2 * bcache journalling code, for btree insertions
4 * Copyright 2012 Google, Inc.
11 #include <trace/events/bcache.h>
14 * Journal replay/recovery:
16 * This code is all driven from run_cache_set(); we first read the journal
17 * entries, do some other stuff, then we mark all the keys in the journal
18 * entries (same as garbage collection would), then we replay them - reinserting
19 * them into the cache in precisely the same order as they appear in the
22 * We only journal keys that go in leaf nodes, which simplifies things quite a
26 static void journal_read_endio(struct bio *bio, int error)
28 struct closure *cl = bio->bi_private;
32 static int journal_read_bucket(struct cache *ca, struct list_head *list,
33 unsigned bucket_index)
35 struct journal_device *ja = &ca->journal;
36 struct bio *bio = &ja->bio;
38 struct journal_replay *i;
39 struct jset *j, *data = ca->set->journal.w[0].data;
41 unsigned len, left, offset = 0;
43 sector_t bucket = bucket_to_sector(ca->set, ca->sb.d[bucket_index]);
45 closure_init_stack(&cl);
47 pr_debug("reading %u", bucket_index);
49 while (offset < ca->sb.bucket_size) {
50 reread: left = ca->sb.bucket_size - offset;
51 len = min_t(unsigned, left, PAGE_SECTORS << JSET_BITS);
54 bio->bi_iter.bi_sector = bucket + offset;
55 bio->bi_bdev = ca->bdev;
57 bio->bi_iter.bi_size = len << 9;
59 bio->bi_end_io = journal_read_endio;
60 bio->bi_private = &cl;
61 bch_bio_map(bio, data);
63 closure_bio_submit(bio, &cl, ca);
66 /* This function could be simpler now since we no longer write
67 * journal entries that overlap bucket boundaries; this means
68 * the start of a bucket will always have a valid journal entry
69 * if it has any journal entries at all.
74 struct list_head *where;
75 size_t blocks, bytes = set_bytes(j);
77 if (j->magic != jset_magic(&ca->sb)) {
78 pr_debug("%u: bad magic", bucket_index);
82 if (bytes > left << 9 ||
83 bytes > PAGE_SIZE << JSET_BITS) {
84 pr_info("%u: too big, %zu bytes, offset %u",
85 bucket_index, bytes, offset);
92 if (j->csum != csum_set(j)) {
93 pr_info("%u: bad csum, %zu bytes, offset %u",
94 bucket_index, bytes, offset);
98 blocks = set_blocks(j, block_bytes(ca->set));
100 while (!list_empty(list)) {
101 i = list_first_entry(list,
102 struct journal_replay, list);
103 if (i->j.seq >= j->last_seq)
109 list_for_each_entry_reverse(i, list, list) {
110 if (j->seq == i->j.seq)
113 if (j->seq < i->j.last_seq)
116 if (j->seq > i->j.seq) {
124 i = kmalloc(offsetof(struct journal_replay, j) +
128 memcpy(&i->j, j, bytes);
129 list_add(&i->list, where);
132 ja->seq[bucket_index] = j->seq;
134 offset += blocks * ca->sb.block_size;
135 len -= blocks * ca->sb.block_size;
136 j = ((void *) j) + blocks * block_bytes(ca);
143 int bch_journal_read(struct cache_set *c, struct list_head *list)
145 #define read_bucket(b) \
147 int ret = journal_read_bucket(ca, list, b); \
148 __set_bit(b, bitmap); \
157 for_each_cache(ca, c, iter) {
158 struct journal_device *ja = &ca->journal;
159 unsigned long bitmap[SB_JOURNAL_BUCKETS / BITS_PER_LONG];
163 bitmap_zero(bitmap, SB_JOURNAL_BUCKETS);
164 pr_debug("%u journal buckets", ca->sb.njournal_buckets);
167 * Read journal buckets ordered by golden ratio hash to quickly
168 * find a sequence of buckets with valid journal entries
170 for (i = 0; i < ca->sb.njournal_buckets; i++) {
171 l = (i * 2654435769U) % ca->sb.njournal_buckets;
173 if (test_bit(l, bitmap))
181 * If that fails, check all the buckets we haven't checked
184 pr_debug("falling back to linear search");
186 for (l = find_first_zero_bit(bitmap, ca->sb.njournal_buckets);
187 l < ca->sb.njournal_buckets;
188 l = find_next_zero_bit(bitmap, ca->sb.njournal_buckets, l + 1))
192 if (list_empty(list))
196 m = r = find_next_bit(bitmap, ca->sb.njournal_buckets, l + 1);
197 pr_debug("starting binary search, l %u r %u", l, r);
200 seq = list_entry(list->prev, struct journal_replay,
206 if (seq != list_entry(list->prev, struct journal_replay,
214 * Read buckets in reverse order until we stop finding more
217 pr_debug("finishing up: m %u njournal_buckets %u",
218 m, ca->sb.njournal_buckets);
223 l = ca->sb.njournal_buckets - 1;
228 if (test_bit(l, bitmap))
237 for (i = 0; i < ca->sb.njournal_buckets; i++)
238 if (ja->seq[i] > seq) {
241 * When journal_reclaim() goes to allocate for
242 * the first time, it'll use the bucket after
246 ja->last_idx = ja->discard_idx = (i + 1) %
247 ca->sb.njournal_buckets;
252 if (!list_empty(list))
253 c->journal.seq = list_entry(list->prev,
254 struct journal_replay,
261 void bch_journal_mark(struct cache_set *c, struct list_head *list)
265 struct journal_replay *i;
266 struct journal *j = &c->journal;
267 uint64_t last = j->seq;
270 * journal.pin should never fill up - we never write a journal
271 * entry when it would fill up. But if for some reason it does, we
272 * iterate over the list in reverse order so that we can just skip that
273 * refcount instead of bugging.
276 list_for_each_entry_reverse(i, list, list) {
277 BUG_ON(last < i->j.seq);
280 while (last-- != i->j.seq)
281 if (fifo_free(&j->pin) > 1) {
282 fifo_push_front(&j->pin, p);
283 atomic_set(&fifo_front(&j->pin), 0);
286 if (fifo_free(&j->pin) > 1) {
287 fifo_push_front(&j->pin, p);
288 i->pin = &fifo_front(&j->pin);
289 atomic_set(i->pin, 1);
293 k < bset_bkey_last(&i->j);
297 for (j = 0; j < KEY_PTRS(k); j++)
298 if (ptr_available(c, k, j))
299 atomic_inc(&PTR_BUCKET(c, k, j)->pin);
301 bch_initial_mark_key(c, 0, k);
306 int bch_journal_replay(struct cache_set *s, struct list_head *list)
308 int ret = 0, keys = 0, entries = 0;
310 struct journal_replay *i =
311 list_entry(list->prev, struct journal_replay, list);
313 uint64_t start = i->j.last_seq, end = i->j.seq, n = start;
314 struct keylist keylist;
316 list_for_each_entry(i, list, list) {
317 BUG_ON(i->pin && atomic_read(i->pin) != 1);
319 cache_set_err_on(n != i->j.seq, s,
320 "bcache: journal entries %llu-%llu missing! (replaying %llu-%llu)",
321 n, i->j.seq - 1, start, end);
324 k < bset_bkey_last(&i->j);
326 trace_bcache_journal_replay_key(k);
328 bch_keylist_init_single(&keylist, k);
330 ret = bch_btree_insert(s, &keylist, i->pin, NULL);
334 BUG_ON(!bch_keylist_empty(&keylist));
346 pr_info("journal replay done, %i keys in %i entries, seq %llu",
349 while (!list_empty(list)) {
350 i = list_first_entry(list, struct journal_replay, list);
360 static void btree_flush_write(struct cache_set *c)
363 * Try to find the btree node with that references the oldest journal
364 * entry, best is our current candidate and is locked if non NULL:
366 struct btree *b, *best;
371 for_each_cached_btree(b, c, i)
372 if (btree_current_write(b)->journal) {
375 else if (journal_pin_cmp(c,
376 btree_current_write(best)->journal,
377 btree_current_write(b)->journal)) {
384 mutex_lock(&b->write_lock);
385 if (!btree_current_write(b)->journal) {
386 mutex_unlock(&b->write_lock);
391 __bch_btree_node_write(b, NULL);
392 mutex_unlock(&b->write_lock);
396 #define last_seq(j) ((j)->seq - fifo_used(&(j)->pin) + 1)
398 static void journal_discard_endio(struct bio *bio, int error)
400 struct journal_device *ja =
401 container_of(bio, struct journal_device, discard_bio);
402 struct cache *ca = container_of(ja, struct cache, journal);
404 atomic_set(&ja->discard_in_flight, DISCARD_DONE);
406 closure_wake_up(&ca->set->journal.wait);
407 closure_put(&ca->set->cl);
410 static void journal_discard_work(struct work_struct *work)
412 struct journal_device *ja =
413 container_of(work, struct journal_device, discard_work);
415 submit_bio(0, &ja->discard_bio);
418 static void do_journal_discard(struct cache *ca)
420 struct journal_device *ja = &ca->journal;
421 struct bio *bio = &ja->discard_bio;
424 ja->discard_idx = ja->last_idx;
428 switch (atomic_read(&ja->discard_in_flight)) {
429 case DISCARD_IN_FLIGHT:
433 ja->discard_idx = (ja->discard_idx + 1) %
434 ca->sb.njournal_buckets;
436 atomic_set(&ja->discard_in_flight, DISCARD_READY);
440 if (ja->discard_idx == ja->last_idx)
443 atomic_set(&ja->discard_in_flight, DISCARD_IN_FLIGHT);
446 bio->bi_iter.bi_sector = bucket_to_sector(ca->set,
447 ca->sb.d[ja->discard_idx]);
448 bio->bi_bdev = ca->bdev;
449 bio->bi_rw = REQ_WRITE|REQ_DISCARD;
450 bio->bi_max_vecs = 1;
451 bio->bi_io_vec = bio->bi_inline_vecs;
452 bio->bi_iter.bi_size = bucket_bytes(ca);
453 bio->bi_end_io = journal_discard_endio;
455 closure_get(&ca->set->cl);
456 INIT_WORK(&ja->discard_work, journal_discard_work);
457 schedule_work(&ja->discard_work);
461 static void journal_reclaim(struct cache_set *c)
463 struct bkey *k = &c->journal.key;
466 unsigned iter, n = 0;
469 while (!atomic_read(&fifo_front(&c->journal.pin)))
470 fifo_pop(&c->journal.pin, p);
472 last_seq = last_seq(&c->journal);
474 /* Update last_idx */
476 for_each_cache(ca, c, iter) {
477 struct journal_device *ja = &ca->journal;
479 while (ja->last_idx != ja->cur_idx &&
480 ja->seq[ja->last_idx] < last_seq)
481 ja->last_idx = (ja->last_idx + 1) %
482 ca->sb.njournal_buckets;
485 for_each_cache(ca, c, iter)
486 do_journal_discard(ca);
488 if (c->journal.blocks_free)
493 * XXX: Sort by free journal space
496 for_each_cache(ca, c, iter) {
497 struct journal_device *ja = &ca->journal;
498 unsigned next = (ja->cur_idx + 1) % ca->sb.njournal_buckets;
500 /* No space available on this device */
501 if (next == ja->discard_idx)
506 bucket_to_sector(c, ca->sb.d[ja->cur_idx]),
514 c->journal.blocks_free = c->sb.bucket_size >> c->block_bits;
516 if (!journal_full(&c->journal))
517 __closure_wake_up(&c->journal.wait);
520 void bch_journal_next(struct journal *j)
524 j->cur = (j->cur == j->w)
529 * The fifo_push() needs to happen at the same time as j->seq is
530 * incremented for last_seq() to be calculated correctly
532 BUG_ON(!fifo_push(&j->pin, p));
533 atomic_set(&fifo_back(&j->pin), 1);
535 j->cur->data->seq = ++j->seq;
536 j->cur->dirty = false;
537 j->cur->need_write = false;
538 j->cur->data->keys = 0;
540 if (fifo_full(&j->pin))
541 pr_debug("journal_pin full (%zu)", fifo_used(&j->pin));
544 static void journal_write_endio(struct bio *bio, int error)
546 struct journal_write *w = bio->bi_private;
548 cache_set_err_on(error, w->c, "journal io error");
549 closure_put(&w->c->journal.io);
552 static void journal_write(struct closure *);
554 static void journal_write_done(struct closure *cl)
556 struct journal *j = container_of(cl, struct journal, io);
557 struct journal_write *w = (j->cur == j->w)
561 __closure_wake_up(&w->wait);
562 continue_at_nobarrier(cl, journal_write, system_wq);
565 static void journal_write_unlock(struct closure *cl)
567 struct cache_set *c = container_of(cl, struct cache_set, journal.io);
569 c->journal.io_in_flight = 0;
570 spin_unlock(&c->journal.lock);
573 static void journal_write_unlocked(struct closure *cl)
574 __releases(c->journal.lock)
576 struct cache_set *c = container_of(cl, struct cache_set, journal.io);
578 struct journal_write *w = c->journal.cur;
579 struct bkey *k = &c->journal.key;
580 unsigned i, sectors = set_blocks(w->data, block_bytes(c)) *
584 struct bio_list list;
585 bio_list_init(&list);
587 if (!w->need_write) {
588 closure_return_with_destructor(cl, journal_write_unlock);
589 } else if (journal_full(&c->journal)) {
591 spin_unlock(&c->journal.lock);
593 btree_flush_write(c);
594 continue_at(cl, journal_write, system_wq);
597 c->journal.blocks_free -= set_blocks(w->data, block_bytes(c));
599 w->data->btree_level = c->root->level;
601 bkey_copy(&w->data->btree_root, &c->root->key);
602 bkey_copy(&w->data->uuid_bucket, &c->uuid_bucket);
604 for_each_cache(ca, c, i)
605 w->data->prio_bucket[ca->sb.nr_this_dev] = ca->prio_buckets[0];
607 w->data->magic = jset_magic(&c->sb);
608 w->data->version = BCACHE_JSET_VERSION;
609 w->data->last_seq = last_seq(&c->journal);
610 w->data->csum = csum_set(w->data);
612 for (i = 0; i < KEY_PTRS(k); i++) {
613 ca = PTR_CACHE(c, k, i);
614 bio = &ca->journal.bio;
616 atomic_long_add(sectors, &ca->meta_sectors_written);
619 bio->bi_iter.bi_sector = PTR_OFFSET(k, i);
620 bio->bi_bdev = ca->bdev;
621 bio->bi_rw = REQ_WRITE|REQ_SYNC|REQ_META|REQ_FLUSH|REQ_FUA;
622 bio->bi_iter.bi_size = sectors << 9;
624 bio->bi_end_io = journal_write_endio;
626 bch_bio_map(bio, w->data);
628 trace_bcache_journal_write(bio);
629 bio_list_add(&list, bio);
631 SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + sectors);
633 ca->journal.seq[ca->journal.cur_idx] = w->data->seq;
636 atomic_dec_bug(&fifo_back(&c->journal.pin));
637 bch_journal_next(&c->journal);
640 spin_unlock(&c->journal.lock);
642 while ((bio = bio_list_pop(&list)))
643 closure_bio_submit(bio, cl, c->cache[0]);
645 continue_at(cl, journal_write_done, NULL);
648 static void journal_write(struct closure *cl)
650 struct cache_set *c = container_of(cl, struct cache_set, journal.io);
652 spin_lock(&c->journal.lock);
653 journal_write_unlocked(cl);
656 static void journal_try_write(struct cache_set *c)
657 __releases(c->journal.lock)
659 struct closure *cl = &c->journal.io;
660 struct journal_write *w = c->journal.cur;
662 w->need_write = true;
664 if (!c->journal.io_in_flight) {
665 c->journal.io_in_flight = 1;
666 closure_call(cl, journal_write_unlocked, NULL, &c->cl);
668 spin_unlock(&c->journal.lock);
672 static struct journal_write *journal_wait_for_write(struct cache_set *c,
679 closure_init_stack(&cl);
681 spin_lock(&c->journal.lock);
684 struct journal_write *w = c->journal.cur;
686 sectors = __set_blocks(w->data, w->data->keys + nkeys,
687 block_bytes(c)) * c->sb.block_size;
689 if (sectors <= min_t(size_t,
690 c->journal.blocks_free * c->sb.block_size,
691 PAGE_SECTORS << JSET_BITS))
695 closure_wait(&c->journal.wait, &cl);
697 if (!journal_full(&c->journal)) {
699 trace_bcache_journal_entry_full(c);
702 * XXX: If we were inserting so many keys that they
703 * won't fit in an _empty_ journal write, we'll
704 * deadlock. For now, handle this in
705 * bch_keylist_realloc() - but something to think about.
707 BUG_ON(!w->data->keys);
709 journal_try_write(c); /* unlocks */
712 trace_bcache_journal_full(c);
715 spin_unlock(&c->journal.lock);
717 btree_flush_write(c);
721 spin_lock(&c->journal.lock);
726 static void journal_write_work(struct work_struct *work)
728 struct cache_set *c = container_of(to_delayed_work(work),
731 spin_lock(&c->journal.lock);
732 if (c->journal.cur->dirty)
733 journal_try_write(c);
735 spin_unlock(&c->journal.lock);
739 * Entry point to the journalling code - bio_insert() and btree_invalidate()
740 * pass bch_journal() a list of keys to be journalled, and then
741 * bch_journal() hands those same keys off to btree_insert_async()
744 atomic_t *bch_journal(struct cache_set *c,
745 struct keylist *keys,
746 struct closure *parent)
748 struct journal_write *w;
751 if (!CACHE_SYNC(&c->sb))
754 w = journal_wait_for_write(c, bch_keylist_nkeys(keys));
756 memcpy(bset_bkey_last(w->data), keys->keys, bch_keylist_bytes(keys));
757 w->data->keys += bch_keylist_nkeys(keys);
759 ret = &fifo_back(&c->journal.pin);
763 closure_wait(&w->wait, parent);
764 journal_try_write(c);
765 } else if (!w->dirty) {
767 schedule_delayed_work(&c->journal.work,
768 msecs_to_jiffies(c->journal_delay_ms));
769 spin_unlock(&c->journal.lock);
771 spin_unlock(&c->journal.lock);
778 void bch_journal_meta(struct cache_set *c, struct closure *cl)
783 bch_keylist_init(&keys);
785 ref = bch_journal(c, &keys, cl);
790 void bch_journal_free(struct cache_set *c)
792 free_pages((unsigned long) c->journal.w[1].data, JSET_BITS);
793 free_pages((unsigned long) c->journal.w[0].data, JSET_BITS);
794 free_fifo(&c->journal.pin);
797 int bch_journal_alloc(struct cache_set *c)
799 struct journal *j = &c->journal;
801 spin_lock_init(&j->lock);
802 INIT_DELAYED_WORK(&j->work, journal_write_work);
804 c->journal_delay_ms = 100;
809 if (!(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)) ||
810 !(j->w[0].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS)) ||
811 !(j->w[1].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS)))