1 // SPDX-License-Identifier: GPL-2.0
4 #include "btree_key_cache.h"
5 #include "btree_update.h"
10 #include "journal_io.h"
11 #include "journal_reclaim.h"
13 #include "sb-members.h"
16 #include <linux/kthread.h>
17 #include <linux/sched/mm.h>
19 /* Free space calculations: */
21 static unsigned journal_space_from(struct journal_device *ja,
22 enum journal_space_from from)
25 case journal_space_discarded:
26 return ja->discard_idx;
27 case journal_space_clean_ondisk:
28 return ja->dirty_idx_ondisk;
29 case journal_space_clean:
36 unsigned bch2_journal_dev_buckets_available(struct journal *j,
37 struct journal_device *ja,
38 enum journal_space_from from)
40 unsigned available = (journal_space_from(ja, from) -
41 ja->cur_idx - 1 + ja->nr) % ja->nr;
44 * Don't use the last bucket unless writing the new last_seq
45 * will make another bucket available:
47 if (available && ja->dirty_idx_ondisk == ja->dirty_idx)
53 static inline void journal_set_watermark(struct journal *j, bool low_on_space)
55 unsigned watermark = BCH_WATERMARK_stripe;
58 watermark = max_t(unsigned, watermark, BCH_WATERMARK_reclaim);
59 if (fifo_free(&j->pin) < j->pin.size / 4)
60 watermark = max_t(unsigned, watermark, BCH_WATERMARK_reclaim);
62 if (watermark == j->watermark)
65 swap(watermark, j->watermark);
66 if (watermark > j->watermark)
70 static struct journal_space
71 journal_dev_space_available(struct journal *j, struct bch_dev *ca,
72 enum journal_space_from from)
74 struct journal_device *ja = &ca->journal;
75 unsigned sectors, buckets, unwritten;
78 if (from == journal_space_total)
79 return (struct journal_space) {
80 .next_entry = ca->mi.bucket_size,
81 .total = ca->mi.bucket_size * ja->nr,
84 buckets = bch2_journal_dev_buckets_available(j, ja, from);
85 sectors = ja->sectors_free;
88 * We that we don't allocate the space for a journal entry
89 * until we write it out - thus, account for it here:
91 for (seq = journal_last_unwritten_seq(j);
92 seq <= journal_cur_seq(j);
94 unwritten = j->buf[seq & JOURNAL_BUF_MASK].sectors;
99 /* entry won't fit on this device, skip: */
100 if (unwritten > ca->mi.bucket_size)
103 if (unwritten >= sectors) {
110 sectors = ca->mi.bucket_size;
113 sectors -= unwritten;
116 if (sectors < ca->mi.bucket_size && buckets) {
118 sectors = ca->mi.bucket_size;
121 return (struct journal_space) {
122 .next_entry = sectors,
123 .total = sectors + buckets * ca->mi.bucket_size,
127 static struct journal_space __journal_space_available(struct journal *j, unsigned nr_devs_want,
128 enum journal_space_from from)
130 struct bch_fs *c = container_of(j, struct bch_fs, journal);
132 unsigned i, pos, nr_devs = 0;
133 struct journal_space space, dev_space[BCH_SB_MEMBERS_MAX];
135 BUG_ON(nr_devs_want > ARRAY_SIZE(dev_space));
138 for_each_member_device_rcu(ca, c, i,
139 &c->rw_devs[BCH_DATA_journal]) {
143 space = journal_dev_space_available(j, ca, from);
144 if (!space.next_entry)
147 for (pos = 0; pos < nr_devs; pos++)
148 if (space.total > dev_space[pos].total)
151 array_insert_item(dev_space, nr_devs, pos, space);
155 if (nr_devs < nr_devs_want)
156 return (struct journal_space) { 0, 0 };
159 * We sorted largest to smallest, and we want the smallest out of the
160 * @nr_devs_want largest devices:
162 return dev_space[nr_devs_want - 1];
165 void bch2_journal_space_available(struct journal *j)
167 struct bch_fs *c = container_of(j, struct bch_fs, journal);
169 unsigned clean, clean_ondisk, total;
170 unsigned max_entry_size = min(j->buf[0].buf_size >> 9,
171 j->buf[1].buf_size >> 9);
172 unsigned i, nr_online = 0, nr_devs_want;
173 bool can_discard = false;
176 lockdep_assert_held(&j->lock);
179 for_each_member_device_rcu(ca, c, i,
180 &c->rw_devs[BCH_DATA_journal]) {
181 struct journal_device *ja = &ca->journal;
186 while (ja->dirty_idx != ja->cur_idx &&
187 ja->bucket_seq[ja->dirty_idx] < journal_last_seq(j))
188 ja->dirty_idx = (ja->dirty_idx + 1) % ja->nr;
190 while (ja->dirty_idx_ondisk != ja->dirty_idx &&
191 ja->bucket_seq[ja->dirty_idx_ondisk] < j->last_seq_ondisk)
192 ja->dirty_idx_ondisk = (ja->dirty_idx_ondisk + 1) % ja->nr;
194 if (ja->discard_idx != ja->dirty_idx_ondisk)
197 max_entry_size = min_t(unsigned, max_entry_size, ca->mi.bucket_size);
202 j->can_discard = can_discard;
204 if (nr_online < c->opts.metadata_replicas_required) {
205 ret = JOURNAL_ERR_insufficient_devices;
209 nr_devs_want = min_t(unsigned, nr_online, c->opts.metadata_replicas);
211 for (i = 0; i < journal_space_nr; i++)
212 j->space[i] = __journal_space_available(j, nr_devs_want, i);
214 clean_ondisk = j->space[journal_space_clean_ondisk].total;
215 clean = j->space[journal_space_clean].total;
216 total = j->space[journal_space_total].total;
218 if (!j->space[journal_space_discarded].next_entry)
219 ret = JOURNAL_ERR_journal_full;
221 if ((j->space[journal_space_clean_ondisk].next_entry <
222 j->space[journal_space_clean_ondisk].total) &&
223 (clean - clean_ondisk <= total / 8) &&
224 (clean_ondisk * 2 > clean))
225 set_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
227 clear_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
229 journal_set_watermark(j, clean * 4 <= total);
231 j->cur_entry_sectors = !ret ? j->space[journal_space_discarded].next_entry : 0;
232 j->cur_entry_error = ret;
238 /* Discards - last part of journal reclaim: */
240 static bool should_discard_bucket(struct journal *j, struct journal_device *ja)
245 ret = ja->discard_idx != ja->dirty_idx_ondisk;
246 spin_unlock(&j->lock);
252 * Advance ja->discard_idx as long as it points to buckets that are no longer
253 * dirty, issuing discards if necessary:
255 void bch2_journal_do_discards(struct journal *j)
257 struct bch_fs *c = container_of(j, struct bch_fs, journal);
261 mutex_lock(&j->discard_lock);
263 for_each_rw_member(ca, c, iter) {
264 struct journal_device *ja = &ca->journal;
266 while (should_discard_bucket(j, ja)) {
267 if (!c->opts.nochanges &&
269 bdev_max_discard_sectors(ca->disk_sb.bdev))
270 blkdev_issue_discard(ca->disk_sb.bdev,
272 ja->buckets[ja->discard_idx]),
273 ca->mi.bucket_size, GFP_NOFS);
276 ja->discard_idx = (ja->discard_idx + 1) % ja->nr;
278 bch2_journal_space_available(j);
279 spin_unlock(&j->lock);
283 mutex_unlock(&j->discard_lock);
287 * Journal entry pinning - machinery for holding a reference on a given journal
288 * entry, holding it open to ensure it gets replayed during recovery:
291 void bch2_journal_reclaim_fast(struct journal *j)
295 lockdep_assert_held(&j->lock);
298 * Unpin journal entries whose reference counts reached zero, meaning
299 * all btree nodes got written out
301 while (!fifo_empty(&j->pin) &&
302 !atomic_read(&fifo_peek_front(&j->pin).count)) {
308 bch2_journal_space_available(j);
311 bool __bch2_journal_pin_put(struct journal *j, u64 seq)
313 struct journal_entry_pin_list *pin_list = journal_seq_pin(j, seq);
315 return atomic_dec_and_test(&pin_list->count);
318 void bch2_journal_pin_put(struct journal *j, u64 seq)
320 if (__bch2_journal_pin_put(j, seq)) {
322 bch2_journal_reclaim_fast(j);
323 spin_unlock(&j->lock);
327 static inline bool __journal_pin_drop(struct journal *j,
328 struct journal_entry_pin *pin)
330 struct journal_entry_pin_list *pin_list;
332 if (!journal_pin_active(pin))
335 if (j->flush_in_progress == pin)
336 j->flush_in_progress_dropped = true;
338 pin_list = journal_seq_pin(j, pin->seq);
340 list_del_init(&pin->list);
343 * Unpinning a journal entry may make journal_next_bucket() succeed, if
344 * writing a new last_seq will now make another bucket available:
346 return atomic_dec_and_test(&pin_list->count) &&
347 pin_list == &fifo_peek_front(&j->pin);
350 void bch2_journal_pin_drop(struct journal *j,
351 struct journal_entry_pin *pin)
354 if (__journal_pin_drop(j, pin))
355 bch2_journal_reclaim_fast(j);
356 spin_unlock(&j->lock);
359 static enum journal_pin_type journal_pin_type(journal_pin_flush_fn fn)
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;
367 return JOURNAL_PIN_other;
370 void bch2_journal_pin_set(struct journal *j, u64 seq,
371 struct journal_entry_pin *pin,
372 journal_pin_flush_fn flush_fn)
374 struct journal_entry_pin_list *pin_list;
379 if (seq < journal_last_seq(j)) {
381 * bch2_journal_pin_copy() raced with bch2_journal_pin_drop() on
382 * the src pin - with the pin dropped, the entry to pin might no
383 * longer to exist, but that means there's no longer anything to
384 * copy and we can bail out here:
386 spin_unlock(&j->lock);
390 pin_list = journal_seq_pin(j, seq);
392 reclaim = __journal_pin_drop(j, pin);
394 atomic_inc(&pin_list->count);
396 pin->flush = flush_fn;
399 list_add(&pin->list, &pin_list->list[journal_pin_type(flush_fn)]);
401 list_add(&pin->list, &pin_list->flushed);
404 bch2_journal_reclaim_fast(j);
405 spin_unlock(&j->lock);
408 * If the journal is currently full, we might want to call flush_fn
415 * bch2_journal_pin_flush: ensure journal pin callback is no longer running
419 void bch2_journal_pin_flush(struct journal *j, struct journal_entry_pin *pin)
421 BUG_ON(journal_pin_active(pin));
423 wait_event(j->pin_flush_wait, j->flush_in_progress != pin);
427 * Journal reclaim: flush references to open journal entries to reclaim space in
430 * May be done by the journal code in the background as needed to free up space
431 * for more journal entries, or as part of doing a clean shutdown, or to migrate
432 * data off of a specific device:
435 static struct journal_entry_pin *
436 journal_get_next_pin(struct journal *j,
438 unsigned allowed_below_seq,
439 unsigned allowed_above_seq,
442 struct journal_entry_pin_list *pin_list;
443 struct journal_entry_pin *ret = NULL;
446 fifo_for_each_entry_ptr(pin_list, &j->pin, *seq) {
447 if (*seq > seq_to_flush && !allowed_above_seq)
450 for (i = 0; i < JOURNAL_PIN_NR; i++)
451 if ((((1U << i) & allowed_below_seq) && *seq <= seq_to_flush) ||
452 ((1U << i) & allowed_above_seq)) {
453 ret = list_first_entry_or_null(&pin_list->list[i],
454 struct journal_entry_pin, list);
463 /* returns true if we did work */
464 static size_t journal_flush_pins(struct journal *j,
466 unsigned allowed_below_seq,
467 unsigned allowed_above_seq,
469 unsigned min_key_cache)
471 struct journal_entry_pin *pin;
472 size_t nr_flushed = 0;
473 journal_pin_flush_fn flush_fn;
477 lockdep_assert_held(&j->reclaim_lock);
480 unsigned allowed_above = allowed_above_seq;
481 unsigned allowed_below = allowed_below_seq;
489 allowed_above |= 1U << JOURNAL_PIN_key_cache;
490 allowed_below |= 1U << JOURNAL_PIN_key_cache;
495 j->last_flushed = jiffies;
498 pin = journal_get_next_pin(j, seq_to_flush, allowed_below, allowed_above, &seq);
500 BUG_ON(j->flush_in_progress);
501 j->flush_in_progress = pin;
502 j->flush_in_progress_dropped = false;
503 flush_fn = pin->flush;
505 spin_unlock(&j->lock);
510 if (min_key_cache && pin->flush == bch2_btree_key_cache_journal_flush)
516 err = flush_fn(j, pin, seq);
519 /* Pin might have been dropped or rearmed: */
520 if (likely(!err && !j->flush_in_progress_dropped))
521 list_move(&pin->list, &journal_seq_pin(j, seq)->flushed);
522 j->flush_in_progress = NULL;
523 j->flush_in_progress_dropped = false;
524 spin_unlock(&j->lock);
526 wake_up(&j->pin_flush_wait);
537 static u64 journal_seq_to_flush(struct journal *j)
539 struct bch_fs *c = container_of(j, struct bch_fs, journal);
541 u64 seq_to_flush = 0;
546 for_each_rw_member(ca, c, iter) {
547 struct journal_device *ja = &ca->journal;
548 unsigned nr_buckets, bucket_to_flush;
553 /* Try to keep the journal at most half full: */
554 nr_buckets = ja->nr / 2;
556 nr_buckets = min(nr_buckets, ja->nr);
558 bucket_to_flush = (ja->cur_idx + nr_buckets) % ja->nr;
559 seq_to_flush = max(seq_to_flush,
560 ja->bucket_seq[bucket_to_flush]);
563 /* Also flush if the pin fifo is more than half full */
564 seq_to_flush = max_t(s64, seq_to_flush,
565 (s64) journal_cur_seq(j) -
567 spin_unlock(&j->lock);
573 * __bch2_journal_reclaim - free up journal buckets
575 * @direct: direct or background reclaim?
576 * @kicked: requested to run since we last ran?
577 * Returns: 0 on success, or -EIO if the journal has been shutdown
579 * Background journal reclaim writes out btree nodes. It should be run
580 * early enough so that we never completely run out of journal buckets.
582 * High watermarks for triggering background reclaim:
583 * - FIFO has fewer than 512 entries left
584 * - fewer than 25% journal buckets free
586 * Background reclaim runs until low watermarks are reached:
587 * - FIFO has more than 1024 entries left
588 * - more than 50% journal buckets free
590 * As long as a reclaim can complete in the time it takes to fill up
591 * 512 journal entries or 25% of all journal buckets, then
592 * journal_next_bucket() should not stall.
594 static int __bch2_journal_reclaim(struct journal *j, bool direct, bool kicked)
596 struct bch_fs *c = container_of(j, struct bch_fs, journal);
597 bool kthread = (current->flags & PF_KTHREAD) != 0;
599 size_t min_nr, min_key_cache, nr_flushed;
604 * We can't invoke memory reclaim while holding the reclaim_lock -
605 * journal reclaim is required to make progress for memory reclaim
606 * (cleaning the caches), so we can't get stuck in memory reclaim while
607 * we're holding the reclaim lock:
609 lockdep_assert_held(&j->reclaim_lock);
610 flags = memalloc_noreclaim_save();
613 if (kthread && kthread_should_stop())
616 if (bch2_journal_error(j)) {
621 bch2_journal_do_discards(j);
623 seq_to_flush = journal_seq_to_flush(j);
627 * If it's been longer than j->reclaim_delay_ms since we last flushed,
628 * make sure to flush at least one journal pin:
630 if (time_after(jiffies, j->last_flushed +
631 msecs_to_jiffies(c->opts.journal_reclaim_delay)))
634 if (j->watermark != BCH_WATERMARK_stripe)
637 if (atomic_read(&c->btree_cache.dirty) * 2 > c->btree_cache.used)
640 min_key_cache = min(bch2_nr_btree_keys_need_flush(c), (size_t) 128);
642 trace_and_count(c, journal_reclaim_start, c,
644 min_nr, min_key_cache,
645 atomic_read(&c->btree_cache.dirty),
647 atomic_long_read(&c->btree_key_cache.nr_dirty),
648 atomic_long_read(&c->btree_key_cache.nr_keys));
650 nr_flushed = journal_flush_pins(j, seq_to_flush,
652 min_nr, min_key_cache);
655 j->nr_direct_reclaim += nr_flushed;
657 j->nr_background_reclaim += nr_flushed;
658 trace_and_count(c, journal_reclaim_finish, c, nr_flushed);
661 wake_up(&j->reclaim_wait);
662 } while ((min_nr || min_key_cache) && nr_flushed && !direct);
664 memalloc_noreclaim_restore(flags);
669 int bch2_journal_reclaim(struct journal *j)
671 return __bch2_journal_reclaim(j, true, true);
674 static int bch2_journal_reclaim_thread(void *arg)
676 struct journal *j = arg;
677 struct bch_fs *c = container_of(j, struct bch_fs, journal);
678 unsigned long delay, now;
684 j->last_flushed = jiffies;
686 while (!ret && !kthread_should_stop()) {
687 bool kicked = j->reclaim_kicked;
689 j->reclaim_kicked = false;
691 mutex_lock(&j->reclaim_lock);
692 ret = __bch2_journal_reclaim(j, false, kicked);
693 mutex_unlock(&j->reclaim_lock);
696 delay = msecs_to_jiffies(c->opts.journal_reclaim_delay);
697 j->next_reclaim = j->last_flushed + delay;
699 if (!time_in_range(j->next_reclaim, now, now + delay))
700 j->next_reclaim = now + delay;
703 set_current_state(TASK_INTERRUPTIBLE|TASK_FREEZABLE);
704 if (kthread_should_stop())
706 if (j->reclaim_kicked)
710 journal_empty = fifo_empty(&j->pin);
711 spin_unlock(&j->lock);
715 else if (time_after(j->next_reclaim, jiffies))
716 schedule_timeout(j->next_reclaim - jiffies);
720 __set_current_state(TASK_RUNNING);
726 void bch2_journal_reclaim_stop(struct journal *j)
728 struct task_struct *p = j->reclaim_thread;
730 j->reclaim_thread = NULL;
738 int bch2_journal_reclaim_start(struct journal *j)
740 struct bch_fs *c = container_of(j, struct bch_fs, journal);
741 struct task_struct *p;
744 if (j->reclaim_thread)
747 p = kthread_create(bch2_journal_reclaim_thread, j,
748 "bch-reclaim/%s", c->name);
749 ret = PTR_ERR_OR_ZERO(p);
751 bch_err_msg(c, ret, "creating journal reclaim thread");
756 j->reclaim_thread = p;
761 static int journal_flush_done(struct journal *j, u64 seq_to_flush,
766 ret = bch2_journal_error(j);
770 mutex_lock(&j->reclaim_lock);
772 if (journal_flush_pins(j, seq_to_flush,
773 (1U << JOURNAL_PIN_key_cache)|
774 (1U << JOURNAL_PIN_other), 0, 0, 0) ||
775 journal_flush_pins(j, seq_to_flush,
776 (1U << JOURNAL_PIN_btree), 0, 0, 0))
781 * If journal replay hasn't completed, the unreplayed journal entries
782 * hold refs on their corresponding sequence numbers
784 ret = !test_bit(JOURNAL_REPLAY_DONE, &j->flags) ||
785 journal_last_seq(j) > seq_to_flush ||
788 spin_unlock(&j->lock);
789 mutex_unlock(&j->reclaim_lock);
794 bool bch2_journal_flush_pins(struct journal *j, u64 seq_to_flush)
796 bool did_work = false;
798 if (!test_bit(JOURNAL_STARTED, &j->flags))
801 closure_wait_event(&j->async_wait,
802 journal_flush_done(j, seq_to_flush, &did_work));
807 int bch2_journal_flush_device_pins(struct journal *j, int dev_idx)
809 struct bch_fs *c = container_of(j, struct bch_fs, journal);
810 struct journal_entry_pin_list *p;
815 fifo_for_each_entry_ptr(p, &j->pin, iter)
817 ? bch2_dev_list_has_dev(p->devs, dev_idx)
818 : p->devs.nr < c->opts.metadata_replicas)
820 spin_unlock(&j->lock);
822 bch2_journal_flush_pins(j, seq);
824 ret = bch2_journal_error(j);
828 mutex_lock(&c->replicas_gc_lock);
829 bch2_replicas_gc_start(c, 1 << BCH_DATA_journal);
832 * Now that we've populated replicas_gc, write to the journal to mark
833 * active journal devices. This handles the case where the journal might
834 * be empty. Otherwise we could clear all journal replicas and
835 * temporarily put the fs into an unrecoverable state. Journal recovery
836 * expects to find devices marked for journal data on unclean mount.
838 ret = bch2_journal_meta(&c->journal);
845 struct bch_replicas_padded replicas;
847 seq = max(seq, journal_last_seq(j));
848 if (seq >= j->pin.back)
850 bch2_devlist_to_replicas(&replicas.e, BCH_DATA_journal,
851 journal_seq_pin(j, seq)->devs);
854 spin_unlock(&j->lock);
855 ret = bch2_mark_replicas(c, &replicas.e);
858 spin_unlock(&j->lock);
860 ret = bch2_replicas_gc_end(c, ret);
861 mutex_unlock(&c->replicas_gc_lock);