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 "btree_write_buffer.h"
   7 #include "buckets.h"
   8 #include "errcode.h"
   9 #include "error.h"
  10 #include "journal.h"
  11 #include "journal_io.h"
  12 #include "journal_reclaim.h"
  13 #include "replicas.h"
  14 #include "sb-members.h"
  15 #include "trace.h"
  16
  17 #include <linux/kthread.h>
  18 #include <linux/sched/mm.h>
  19
  20 /* Free space calculations: */
  21
  22 static unsigned journal_space_from(struct journal_device *ja,
  23                                    enum journal_space_from from)
  24 {
  25         switch (from) {
  26         case journal_space_discarded:
  27                 return ja->discard_idx;
  28         case journal_space_clean_ondisk:
  29                 return ja->dirty_idx_ondisk;
  30         case journal_space_clean:
  31                 return ja->dirty_idx;
  32         default:
  33                 BUG();
  34         }
  35 }
  36
  37 unsigned bch2_journal_dev_buckets_available(struct journal *j,
  38                                             struct journal_device *ja,
  39                                             enum journal_space_from from)
  40 {
  41         unsigned available = (journal_space_from(ja, from) -
  42                               ja->cur_idx - 1 + ja->nr) % ja->nr;
  43
  44         /*
  45          * Don't use the last bucket unless writing the new last_seq
  46          * will make another bucket available:
  47          */
  48         if (available && ja->dirty_idx_ondisk == ja->dirty_idx)
  49                 --available;
  50
  51         return available;
  52 }
  53
  54 void bch2_journal_set_watermark(struct journal *j)
  55 {
  56         struct bch_fs *c = container_of(j, struct bch_fs, journal);
  57         bool low_on_space = j->space[journal_space_clean].total * 4 <=
  58                 j->space[journal_space_total].total;
  59         bool low_on_pin = fifo_free(&j->pin) < j->pin.size / 4;
  60         bool low_on_wb = bch2_btree_write_buffer_must_wait(c);
  61         unsigned watermark = low_on_space || low_on_pin || low_on_wb
  62                 ? BCH_WATERMARK_reclaim
  63                 : BCH_WATERMARK_stripe;
  64
  65         if (track_event_change(&c->times[BCH_TIME_blocked_journal_low_on_space], low_on_space) ||
  66             track_event_change(&c->times[BCH_TIME_blocked_journal_low_on_pin], low_on_pin) ||
  67             track_event_change(&c->times[BCH_TIME_blocked_write_buffer_full], low_on_wb))
  68                 trace_and_count(c, journal_full, c);
  69
  70         swap(watermark, j->watermark);
  71         if (watermark > j->watermark)
  72                 journal_wake(j);
  73 }
  74
  75 static struct journal_space
  76 journal_dev_space_available(struct journal *j, struct bch_dev *ca,
  77                             enum journal_space_from from)
  78 {
  79         struct journal_device *ja = &ca->journal;
  80         unsigned sectors, buckets, unwritten;
  81         u64 seq;
  82
  83         if (from == journal_space_total)
  84                 return (struct journal_space) {
  85                         .next_entry     = ca->mi.bucket_size,
  86                         .total          = ca->mi.bucket_size * ja->nr,
  87                 };
  88
  89         buckets = bch2_journal_dev_buckets_available(j, ja, from);
  90         sectors = ja->sectors_free;
  91
  92         /*
  93          * We that we don't allocate the space for a journal entry
  94          * until we write it out - thus, account for it here:
  95          */
  96         for (seq = journal_last_unwritten_seq(j);
  97              seq <= journal_cur_seq(j);
  98              seq++) {
  99                 unwritten = j->buf[seq & JOURNAL_BUF_MASK].sectors;
 100
 101                 if (!unwritten)
 102                         continue;
 103
 104                 /* entry won't fit on this device, skip: */
 105                 if (unwritten > ca->mi.bucket_size)
 106                         continue;
 107
 108                 if (unwritten >= sectors) {
 109                         if (!buckets) {
 110                                 sectors = 0;
 111                                 break;
 112                         }
 113
 114                         buckets--;
 115                         sectors = ca->mi.bucket_size;
 116                 }
 117
 118                 sectors -= unwritten;
 119         }
 120
 121         if (sectors < ca->mi.bucket_size && buckets) {
 122                 buckets--;
 123                 sectors = ca->mi.bucket_size;
 124         }
 125
 126         return (struct journal_space) {
 127                 .next_entry     = sectors,
 128                 .total          = sectors + buckets * ca->mi.bucket_size,
 129         };
 130 }
 131
 132 static struct journal_space __journal_space_available(struct journal *j, unsigned nr_devs_want,
 133                             enum journal_space_from from)
 134 {
 135         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 136         unsigned pos, nr_devs = 0;
 137         struct journal_space space, dev_space[BCH_SB_MEMBERS_MAX];
 138
 139         BUG_ON(nr_devs_want > ARRAY_SIZE(dev_space));
 140
 141         rcu_read_lock();
 142         for_each_member_device_rcu(c, ca, &c->rw_devs[BCH_DATA_journal]) {
 143                 if (!ca->journal.nr)
 144                         continue;
 145
 146                 space = journal_dev_space_available(j, ca, from);
 147                 if (!space.next_entry)
 148                         continue;
 149
 150                 for (pos = 0; pos < nr_devs; pos++)
 151                         if (space.total > dev_space[pos].total)
 152                                 break;
 153
 154                 array_insert_item(dev_space, nr_devs, pos, space);
 155         }
 156         rcu_read_unlock();
 157
 158         if (nr_devs < nr_devs_want)
 159                 return (struct journal_space) { 0, 0 };
 160
 161         /*
 162          * We sorted largest to smallest, and we want the smallest out of the
 163          * @nr_devs_want largest devices:
 164          */
 165         return dev_space[nr_devs_want - 1];
 166 }
 167
 168 void bch2_journal_space_available(struct journal *j)
 169 {
 170         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 171         unsigned clean, clean_ondisk, total;
 172         unsigned max_entry_size  = min(j->buf[0].buf_size >> 9,
 173                                        j->buf[1].buf_size >> 9);
 174         unsigned nr_online = 0, nr_devs_want;
 175         bool can_discard = false;
 176         int ret = 0;
 177
 178         lockdep_assert_held(&j->lock);
 179
 180         rcu_read_lock();
 181         for_each_member_device_rcu(c, ca, &c->rw_devs[BCH_DATA_journal]) {
 182                 struct journal_device *ja = &ca->journal;
 183
 184                 if (!ja->nr)
 185                         continue;
 186
 187                 while (ja->dirty_idx != ja->cur_idx &&
 188                        ja->bucket_seq[ja->dirty_idx] < journal_last_seq(j))
 189                         ja->dirty_idx = (ja->dirty_idx + 1) % ja->nr;
 190
 191                 while (ja->dirty_idx_ondisk != ja->dirty_idx &&
 192                        ja->bucket_seq[ja->dirty_idx_ondisk] < j->last_seq_ondisk)
 193                         ja->dirty_idx_ondisk = (ja->dirty_idx_ondisk + 1) % ja->nr;
 194
 195                 if (ja->discard_idx != ja->dirty_idx_ondisk)
 196                         can_discard = true;
 197
 198                 max_entry_size = min_t(unsigned, max_entry_size, ca->mi.bucket_size);
 199                 nr_online++;
 200         }
 201         rcu_read_unlock();
 202
 203         j->can_discard = can_discard;
 204
 205         if (nr_online < metadata_replicas_required(c)) {
 206                 ret = JOURNAL_ERR_insufficient_devices;
 207                 goto out;
 208         }
 209
 210         nr_devs_want = min_t(unsigned, nr_online, c->opts.metadata_replicas);
 211
 212         for (unsigned i = 0; i < journal_space_nr; i++)
 213                 j->space[i] = __journal_space_available(j, nr_devs_want, i);
 214
 215         clean_ondisk    = j->space[journal_space_clean_ondisk].total;
 216         clean           = j->space[journal_space_clean].total;
 217         total           = j->space[journal_space_total].total;
 218
 219         if (!j->space[journal_space_discarded].next_entry)
 220                 ret = JOURNAL_ERR_journal_full;
 221
 222         if ((j->space[journal_space_clean_ondisk].next_entry <
 223              j->space[journal_space_clean_ondisk].total) &&
 224             (clean - clean_ondisk <= total / 8) &&
 225             (clean_ondisk * 2 > clean))
 226                 set_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
 227         else
 228                 clear_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
 229
 230         bch2_journal_set_watermark(j);
 231 out:
 232         j->cur_entry_sectors    = !ret ? j->space[journal_space_discarded].next_entry : 0;
 233         j->cur_entry_error      = ret;
 234
 235         if (!ret)
 236                 journal_wake(j);
 237 }
 238
 239 /* Discards - last part of journal reclaim: */
 240
 241 static bool should_discard_bucket(struct journal *j, struct journal_device *ja)
 242 {
 243         bool ret;
 244
 245         spin_lock(&j->lock);
 246         ret = ja->discard_idx != ja->dirty_idx_ondisk;
 247         spin_unlock(&j->lock);
 248
 249         return ret;
 250 }
 251
 252 /*
 253  * Advance ja->discard_idx as long as it points to buckets that are no longer
 254  * dirty, issuing discards if necessary:
 255  */
 256 void bch2_journal_do_discards(struct journal *j)
 257 {
 258         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 259
 260         mutex_lock(&j->discard_lock);
 261
 262         for_each_rw_member(c, ca) {
 263                 struct journal_device *ja = &ca->journal;
 264
 265                 while (should_discard_bucket(j, ja)) {
 266                         if (!c->opts.nochanges &&
 267                             ca->mi.discard &&
 268                             bdev_max_discard_sectors(ca->disk_sb.bdev))
 269                                 blkdev_issue_discard(ca->disk_sb.bdev,
 270                                         bucket_to_sector(ca,
 271                                                 ja->buckets[ja->discard_idx]),
 272                                         ca->mi.bucket_size, GFP_NOFS);
 273
 274                         spin_lock(&j->lock);
 275                         ja->discard_idx = (ja->discard_idx + 1) % ja->nr;
 276
 277                         bch2_journal_space_available(j);
 278                         spin_unlock(&j->lock);
 279                 }
 280         }
 281
 282         mutex_unlock(&j->discard_lock);
 283 }
 284
 285 /*
 286  * Journal entry pinning - machinery for holding a reference on a given journal
 287  * entry, holding it open to ensure it gets replayed during recovery:
 288  */
 289
 290 void bch2_journal_reclaim_fast(struct journal *j)
 291 {
 292         bool popped = false;
 293
 294         lockdep_assert_held(&j->lock);
 295
 296         /*
 297          * Unpin journal entries whose reference counts reached zero, meaning
 298          * all btree nodes got written out
 299          */
 300         while (!fifo_empty(&j->pin) &&
 301                j->pin.front <= j->seq_ondisk &&
 302                !atomic_read(&fifo_peek_front(&j->pin).count)) {
 303                 j->pin.front++;
 304                 popped = true;
 305         }
 306
 307         if (popped)
 308                 bch2_journal_space_available(j);
 309 }
 310
 311 bool __bch2_journal_pin_put(struct journal *j, u64 seq)
 312 {
 313         struct journal_entry_pin_list *pin_list = journal_seq_pin(j, seq);
 314
 315         return atomic_dec_and_test(&pin_list->count);
 316 }
 317
 318 void bch2_journal_pin_put(struct journal *j, u64 seq)
 319 {
 320         if (__bch2_journal_pin_put(j, seq)) {
 321                 spin_lock(&j->lock);
 322                 bch2_journal_reclaim_fast(j);
 323                 spin_unlock(&j->lock);
 324         }
 325 }
 326
 327 static inline bool __journal_pin_drop(struct journal *j,
 328                                       struct journal_entry_pin *pin)
 329 {
 330         struct journal_entry_pin_list *pin_list;
 331
 332         if (!journal_pin_active(pin))
 333                 return false;
 334
 335         if (j->flush_in_progress == pin)
 336                 j->flush_in_progress_dropped = true;
 337
 338         pin_list = journal_seq_pin(j, pin->seq);
 339         pin->seq = 0;
 340         list_del_init(&pin->list);
 341
 342         /*
 343          * Unpinning a journal entry may make journal_next_bucket() succeed, if
 344          * writing a new last_seq will now make another bucket available:
 345          */
 346         return atomic_dec_and_test(&pin_list->count) &&
 347                 pin_list == &fifo_peek_front(&j->pin);
 348 }
 349
 350 void bch2_journal_pin_drop(struct journal *j,
 351                            struct journal_entry_pin *pin)
 352 {
 353         spin_lock(&j->lock);
 354         if (__journal_pin_drop(j, pin))
 355                 bch2_journal_reclaim_fast(j);
 356         spin_unlock(&j->lock);
 357 }
 358
 359 static enum journal_pin_type journal_pin_type(journal_pin_flush_fn fn)
 360 {
 361         if (fn == bch2_btree_node_flush0 ||
 362             fn == bch2_btree_node_flush1)
 363                 return JOURNAL_PIN_btree;
 364         else if (fn == bch2_btree_key_cache_journal_flush)
 365                 return JOURNAL_PIN_key_cache;
 366         else
 367                 return JOURNAL_PIN_other;
 368 }
 369
 370 static inline void bch2_journal_pin_set_locked(struct journal *j, u64 seq,
 371                           struct journal_entry_pin *pin,
 372                           journal_pin_flush_fn flush_fn,
 373                           enum journal_pin_type type)
 374 {
 375         struct journal_entry_pin_list *pin_list = journal_seq_pin(j, seq);
 376
 377         /*
 378          * flush_fn is how we identify journal pins in debugfs, so must always
 379          * exist, even if it doesn't do anything:
 380          */
 381         BUG_ON(!flush_fn);
 382
 383         atomic_inc(&pin_list->count);
 384         pin->seq        = seq;
 385         pin->flush      = flush_fn;
 386         list_add(&pin->list, &pin_list->list[type]);
 387 }
 388
 389 void bch2_journal_pin_copy(struct journal *j,
 390                            struct journal_entry_pin *dst,
 391                            struct journal_entry_pin *src,
 392                            journal_pin_flush_fn flush_fn)
 393 {
 394         spin_lock(&j->lock);
 395
 396         u64 seq = READ_ONCE(src->seq);
 397
 398         if (seq < journal_last_seq(j)) {
 399                 /*
 400                  * bch2_journal_pin_copy() raced with bch2_journal_pin_drop() on
 401                  * the src pin - with the pin dropped, the entry to pin might no
 402                  * longer to exist, but that means there's no longer anything to
 403                  * copy and we can bail out here:
 404                  */
 405                 spin_unlock(&j->lock);
 406                 return;
 407         }
 408
 409         bool reclaim = __journal_pin_drop(j, dst);
 410
 411         bch2_journal_pin_set_locked(j, seq, dst, flush_fn, journal_pin_type(flush_fn));
 412
 413         if (reclaim)
 414                 bch2_journal_reclaim_fast(j);
 415
 416         /*
 417          * If the journal is currently full,  we might want to call flush_fn
 418          * immediately:
 419          */
 420         if (seq == journal_last_seq(j))
 421                 journal_wake(j);
 422         spin_unlock(&j->lock);
 423 }
 424
 425 void bch2_journal_pin_set(struct journal *j, u64 seq,
 426                           struct journal_entry_pin *pin,
 427                           journal_pin_flush_fn flush_fn)
 428 {
 429         spin_lock(&j->lock);
 430
 431         BUG_ON(seq < journal_last_seq(j));
 432
 433         bool reclaim = __journal_pin_drop(j, pin);
 434
 435         bch2_journal_pin_set_locked(j, seq, pin, flush_fn, journal_pin_type(flush_fn));
 436
 437         if (reclaim)
 438                 bch2_journal_reclaim_fast(j);
 439         /*
 440          * If the journal is currently full,  we might want to call flush_fn
 441          * immediately:
 442          */
 443         if (seq == journal_last_seq(j))
 444                 journal_wake(j);
 445
 446         spin_unlock(&j->lock);
 447 }
 448
 449 /**
 450  * bch2_journal_pin_flush: ensure journal pin callback is no longer running
 451  * @j:          journal object
 452  * @pin:        pin to flush
 453  */
 454 void bch2_journal_pin_flush(struct journal *j, struct journal_entry_pin *pin)
 455 {
 456         BUG_ON(journal_pin_active(pin));
 457
 458         wait_event(j->pin_flush_wait, j->flush_in_progress != pin);
 459 }
 460
 461 /*
 462  * Journal reclaim: flush references to open journal entries to reclaim space in
 463  * the journal
 464  *
 465  * May be done by the journal code in the background as needed to free up space
 466  * for more journal entries, or as part of doing a clean shutdown, or to migrate
 467  * data off of a specific device:
 468  */
 469
 470 static struct journal_entry_pin *
 471 journal_get_next_pin(struct journal *j,
 472                      u64 seq_to_flush,
 473                      unsigned allowed_below_seq,
 474                      unsigned allowed_above_seq,
 475                      u64 *seq)
 476 {
 477         struct journal_entry_pin_list *pin_list;
 478         struct journal_entry_pin *ret = NULL;
 479         unsigned i;
 480
 481         fifo_for_each_entry_ptr(pin_list, &j->pin, *seq) {
 482                 if (*seq > seq_to_flush && !allowed_above_seq)
 483                         break;
 484
 485                 for (i = 0; i < JOURNAL_PIN_NR; i++)
 486                         if ((((1U << i) & allowed_below_seq) && *seq <= seq_to_flush) ||
 487                             ((1U << i) & allowed_above_seq)) {
 488                                 ret = list_first_entry_or_null(&pin_list->list[i],
 489                                         struct journal_entry_pin, list);
 490                                 if (ret)
 491                                         return ret;
 492                         }
 493         }
 494
 495         return NULL;
 496 }
 497
 498 /* returns true if we did work */
 499 static size_t journal_flush_pins(struct journal *j,
 500                                  u64 seq_to_flush,
 501                                  unsigned allowed_below_seq,
 502                                  unsigned allowed_above_seq,
 503                                  unsigned min_any,
 504                                  unsigned min_key_cache)
 505 {
 506         struct journal_entry_pin *pin;
 507         size_t nr_flushed = 0;
 508         journal_pin_flush_fn flush_fn;
 509         u64 seq;
 510         int err;
 511
 512         lockdep_assert_held(&j->reclaim_lock);
 513
 514         while (1) {
 515                 unsigned allowed_above = allowed_above_seq;
 516                 unsigned allowed_below = allowed_below_seq;
 517
 518                 if (min_any) {
 519                         allowed_above |= ~0;
 520                         allowed_below |= ~0;
 521                 }
 522
 523                 if (min_key_cache) {
 524                         allowed_above |= 1U << JOURNAL_PIN_key_cache;
 525                         allowed_below |= 1U << JOURNAL_PIN_key_cache;
 526                 }
 527
 528                 cond_resched();
 529
 530                 j->last_flushed = jiffies;
 531
 532                 spin_lock(&j->lock);
 533                 pin = journal_get_next_pin(j, seq_to_flush, allowed_below, allowed_above, &seq);
 534                 if (pin) {
 535                         BUG_ON(j->flush_in_progress);
 536                         j->flush_in_progress = pin;
 537                         j->flush_in_progress_dropped = false;
 538                         flush_fn = pin->flush;
 539                 }
 540                 spin_unlock(&j->lock);
 541
 542                 if (!pin)
 543                         break;
 544
 545                 if (min_key_cache && pin->flush == bch2_btree_key_cache_journal_flush)
 546                         min_key_cache--;
 547
 548                 if (min_any)
 549                         min_any--;
 550
 551                 err = flush_fn(j, pin, seq);
 552
 553                 spin_lock(&j->lock);
 554                 /* Pin might have been dropped or rearmed: */
 555                 if (likely(!err && !j->flush_in_progress_dropped))
 556                         list_move(&pin->list, &journal_seq_pin(j, seq)->flushed);
 557                 j->flush_in_progress = NULL;
 558                 j->flush_in_progress_dropped = false;
 559                 spin_unlock(&j->lock);
 560
 561                 wake_up(&j->pin_flush_wait);
 562
 563                 if (err)
 564                         break;
 565
 566                 nr_flushed++;
 567         }
 568
 569         return nr_flushed;
 570 }
 571
 572 static u64 journal_seq_to_flush(struct journal *j)
 573 {
 574         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 575         u64 seq_to_flush = 0;
 576
 577         spin_lock(&j->lock);
 578
 579         for_each_rw_member(c, ca) {
 580                 struct journal_device *ja = &ca->journal;
 581                 unsigned nr_buckets, bucket_to_flush;
 582
 583                 if (!ja->nr)
 584                         continue;
 585
 586                 /* Try to keep the journal at most half full: */
 587                 nr_buckets = ja->nr / 2;
 588
 589                 nr_buckets = min(nr_buckets, ja->nr);
 590
 591                 bucket_to_flush = (ja->cur_idx + nr_buckets) % ja->nr;
 592                 seq_to_flush = max(seq_to_flush,
 593                                    ja->bucket_seq[bucket_to_flush]);
 594         }
 595
 596         /* Also flush if the pin fifo is more than half full */
 597         seq_to_flush = max_t(s64, seq_to_flush,
 598                              (s64) journal_cur_seq(j) -
 599                              (j->pin.size >> 1));
 600         spin_unlock(&j->lock);
 601
 602         return seq_to_flush;
 603 }
 604
 605 /**
 606  * __bch2_journal_reclaim - free up journal buckets
 607  * @j:          journal object
 608  * @direct:     direct or background reclaim?
 609  * @kicked:     requested to run since we last ran?
 610  * Returns:     0 on success, or -EIO if the journal has been shutdown
 611  *
 612  * Background journal reclaim writes out btree nodes. It should be run
 613  * early enough so that we never completely run out of journal buckets.
 614  *
 615  * High watermarks for triggering background reclaim:
 616  * - FIFO has fewer than 512 entries left
 617  * - fewer than 25% journal buckets free
 618  *
 619  * Background reclaim runs until low watermarks are reached:
 620  * - FIFO has more than 1024 entries left
 621  * - more than 50% journal buckets free
 622  *
 623  * As long as a reclaim can complete in the time it takes to fill up
 624  * 512 journal entries or 25% of all journal buckets, then
 625  * journal_next_bucket() should not stall.
 626  */
 627 static int __bch2_journal_reclaim(struct journal *j, bool direct, bool kicked)
 628 {
 629         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 630         bool kthread = (current->flags & PF_KTHREAD) != 0;
 631         u64 seq_to_flush;
 632         size_t min_nr, min_key_cache, nr_flushed;
 633         unsigned flags;
 634         int ret = 0;
 635
 636         /*
 637          * We can't invoke memory reclaim while holding the reclaim_lock -
 638          * journal reclaim is required to make progress for memory reclaim
 639          * (cleaning the caches), so we can't get stuck in memory reclaim while
 640          * we're holding the reclaim lock:
 641          */
 642         lockdep_assert_held(&j->reclaim_lock);
 643         flags = memalloc_noreclaim_save();
 644
 645         do {
 646                 if (kthread && kthread_should_stop())
 647                         break;
 648
 649                 if (bch2_journal_error(j)) {
 650                         ret = -EIO;
 651                         break;
 652                 }
 653
 654                 bch2_journal_do_discards(j);
 655
 656                 seq_to_flush = journal_seq_to_flush(j);
 657                 min_nr = 0;
 658
 659                 /*
 660                  * If it's been longer than j->reclaim_delay_ms since we last flushed,
 661                  * make sure to flush at least one journal pin:
 662                  */
 663                 if (time_after(jiffies, j->last_flushed +
 664                                msecs_to_jiffies(c->opts.journal_reclaim_delay)))
 665                         min_nr = 1;
 666
 667                 if (j->watermark != BCH_WATERMARK_stripe)
 668                         min_nr = 1;
 669
 670                 if (atomic_read(&c->btree_cache.dirty) * 2 > c->btree_cache.used)
 671                         min_nr = 1;
 672
 673                 min_key_cache = min(bch2_nr_btree_keys_need_flush(c), (size_t) 128);
 674
 675                 trace_and_count(c, journal_reclaim_start, c,
 676                                 direct, kicked,
 677                                 min_nr, min_key_cache,
 678                                 atomic_read(&c->btree_cache.dirty),
 679                                 c->btree_cache.used,
 680                                 atomic_long_read(&c->btree_key_cache.nr_dirty),
 681                                 atomic_long_read(&c->btree_key_cache.nr_keys));
 682
 683                 nr_flushed = journal_flush_pins(j, seq_to_flush,
 684                                                 ~0, 0,
 685                                                 min_nr, min_key_cache);
 686
 687                 if (direct)
 688                         j->nr_direct_reclaim += nr_flushed;
 689                 else
 690                         j->nr_background_reclaim += nr_flushed;
 691                 trace_and_count(c, journal_reclaim_finish, c, nr_flushed);
 692
 693                 if (nr_flushed)
 694                         wake_up(&j->reclaim_wait);
 695         } while ((min_nr || min_key_cache) && nr_flushed && !direct);
 696
 697         memalloc_noreclaim_restore(flags);
 698
 699         return ret;
 700 }
 701
 702 int bch2_journal_reclaim(struct journal *j)
 703 {
 704         return __bch2_journal_reclaim(j, true, true);
 705 }
 706
 707 static int bch2_journal_reclaim_thread(void *arg)
 708 {
 709         struct journal *j = arg;
 710         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 711         unsigned long delay, now;
 712         bool journal_empty;
 713         int ret = 0;
 714
 715         set_freezable();
 716
 717         j->last_flushed = jiffies;
 718
 719         while (!ret && !kthread_should_stop()) {
 720                 bool kicked = j->reclaim_kicked;
 721
 722                 j->reclaim_kicked = false;
 723
 724                 mutex_lock(&j->reclaim_lock);
 725                 ret = __bch2_journal_reclaim(j, false, kicked);
 726                 mutex_unlock(&j->reclaim_lock);
 727
 728                 now = jiffies;
 729                 delay = msecs_to_jiffies(c->opts.journal_reclaim_delay);
 730                 j->next_reclaim = j->last_flushed + delay;
 731
 732                 if (!time_in_range(j->next_reclaim, now, now + delay))
 733                         j->next_reclaim = now + delay;
 734
 735                 while (1) {
 736                         set_current_state(TASK_INTERRUPTIBLE|TASK_FREEZABLE);
 737                         if (kthread_should_stop())
 738                                 break;
 739                         if (j->reclaim_kicked)
 740                                 break;
 741
 742                         spin_lock(&j->lock);
 743                         journal_empty = fifo_empty(&j->pin);
 744                         spin_unlock(&j->lock);
 745
 746                         if (journal_empty)
 747                                 schedule();
 748                         else if (time_after(j->next_reclaim, jiffies))
 749                                 schedule_timeout(j->next_reclaim - jiffies);
 750                         else
 751                                 break;
 752                 }
 753                 __set_current_state(TASK_RUNNING);
 754         }
 755
 756         return 0;
 757 }
 758
 759 void bch2_journal_reclaim_stop(struct journal *j)
 760 {
 761         struct task_struct *p = j->reclaim_thread;
 762
 763         j->reclaim_thread = NULL;
 764
 765         if (p) {
 766                 kthread_stop(p);
 767                 put_task_struct(p);
 768         }
 769 }
 770
 771 int bch2_journal_reclaim_start(struct journal *j)
 772 {
 773         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 774         struct task_struct *p;
 775         int ret;
 776
 777         if (j->reclaim_thread)
 778                 return 0;
 779
 780         p = kthread_create(bch2_journal_reclaim_thread, j,
 781                            "bch-reclaim/%s", c->name);
 782         ret = PTR_ERR_OR_ZERO(p);
 783         bch_err_msg(c, ret, "creating journal reclaim thread");
 784         if (ret)
 785                 return ret;
 786
 787         get_task_struct(p);
 788         j->reclaim_thread = p;
 789         wake_up_process(p);
 790         return 0;
 791 }
 792
 793 static int journal_flush_done(struct journal *j, u64 seq_to_flush,
 794                               bool *did_work)
 795 {
 796         int ret;
 797
 798         ret = bch2_journal_error(j);
 799         if (ret)
 800                 return ret;
 801
 802         mutex_lock(&j->reclaim_lock);
 803
 804         if (journal_flush_pins(j, seq_to_flush,
 805                                (1U << JOURNAL_PIN_key_cache)|
 806                                (1U << JOURNAL_PIN_other), 0, 0, 0) ||
 807             journal_flush_pins(j, seq_to_flush,
 808                                (1U << JOURNAL_PIN_btree), 0, 0, 0))
 809                 *did_work = true;
 810
 811         if (seq_to_flush > journal_cur_seq(j))
 812                 bch2_journal_entry_close(j);
 813
 814         spin_lock(&j->lock);
 815         /*
 816          * If journal replay hasn't completed, the unreplayed journal entries
 817          * hold refs on their corresponding sequence numbers
 818          */
 819         ret = !test_bit(JOURNAL_REPLAY_DONE, &j->flags) ||
 820                 journal_last_seq(j) > seq_to_flush ||
 821                 !fifo_used(&j->pin);
 822
 823         spin_unlock(&j->lock);
 824         mutex_unlock(&j->reclaim_lock);
 825
 826         return ret;
 827 }
 828
 829 bool bch2_journal_flush_pins(struct journal *j, u64 seq_to_flush)
 830 {
 831         /* time_stats this */
 832         bool did_work = false;
 833
 834         if (!test_bit(JOURNAL_STARTED, &j->flags))
 835                 return false;
 836
 837         closure_wait_event(&j->async_wait,
 838                 journal_flush_done(j, seq_to_flush, &did_work));
 839
 840         return did_work;
 841 }
 842
 843 int bch2_journal_flush_device_pins(struct journal *j, int dev_idx)
 844 {
 845         struct bch_fs *c = container_of(j, struct bch_fs, journal);
 846         struct journal_entry_pin_list *p;
 847         u64 iter, seq = 0;
 848         int ret = 0;
 849
 850         spin_lock(&j->lock);
 851         fifo_for_each_entry_ptr(p, &j->pin, iter)
 852                 if (dev_idx >= 0
 853                     ? bch2_dev_list_has_dev(p->devs, dev_idx)
 854                     : p->devs.nr < c->opts.metadata_replicas)
 855                         seq = iter;
 856         spin_unlock(&j->lock);
 857
 858         bch2_journal_flush_pins(j, seq);
 859
 860         ret = bch2_journal_error(j);
 861         if (ret)
 862                 return ret;
 863
 864         mutex_lock(&c->replicas_gc_lock);
 865         bch2_replicas_gc_start(c, 1 << BCH_DATA_journal);
 866
 867         /*
 868          * Now that we've populated replicas_gc, write to the journal to mark
 869          * active journal devices. This handles the case where the journal might
 870          * be empty. Otherwise we could clear all journal replicas and
 871          * temporarily put the fs into an unrecoverable state. Journal recovery
 872          * expects to find devices marked for journal data on unclean mount.
 873          */
 874         ret = bch2_journal_meta(&c->journal);
 875         if (ret)
 876                 goto err;
 877
 878         seq = 0;
 879         spin_lock(&j->lock);
 880         while (!ret) {
 881                 struct bch_replicas_padded replicas;
 882
 883                 seq = max(seq, journal_last_seq(j));
 884                 if (seq >= j->pin.back)
 885                         break;
 886                 bch2_devlist_to_replicas(&replicas.e, BCH_DATA_journal,
 887                                          journal_seq_pin(j, seq)->devs);
 888                 seq++;
 889
 890                 if (replicas.e.nr_devs) {
 891                         spin_unlock(&j->lock);
 892                         ret = bch2_mark_replicas(c, &replicas.e);
 893                         spin_lock(&j->lock);
 894                 }
 895         }
 896         spin_unlock(&j->lock);
 897 err:
 898         ret = bch2_replicas_gc_end(c, ret);
 899         mutex_unlock(&c->replicas_gc_lock);
 900
 901         return ret;
 902 }