ca->mi.bucket_size;
 104                 }
 105
 106                 sectors -= unwritten;
 107         }
 108
 109         if (sectors < ca->mi.bucket_size && buckets) {
 110                 buckets--;
 111                 sectors = ca->mi.bucket_size;
 112         }
 113
 114         return (struct journal_space) {
 115                 .next_entry     = sectors,
 116                 .total          = sectors + buckets * ca->mi.bucket_size,
 117         };
 118 }
 119
 120 static struct journal_space __journal_space_available(struct journal *j, unsigned nr_devs_want,
 121                             enum journal_space_from from)
 122 {
 123         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 124         struct bch_dev *ca;
 125         unsigned i, pos, nr_devs = 0;
 126         struct journal_space space, dev_space[BCH_SB_MEMBERS_MAX];
 127
 128         BUG_ON(nr_devs_want > ARRAY_SIZE(dev_space));
 129
 130         rcu_read_lock();
 131         for_each_member_device_rcu(ca, c, i,
 132                                    &c->rw_devs[BCH_DATA_journal]) {
 133                 if (!ca->journal.nr)
 134                         continue;
 135
 136                 space = journal_dev_space_available(j, ca, from);
 137                 if (!space.next_entry)
 138                         continue;
 139
 140                 for (pos = 0; pos < nr_devs; pos++)
 141                         if (space.total > dev_space[pos].total)
 142                                 break;
 143
 144                 array_insert_item(dev_space, nr_devs, pos, space);
 145         }
 146         rcu_read_unlock();
 147
 148         if (nr_devs < nr_devs_want)
 149                 return (struct journal_space) { 0, 0 };
 150
 151         /*
 152          * We sorted largest to smallest, and we want the smallest out of the
 153          * @nr_devs_want largest devices:
 154          */
 155         return dev_space[nr_devs_want - 1];
 156 }
 157
 158 void bch2_journal_space_available(struct journal *j)
 159 {
 160         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 161         struct bch_dev *ca;
 162         unsigned clean, clean_ondisk, total;
 163         s64 u64s_remaining = 0;
 164         unsigned max_entry_size  = min(j->buf[0].buf_size >> 9,
 165                                        j->buf[1].buf_size >> 9);
 166         unsigned i, nr_online = 0, nr_devs_want;
 167         bool can_discard = false;
 168         int ret = 0;
 169
 170         lockdep_assert_held(&j->lock);
 171
 172         rcu_read_lock();
 173         for_each_member_device_rcu(ca, c, i,
 174                                    &c->rw_devs[BCH_DATA_journal]) {
 175                 struct journal_device *ja = &ca->journal;
 176
 177                 if (!ja->nr)
 178                         continue;
 179
 180                 while (ja->dirty_idx != ja->cur_idx &&
 181                        ja->bucket_seq[ja->dirty_idx] < journal_last_seq(j))
 182                         ja->dirty_idx = (ja->dirty_idx + 1) % ja->nr;
 183
 184                 while (ja->dirty_idx_ondisk != ja->dirty_idx &&
 185                        ja->bucket_seq[ja->dirty_idx_ondisk] < j->last_seq_ondisk)
 186                         ja->dirty_idx_ondisk = (ja->dirty_idx_ondisk + 1) % ja->nr;
 187
 188                 if (ja->discard_idx != ja->dirty_idx_ondisk)
 189                         can_discard = true;
 190
 191                 max_entry_size = min_t(unsigned, max_entry_size, ca->mi.bucket_size);
 192                 nr_online++;
 193         }
 194         rcu_read_unlock();
 195
 196         j->can_discard = can_discard;
 197
 198         if (nr_online < c->opts.metadata_replicas_required) {
 199                 ret = JOURNAL_ERR_insufficient_devices;
 200                 goto out;
 201         }
 202
 203         nr_devs_want = min_t(unsigned, nr_online, c->opts.metadata_replicas);
 204
 205         for (i = 0; i < journal_space_nr; i++)
 206                 j->space[i] = __journal_space_available(j, nr_devs_want, i);
 207
 208         clean_ondisk    = j->space[journal_space_clean_ondisk].total;
 209         clean           = j->space[journal_space_clean].total;
 210         total           = j->space[journal_space_total].total;
 211
 212         if (!clean_ondisk &&
 213             journal_cur_seq(j) == j->seq_ondisk) {
 214                 struct printbuf buf = PRINTBUF;
 215
 216                 __bch2_journal_debug_to_text(&buf, j);
 217                 bch_err(c, "journal stuck\n%s", buf.buf);
 218                 printbuf_exit(&buf);
 219
 220                 /*
 221                  * Hack: bch2_fatal_error() calls bch2_journal_halt() which
 222                  * takes journal lock:
 223                  */
 224                 spin_unlock(&j->lock);
 225                 bch2_fatal_error(c);
 226                 spin_lock(&j->lock);
 227
 228                 ret = JOURNAL_ERR_journal_stuck;
 229         } else if (!j->space[journal_space_discarded].next_entry)
 230                 ret = JOURNAL_ERR_journal_full;
 231
 232         if ((j->space[journal_space_clean_ondisk].next_entry <
 233              j->space[journal_space_clean_ondisk].total) &&
 234             (clean - clean_ondisk <= total / 8) &&
 235             (clean_ondisk * 2 > clean))
 236                 set_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
 237         else
 238                 clear_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
 239
 240         u64s_remaining  = (u64) clean << 6;
 241         u64s_remaining -= (u64) total << 3;
 242         u64s_remaining = max(0LL, u64s_remaining);
 243         u64s_remaining /= 4;
 244         u64s_remaining = min_t(u64, u64s_remaining, U32_MAX);
 245 out:
 246         j->cur_entry_sectors    = !ret ? j->space[journal_space_discarded].next_entry : 0;
 247         j->cur_entry_error      = ret;
 248         journal_set_remaining(j, u64s_remaining);
 249         journal_set_watermark(j);
 250
 251         if (!ret)
 252                 journal_wake(j);
 253 }
 254
 255 /* Discards - last part of journal reclaim: */
 256
 257 static bool should_discard_bucket(struct journal *j, struct journal_device *ja)
 258 {
 259         bool ret;
 260
 261         spin_lock(&j->lock);
 262         ret = ja->discard_idx != ja->dirty_idx_ondisk;
 263         spin_unlock(&j->lock);
 264
 265         return ret;
 266 }
 267
 268 /*
 269  * Advance ja->discard_idx as long as it points to buckets that are no longer
 270  * dirty, issuing discards if necessary:
 271  */
 272 void bch2_journal_do_discards(struct journal *j)
 273 {
 274         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 275         struct bch_dev *ca;
 276         unsigned iter;
 277
 278         mutex_lock(&j->discard_lock);
 279
 280         for_each_rw_member(ca, c, iter) {
 281                 struct journal_device *ja = &ca->journal;
 282
 283                 while (should_discard_bucket(j, ja)) {
 284                         if (!c->opts.nochanges &&
 285                             ca->mi.discard &&
 286                             bdev_max_discard_sectors(ca->disk_sb.bdev))
 287                                 blkdev_issue_discard(ca->disk_sb.bdev,
 288                                         bucket_to_sector(ca,
 289                                                 ja->buckets[ja->discard_idx]),
 290                                         ca->mi.bucket_size, GFP_NOIO);
 291
 292                         spin_lock(&j->lock);
 293                         ja->discard_idx = (ja->discard_idx + 1) % ja->nr;
 294
 295                         bch2_journal_space_available(j);
 296                         spin_unlock(&j->lock);
 297                 }
 298         }
 299
 300         mutex_unlock(&j->discard_lock);
 301 }
 302
 303 /*
 304  * Journal entry pinning - machinery for holding a reference on a given journal
 305  * entry, holding it open to ensure it gets replayed during recovery:
 306  */
 307
 308 static void bch2_journal_reclaim_fast(struct journal *j)
 309 {
 310         struct journal_entry_pin_list temp;
 311         bool popped = false;
 312
 313         lockdep_assert_held(&j->lock);
 314
 315         /*
 316          * Unpin journal entries whose reference counts reached zero, meaning
 317          * all btree nodes got written out
 318          */
 319         while (!fifo_empty(&j->pin) &&
 320                !atomic_read(&fifo_peek_front(&j->pin).count)) {
 321                 BUG_ON(!list_empty(&fifo_peek_front(&j->pin).list));
 322                 BUG_ON(!list_empty(&fifo_peek_front(&j->pin).flushed));
 323                 BUG_ON(!fifo_pop(&j->pin, temp));
 324                 popped = true;
 325         }
 326
 327         if (popped)
 328                 bch2_journal_space_available(j);
 329 }
 330
 331 void __bch2_journal_pin_put(struct journal *j, u64 seq)
 332 {
 333         struct journal_entry_pin_list *pin_list = journal_seq_pin(j, seq);
 334
 335         if (atomic_dec_and_test(&pin_list->count))
 336                 bch2_journal_reclaim_fast(j);
 337 }
 338
 339 void bch2_journal_pin_put(struct journal *j, u64 seq)
 340 {
 341         struct journal_entry_pin_list *pin_list = journal_seq_pin(j, seq);
 342
 343         if (atomic_dec_and_test(&pin_list->count)) {
 344                 spin_lock(&j->lock);
 345                 bch2_journal_reclaim_fast(j);
 346                 spin_unlock(&j->lock);
 347         }
 348 }
 349
 350 static inline bool __journal_pin_drop(struct journal *j,
 351                                       struct journal_entry_pin *pin)
 352 {
 353         struct journal_entry_pin_list *pin_list;
 354
 355         if (!journal_pin_active(pin))
 356                 return false;
 357
 358         if (j->flush_in_progress == pin)
 359                 j->flush_in_progress_dropped = true;
 360
 361         pin_list = journal_seq_pin(j, pin->seq);
 362         pin->seq = 0;
 363         list_del_init(&pin->list);
 364
 365         /*
 366          * Unpinning a journal entry make make journal_next_bucket() succeed, if
 367          * writing a new last_seq will now make another bucket available:
 368          */
 369         return atomic_dec_and_test(&pin_list->count) &&
 370                 pin_list == &fifo_peek_front(&j->pin);
 371 }
 372
 373 void bch2_journal_pin_drop(struct journal *j,
 374                            struct journal_entry_pin *pin)
 375 {
 376         spin_lock(&j->lock);
 377         if (__journal_pin_drop(j, pin))
 378                 bch2_journal_reclaim_fast(j);
 379         spin_unlock(&j->lock);
 380 }
 381
 382 void bch2_journal_pin_set(struct journal *j, u64 seq,
 383                           struct journal_entry_pin *pin,
 384                           journal_pin_flush_fn flush_fn)
 385 {
 386         struct journal_entry_pin_list *pin_list;
 387         bool reclaim;
 388
 389         spin_lock(&j->lock);
 390
 391         if (seq < journal_last_seq(j)) {
 392                 /*
 393                  * bch2_journal_pin_copy() raced with bch2_journal_pin_drop() on
 394                  * the src pin - with the pin dropped, the entry to pin might no
 395                  * longer to exist, but that means there's no longer anything to
 396                  * copy and we can bail out here:
 397                  */
 398                 spin_unlock(&j->lock);
 399                 return;
 400         }
 401
 402         pin_list = journal_seq_pin(j, seq);
 403
 404         reclaim = __journal_pin_drop(j, pin);
 405
 406         atomic_inc(&pin_list->count);
 407         pin->seq        = seq;
 408         pin->flush      = flush_fn;
 409
 410         if (flush_fn == bch2_btree_key_cache_journal_flush)
 411                 list_add(&pin->list, &pin_list->key_cache_list);
 412         else if (flush_fn)
 413                 list_add(&pin->list, &pin_list->list);
 414         else
 415                 list_add(&pin->list, &pin_list->flushed);
 416
 417         if (reclaim)
 418                 bch2_journal_reclaim_fast(j);
 419         spin_unlock(&j->lock);
 420
 421         /*
 422          * If the journal is currently full,  we might want to call flush_fn
 423          * immediately:
 424          */
 425         journal_wake(j);
 426 }
 427
 428 /**
 429  * bch2_journal_pin_flush: ensure journal pin callback is no longer running
 430  */
 431 void bch2_journal_pin_flush(struct journal *j, struct journal_entry_pin *pin)
 432 {
 433         BUG_ON(journal_pin_active(pin));
 434
 435         wait_event(j->pin_flush_wait, j->flush_in_progress != pin);
 436 }
 437
 438 /*
 439  * Journal reclaim: flush references to open journal entries to reclaim space in
 440  * the journal
 441  *
 442  * May be done by the journal code in the background as needed to free up space
 443  * for more journal entries, or as part of doing a clean shutdown, or to migrate
 444  * data off of a specific device:
 445  */
 446
 447 static struct journal_entry_pin *
 448 journal_get_next_pin(struct journal *j,
 449                      bool get_any,
 450                      bool get_key_cache,
 451                      u64 max_seq, u64 *seq)
 452 {
 453         struct journal_entry_pin_list *pin_list;
 454         struct journal_entry_pin *ret = NULL;
 455
 456         fifo_for_each_entry_ptr(pin_list, &j->pin, *seq) {
 457                 if (*seq > max_seq && !get_any && !get_key_cache)
 458                         break;
 459
 460                 if (*seq <= max_seq || get_any) {
 461                         ret = list_first_entry_or_null(&pin_list->list,
 462                                 struct journal_entry_pin, list);
 463                         if (ret)
 464                                 return ret;
 465                 }
 466
 467                 if (*seq <= max_seq || get_any || get_key_cache) {
 468                         ret = list_first_entry_or_null(&pin_list->key_cache_list,
 469                                 struct journal_entry_pin, list);
 470                         if (ret)
 471                                 return ret;
 472                 }
 473         }
 474
 475         return NULL;
 476 }
 477
 478 /* returns true if we did work */
 479 static size_t journal_flush_pins(struct journal *j, u64 seq_to_flush,
 480                                  unsigned min_any,
 481                                  unsigned min_key_cache)
 482 {
 483         struct journal_entry_pin *pin;
 484         size_t nr_flushed = 0;
 485         journal_pin_flush_fn flush_fn;
 486         u64 seq;
 487         int err;
 488
 489         lockdep_assert_held(&j->reclaim_lock);
 490
 491         while (1) {
 492                 cond_resched();
 493
 494                 j->last_flushed = jiffies;
 495
 496                 spin_lock(&j->lock);
 497                 pin = journal_get_next_pin(j,
 498                                            min_any != 0,
 499                                            min_key_cache != 0,
 500                                            seq_to_flush, &seq);
 501                 if (pin) {
 502                         BUG_ON(j->flush_in_progress);
 503                         j->flush_in_progress = pin;
 504                         j->flush_in_progress_dropped = false;
 505                         flush_fn = pin->flush;
 506                 }
 507                 spin_unlock(&j->lock);
 508
 509                 if (!pin)
 510                         break;
 511
 512                 if (min_key_cache && pin->flush == bch2_btree_key_cache_journal_flush)
 513                         min_key_cache--;
 514
 515                 if (min_any)
 516                         min_any--;
 517
 518                 err = flush_fn(j, pin, seq);
 519
 520                 spin_lock(&j->lock);
 521                 /* Pin might have been dropped or rearmed: */
 522                 if (likely(!err && !j->flush_in_progress_dropped))
 523                         list_move(&pin->list, &journal_seq_pin(j, seq)->flushed);
 524                 j->flush_in_progress = NULL;
 525                 j->flush_in_progress_dropped = false;
 526                 spin_unlock(&j->lock);
 527
 528                 wake_up(&j->pin_flush_wait);
 529
 530                 if (err)
 531                         break;
 532
 533                 nr_flushed++;
 534         }
 535
 536         return nr_flushed;
 537 }
 538
 539 static u64 journal_seq_to_flush(struct journal *j)
 540 {
 541         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 542         struct bch_dev *ca;
 543         u64 seq_to_flush = 0;
 544         unsigned iter;
 545
 546         spin_lock(&j->lock);
 547
 548         for_each_rw_member(ca, c, iter) {
 549                 struct journal_device *ja = &ca->journal;
 550                 unsigned nr_buckets, bucket_to_flush;
 551
 552                 if (!ja->nr)
 553                         continue;
 554
 555                 /* Try to keep the journal at most half full: */
 556                 nr_buckets = ja->nr / 2;
 557
 558                 /* And include pre-reservations: */
 559                 nr_buckets += DIV_ROUND_UP(j->prereserved.reserved,
 560                                            (ca->mi.bucket_size << 6) -
 561                                            journal_entry_overhead(j));
 562
 563                 nr_buckets = min(nr_buckets, ja->nr);
 564
 565                 bucket_to_flush = (ja->cur_idx + nr_buckets) % ja->nr;
 566                 seq_to_flush = max(seq_to_flush,
 567                                    ja->bucket_seq[bucket_to_flush]);
 568         }
 569
 570         /* Also flush if the pin fifo is more than half full */
 571         seq_to_flush = max_t(s64, seq_to_flush,
 572                              (s64) journal_cur_seq(j) -
 573                              (j->pin.size >> 1));
 574         spin_unlock(&j->lock);
 575
 576         return seq_to_flush;
 577 }
 578
 579 /**
 580  * bch2_journal_reclaim - free up journal buckets
 581  *
 582  * Background journal reclaim writes out btree nodes. It should be run
 583  * early enough so that we never completely run out of journal buckets.
 584  *
 585  * High watermarks for triggering background reclaim:
 586  * - FIFO has fewer than 512 entries left
 587  * - fewer than 25% journal buckets free
 588  *
 589  * Background reclaim runs until low watermarks are reached:
 590  * - FIFO has more than 1024 entries left
 591  * - more than 50% journal buckets free
 592  *
 593  * As long as a reclaim can complete in the time it takes to fill up
 594  * 512 journal entries or 25% of all journal buckets, then
 595  * journal_next_bucket() should not stall.
 596  */
 597 static int __bch2_journal_reclaim(struct journal *j, bool direct, bool kicked)
 598 {
 599         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 600         bool kthread = (current->flags & PF_KTHREAD) != 0;
 601         u64 seq_to_flush;
 602         size_t min_nr, min_key_cache, nr_flushed;
 603         unsigned flags;
 604         int ret = 0;
 605
 606         /*
 607          * We can't invoke memory reclaim while holding the reclaim_lock -
 608          * journal reclaim is required to make progress for memory reclaim
 609          * (cleaning the caches), so we can't get stuck in memory reclaim while
 610          * we're holding the reclaim lock:
 611          */
 612         lockdep_assert_held(&j->reclaim_lock);
 613         flags = memalloc_noreclaim_save();
 614
 615         do {
 616                 if (kthread && kthread_should_stop())
 617                         break;
 618
 619                 if (bch2_journal_error(j)) {
 620                         ret = -EIO;
 621                         break;
 622                 }
 623
 624                 bch2_journal_do_discards(j);
 625
 626                 seq_to_flush = journal_seq_to_flush(j);
 627                 min_nr = 0;
 628
 629                 /*
 630                  * If it's been longer than j->reclaim_delay_ms since we last flushed,
 631                  * make sure to flush at least one journal pin:
 632                  */
 633                 if (time_after(jiffies, j->last_flushed +
 634                                msecs_to_jiffies(c->opts.journal_reclaim_delay)))
 635                         min_nr = 1;
 636
 637                 if (j->prereserved.reserved * 4 > j->prereserved.remaining)
 638                         min_nr = 1;
 639
 640                 if (fifo_free(&j->pin) <= 32)
 641                         min_nr = 1;
 642
 643                 if (atomic_read(&c->btree_cache.dirty) * 2 > c->btree_cache.used)
 644                         min_nr = 1;
 645
 646                 min_key_cache = min(bch2_nr_btree_keys_need_flush(c), (size_t) 128);
 647
 648                 trace_and_count(c, journal_reclaim_start, c,
 649                                 direct, kicked,
 650                                 min_nr, min_key_cache,
 651                                 j->prereserved.reserved,
 652                                 j->prereserved.remaining,
 653                                 atomic_read(&c->btree_cache.dirty),
 654                                 c->btree_cache.used,
 655                                 atomic_long_read(&c->btree_key_cache.nr_dirty),
 656                                 atomic_long_read(&c->btree_key_cache.nr_keys));
 657
 658                 nr_flushed = journal_flush_pins(j, seq_to_flush,
 659                                                 min_nr, min_key_cache);
 660
 661                 if (direct)
 662                         j->nr_direct_reclaim += nr_flushed;
 663                 else
 664                         j->nr_background_reclaim += nr_flushed;
 665                 trace_and_count(c, journal_reclaim_finish, c, nr_flushed);
 666
 667                 if (nr_flushed)
 668                         wake_up(&j->reclaim_wait);
 669         } while ((min_nr || min_key_cache) && nr_flushed && !direct);
 670
 671         memalloc_noreclaim_restore(flags);
 672
 673         return ret;
 674 }
 675
 676 int bch2_journal_reclaim(struct journal *j)
 677 {
 678         return __bch2_journal_reclaim(j, true, true);
 679 }
 680
 681 static int bch2_journal_reclaim_thread(void *arg)
 682 {
 683         struct journal *j = arg;
 684         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 685         unsigned long delay, now;
 686         bool journal_empty;
 687         int ret = 0;
 688
 689         set_freezable();
 690
 691         j->last_flushed = jiffies;
 692
 693         while (!ret && !kthread_should_stop()) {
 694                 bool kicked = j->reclaim_kicked;
 695
 696                 j->reclaim_kicked = false;
 697
 698                 mutex_lock(&j->reclaim_lock);
 699                 ret = __bch2_journal_reclaim(j, false, kicked);
 700                 mutex_unlock(&j->reclaim_lock);
 701
 702                 now = jiffies;
 703                 delay = msecs_to_jiffies(c->opts.journal_reclaim_delay);
 704                 j->next_reclaim = j->last_flushed + delay;
 705
 706                 if (!time_in_range(j->next_reclaim, now, now + delay))
 707                         j->next_reclaim = now + delay;
 708
 709                 while (1) {
 710                         set_current_state(TASK_INTERRUPTIBLE|TASK_FREEZABLE);
 711                         if (kthread_should_stop())
 712                                 break;
 713                         if (j->reclaim_kicked)
 714                                 break;
 715
 716                         spin_lock(&j->lock);
 717                         journal_empty = fifo_empty(&j->pin);
 718                         spin_unlock(&j->lock);
 719
 720                         if (journal_empty)
 721                                 schedule();
 722                         else if (time_after(j->next_reclaim, jiffies))
 723                                 schedule_timeout(j->next_reclaim - jiffies);
 724                         else
 725                                 break;
 726                 }
 727                 __set_current_state(TASK_RUNNING);
 728         }
 729
 730         return 0;
 731 }
 732
 733 void bch2_journal_reclaim_stop(struct journal *j)
 734 {
 735         struct task_struct *p = j->reclaim_thread;
 736
 737         j->reclaim_thread = NULL;
 738
 739         if (p) {
 740                 kthread_stop(p);
 741                 put_task_struct(p);
 742         }
 743 }
 744
 745 int bch2_journal_reclaim_start(struct journal *j)
 746 {
 747         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 748         struct task_struct *p;
 749         int ret;
 750
 751         if (j->reclaim_thread)
 752                 return 0;
 753
 754         p = kthread_create(bch2_journal_reclaim_thread, j,
 755                            "bch-reclaim/%s", c->name);
 756         ret = PTR_ERR_OR_ZERO(p);
 757         if (ret) {
 758                 bch_err(c, "error creating journal reclaim thread: %s", bch2_err_str(ret));
 759                 return ret;
 760         }
 761
 762         get_task_struct(p);
 763         j->reclaim_thread = p;
 764         wake_up_process(p);
 765         return 0;
 766 }
 767
 768 static int journal_flush_done(struct journal *j, u64 seq_to_flush,
 769                               bool *did_work)
 770 {
 771         int ret;
 772
 773         ret = bch2_journal_error(j);
 774         if (ret)
 775                 return ret;
 776
 777         mutex_lock(&j->reclaim_lock);
 778
 779         if (journal_flush_pins(j, seq_to_flush, 0, 0))
 780                 *did_work = true;
 781
 782         spin_lock(&j->lock);
 783         /*
 784          * If journal replay hasn't completed, the unreplayed journal entries
 785          * hold refs on their corresponding sequence numbers
 786          */
 787         ret = !test_bit(JOURNAL_REPLAY_DONE, &j->flags) ||
 788                 journal_last_seq(j) > seq_to_flush ||
 789                 !fifo_used(&j->pin);
 790
 791         spin_unlock(&j->lock);
 792         mutex_unlock(&j->reclaim_lock);
 793
 794         return ret;
 795 }
 796
 797 bool bch2_journal_flush_pins(struct journal *j, u64 seq_to_flush)
 798 {
 799         bool did_work = false;
 800
 801         if (!test_bit(JOURNAL_STARTED, &j->flags))
 802                 return false;
 803
 804         closure_wait_event(&j->async_wait,
 805                 journal_flush_done(j, seq_to_flush, &did_work));
 806
 807         return did_work;
 808 }
 809
 810 int bch2_journal_flush_device_pins(struct journal *j, int dev_idx)
 811 {
 812         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 813         struct journal_entry_pin_list *p;
 814         u64 iter, seq = 0;
 815         int ret = 0;
 816
 817         spin_lock(&j->lock);
 818         fifo_for_each_entry_ptr(p, &j->pin, iter)
 819                 if (dev_idx >= 0
 820                     ? bch2_dev_list_has_dev(p->devs, dev_idx)
 821                     : p->devs.nr < c->opts.metadata_replicas)
 822                         seq = iter;
 823         spin_unlock(&j->lock);
 824
 825         bch2_journal_flush_pins(j, seq);
 826
 827         ret = bch2_journal_error(j);
 828         if (ret)
 829                 return ret;
 830
 831         mutex_lock(&c->replicas_gc_lock);
 832         bch2_replicas_gc_start(c, 1 << BCH_DATA_journal);
 833
 834         seq = 0;
 835
 836         spin_lock(&j->lock);
 837         while (!ret) {
 838                 struct bch_replicas_padded replicas;
 839
 840                 seq = max(seq, journal_last_seq(j));
 841                 if (seq >= j->pin.back)
 842                         break;
 843                 bch2_devlist_to_replicas(&replicas.e, BCH_DATA_journal,
 844                                          journal_seq_pin(j, seq)->devs);
 845                 seq++;
 846
 847                 spin_unlock(&j->lock);
 848                 ret = bch2_mark_replicas(c, &replicas.e);
 849                 spin_lock(&j->lock);
 850         }
 851         spin_unlock(&j->lock);
 852
 853         ret = bch2_replicas_gc_end(c, ret);
 854         mutex_unlock(&c->replicas_gc_lock);
 855
 856         return ret;
 857 }