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 mod_bit(JOURNAL_space_low, &j->flags, low_on_space || low_on_pin);
71
72 swap(watermark, j->watermark);
73 if (watermark > j->watermark)
74 journal_wake(j);
75 }
76
77 static struct journal_space
78 journal_dev_space_available(struct journal *j, struct bch_dev *ca,
79 enum journal_space_from from)
80 {
81 struct journal_device *ja = &ca->journal;
82 unsigned sectors, buckets, unwritten;
83 u64 seq;
84
85 if (from == journal_space_total)
86 return (struct journal_space) {
87 .next_entry = ca->mi.bucket_size,
88 .total = ca->mi.bucket_size * ja->nr,
89 };
90
91 buckets = bch2_journal_dev_buckets_available(j, ja, from);
92 sectors = ja->sectors_free;
93
94 /*
95 * We that we don't allocate the space for a journal entry
96 * until we write it out - thus, account for it here:
97 */
98 for (seq = journal_last_unwritten_seq(j);
99 seq <= journal_cur_seq(j);
100 seq++) {
101 unwritten = j->buf[seq & JOURNAL_BUF_MASK].sectors;
102
103 if (!unwritten)
104 continue;
105
106 /* entry won't fit on this device, skip: */
107 if (unwritten > ca->mi.bucket_size)
108 continue;
109
110 if (unwritten >= sectors) {
111 if (!buckets) {
112 sectors = 0;
113 break;
114 }
115
116 buckets--;
117 sectors = ca->mi.bucket_size;
118 }
119
120 sectors -= unwritten;
121 }
122
123 if (sectors < ca->mi.bucket_size && buckets) {
124 buckets--;
125 sectors = ca->mi.bucket_size;
126 }
127
128 return (struct journal_space) {
129 .next_entry = sectors,
130 .total = sectors + buckets * ca->mi.bucket_size,
131 };
132 }
133
134 static struct journal_space __journal_space_available(struct journal *j, unsigned nr_devs_want,
135 enum journal_space_from from)
136 {
137 struct bch_fs *c = container_of(j, struct bch_fs, journal);
138 unsigned pos, nr_devs = 0;
139 struct journal_space space, dev_space[BCH_SB_MEMBERS_MAX];
140
141 BUG_ON(nr_devs_want > ARRAY_SIZE(dev_space));
142
143 rcu_read_lock();
144 for_each_member_device_rcu(c, ca, &c->rw_devs[BCH_DATA_journal]) {
145 if (!ca->journal.nr)
146 continue;
147
148 space = journal_dev_space_available(j, ca, from);
149 if (!space.next_entry)
150 continue;
151
152 for (pos = 0; pos < nr_devs; pos++)
153 if (space.total > dev_space[pos].total)
154 break;
155
156 array_insert_item(dev_space, nr_devs, pos, space);
157 }
158 rcu_read_unlock();
159
160 if (nr_devs < nr_devs_want)
161 return (struct journal_space) { 0, 0 };
162
163 /*
164 * We sorted largest to smallest, and we want the smallest out of the
165 * @nr_devs_want largest devices:
166 */
167 return dev_space[nr_devs_want - 1];
168 }
169
170 void bch2_journal_space_available(struct journal *j)
171 {
172 struct bch_fs *c = container_of(j, struct bch_fs, journal);
173 unsigned clean, clean_ondisk, total;
174 unsigned max_entry_size = min(j->buf[0].buf_size >> 9,
175 j->buf[1].buf_size >> 9);
176 unsigned nr_online = 0, nr_devs_want;
177 bool can_discard = false;
178 int ret = 0;
179
180 lockdep_assert_held(&j->lock);
181
182 rcu_read_lock();
183 for_each_member_device_rcu(c, ca, &c->rw_devs[BCH_DATA_journal]) {
184 struct journal_device *ja = &ca->journal;
185
186 if (!ja->nr)
187 continue;
188
189 while (ja->dirty_idx != ja->cur_idx &&
190 ja->bucket_seq[ja->dirty_idx] < journal_last_seq(j))
191 ja->dirty_idx = (ja->dirty_idx + 1) % ja->nr;
192
193 while (ja->dirty_idx_ondisk != ja->dirty_idx &&
194 ja->bucket_seq[ja->dirty_idx_ondisk] < j->last_seq_ondisk)
195 ja->dirty_idx_ondisk = (ja->dirty_idx_ondisk + 1) % ja->nr;
196
197 if (ja->discard_idx != ja->dirty_idx_ondisk)
198 can_discard = true;
199
200 max_entry_size = min_t(unsigned, max_entry_size, ca->mi.bucket_size);
201 nr_online++;
202 }
203 rcu_read_unlock();
204
205 j->can_discard = can_discard;
206
207 if (nr_online < metadata_replicas_required(c)) {
208 struct printbuf buf = PRINTBUF;
209 buf.atomic++;
210 prt_printf(&buf, "insufficient writeable journal devices available: have %u, need %u\n"
211 "rw journal devs:", nr_online, metadata_replicas_required(c));
212
213 rcu_read_lock();
214 for_each_member_device_rcu(c, ca, &c->rw_devs[BCH_DATA_journal])
215 prt_printf(&buf, " %s", ca->name);
216 rcu_read_unlock();
217
218 bch_err(c, "%s", buf.buf);
219 printbuf_exit(&buf);
220 ret = JOURNAL_ERR_insufficient_devices;
221 goto out;
222 }
223
224 nr_devs_want = min_t(unsigned, nr_online, c->opts.metadata_replicas);
225
226 for (unsigned i = 0; i < journal_space_nr; i++)
227 j->space[i] = __journal_space_available(j, nr_devs_want, i);
228
229 clean_ondisk = j->space[journal_space_clean_ondisk].total;
230 clean = j->space[journal_space_clean].total;
231 total = j->space[journal_space_total].total;
232
233 if (!j->space[journal_space_discarded].next_entry)
234 ret = JOURNAL_ERR_journal_full;
235
236 if ((j->space[journal_space_clean_ondisk].next_entry <
237 j->space[journal_space_clean_ondisk].total) &&
238 (clean - clean_ondisk <= total / 8) &&
239 (clean_ondisk * 2 > clean))
240 set_bit(JOURNAL_may_skip_flush, &j->flags);
241 else
242 clear_bit(JOURNAL_may_skip_flush, &j->flags);
243
244 bch2_journal_set_watermark(j);
245 out:
246 j->cur_entry_sectors = !ret ? j->space[journal_space_discarded].next_entry : 0;
247 j->cur_entry_error = ret;
248
249 if (!ret)
250 journal_wake(j);
251 }
252
253 /* Discards - last part of journal reclaim: */
254
255 static bool should_discard_bucket(struct journal *j, struct journal_device *ja)
256 {
257 bool ret;
258
259 spin_lock(&j->lock);
260 ret = ja->discard_idx != ja->dirty_idx_ondisk;
261 spin_unlock(&j->lock);
262
263 return ret;
264 }
265
266 /*
267 * Advance ja->discard_idx as long as it points to buckets that are no longer
268 * dirty, issuing discards if necessary:
269 */
270 void bch2_journal_do_discards(struct journal *j)
271 {
272 struct bch_fs *c = container_of(j, struct bch_fs, journal);
273
274 mutex_lock(&j->discard_lock);
275
276 for_each_rw_member(c, ca) {
277 struct journal_device *ja = &ca->journal;
278
279 while (should_discard_bucket(j, ja)) {
280 if (!c->opts.nochanges &&
281 ca->mi.discard &&
282 bdev_max_discard_sectors(ca->disk_sb.bdev))
283 blkdev_issue_discard(ca->disk_sb.bdev,
284 bucket_to_sector(ca,
285 ja->buckets[ja->discard_idx]),
286 ca->mi.bucket_size, GFP_NOFS);
287
288 spin_lock(&j->lock);
289 ja->discard_idx = (ja->discard_idx + 1) % ja->nr;
290
291 bch2_journal_space_available(j);
292 spin_unlock(&j->lock);
293 }
294 }
295
296 mutex_unlock(&j->discard_lock);
297 }
298
299 /*
300 * Journal entry pinning - machinery for holding a reference on a given journal
301 * entry, holding it open to ensure it gets replayed during recovery:
302 */
303
304 void bch2_journal_reclaim_fast(struct journal *j)
305 {
306 bool popped = false;
307
308 lockdep_assert_held(&j->lock);
309
310 /*
311 * Unpin journal entries whose reference counts reached zero, meaning
312 * all btree nodes got written out
313 */
314 while (!fifo_empty(&j->pin) &&
315 j->pin.front <= j->seq_ondisk &&
316 !atomic_read(&fifo_peek_front(&j->pin).count)) {
317 j->pin.front++;
318 popped = true;
319 }
320
321 if (popped)
322 bch2_journal_space_available(j);
323 }
324
325 bool __bch2_journal_pin_put(struct journal *j, u64 seq)
326 {
327 struct journal_entry_pin_list *pin_list = journal_seq_pin(j, seq);
328
329 return atomic_dec_and_test(&pin_list->count);
330 }
331
332 void bch2_journal_pin_put(struct journal *j, u64 seq)
333 {
334 if (__bch2_journal_pin_put(j, seq)) {
335 spin_lock(&j->lock);
336 bch2_journal_reclaim_fast(j);
337 spin_unlock(&j->lock);
338 }
339 }
340
341 static inline bool __journal_pin_drop(struct journal *j,
342 struct journal_entry_pin *pin)
343 {
344 struct journal_entry_pin_list *pin_list;
345
346 if (!journal_pin_active(pin))
347 return false;
348
349 if (j->flush_in_progress == pin)
350 j->flush_in_progress_dropped = true;
351
352 pin_list = journal_seq_pin(j, pin->seq);
353 pin->seq = 0;
354 list_del_init(&pin->list);
355
356 /*
357 * Unpinning a journal entry may make journal_next_bucket() succeed, if
358 * writing a new last_seq will now make another bucket available:
359 */
360 return atomic_dec_and_test(&pin_list->count) &&
361 pin_list == &fifo_peek_front(&j->pin);
362 }
363
364 void bch2_journal_pin_drop(struct journal *j,
365 struct journal_entry_pin *pin)
366 {
367 spin_lock(&j->lock);
368 if (__journal_pin_drop(j, pin))
369 bch2_journal_reclaim_fast(j);
370 spin_unlock(&j->lock);
371 }
372
373 static enum journal_pin_type journal_pin_type(journal_pin_flush_fn fn)
374 {
375 if (fn == bch2_btree_node_flush0 ||
376 fn == bch2_btree_node_flush1)
377 return JOURNAL_PIN_btree;
378 else if (fn == bch2_btree_key_cache_journal_flush)
379 return JOURNAL_PIN_key_cache;
380 else
381 return JOURNAL_PIN_other;
382 }
383
384 static inline void bch2_journal_pin_set_locked(struct journal *j, u64 seq,
385 struct journal_entry_pin *pin,
386 journal_pin_flush_fn flush_fn,
387 enum journal_pin_type type)
388 {
389 struct journal_entry_pin_list *pin_list = journal_seq_pin(j, seq);
390
391 /*
392 * flush_fn is how we identify journal pins in debugfs, so must always
393 * exist, even if it doesn't do anything:
394 */
395 BUG_ON(!flush_fn);
396
397 atomic_inc(&pin_list->count);
398 pin->seq = seq;
399 pin->flush = flush_fn;
400 list_add(&pin->list, &pin_list->list[type]);
401 }
402
403 void bch2_journal_pin_copy(struct journal *j,
404 struct journal_entry_pin *dst,
405 struct journal_entry_pin *src,
406 journal_pin_flush_fn flush_fn)
407 {
408 spin_lock(&j->lock);
409
410 u64 seq = READ_ONCE(src->seq);
411
412 if (seq < journal_last_seq(j)) {
413 /*
414 * bch2_journal_pin_copy() raced with bch2_journal_pin_drop() on
415 * the src pin - with the pin dropped, the entry to pin might no
416 * longer to exist, but that means there's no longer anything to
417 * copy and we can bail out here:
418 */
419 spin_unlock(&j->lock);
420 return;
421 }
422
423 bool reclaim = __journal_pin_drop(j, dst);
424
425 bch2_journal_pin_set_locked(j, seq, dst, flush_fn, journal_pin_type(flush_fn));
426
427 if (reclaim)
428 bch2_journal_reclaim_fast(j);
429
430 /*
431 * If the journal is currently full, we might want to call flush_fn
432 * immediately:
433 */
434 if (seq == journal_last_seq(j))
435 journal_wake(j);
436 spin_unlock(&j->lock);
437 }
438
439 void bch2_journal_pin_set(struct journal *j, u64 seq,
440 struct journal_entry_pin *pin,
441 journal_pin_flush_fn flush_fn)
442 {
443 spin_lock(&j->lock);
444
445 BUG_ON(seq < journal_last_seq(j));
446
447 bool reclaim = __journal_pin_drop(j, pin);
448
449 bch2_journal_pin_set_locked(j, seq, pin, flush_fn, journal_pin_type(flush_fn));
450
451 if (reclaim)
452 bch2_journal_reclaim_fast(j);
453 /*
454 * If the journal is currently full, we might want to call flush_fn
455 * immediately:
456 */
457 if (seq == journal_last_seq(j))
458 journal_wake(j);
459
460 spin_unlock(&j->lock);
461 }
462
463 /**
464 * bch2_journal_pin_flush: ensure journal pin callback is no longer running
465 * @j: journal object
466 * @pin: pin to flush
467 */
468 void bch2_journal_pin_flush(struct journal *j, struct journal_entry_pin *pin)
469 {
470 BUG_ON(journal_pin_active(pin));
471
472 wait_event(j->pin_flush_wait, j->flush_in_progress != pin);
473 }
474
475 /*
476 * Journal reclaim: flush references to open journal entries to reclaim space in
477 * the journal
478 *
479 * May be done by the journal code in the background as needed to free up space
480 * for more journal entries, or as part of doing a clean shutdown, or to migrate
481 * data off of a specific device:
482 */
483
484 static struct journal_entry_pin *
485 journal_get_next_pin(struct journal *j,
486 u64 seq_to_flush,
487 unsigned allowed_below_seq,
488 unsigned allowed_above_seq,
489 u64 *seq)
490 {
491 struct journal_entry_pin_list *pin_list;
492 struct journal_entry_pin *ret = NULL;
493 unsigned i;
494
495 fifo_for_each_entry_ptr(pin_list, &j->pin, *seq) {
496 if (*seq > seq_to_flush && !allowed_above_seq)
497 break;
498
499 for (i = 0; i < JOURNAL_PIN_NR; i++)
500 if ((((1U << i) & allowed_below_seq) && *seq <= seq_to_flush) ||
501 ((1U << i) & allowed_above_seq)) {
502 ret = list_first_entry_or_null(&pin_list->list[i],
503 struct journal_entry_pin, list);
504 if (ret)
505 return ret;
506 }
507 }
508
509 return NULL;
510 }
511
512 /* returns true if we did work */
513 static size_t journal_flush_pins(struct journal *j,
514 u64 seq_to_flush,
515 unsigned allowed_below_seq,
516 unsigned allowed_above_seq,
517 unsigned min_any,
518 unsigned min_key_cache)
519 {
520 struct journal_entry_pin *pin;
521 size_t nr_flushed = 0;
522 journal_pin_flush_fn flush_fn;
523 u64 seq;
524 int err;
525
526 lockdep_assert_held(&j->reclaim_lock);
527
528 while (1) {
529 unsigned allowed_above = allowed_above_seq;
530 unsigned allowed_below = allowed_below_seq;
531
532 if (min_any) {
533 allowed_above |= ~0;
534 allowed_below |= ~0;
535 }
536
537 if (min_key_cache) {
538 allowed_above |= 1U << JOURNAL_PIN_key_cache;
539 allowed_below |= 1U << JOURNAL_PIN_key_cache;
540 }
541
542 cond_resched();
543
544 j->last_flushed = jiffies;
545
546 spin_lock(&j->lock);
547 pin = journal_get_next_pin(j, seq_to_flush, allowed_below, allowed_above, &seq);
548 if (pin) {
549 BUG_ON(j->flush_in_progress);
550 j->flush_in_progress = pin;
551 j->flush_in_progress_dropped = false;
552 flush_fn = pin->flush;
553 }
554 spin_unlock(&j->lock);
555
556 if (!pin)
557 break;
558
559 if (min_key_cache && pin->flush == bch2_btree_key_cache_journal_flush)
560 min_key_cache--;
561
562 if (min_any)
563 min_any--;
564
565 err = flush_fn(j, pin, seq);
566
567 spin_lock(&j->lock);
568 /* Pin might have been dropped or rearmed: */
569 if (likely(!err && !j->flush_in_progress_dropped))
570 list_move(&pin->list, &journal_seq_pin(j, seq)->flushed);
571 j->flush_in_progress = NULL;
572 j->flush_in_progress_dropped = false;
573 spin_unlock(&j->lock);
574
575 wake_up(&j->pin_flush_wait);
576
577 if (err)
578 break;
579
580 nr_flushed++;
581 }
582
583 return nr_flushed;
584 }
585
586 static u64 journal_seq_to_flush(struct journal *j)
587 {
588 struct bch_fs *c = container_of(j, struct bch_fs, journal);
589 u64 seq_to_flush = 0;
590
591 spin_lock(&j->lock);
592
593 for_each_rw_member(c, ca) {
594 struct journal_device *ja = &ca->journal;
595 unsigned nr_buckets, bucket_to_flush;
596
597 if (!ja->nr)
598 continue;
599
600 /* Try to keep the journal at most half full: */
601 nr_buckets = ja->nr / 2;
602
603 nr_buckets = min(nr_buckets, ja->nr);
604
605 bucket_to_flush = (ja->cur_idx + nr_buckets) % ja->nr;
606 seq_to_flush = max(seq_to_flush,
607 ja->bucket_seq[bucket_to_flush]);
608 }
609
610 /* Also flush if the pin fifo is more than half full */
611 seq_to_flush = max_t(s64, seq_to_flush,
612 (s64) journal_cur_seq(j) -
613 (j->pin.size >> 1));
614 spin_unlock(&j->lock);
615
616 return seq_to_flush;
617 }
618
619 /**
620 * __bch2_journal_reclaim - free up journal buckets
621 * @j: journal object
622 * @direct: direct or background reclaim?
623 * @kicked: requested to run since we last ran?
624 * Returns: 0 on success, or -EIO if the journal has been shutdown
625 *
626 * Background journal reclaim writes out btree nodes. It should be run
627 * early enough so that we never completely run out of journal buckets.
628 *
629 * High watermarks for triggering background reclaim:
630 * - FIFO has fewer than 512 entries left
631 * - fewer than 25% journal buckets free
632 *
633 * Background reclaim runs until low watermarks are reached:
634 * - FIFO has more than 1024 entries left
635 * - more than 50% journal buckets free
636 *
637 * As long as a reclaim can complete in the time it takes to fill up
638 * 512 journal entries or 25% of all journal buckets, then
639 * journal_next_bucket() should not stall.
640 */
641 static int __bch2_journal_reclaim(struct journal *j, bool direct, bool kicked)
642 {
643 struct bch_fs *c = container_of(j, struct bch_fs, journal);
644 bool kthread = (current->flags & PF_KTHREAD) != 0;
645 u64 seq_to_flush;
646 size_t min_nr, min_key_cache, nr_flushed;
647 unsigned flags;
648 int ret = 0;
649
650 /*
651 * We can't invoke memory reclaim while holding the reclaim_lock -
652 * journal reclaim is required to make progress for memory reclaim
653 * (cleaning the caches), so we can't get stuck in memory reclaim while
654 * we're holding the reclaim lock:
655 */
656 lockdep_assert_held(&j->reclaim_lock);
657 flags = memalloc_noreclaim_save();
658
659 do {
660 if (kthread && kthread_should_stop())
661 break;
662
663 if (bch2_journal_error(j)) {
664 ret = -EIO;
665 break;
666 }
667
668 bch2_journal_do_discards(j);
669
670 seq_to_flush = journal_seq_to_flush(j);
671 min_nr = 0;
672
673 /*
674 * If it's been longer than j->reclaim_delay_ms since we last flushed,
675 * make sure to flush at least one journal pin:
676 */
677 if (time_after(jiffies, j->last_flushed +
678 msecs_to_jiffies(c->opts.journal_reclaim_delay)))
679 min_nr = 1;
680
681 if (j->watermark != BCH_WATERMARK_stripe)
682 min_nr = 1;
683
684 if (atomic_read(&c->btree_cache.dirty) * 2 > c->btree_cache.used)
685 min_nr = 1;
686
687 min_key_cache = min(bch2_nr_btree_keys_need_flush(c), (size_t) 128);
688
689 trace_and_count(c, journal_reclaim_start, c,
690 direct, kicked,
691 min_nr, min_key_cache,
692 atomic_read(&c->btree_cache.dirty),
693 c->btree_cache.used,
694 atomic_long_read(&c->btree_key_cache.nr_dirty),
695 atomic_long_read(&c->btree_key_cache.nr_keys));
696
697 nr_flushed = journal_flush_pins(j, seq_to_flush,
698 ~0, 0,
699 min_nr, min_key_cache);
700
701 if (direct)
702 j->nr_direct_reclaim += nr_flushed;
703 else
704 j->nr_background_reclaim += nr_flushed;
705 trace_and_count(c, journal_reclaim_finish, c, nr_flushed);
706
707 if (nr_flushed)
708 wake_up(&j->reclaim_wait);
709 } while ((min_nr || min_key_cache) && nr_flushed && !direct);
710
711 memalloc_noreclaim_restore(flags);
712
713 return ret;
714 }
715
716 int bch2_journal_reclaim(struct journal *j)
717 {
718 return __bch2_journal_reclaim(j, true, true);
719 }
720
721 static int bch2_journal_reclaim_thread(void *arg)
722 {
723 struct journal *j = arg;
724 struct bch_fs *c = container_of(j, struct bch_fs, journal);
725 unsigned long delay, now;
726 bool journal_empty;
727 int ret = 0;
728
729 set_freezable();
730
731 j->last_flushed = jiffies;
732
733 while (!ret && !kthread_should_stop()) {
734 bool kicked = j->reclaim_kicked;
735
736 j->reclaim_kicked = false;
737
738 mutex_lock(&j->reclaim_lock);
739 ret = __bch2_journal_reclaim(j, false, kicked);
740 mutex_unlock(&j->reclaim_lock);
741
742 now = jiffies;
743 delay = msecs_to_jiffies(c->opts.journal_reclaim_delay);
744 j->next_reclaim = j->last_flushed + delay;
745
746 if (!time_in_range(j->next_reclaim, now, now + delay))
747 j->next_reclaim = now + delay;
748
749 while (1) {
750 set_current_state(TASK_INTERRUPTIBLE|TASK_FREEZABLE);
751 if (kthread_should_stop())
752 break;
753 if (j->reclaim_kicked)
754 break;
755
756 spin_lock(&j->lock);
757 journal_empty = fifo_empty(&j->pin);
758 spin_unlock(&j->lock);
759
760 if (journal_empty)
761 schedule();
762 else if (time_after(j->next_reclaim, jiffies))
763 schedule_timeout(j->next_reclaim - jiffies);
764 else
765 break;
766 }
767 __set_current_state(TASK_RUNNING);
768 }
769
770 return 0;
771 }
772
773 void bch2_journal_reclaim_stop(struct journal *j)
774 {
775 struct task_struct *p = j->reclaim_thread;
776
777 j->reclaim_thread = NULL;
778
779 if (p) {
780 kthread_stop(p);
781 put_task_struct(p);
782 }
783 }
784
785 int bch2_journal_reclaim_start(struct journal *j)
786 {
787 struct bch_fs *c = container_of(j, struct bch_fs, journal);
788 struct task_struct *p;
789 int ret;
790
791 if (j->reclaim_thread)
792 return 0;
793
794 p = kthread_create(bch2_journal_reclaim_thread, j,
795 "bch-reclaim/%s", c->name);
796 ret = PTR_ERR_OR_ZERO(p);
797 bch_err_msg(c, ret, "creating journal reclaim thread");
798 if (ret)
799 return ret;
800
801 get_task_struct(p);
802 j->reclaim_thread = p;
803 wake_up_process(p);
804 return 0;
805 }
806
807 static int journal_flush_done(struct journal *j, u64 seq_to_flush,
808 bool *did_work)
809 {
810 int ret;
811
812 ret = bch2_journal_error(j);
813 if (ret)
814 return ret;
815
816 mutex_lock(&j->reclaim_lock);
817
818 if (journal_flush_pins(j, seq_to_flush,
819 (1U << JOURNAL_PIN_key_cache)|
820 (1U << JOURNAL_PIN_other), 0, 0, 0) ||
821 journal_flush_pins(j, seq_to_flush,
822 (1U << JOURNAL_PIN_btree), 0, 0, 0))
823 *did_work = true;
824
825 if (seq_to_flush > journal_cur_seq(j))
826 bch2_journal_entry_close(j);
827
828 spin_lock(&j->lock);
829 /*
830 * If journal replay hasn't completed, the unreplayed journal entries
831 * hold refs on their corresponding sequence numbers
832 */
833 ret = !test_bit(JOURNAL_replay_done, &j->flags) ||
834 journal_last_seq(j) > seq_to_flush ||
835 !fifo_used(&j->pin);
836
837 spin_unlock(&j->lock);
838 mutex_unlock(&j->reclaim_lock);
839
840 return ret;
841 }
842
843 bool bch2_journal_flush_pins(struct journal *j, u64 seq_to_flush)
844 {
845 /* time_stats this */
846 bool did_work = false;
847
848 if (!test_bit(JOURNAL_running, &j->flags))
849 return false;
850
851 closure_wait_event(&j->async_wait,
852 journal_flush_done(j, seq_to_flush, &did_work));
853
854 return did_work;
855 }
856
857 int bch2_journal_flush_device_pins(struct journal *j, int dev_idx)
858 {
859 struct bch_fs *c = container_of(j, struct bch_fs, journal);
860 struct journal_entry_pin_list *p;
861 u64 iter, seq = 0;
862 int ret = 0;
863
864 spin_lock(&j->lock);
865 fifo_for_each_entry_ptr(p, &j->pin, iter)
866 if (dev_idx >= 0
867 ? bch2_dev_list_has_dev(p->devs, dev_idx)
868 : p->devs.nr < c->opts.metadata_replicas)
869 seq = iter;
870 spin_unlock(&j->lock);
871
872 bch2_journal_flush_pins(j, seq);
873
874 ret = bch2_journal_error(j);
875 if (ret)
876 return ret;
877
878 mutex_lock(&c->replicas_gc_lock);
879 bch2_replicas_gc_start(c, 1 << BCH_DATA_journal);
880
881 /*
882 * Now that we've populated replicas_gc, write to the journal to mark
883 * active journal devices. This handles the case where the journal might
884 * be empty. Otherwise we could clear all journal replicas and
885 * temporarily put the fs into an unrecoverable state. Journal recovery
886 * expects to find devices marked for journal data on unclean mount.
887 */
888 ret = bch2_journal_meta(&c->journal);
889 if (ret)
890 goto err;
891
892 seq = 0;
893 spin_lock(&j->lock);
894 while (!ret) {
895 struct bch_replicas_padded replicas;
896
897 seq = max(seq, journal_last_seq(j));
898 if (seq >= j->pin.back)
899 break;
900 bch2_devlist_to_replicas(&replicas.e, BCH_DATA_journal,
901 journal_seq_pin(j, seq)->devs);
902 seq++;
903
904 if (replicas.e.nr_devs) {
905 spin_unlock(&j->lock);
906 ret = bch2_mark_replicas(c, &replicas.e);
907 spin_lock(&j->lock);
908 }
909 }
910 spin_unlock(&j->lock);
911 err:
912 ret = bch2_replicas_gc_end(c, ret);
913 mutex_unlock(&c->replicas_gc_lock);
914
915 return ret;
916 }
917
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