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 "btree_update.h"
   6 #include "errcode.h"
   7 #include "error.h"
   8 #include "journal.h"
   9 #include "journal_io.h"
  10 #include "journal_reclaim.h"
  11 #include "replicas.h"
  12 #include "super.h"
  13
  14 #include <linux/kthread.h>
  15 #include <linux/sched/mm.h>
  16 #include <trace/events/bcachefs.h>
  17
  18 /* Free space calculations: */
  19
  20 static unsigned journal_space_from(struct journal_device *ja,
  21                                    enum journal_space_from from)
  22 {
  23         switch (from) {
  24         case journal_space_discarded:
  25                 return ja->discard_idx;
  26         case journal_space_clean_ondisk:
  27                 return ja->dirty_idx_ondisk;
  28         case journal_space_clean:
  29                 return ja->dirty_idx;
  30         default:
  31                 BUG();
  32         }
  33 }
  34
  35 unsigned bch2_journal_dev_buckets_available(struct journal *j,
  36                                             struct journal_device *ja,
  37                                             enum journal_space_from from)
  38 {
  39         unsigned available = (journal_space_from(ja, from) -
  40                               ja->cur_idx - 1 + ja->nr) % ja->nr;
  41
  42         /*
  43          * Don't use the last bucket unless writing the new last_seq
  44          * will make another bucket available:
  45          */
  46         if (available && ja->dirty_idx_ondisk == ja->dirty_idx)
  47                 --available;
  48
  49         return available;
  50 }
  51
  52 static void journal_set_remaining(struct journal *j, unsigned u64s_remaining)
  53 {
  54         union journal_preres_state old, new;
  55         u64 v = atomic64_read(&j->prereserved.counter);
  56
  57         do {
  58                 old.v = new.v = v;
  59                 new.remaining = u64s_remaining;
  60         } while ((v = atomic64_cmpxchg(&j->prereserved.counter,
  61                                        old.v, new.v)) != old.v);
  62 }
  63
  64 static struct journal_space
  65 journal_dev_space_available(struct journal *j, struct bch_dev *ca,
  66                             enum journal_space_from from)
  67 {
  68         struct journal_device *ja = &ca->journal;
  69         unsigned sectors, buckets, unwritten;
  70         u64 seq;
  71
  72         if (from == journal_space_total)
  73                 return (struct journal_space) {
  74                         .next_entry     = ca->mi.bucket_size,
  75                         .total          = ca->mi.bucket_size * ja->nr,
  76                 };
  77
  78         buckets = bch2_journal_dev_buckets_available(j, ja, from);
  79         sectors = ja->sectors_free;
  80
  81         /*
  82          * We that we don't allocate the space for a journal entry
  83          * until we write it out - thus, account for it here:
  84          */
  85         for (seq = journal_last_unwritten_seq(j);
  86              seq <= journal_cur_seq(j);
  87              seq++) {
  88                 unwritten = j->buf[seq & JOURNAL_BUF_MASK].sectors;
  89
  90                 if (!unwritten)
  91                         continue;
  92
  93                 /* entry won't fit on this device, skip: */
  94                 if (unwritten > ca->mi.bucket_size)
  95                         continue;
  96
  97                 if (unwritten >= sectors) {
  98                         if (!buckets) {
  99                                 sectors = 0;
 100                                 break;
 101                         }
 102
 103                         buckets--;
 104                         sectors = ca->mi.bucket_size;
 105                 }
 106
 107                 sectors -= unwritten;
 108         }
 109
 110         if (sectors < ca->mi.bucket_size && buckets) {
 111                 buckets--;
 112                 sectors = ca->mi.bucket_size;
 113         }
 114
 115         return (struct journal_space) {
 116                 .next_entry     = sectors,
 117                 .total          = sectors + buckets * ca->mi.bucket_size,
 118         };
 119 }
 120
 121 static struct journal_space __journal_space_available(struct journal *j, unsigned nr_devs_want,
 122                             enum journal_space_from from)
 123 {
 124         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 125         struct bch_dev *ca;
 126         unsigned i, pos, nr_devs = 0;
 127         struct journal_space space, dev_space[BCH_SB_MEMBERS_MAX];
 128
 129         BUG_ON(nr_devs_want > ARRAY_SIZE(dev_space));
 130
 131         rcu_read_lock();
 132         for_each_member_device_rcu(ca, c, i,
 133                                    &c->rw_devs[BCH_DATA_journal]) {
 134                 if (!ca->journal.nr)
 135                         continue;
 136
 137                 space = journal_dev_space_available(j, ca, from);
 138                 if (!space.next_entry)
 139                         continue;
 140
 141                 for (pos = 0; pos < nr_devs; pos++)
 142                         if (space.total > dev_space[pos].total)
 143                                 break;
 144
 145                 array_insert_item(dev_space, nr_devs, pos, space);
 146         }
 147         rcu_read_unlock();
 148
 149         if (nr_devs < nr_devs_want)
 150                 return (struct journal_space) { 0, 0 };
 151
 152         /*
 153          * We sorted largest to smallest, and we want the smallest out of the
 154          * @nr_devs_want largest devices:
 155          */
 156         return dev_space[nr_devs_want - 1];
 157 }
 158
 159 void bch2_journal_space_available(struct journal *j)
 160 {
 161         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 162         struct bch_dev *ca;
 163         unsigned clean, clean_ondisk, total;
 164         s64 u64s_remaining = 0;
 165         unsigned max_entry_size  = min(j->buf[0].buf_size >> 9,
 166                                        j->buf[1].buf_size >> 9);
 167         unsigned i, nr_online = 0, nr_devs_want;
 168         bool can_discard = false;
 169         int ret = 0;
 170
 171         lockdep_assert_held(&j->lock);
 172
 173         rcu_read_lock();
 174         for_each_member_device_rcu(ca, c, i,
 175                                    &c->rw_devs[BCH_DATA_journal]) {
 176                 struct journal_device *ja = &ca->journal;
 177
 178                 if (!ja->nr)
 179                         continue;
 180
 181                 while (ja->dirty_idx != ja->cur_idx &&
 182                        ja->bucket_seq[ja->dirty_idx] < journal_last_seq(j))
 183                         ja->dirty_idx = (ja->dirty_idx + 1) % ja->nr;
 184
 185                 while (ja->dirty_idx_ondisk != ja->dirty_idx &&
 186                        ja->bucket_seq[ja->dirty_idx_ondisk] < j->last_seq_ondisk)
 187                         ja->dirty_idx_ondisk = (ja->dirty_idx_ondisk + 1) % ja->nr;
 188
 189                 if (ja->discard_idx != ja->dirty_idx_ondisk)
 190                         can_discard = true;
 191
 192                 max_entry_size = min_t(unsigned, max_entry_size, ca->mi.bucket_size);
 193                 nr_online++;
 194         }
 195         rcu_read_unlock();
 196
 197         j->can_discard = can_discard;
 198
 199         if (nr_online < c->opts.metadata_replicas_required) {
 200                 ret = JOURNAL_ERR_insufficient_devices;
 201                 goto out;
 202         }
 203
 204         nr_devs_want = min_t(unsigned, nr_online, c->opts.metadata_replicas);
 205
 206         for (i = 0; i < journal_space_nr; i++)
 207                 j->space[i] = __journal_space_available(j, nr_devs_want, i);
 208
 209         clean_ondisk    = j->space[journal_space_clean_ondisk].total;
 210         clean           = j->space[journal_space_clean].total;
 211         total           = j->space[journal_space_total].total;
 212
 213         if (!clean_ondisk &&
 214             journal_cur_seq(j) == j->seq_ondisk) {
 215                 struct printbuf buf = PRINTBUF;
 216
 217                 __bch2_journal_debug_to_text(&buf, j);
 218                 bch_err(c, "journal stuck\n%s", buf.buf);
 219                 printbuf_exit(&buf);
 220
 221                 /*
 222                  * Hack: bch2_fatal_error() calls bch2_journal_halt() which
 223                  * takes journal lock:
 224                  */
 225                 spin_unlock(&j->lock);
 226                 bch2_fatal_error(c);
 227                 spin_lock(&j->lock);
 228
 229                 ret = JOURNAL_ERR_journal_stuck;
 230         } else if (!j->space[journal_space_discarded].next_entry)
 231                 ret = JOURNAL_ERR_journal_full;
 232
 233         if ((j->space[journal_space_clean_ondisk].next_entry <
 234              j->space[journal_space_clean_ondisk].total) &&
 235             (clean - clean_ondisk <= total / 8) &&
 236             (clean_ondisk * 2 > clean))
 237                 set_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
 238         else
 239                 clear_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
 240
 241         u64s_remaining  = (u64) clean << 6;
 242         u64s_remaining -= (u64) total << 3;
 243         u64s_remaining = max(0LL, u64s_remaining);
 244         u64s_remaining /= 4;
 245         u64s_remaining = min_t(u64, u64s_remaining, U32_MAX);
 246 out:
 247         j->cur_entry_sectors    = !ret ? j->space[journal_space_discarded].next_entry : 0;
 248         j->cur_entry_error      = ret;
 249         journal_set_remaining(j, u64s_remaining);
 250         journal_set_watermark(j);
 251
 252         if (!ret)
 253                 journal_wake(j);
 254 }
 255
 256 /* Discards - last part of journal reclaim: */
 257
 258 static bool should_discard_bucket(struct journal *j, struct journal_device *ja)
 259 {
 260         bool ret;
 261
 262         spin_lock(&j->lock);
 263         ret = ja->discard_idx != ja->dirty_idx_ondisk;
 264         spin_unlock(&j->lock);
 265
 266         return ret;
 267 }
 268
 269 /*
 270  * Advance ja->discard_idx as long as it points to buckets that are no longer
 271  * dirty, issuing discards if necessary:
 272  */
 273 void bch2_journal_do_discards(struct journal *j)
 274 {
 275         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 276         struct bch_dev *ca;
 277         unsigned iter;
 278
 279         mutex_lock(&j->discard_lock);
 280
 281         for_each_rw_member(ca, c, iter) {
 282                 struct journal_device *ja = &ca->journal;
 283
 284                 while (should_discard_bucket(j, ja)) {
 285                         if (!c->opts.nochanges &&
 286                             ca->mi.discard &&
 287                             bdev_max_discard_sectors(ca->disk_sb.bdev))
 288                                 blkdev_issue_discard(ca->disk_sb.bdev,
 289                                         bucket_to_sector(ca,
 290                                                 ja->buckets[ja->discard_idx]),
 291                                         ca->mi.bucket_size, GFP_NOIO);
 292
 293                         spin_lock(&j->lock);
 294                         ja->discard_idx = (ja->discard_idx + 1) % ja->nr;
 295
 296                         bch2_journal_space_available(j);
 297                         spin_unlock(&j->lock);
 298                 }
 299         }
 300
 301         mutex_unlock(&j->discard_lock);
 302 }
 303
 304 /*
 305  * Journal entry pinning - machinery for holding a reference on a given journal
 306  * entry, holding it open to ensure it gets replayed during recovery:
 307  */
 308
 309 static void bch2_journal_reclaim_fast(struct journal *j)
 310 {
 311         struct journal_entry_pin_list temp;
 312         bool popped = false;
 313
 314         lockdep_assert_held(&j->lock);
 315
 316         /*
 317          * Unpin journal entries whose reference counts reached zero, meaning
 318          * all btree nodes got written out
 319          */
 320         while (!fifo_empty(&j->pin) &&
 321                !atomic_read(&fifo_peek_front(&j->pin).count)) {
 322                 fifo_pop(&j->pin, temp);
 323                 popped = true;
 324         }
 325
 326         if (popped)
 327                 bch2_journal_space_available(j);
 328 }
 329
 330 void __bch2_journal_pin_put(struct journal *j, u64 seq)
 331 {
 332         struct journal_entry_pin_list *pin_list = journal_seq_pin(j, seq);
 333
 334         if (atomic_dec_and_test(&pin_list->count))
 335                 bch2_journal_reclaim_fast(j);
 336 }
 337
 338 void bch2_journal_pin_put(struct journal *j, u64 seq)
 339 {
 340         struct journal_entry_pin_list *pin_list = journal_seq_pin(j, seq);
 341
 342         if (atomic_dec_and_test(&pin_list->count)) {
 343                 spin_lock(&j->lock);
 344                 bch2_journal_reclaim_fast(j);
 345                 spin_unlock(&j->lock);
 346         }
 347 }
 348
 349 static inline bool __journal_pin_drop(struct journal *j,
 350                                       struct journal_entry_pin *pin)
 351 {
 352         struct journal_entry_pin_list *pin_list;
 353
 354         if (!journal_pin_active(pin))
 355                 return false;
 356
 357         if (j->flush_in_progress == pin)
 358                 j->flush_in_progress_dropped = true;
 359
 360         pin_list = journal_seq_pin(j, pin->seq);
 361         pin->seq = 0;
 362         list_del_init(&pin->list);
 363
 364         /*
 365          * Unpinning a journal entry make make journal_next_bucket() succeed, if
 366          * writing a new last_seq will now make another bucket available:
 367          */
 368         return atomic_dec_and_test(&pin_list->count) &&
 369                 pin_list == &fifo_peek_front(&j->pin);
 370 }
 371
 372 void bch2_journal_pin_drop(struct journal *j,
 373                            struct journal_entry_pin *pin)
 374 {
 375         spin_lock(&j->lock);
 376         if (__journal_pin_drop(j, pin))
 377                 bch2_journal_reclaim_fast(j);
 378         spin_unlock(&j->lock);
 379 }
 380
 381 enum journal_pin_type journal_pin_type(journal_pin_flush_fn fn)
 382 {
 383         if (fn == bch2_btree_node_flush0 ||
 384             fn == bch2_btree_node_flush1)
 385                 return JOURNAL_PIN_btree;
 386         else if (fn == bch2_btree_key_cache_journal_flush)
 387                 return JOURNAL_PIN_key_cache;
 388         else
 389                 return JOURNAL_PIN_other;
 390 }
 391
 392 void bch2_journal_pin_set(struct journal *j, u64 seq,
 393                           struct journal_entry_pin *pin,
 394                           journal_pin_flush_fn flush_fn)
 395 {
 396         struct journal_entry_pin_list *pin_list;
 397         bool reclaim;
 398
 399         spin_lock(&j->lock);
 400
 401         if (seq < journal_last_seq(j)) {
 402                 /*
 403                  * bch2_journal_pin_copy() raced with bch2_journal_pin_drop() on
 404                  * the src pin - with the pin dropped, the entry to pin might no
 405                  * longer to exist, but that means there's no longer anything to
 406                  * copy and we can bail out here:
 407                  */
 408                 spin_unlock(&j->lock);
 409                 return;
 410         }
 411
 412         pin_list = journal_seq_pin(j, seq);
 413
 414         reclaim = __journal_pin_drop(j, pin);
 415
 416         atomic_inc(&pin_list->count);
 417         pin->seq        = seq;
 418         pin->flush      = flush_fn;
 419
 420         if (flush_fn)
 421                 list_add(&pin->list, &pin_list->list[journal_pin_type(flush_fn)]);
 422         else
 423                 list_add(&pin->list, &pin_list->flushed);
 424
 425         if (reclaim)
 426                 bch2_journal_reclaim_fast(j);
 427         spin_unlock(&j->lock);
 428
 429         /*
 430          * If the journal is currently full,  we might want to call flush_fn
 431          * immediately:
 432          */
 433         journal_wake(j);
 434 }
 435
 436 /**
 437  * bch2_journal_pin_flush: ensure journal pin callback is no longer running
 438  */
 439 void bch2_journal_pin_flush(struct journal *j, struct journal_entry_pin *pin)
 440 {
 441         BUG_ON(journal_pin_active(pin));
 442
 443         wait_event(j->pin_flush_wait, j->flush_in_progress != pin);
 444 }
 445
 446 /*
 447  * Journal reclaim: flush references to open journal entries to reclaim space in
 448  * the journal
 449  *
 450  * May be done by the journal code in the background as needed to free up space
 451  * for more journal entries, or as part of doing a clean shutdown, or to migrate
 452  * data off of a specific device:
 453  */
 454
 455 static struct journal_entry_pin *
 456 journal_get_next_pin(struct journal *j,
 457                      u64 seq_to_flush,
 458                      unsigned allowed_below_seq,
 459                      unsigned allowed_above_seq,
 460                      u64 *seq)
 461 {
 462         struct journal_entry_pin_list *pin_list;
 463         struct journal_entry_pin *ret = NULL;
 464         unsigned i;
 465
 466         fifo_for_each_entry_ptr(pin_list, &j->pin, *seq) {
 467                 if (*seq > seq_to_flush && !allowed_above_seq)
 468                         break;
 469
 470                 for (i = 0; i < JOURNAL_PIN_NR; i++)
 471                         if ((((1U << i) & allowed_below_seq) && *seq <= seq_to_flush) ||
 472                             ((1U << i) & allowed_above_seq)) {
 473                                 ret = list_first_entry_or_null(&pin_list->list[i],
 474                                         struct journal_entry_pin, list);
 475                                 if (ret)
 476                                         return ret;
 477                         }
 478         }
 479
 480         return NULL;
 481 }
 482
 483 /* returns true if we did work */
 484 static size_t journal_flush_pins(struct journal *j,
 485                                  u64 seq_to_flush,
 486                                  unsigned allowed_below_seq,
 487                                  unsigned allowed_above_seq,
 488                                  unsigned min_any,
 489                                  unsigned min_key_cache)
 490 {
 491         struct journal_entry_pin *pin;
 492         size_t nr_flushed = 0;
 493         journal_pin_flush_fn flush_fn;
 494         u64 seq;
 495         int err;
 496
 497         lockdep_assert_held(&j->reclaim_lock);
 498
 499         while (1) {
 500                 unsigned allowed_above = allowed_above_seq;
 501                 unsigned allowed_below = allowed_below_seq;
 502
 503                 if (min_any) {
 504                         allowed_above |= ~0;
 505                         allowed_below |= ~0;
 506                 }
 507
 508                 if (min_key_cache) {
 509                         allowed_above |= 1U << JOURNAL_PIN_key_cache;
 510                         allowed_below |= 1U << JOURNAL_PIN_key_cache;
 511                 }
 512
 513                 cond_resched();
 514
 515                 j->last_flushed = jiffies;
 516
 517                 spin_lock(&j->lock);
 518                 pin = journal_get_next_pin(j, seq_to_flush, allowed_below, allowed_above, &seq);
 519                 if (pin) {
 520                         BUG_ON(j->flush_in_progress);
 521                         j->flush_in_progress = pin;
 522                         j->flush_in_progress_dropped = false;
 523                         flush_fn = pin->flush;
 524                 }
 525                 spin_unlock(&j->lock);
 526
 527                 if (!pin)
 528                         break;
 529
 530                 if (min_key_cache && pin->flush == bch2_btree_key_cache_journal_flush)
 531                         min_key_cache--;
 532
 533                 if (min_any)
 534                         min_any--;
 535
 536                 err = flush_fn(j, pin, seq);
 537
 538                 spin_lock(&j->lock);
 539                 /* Pin might have been dropped or rearmed: */
 540                 if (likely(!err && !j->flush_in_progress_dropped))
 541                         list_move(&pin->list, &journal_seq_pin(j, seq)->flushed);
 542                 j->flush_in_progress = NULL;
 543                 j->flush_in_progress_dropped = false;
 544                 spin_unlock(&j->lock);
 545
 546                 wake_up(&j->pin_flush_wait);
 547
 548                 if (err)
 549                         break;
 550
 551                 nr_flushed++;
 552         }
 553
 554         return nr_flushed;
 555 }
 556
 557 static u64 journal_seq_to_flush(struct journal *j)
 558 {
 559         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 560         struct bch_dev *ca;
 561         u64 seq_to_flush = 0;
 562         unsigned iter;
 563
 564         spin_lock(&j->lock);
 565
 566         for_each_rw_member(ca, c, iter) {
 567                 struct journal_device *ja = &ca->journal;
 568                 unsigned nr_buckets, bucket_to_flush;
 569
 570                 if (!ja->nr)
 571                         continue;
 572
 573                 /* Try to keep the journal at most half full: */
 574                 nr_buckets = ja->nr / 2;
 575
 576                 /* And include pre-reservations: */
 577                 nr_buckets += DIV_ROUND_UP(j->prereserved.reserved,
 578                                            (ca->mi.bucket_size << 6) -
 579                                            journal_entry_overhead(j));
 580
 581                 nr_buckets = min(nr_buckets, ja->nr);
 582
 583                 bucket_to_flush = (ja->cur_idx + nr_buckets) % ja->nr;
 584                 seq_to_flush = max(seq_to_flush,
 585                                    ja->bucket_seq[bucket_to_flush]);
 586         }
 587
 588         /* Also flush if the pin fifo is more than half full */
 589         seq_to_flush = max_t(s64, seq_to_flush,
 590                              (s64) journal_cur_seq(j) -
 591                              (j->pin.size >> 1));
 592         spin_unlock(&j->lock);
 593
 594         return seq_to_flush;
 595 }
 596
 597 /**
 598  * bch2_journal_reclaim - free up journal buckets
 599  *
 600  * Background journal reclaim writes out btree nodes. It should be run
 601  * early enough so that we never completely run out of journal buckets.
 602  *
 603  * High watermarks for triggering background reclaim:
 604  * - FIFO has fewer than 512 entries left
 605  * - fewer than 25% journal buckets free
 606  *
 607  * Background reclaim runs until low watermarks are reached:
 608  * - FIFO has more than 1024 entries left
 609  * - more than 50% journal buckets free
 610  *
 611  * As long as a reclaim can complete in the time it takes to fill up
 612  * 512 journal entries or 25% of all journal buckets, then
 613  * journal_next_bucket() should not stall.
 614  */
 615 static int __bch2_journal_reclaim(struct journal *j, bool direct, bool kicked)
 616 {
 617         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 618         bool kthread = (current->flags & PF_KTHREAD) != 0;
 619         u64 seq_to_flush;
 620         size_t min_nr, min_key_cache, nr_flushed;
 621         unsigned flags;
 622         int ret = 0;
 623
 624         /*
 625          * We can't invoke memory reclaim while holding the reclaim_lock -
 626          * journal reclaim is required to make progress for memory reclaim
 627          * (cleaning the caches), so we can't get stuck in memory reclaim while
 628          * we're holding the reclaim lock:
 629          */
 630         lockdep_assert_held(&j->reclaim_lock);
 631         flags = memalloc_noreclaim_save();
 632
 633         do {
 634                 if (kthread && kthread_should_stop())
 635                         break;
 636
 637                 if (bch2_journal_error(j)) {
 638                         ret = -EIO;
 639                         break;
 640                 }
 641
 642                 bch2_journal_do_discards(j);
 643
 644                 seq_to_flush = journal_seq_to_flush(j);
 645                 min_nr = 0;
 646
 647                 /*
 648                  * If it's been longer than j->reclaim_delay_ms since we last flushed,
 649                  * make sure to flush at least one journal pin:
 650                  */
 651                 if (time_after(jiffies, j->last_flushed +
 652                                msecs_to_jiffies(c->opts.journal_reclaim_delay)))
 653                         min_nr = 1;
 654
 655                 if (j->prereserved.reserved * 4 > j->prereserved.remaining)
 656                         min_nr = 1;
 657
 658                 if (fifo_free(&j->pin) <= 32)
 659                         min_nr = 1;
 660
 661                 if (atomic_read(&c->btree_cache.dirty) * 2 > c->btree_cache.used)
 662                         min_nr = 1;
 663
 664                 min_key_cache = min(bch2_nr_btree_keys_need_flush(c), (size_t) 128);
 665
 666                 trace_and_count(c, journal_reclaim_start, c,
 667                                 direct, kicked,
 668                                 min_nr, min_key_cache,
 669                                 j->prereserved.reserved,
 670                                 j->prereserved.remaining,
 671                                 atomic_read(&c->btree_cache.dirty),
 672                                 c->btree_cache.used,
 673                                 atomic_long_read(&c->btree_key_cache.nr_dirty),
 674                                 atomic_long_read(&c->btree_key_cache.nr_keys));
 675
 676                 nr_flushed = journal_flush_pins(j, seq_to_flush,
 677                                                 ~0, 0,
 678                                                 min_nr, min_key_cache);
 679
 680                 if (direct)
 681                         j->nr_direct_reclaim += nr_flushed;
 682                 else
 683                         j->nr_background_reclaim += nr_flushed;
 684                 trace_and_count(c, journal_reclaim_finish, c, nr_flushed);
 685
 686                 if (nr_flushed)
 687                         wake_up(&j->reclaim_wait);
 688         } while ((min_nr || min_key_cache) && nr_flushed && !direct);
 689
 690         memalloc_noreclaim_restore(flags);
 691
 692         return ret;
 693 }
 694
 695 int bch2_journal_reclaim(struct journal *j)
 696 {
 697         return __bch2_journal_reclaim(j, true, true);
 698 }
 699
 700 static int bch2_journal_reclaim_thread(void *arg)
 701 {
 702         struct journal *j = arg;
 703         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 704         unsigned long delay, now;
 705         bool journal_empty;
 706         int ret = 0;
 707
 708         set_freezable();
 709
 710         j->last_flushed = jiffies;
 711
 712         while (!ret && !kthread_should_stop()) {
 713                 bool kicked = j->reclaim_kicked;
 714
 715                 j->reclaim_kicked = false;
 716
 717                 mutex_lock(&j->reclaim_lock);
 718                 ret = __bch2_journal_reclaim(j, false, kicked);
 719                 mutex_unlock(&j->reclaim_lock);
 720
 721                 now = jiffies;
 722                 delay = msecs_to_jiffies(c->opts.journal_reclaim_delay);
 723                 j->next_reclaim = j->last_flushed + delay;
 724
 725                 if (!time_in_range(j->next_reclaim, now, now + delay))
 726                         j->next_reclaim = now + delay;
 727
 728                 while (1) {
 729                         set_current_state(TASK_INTERRUPTIBLE|TASK_FREEZABLE);
 730                         if (kthread_should_stop())
 731                                 break;
 732                         if (j->reclaim_kicked)
 733                                 break;
 734
 735                         spin_lock(&j->lock);
 736                         journal_empty = fifo_empty(&j->pin);
 737                         spin_unlock(&j->lock);
 738
 739                         if (journal_empty)
 740                                 schedule();
 741                         else if (time_after(j->next_reclaim, jiffies))
 742                                 schedule_timeout(j->next_reclaim - jiffies);
 743                         else
 744                                 break;
 745                 }
 746                 __set_current_state(TASK_RUNNING);
 747         }
 748
 749         return 0;
 750 }
 751
 752 void bch2_journal_reclaim_stop(struct journal *j)
 753 {
 754         struct task_struct *p = j->reclaim_thread;
 755
 756         j->reclaim_thread = NULL;
 757
 758         if (p) {
 759                 kthread_stop(p);
 760                 put_task_struct(p);
 761         }
 762 }
 763
 764 int bch2_journal_reclaim_start(struct journal *j)
 765 {
 766         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 767         struct task_struct *p;
 768         int ret;
 769
 770         if (j->reclaim_thread)
 771                 return 0;
 772
 773         p = kthread_create(bch2_journal_reclaim_thread, j,
 774                            "bch-reclaim/%s", c->name);
 775         ret = PTR_ERR_OR_ZERO(p);
 776         if (ret) {
 777                 bch_err(c, "error creating journal reclaim thread: %s", bch2_err_str(ret));
 778                 return ret;
 779         }
 780
 781         get_task_struct(p);
 782         j->reclaim_thread = p;
 783         wake_up_process(p);
 784         return 0;
 785 }
 786
 787 static int journal_flush_done(struct journal *j, u64 seq_to_flush,
 788                               bool *did_work)
 789 {
 790         int ret;
 791
 792         ret = bch2_journal_error(j);
 793         if (ret)
 794                 return ret;
 795
 796         mutex_lock(&j->reclaim_lock);
 797
 798         if (journal_flush_pins(j, seq_to_flush,
 799                                (1U << JOURNAL_PIN_key_cache)|
 800                                (1U << JOURNAL_PIN_other), 0, 0, 0) ||
 801             journal_flush_pins(j, seq_to_flush,
 802                                (1U << JOURNAL_PIN_btree), 0, 0, 0))
 803                 *did_work = true;
 804
 805         spin_lock(&j->lock);
 806         /*
 807          * If journal replay hasn't completed, the unreplayed journal entries
 808          * hold refs on their corresponding sequence numbers
 809          */
 810         ret = !test_bit(JOURNAL_REPLAY_DONE, &j->flags) ||
 811                 journal_last_seq(j) > seq_to_flush ||
 812                 !fifo_used(&j->pin);
 813
 814         spin_unlock(&j->lock);
 815         mutex_unlock(&j->reclaim_lock);
 816
 817         return ret;
 818 }
 819
 820 bool bch2_journal_flush_pins(struct journal *j, u64 seq_to_flush)
 821 {
 822         bool did_work = false;
 823
 824         if (!test_bit(JOURNAL_STARTED, &j->flags))
 825                 return false;
 826
 827         closure_wait_event(&j->async_wait,
 828                 journal_flush_done(j, seq_to_flush, &did_work));
 829
 830         return did_work;
 831 }
 832
 833 int bch2_journal_flush_device_pins(struct journal *j, int dev_idx)
 834 {
 835         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 836         struct journal_entry_pin_list *p;
 837         u64 iter, seq = 0;
 838         int ret = 0;
 839
 840         spin_lock(&j->lock);
 841         fifo_for_each_entry_ptr(p, &j->pin, iter)
 842                 if (dev_idx >= 0
 843                     ? bch2_dev_list_has_dev(p->devs, dev_idx)
 844                     : p->devs.nr < c->opts.metadata_replicas)
 845                         seq = iter;
 846         spin_unlock(&j->lock);
 847
 848         bch2_journal_flush_pins(j, seq);
 849
 850         ret = bch2_journal_error(j);
 851         if (ret)
 852                 return ret;
 853
 854         mutex_lock(&c->replicas_gc_lock);
 855         bch2_replicas_gc_start(c, 1 << BCH_DATA_journal);
 856
 857         seq = 0;
 858
 859         spin_lock(&j->lock);
 860         while (!ret) {
 861                 struct bch_replicas_padded replicas;
 862
 863                 seq = max(seq, journal_last_seq(j));
 864                 if (seq >= j->pin.back)
 865                         break;
 866                 bch2_devlist_to_replicas(&replicas.e, BCH_DATA_journal,
 867                                          journal_seq_pin(j, seq)->devs);
 868                 seq++;
 869
 870                 spin_unlock(&j->lock);
 871                 ret = bch2_mark_replicas(c, &replicas.e);
 872                 spin_lock(&j->lock);
 873         }
 874         spin_unlock(&j->lock);
 875
 876         ret = bch2_replicas_gc_end(c, ret);
 877         mutex_unlock(&c->replicas_gc_lock);
 878
 879         return ret;
 880 }