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 %llu", (uint64_t) bucket
);
49 while (offset
< ca
->sb
.bucket_size
) {
50 reread
: left
= ca
->sb
.bucket_size
- offset
;
51 len
= min_t(unsigned, left
, PAGE_SECTORS
* 8);
54 bio
->bi_sector
= bucket
+ offset
;
55 bio
->bi_bdev
= ca
->bdev
;
57 bio
->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
->set
))
80 if (bytes
> left
<< 9)
86 if (j
->csum
!= csum_set(j
))
89 blocks
= set_blocks(j
, ca
->set
);
91 while (!list_empty(list
)) {
92 i
= list_first_entry(list
,
93 struct journal_replay
, list
);
94 if (i
->j
.seq
>= j
->last_seq
)
100 list_for_each_entry_reverse(i
, list
, list
) {
101 if (j
->seq
== i
->j
.seq
)
104 if (j
->seq
< i
->j
.last_seq
)
107 if (j
->seq
> i
->j
.seq
) {
115 i
= kmalloc(offsetof(struct journal_replay
, j
) +
119 memcpy(&i
->j
, j
, bytes
);
120 list_add(&i
->list
, where
);
123 ja
->seq
[bucket_index
] = j
->seq
;
125 offset
+= blocks
* ca
->sb
.block_size
;
126 len
-= blocks
* ca
->sb
.block_size
;
127 j
= ((void *) j
) + blocks
* block_bytes(ca
);
134 int bch_journal_read(struct cache_set
*c
, struct list_head
*list
)
136 #define read_bucket(b) \
138 int ret = journal_read_bucket(ca, list, b); \
139 __set_bit(b, bitmap); \
148 for_each_cache(ca
, c
, iter
) {
149 struct journal_device
*ja
= &ca
->journal
;
150 unsigned long bitmap
[SB_JOURNAL_BUCKETS
/ BITS_PER_LONG
];
154 bitmap_zero(bitmap
, SB_JOURNAL_BUCKETS
);
155 pr_debug("%u journal buckets", ca
->sb
.njournal_buckets
);
158 * Read journal buckets ordered by golden ratio hash to quickly
159 * find a sequence of buckets with valid journal entries
161 for (i
= 0; i
< ca
->sb
.njournal_buckets
; i
++) {
162 l
= (i
* 2654435769U) % ca
->sb
.njournal_buckets
;
164 if (test_bit(l
, bitmap
))
172 * If that fails, check all the buckets we haven't checked
175 pr_debug("falling back to linear search");
177 for (l
= find_first_zero_bit(bitmap
, ca
->sb
.njournal_buckets
);
178 l
< ca
->sb
.njournal_buckets
;
179 l
= find_next_zero_bit(bitmap
, ca
->sb
.njournal_buckets
, l
+ 1))
183 if (list_empty(list
))
187 m
= r
= find_next_bit(bitmap
, ca
->sb
.njournal_buckets
, l
+ 1);
188 pr_debug("starting binary search, l %u r %u", l
, r
);
191 seq
= list_entry(list
->prev
, struct journal_replay
,
197 if (seq
!= list_entry(list
->prev
, struct journal_replay
,
205 * Read buckets in reverse order until we stop finding more
208 pr_debug("finishing up: m %u njournal_buckets %u",
209 m
, ca
->sb
.njournal_buckets
);
214 l
= ca
->sb
.njournal_buckets
- 1;
219 if (test_bit(l
, bitmap
))
228 for (i
= 0; i
< ca
->sb
.njournal_buckets
; i
++)
229 if (ja
->seq
[i
] > seq
) {
231 ja
->cur_idx
= ja
->discard_idx
=
237 if (!list_empty(list
))
238 c
->journal
.seq
= list_entry(list
->prev
,
239 struct journal_replay
,
246 void bch_journal_mark(struct cache_set
*c
, struct list_head
*list
)
250 struct journal_replay
*i
;
251 struct journal
*j
= &c
->journal
;
252 uint64_t last
= j
->seq
;
255 * journal.pin should never fill up - we never write a journal
256 * entry when it would fill up. But if for some reason it does, we
257 * iterate over the list in reverse order so that we can just skip that
258 * refcount instead of bugging.
261 list_for_each_entry_reverse(i
, list
, list
) {
262 BUG_ON(last
< i
->j
.seq
);
265 while (last
-- != i
->j
.seq
)
266 if (fifo_free(&j
->pin
) > 1) {
267 fifo_push_front(&j
->pin
, p
);
268 atomic_set(&fifo_front(&j
->pin
), 0);
271 if (fifo_free(&j
->pin
) > 1) {
272 fifo_push_front(&j
->pin
, p
);
273 i
->pin
= &fifo_front(&j
->pin
);
274 atomic_set(i
->pin
, 1);
282 for (j
= 0; j
< KEY_PTRS(k
); j
++) {
283 struct bucket
*g
= PTR_BUCKET(c
, k
, j
);
286 if (g
->prio
== BTREE_PRIO
&&
288 g
->prio
= INITIAL_PRIO
;
291 __bch_btree_mark_key(c
, 0, k
);
296 int bch_journal_replay(struct cache_set
*s
, struct list_head
*list
)
298 int ret
= 0, keys
= 0, entries
= 0;
300 struct journal_replay
*i
=
301 list_entry(list
->prev
, struct journal_replay
, list
);
303 uint64_t start
= i
->j
.last_seq
, end
= i
->j
.seq
, n
= start
;
304 struct keylist keylist
;
306 bch_keylist_init(&keylist
);
308 list_for_each_entry(i
, list
, list
) {
309 BUG_ON(i
->pin
&& atomic_read(i
->pin
) != 1);
311 cache_set_err_on(n
!= i
->j
.seq
, s
,
312 "bcache: journal entries %llu-%llu missing! (replaying %llu-%llu)",
313 n
, i
->j
.seq
- 1, start
, end
);
318 trace_bcache_journal_replay_key(k
);
320 bkey_copy(keylist
.top
, k
);
321 bch_keylist_push(&keylist
);
323 ret
= bch_btree_insert(s
, &keylist
, i
->pin
, NULL
);
327 BUG_ON(!bch_keylist_empty(&keylist
));
339 pr_info("journal replay done, %i keys in %i entries, seq %llu",
342 while (!list_empty(list
)) {
343 i
= list_first_entry(list
, struct journal_replay
, list
);
353 static void btree_flush_write(struct cache_set
*c
)
356 * Try to find the btree node with that references the oldest journal
357 * entry, best is our current candidate and is locked if non NULL:
359 struct btree
*b
, *best
;
364 for_each_cached_btree(b
, c
, i
)
365 if (btree_current_write(b
)->journal
) {
368 else if (journal_pin_cmp(c
,
369 btree_current_write(best
)->journal
,
370 btree_current_write(b
)->journal
)) {
377 rw_lock(true, b
, b
->level
);
379 if (!btree_current_write(b
)->journal
) {
385 bch_btree_node_write(b
, NULL
);
390 #define last_seq(j) ((j)->seq - fifo_used(&(j)->pin) + 1)
392 static void journal_discard_endio(struct bio
*bio
, int error
)
394 struct journal_device
*ja
=
395 container_of(bio
, struct journal_device
, discard_bio
);
396 struct cache
*ca
= container_of(ja
, struct cache
, journal
);
398 atomic_set(&ja
->discard_in_flight
, DISCARD_DONE
);
400 closure_wake_up(&ca
->set
->journal
.wait
);
401 closure_put(&ca
->set
->cl
);
404 static void journal_discard_work(struct work_struct
*work
)
406 struct journal_device
*ja
=
407 container_of(work
, struct journal_device
, discard_work
);
409 submit_bio(0, &ja
->discard_bio
);
412 static void do_journal_discard(struct cache
*ca
)
414 struct journal_device
*ja
= &ca
->journal
;
415 struct bio
*bio
= &ja
->discard_bio
;
418 ja
->discard_idx
= ja
->last_idx
;
422 switch (atomic_read(&ja
->discard_in_flight
)) {
423 case DISCARD_IN_FLIGHT
:
427 ja
->discard_idx
= (ja
->discard_idx
+ 1) %
428 ca
->sb
.njournal_buckets
;
430 atomic_set(&ja
->discard_in_flight
, DISCARD_READY
);
434 if (ja
->discard_idx
== ja
->last_idx
)
437 atomic_set(&ja
->discard_in_flight
, DISCARD_IN_FLIGHT
);
440 bio
->bi_sector
= bucket_to_sector(ca
->set
,
441 ca
->sb
.d
[ja
->discard_idx
]);
442 bio
->bi_bdev
= ca
->bdev
;
443 bio
->bi_rw
= REQ_WRITE
|REQ_DISCARD
;
444 bio
->bi_max_vecs
= 1;
445 bio
->bi_io_vec
= bio
->bi_inline_vecs
;
446 bio
->bi_size
= bucket_bytes(ca
);
447 bio
->bi_end_io
= journal_discard_endio
;
449 closure_get(&ca
->set
->cl
);
450 INIT_WORK(&ja
->discard_work
, journal_discard_work
);
451 schedule_work(&ja
->discard_work
);
455 static void journal_reclaim(struct cache_set
*c
)
457 struct bkey
*k
= &c
->journal
.key
;
460 unsigned iter
, n
= 0;
463 while (!atomic_read(&fifo_front(&c
->journal
.pin
)))
464 fifo_pop(&c
->journal
.pin
, p
);
466 last_seq
= last_seq(&c
->journal
);
468 /* Update last_idx */
470 for_each_cache(ca
, c
, iter
) {
471 struct journal_device
*ja
= &ca
->journal
;
473 while (ja
->last_idx
!= ja
->cur_idx
&&
474 ja
->seq
[ja
->last_idx
] < last_seq
)
475 ja
->last_idx
= (ja
->last_idx
+ 1) %
476 ca
->sb
.njournal_buckets
;
479 for_each_cache(ca
, c
, iter
)
480 do_journal_discard(ca
);
482 if (c
->journal
.blocks_free
)
487 * XXX: Sort by free journal space
490 for_each_cache(ca
, c
, iter
) {
491 struct journal_device
*ja
= &ca
->journal
;
492 unsigned next
= (ja
->cur_idx
+ 1) % ca
->sb
.njournal_buckets
;
494 /* No space available on this device */
495 if (next
== ja
->discard_idx
)
500 bucket_to_sector(c
, ca
->sb
.d
[ja
->cur_idx
]),
508 c
->journal
.blocks_free
= c
->sb
.bucket_size
>> c
->block_bits
;
510 if (!journal_full(&c
->journal
))
511 __closure_wake_up(&c
->journal
.wait
);
514 void bch_journal_next(struct journal
*j
)
518 j
->cur
= (j
->cur
== j
->w
)
523 * The fifo_push() needs to happen at the same time as j->seq is
524 * incremented for last_seq() to be calculated correctly
526 BUG_ON(!fifo_push(&j
->pin
, p
));
527 atomic_set(&fifo_back(&j
->pin
), 1);
529 j
->cur
->data
->seq
= ++j
->seq
;
530 j
->cur
->need_write
= false;
531 j
->cur
->data
->keys
= 0;
533 if (fifo_full(&j
->pin
))
534 pr_debug("journal_pin full (%zu)", fifo_used(&j
->pin
));
537 static void journal_write_endio(struct bio
*bio
, int error
)
539 struct journal_write
*w
= bio
->bi_private
;
541 cache_set_err_on(error
, w
->c
, "journal io error");
542 closure_put(&w
->c
->journal
.io
);
545 static void journal_write(struct closure
*);
547 static void journal_write_done(struct closure
*cl
)
549 struct journal
*j
= container_of(cl
, struct journal
, io
);
550 struct journal_write
*w
= (j
->cur
== j
->w
)
554 __closure_wake_up(&w
->wait
);
555 continue_at_nobarrier(cl
, journal_write
, system_wq
);
558 static void journal_write_unlocked(struct closure
*cl
)
559 __releases(c
->journal
.lock
)
561 struct cache_set
*c
= container_of(cl
, struct cache_set
, journal
.io
);
563 struct journal_write
*w
= c
->journal
.cur
;
564 struct bkey
*k
= &c
->journal
.key
;
565 unsigned i
, sectors
= set_blocks(w
->data
, c
) * c
->sb
.block_size
;
568 struct bio_list list
;
569 bio_list_init(&list
);
571 if (!w
->need_write
) {
573 * XXX: have to unlock closure before we unlock journal lock,
574 * else we race with bch_journal(). But this way we race
575 * against cache set unregister. Doh.
577 set_closure_fn(cl
, NULL
, NULL
);
578 closure_sub(cl
, CLOSURE_RUNNING
+ 1);
579 spin_unlock(&c
->journal
.lock
);
581 } else if (journal_full(&c
->journal
)) {
583 spin_unlock(&c
->journal
.lock
);
585 btree_flush_write(c
);
586 continue_at(cl
, journal_write
, system_wq
);
589 c
->journal
.blocks_free
-= set_blocks(w
->data
, c
);
591 w
->data
->btree_level
= c
->root
->level
;
593 bkey_copy(&w
->data
->btree_root
, &c
->root
->key
);
594 bkey_copy(&w
->data
->uuid_bucket
, &c
->uuid_bucket
);
596 for_each_cache(ca
, c
, i
)
597 w
->data
->prio_bucket
[ca
->sb
.nr_this_dev
] = ca
->prio_buckets
[0];
599 w
->data
->magic
= jset_magic(c
);
600 w
->data
->version
= BCACHE_JSET_VERSION
;
601 w
->data
->last_seq
= last_seq(&c
->journal
);
602 w
->data
->csum
= csum_set(w
->data
);
604 for (i
= 0; i
< KEY_PTRS(k
); i
++) {
605 ca
= PTR_CACHE(c
, k
, i
);
606 bio
= &ca
->journal
.bio
;
608 atomic_long_add(sectors
, &ca
->meta_sectors_written
);
611 bio
->bi_sector
= PTR_OFFSET(k
, i
);
612 bio
->bi_bdev
= ca
->bdev
;
613 bio
->bi_rw
= REQ_WRITE
|REQ_SYNC
|REQ_META
|REQ_FLUSH
|REQ_FUA
;
614 bio
->bi_size
= sectors
<< 9;
616 bio
->bi_end_io
= journal_write_endio
;
618 bch_bio_map(bio
, w
->data
);
620 trace_bcache_journal_write(bio
);
621 bio_list_add(&list
, bio
);
623 SET_PTR_OFFSET(k
, i
, PTR_OFFSET(k
, i
) + sectors
);
625 ca
->journal
.seq
[ca
->journal
.cur_idx
] = w
->data
->seq
;
628 atomic_dec_bug(&fifo_back(&c
->journal
.pin
));
629 bch_journal_next(&c
->journal
);
632 spin_unlock(&c
->journal
.lock
);
634 while ((bio
= bio_list_pop(&list
)))
635 closure_bio_submit(bio
, cl
, c
->cache
[0]);
637 continue_at(cl
, journal_write_done
, NULL
);
640 static void journal_write(struct closure
*cl
)
642 struct cache_set
*c
= container_of(cl
, struct cache_set
, journal
.io
);
644 spin_lock(&c
->journal
.lock
);
645 journal_write_unlocked(cl
);
648 static void journal_try_write(struct cache_set
*c
)
649 __releases(c
->journal
.lock
)
651 struct closure
*cl
= &c
->journal
.io
;
652 struct journal_write
*w
= c
->journal
.cur
;
654 w
->need_write
= true;
656 if (closure_trylock(cl
, &c
->cl
))
657 journal_write_unlocked(cl
);
659 spin_unlock(&c
->journal
.lock
);
662 static struct journal_write
*journal_wait_for_write(struct cache_set
*c
,
668 closure_init_stack(&cl
);
670 spin_lock(&c
->journal
.lock
);
673 struct journal_write
*w
= c
->journal
.cur
;
675 sectors
= __set_blocks(w
->data
, w
->data
->keys
+ nkeys
,
676 c
) * c
->sb
.block_size
;
678 if (sectors
<= min_t(size_t,
679 c
->journal
.blocks_free
* c
->sb
.block_size
,
680 PAGE_SECTORS
<< JSET_BITS
))
683 /* XXX: tracepoint */
684 if (!journal_full(&c
->journal
)) {
685 trace_bcache_journal_entry_full(c
);
688 * XXX: If we were inserting so many keys that they
689 * won't fit in an _empty_ journal write, we'll
690 * deadlock. For now, handle this in
691 * bch_keylist_realloc() - but something to think about.
693 BUG_ON(!w
->data
->keys
);
695 closure_wait(&w
->wait
, &cl
);
696 journal_try_write(c
); /* unlocks */
698 trace_bcache_journal_full(c
);
700 closure_wait(&c
->journal
.wait
, &cl
);
702 spin_unlock(&c
->journal
.lock
);
704 btree_flush_write(c
);
708 spin_lock(&c
->journal
.lock
);
712 static void journal_write_work(struct work_struct
*work
)
714 struct cache_set
*c
= container_of(to_delayed_work(work
),
717 spin_lock(&c
->journal
.lock
);
718 journal_try_write(c
);
722 * Entry point to the journalling code - bio_insert() and btree_invalidate()
723 * pass bch_journal() a list of keys to be journalled, and then
724 * bch_journal() hands those same keys off to btree_insert_async()
727 atomic_t
*bch_journal(struct cache_set
*c
,
728 struct keylist
*keys
,
729 struct closure
*parent
)
731 struct journal_write
*w
;
734 if (!CACHE_SYNC(&c
->sb
))
737 w
= journal_wait_for_write(c
, bch_keylist_nkeys(keys
));
739 memcpy(end(w
->data
), keys
->keys
, bch_keylist_bytes(keys
));
740 w
->data
->keys
+= bch_keylist_nkeys(keys
);
742 ret
= &fifo_back(&c
->journal
.pin
);
746 closure_wait(&w
->wait
, parent
);
747 journal_try_write(c
);
748 } else if (!w
->need_write
) {
749 schedule_delayed_work(&c
->journal
.work
,
750 msecs_to_jiffies(c
->journal_delay_ms
));
751 spin_unlock(&c
->journal
.lock
);
753 spin_unlock(&c
->journal
.lock
);
760 void bch_journal_meta(struct cache_set
*c
, struct closure
*cl
)
765 bch_keylist_init(&keys
);
767 ref
= bch_journal(c
, &keys
, cl
);
772 void bch_journal_free(struct cache_set
*c
)
774 free_pages((unsigned long) c
->journal
.w
[1].data
, JSET_BITS
);
775 free_pages((unsigned long) c
->journal
.w
[0].data
, JSET_BITS
);
776 free_fifo(&c
->journal
.pin
);
779 int bch_journal_alloc(struct cache_set
*c
)
781 struct journal
*j
= &c
->journal
;
783 closure_init_unlocked(&j
->io
);
784 spin_lock_init(&j
->lock
);
785 INIT_DELAYED_WORK(&j
->work
, journal_write_work
);
787 c
->journal_delay_ms
= 100;
792 if (!(init_fifo(&j
->pin
, JOURNAL_PIN
, GFP_KERNEL
)) ||
793 !(j
->w
[0].data
= (void *) __get_free_pages(GFP_KERNEL
, JSET_BITS
)) ||
794 !(j
->w
[1].data
= (void *) __get_free_pages(GFP_KERNEL
, JSET_BITS
)))
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