Merge tag 'for-linus-20180210' of git://git.kernel.dk/linux-block
[sfrench/cifs-2.6.git] / drivers / md / bcache / journal.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * bcache journalling code, for btree insertions
4  *
5  * Copyright 2012 Google, Inc.
6  */
7
8 #include "bcache.h"
9 #include "btree.h"
10 #include "debug.h"
11 #include "extents.h"
12
13 #include <trace/events/bcache.h>
14
15 /*
16  * Journal replay/recovery:
17  *
18  * This code is all driven from run_cache_set(); we first read the journal
19  * entries, do some other stuff, then we mark all the keys in the journal
20  * entries (same as garbage collection would), then we replay them - reinserting
21  * them into the cache in precisely the same order as they appear in the
22  * journal.
23  *
24  * We only journal keys that go in leaf nodes, which simplifies things quite a
25  * bit.
26  */
27
28 static void journal_read_endio(struct bio *bio)
29 {
30         struct closure *cl = bio->bi_private;
31         closure_put(cl);
32 }
33
34 static int journal_read_bucket(struct cache *ca, struct list_head *list,
35                                unsigned bucket_index)
36 {
37         struct journal_device *ja = &ca->journal;
38         struct bio *bio = &ja->bio;
39
40         struct journal_replay *i;
41         struct jset *j, *data = ca->set->journal.w[0].data;
42         struct closure cl;
43         unsigned len, left, offset = 0;
44         int ret = 0;
45         sector_t bucket = bucket_to_sector(ca->set, ca->sb.d[bucket_index]);
46
47         closure_init_stack(&cl);
48
49         pr_debug("reading %u", bucket_index);
50
51         while (offset < ca->sb.bucket_size) {
52 reread:         left = ca->sb.bucket_size - offset;
53                 len = min_t(unsigned, left, PAGE_SECTORS << JSET_BITS);
54
55                 bio_reset(bio);
56                 bio->bi_iter.bi_sector  = bucket + offset;
57                 bio_set_dev(bio, ca->bdev);
58                 bio->bi_iter.bi_size    = len << 9;
59
60                 bio->bi_end_io  = journal_read_endio;
61                 bio->bi_private = &cl;
62                 bio_set_op_attrs(bio, REQ_OP_READ, 0);
63                 bch_bio_map(bio, data);
64
65                 closure_bio_submit(bio, &cl);
66                 closure_sync(&cl);
67
68                 /* This function could be simpler now since we no longer write
69                  * journal entries that overlap bucket boundaries; this means
70                  * the start of a bucket will always have a valid journal entry
71                  * if it has any journal entries at all.
72                  */
73
74                 j = data;
75                 while (len) {
76                         struct list_head *where;
77                         size_t blocks, bytes = set_bytes(j);
78
79                         if (j->magic != jset_magic(&ca->sb)) {
80                                 pr_debug("%u: bad magic", bucket_index);
81                                 return ret;
82                         }
83
84                         if (bytes > left << 9 ||
85                             bytes > PAGE_SIZE << JSET_BITS) {
86                                 pr_info("%u: too big, %zu bytes, offset %u",
87                                         bucket_index, bytes, offset);
88                                 return ret;
89                         }
90
91                         if (bytes > len << 9)
92                                 goto reread;
93
94                         if (j->csum != csum_set(j)) {
95                                 pr_info("%u: bad csum, %zu bytes, offset %u",
96                                         bucket_index, bytes, offset);
97                                 return ret;
98                         }
99
100                         blocks = set_blocks(j, block_bytes(ca->set));
101
102                         while (!list_empty(list)) {
103                                 i = list_first_entry(list,
104                                         struct journal_replay, list);
105                                 if (i->j.seq >= j->last_seq)
106                                         break;
107                                 list_del(&i->list);
108                                 kfree(i);
109                         }
110
111                         list_for_each_entry_reverse(i, list, list) {
112                                 if (j->seq == i->j.seq)
113                                         goto next_set;
114
115                                 if (j->seq < i->j.last_seq)
116                                         goto next_set;
117
118                                 if (j->seq > i->j.seq) {
119                                         where = &i->list;
120                                         goto add;
121                                 }
122                         }
123
124                         where = list;
125 add:
126                         i = kmalloc(offsetof(struct journal_replay, j) +
127                                     bytes, GFP_KERNEL);
128                         if (!i)
129                                 return -ENOMEM;
130                         memcpy(&i->j, j, bytes);
131                         list_add(&i->list, where);
132                         ret = 1;
133
134                         ja->seq[bucket_index] = j->seq;
135 next_set:
136                         offset  += blocks * ca->sb.block_size;
137                         len     -= blocks * ca->sb.block_size;
138                         j = ((void *) j) + blocks * block_bytes(ca);
139                 }
140         }
141
142         return ret;
143 }
144
145 int bch_journal_read(struct cache_set *c, struct list_head *list)
146 {
147 #define read_bucket(b)                                                  \
148         ({                                                              \
149                 int ret = journal_read_bucket(ca, list, b);             \
150                 __set_bit(b, bitmap);                                   \
151                 if (ret < 0)                                            \
152                         return ret;                                     \
153                 ret;                                                    \
154         })
155
156         struct cache *ca;
157         unsigned iter;
158
159         for_each_cache(ca, c, iter) {
160                 struct journal_device *ja = &ca->journal;
161                 DECLARE_BITMAP(bitmap, SB_JOURNAL_BUCKETS);
162                 unsigned i, l, r, m;
163                 uint64_t seq;
164
165                 bitmap_zero(bitmap, SB_JOURNAL_BUCKETS);
166                 pr_debug("%u journal buckets", ca->sb.njournal_buckets);
167
168                 /*
169                  * Read journal buckets ordered by golden ratio hash to quickly
170                  * find a sequence of buckets with valid journal entries
171                  */
172                 for (i = 0; i < ca->sb.njournal_buckets; i++) {
173                         /*
174                          * We must try the index l with ZERO first for
175                          * correctness due to the scenario that the journal
176                          * bucket is circular buffer which might have wrapped
177                          */
178                         l = (i * 2654435769U) % ca->sb.njournal_buckets;
179
180                         if (test_bit(l, bitmap))
181                                 break;
182
183                         if (read_bucket(l))
184                                 goto bsearch;
185                 }
186
187                 /*
188                  * If that fails, check all the buckets we haven't checked
189                  * already
190                  */
191                 pr_debug("falling back to linear search");
192
193                 for (l = find_first_zero_bit(bitmap, ca->sb.njournal_buckets);
194                      l < ca->sb.njournal_buckets;
195                      l = find_next_zero_bit(bitmap, ca->sb.njournal_buckets, l + 1))
196                         if (read_bucket(l))
197                                 goto bsearch;
198
199                 /* no journal entries on this device? */
200                 if (l == ca->sb.njournal_buckets)
201                         continue;
202 bsearch:
203                 BUG_ON(list_empty(list));
204
205                 /* Binary search */
206                 m = l;
207                 r = find_next_bit(bitmap, ca->sb.njournal_buckets, l + 1);
208                 pr_debug("starting binary search, l %u r %u", l, r);
209
210                 while (l + 1 < r) {
211                         seq = list_entry(list->prev, struct journal_replay,
212                                          list)->j.seq;
213
214                         m = (l + r) >> 1;
215                         read_bucket(m);
216
217                         if (seq != list_entry(list->prev, struct journal_replay,
218                                               list)->j.seq)
219                                 l = m;
220                         else
221                                 r = m;
222                 }
223
224                 /*
225                  * Read buckets in reverse order until we stop finding more
226                  * journal entries
227                  */
228                 pr_debug("finishing up: m %u njournal_buckets %u",
229                          m, ca->sb.njournal_buckets);
230                 l = m;
231
232                 while (1) {
233                         if (!l--)
234                                 l = ca->sb.njournal_buckets - 1;
235
236                         if (l == m)
237                                 break;
238
239                         if (test_bit(l, bitmap))
240                                 continue;
241
242                         if (!read_bucket(l))
243                                 break;
244                 }
245
246                 seq = 0;
247
248                 for (i = 0; i < ca->sb.njournal_buckets; i++)
249                         if (ja->seq[i] > seq) {
250                                 seq = ja->seq[i];
251                                 /*
252                                  * When journal_reclaim() goes to allocate for
253                                  * the first time, it'll use the bucket after
254                                  * ja->cur_idx
255                                  */
256                                 ja->cur_idx = i;
257                                 ja->last_idx = ja->discard_idx = (i + 1) %
258                                         ca->sb.njournal_buckets;
259
260                         }
261         }
262
263         if (!list_empty(list))
264                 c->journal.seq = list_entry(list->prev,
265                                             struct journal_replay,
266                                             list)->j.seq;
267
268         return 0;
269 #undef read_bucket
270 }
271
272 void bch_journal_mark(struct cache_set *c, struct list_head *list)
273 {
274         atomic_t p = { 0 };
275         struct bkey *k;
276         struct journal_replay *i;
277         struct journal *j = &c->journal;
278         uint64_t last = j->seq;
279
280         /*
281          * journal.pin should never fill up - we never write a journal
282          * entry when it would fill up. But if for some reason it does, we
283          * iterate over the list in reverse order so that we can just skip that
284          * refcount instead of bugging.
285          */
286
287         list_for_each_entry_reverse(i, list, list) {
288                 BUG_ON(last < i->j.seq);
289                 i->pin = NULL;
290
291                 while (last-- != i->j.seq)
292                         if (fifo_free(&j->pin) > 1) {
293                                 fifo_push_front(&j->pin, p);
294                                 atomic_set(&fifo_front(&j->pin), 0);
295                         }
296
297                 if (fifo_free(&j->pin) > 1) {
298                         fifo_push_front(&j->pin, p);
299                         i->pin = &fifo_front(&j->pin);
300                         atomic_set(i->pin, 1);
301                 }
302
303                 for (k = i->j.start;
304                      k < bset_bkey_last(&i->j);
305                      k = bkey_next(k))
306                         if (!__bch_extent_invalid(c, k)) {
307                                 unsigned j;
308
309                                 for (j = 0; j < KEY_PTRS(k); j++)
310                                         if (ptr_available(c, k, j))
311                                                 atomic_inc(&PTR_BUCKET(c, k, j)->pin);
312
313                                 bch_initial_mark_key(c, 0, k);
314                         }
315         }
316 }
317
318 int bch_journal_replay(struct cache_set *s, struct list_head *list)
319 {
320         int ret = 0, keys = 0, entries = 0;
321         struct bkey *k;
322         struct journal_replay *i =
323                 list_entry(list->prev, struct journal_replay, list);
324
325         uint64_t start = i->j.last_seq, end = i->j.seq, n = start;
326         struct keylist keylist;
327
328         list_for_each_entry(i, list, list) {
329                 BUG_ON(i->pin && atomic_read(i->pin) != 1);
330
331                 cache_set_err_on(n != i->j.seq, s,
332 "bcache: journal entries %llu-%llu missing! (replaying %llu-%llu)",
333                                  n, i->j.seq - 1, start, end);
334
335                 for (k = i->j.start;
336                      k < bset_bkey_last(&i->j);
337                      k = bkey_next(k)) {
338                         trace_bcache_journal_replay_key(k);
339
340                         bch_keylist_init_single(&keylist, k);
341
342                         ret = bch_btree_insert(s, &keylist, i->pin, NULL);
343                         if (ret)
344                                 goto err;
345
346                         BUG_ON(!bch_keylist_empty(&keylist));
347                         keys++;
348
349                         cond_resched();
350                 }
351
352                 if (i->pin)
353                         atomic_dec(i->pin);
354                 n = i->j.seq + 1;
355                 entries++;
356         }
357
358         pr_info("journal replay done, %i keys in %i entries, seq %llu",
359                 keys, entries, end);
360 err:
361         while (!list_empty(list)) {
362                 i = list_first_entry(list, struct journal_replay, list);
363                 list_del(&i->list);
364                 kfree(i);
365         }
366
367         return ret;
368 }
369
370 /* Journalling */
371 #define journal_max_cmp(l, r) \
372         (fifo_idx(&c->journal.pin, btree_current_write(l)->journal) < \
373          fifo_idx(&(c)->journal.pin, btree_current_write(r)->journal))
374 #define journal_min_cmp(l, r) \
375         (fifo_idx(&c->journal.pin, btree_current_write(l)->journal) > \
376          fifo_idx(&(c)->journal.pin, btree_current_write(r)->journal))
377
378 static void btree_flush_write(struct cache_set *c)
379 {
380         /*
381          * Try to find the btree node with that references the oldest journal
382          * entry, best is our current candidate and is locked if non NULL:
383          */
384         struct btree *b;
385         int i;
386
387         atomic_long_inc(&c->flush_write);
388
389 retry:
390         spin_lock(&c->journal.lock);
391         if (heap_empty(&c->flush_btree)) {
392                 for_each_cached_btree(b, c, i)
393                         if (btree_current_write(b)->journal) {
394                                 if (!heap_full(&c->flush_btree))
395                                         heap_add(&c->flush_btree, b,
396                                                  journal_max_cmp);
397                                 else if (journal_max_cmp(b,
398                                          heap_peek(&c->flush_btree))) {
399                                         c->flush_btree.data[0] = b;
400                                         heap_sift(&c->flush_btree, 0,
401                                                   journal_max_cmp);
402                                 }
403                         }
404
405                 for (i = c->flush_btree.used / 2 - 1; i >= 0; --i)
406                         heap_sift(&c->flush_btree, i, journal_min_cmp);
407         }
408
409         b = NULL;
410         heap_pop(&c->flush_btree, b, journal_min_cmp);
411         spin_unlock(&c->journal.lock);
412
413         if (b) {
414                 mutex_lock(&b->write_lock);
415                 if (!btree_current_write(b)->journal) {
416                         mutex_unlock(&b->write_lock);
417                         /* We raced */
418                         atomic_long_inc(&c->retry_flush_write);
419                         goto retry;
420                 }
421
422                 __bch_btree_node_write(b, NULL);
423                 mutex_unlock(&b->write_lock);
424         }
425 }
426
427 #define last_seq(j)     ((j)->seq - fifo_used(&(j)->pin) + 1)
428
429 static void journal_discard_endio(struct bio *bio)
430 {
431         struct journal_device *ja =
432                 container_of(bio, struct journal_device, discard_bio);
433         struct cache *ca = container_of(ja, struct cache, journal);
434
435         atomic_set(&ja->discard_in_flight, DISCARD_DONE);
436
437         closure_wake_up(&ca->set->journal.wait);
438         closure_put(&ca->set->cl);
439 }
440
441 static void journal_discard_work(struct work_struct *work)
442 {
443         struct journal_device *ja =
444                 container_of(work, struct journal_device, discard_work);
445
446         submit_bio(&ja->discard_bio);
447 }
448
449 static void do_journal_discard(struct cache *ca)
450 {
451         struct journal_device *ja = &ca->journal;
452         struct bio *bio = &ja->discard_bio;
453
454         if (!ca->discard) {
455                 ja->discard_idx = ja->last_idx;
456                 return;
457         }
458
459         switch (atomic_read(&ja->discard_in_flight)) {
460         case DISCARD_IN_FLIGHT:
461                 return;
462
463         case DISCARD_DONE:
464                 ja->discard_idx = (ja->discard_idx + 1) %
465                         ca->sb.njournal_buckets;
466
467                 atomic_set(&ja->discard_in_flight, DISCARD_READY);
468                 /* fallthrough */
469
470         case DISCARD_READY:
471                 if (ja->discard_idx == ja->last_idx)
472                         return;
473
474                 atomic_set(&ja->discard_in_flight, DISCARD_IN_FLIGHT);
475
476                 bio_init(bio, bio->bi_inline_vecs, 1);
477                 bio_set_op_attrs(bio, REQ_OP_DISCARD, 0);
478                 bio->bi_iter.bi_sector  = bucket_to_sector(ca->set,
479                                                 ca->sb.d[ja->discard_idx]);
480                 bio_set_dev(bio, ca->bdev);
481                 bio->bi_iter.bi_size    = bucket_bytes(ca);
482                 bio->bi_end_io          = journal_discard_endio;
483
484                 closure_get(&ca->set->cl);
485                 INIT_WORK(&ja->discard_work, journal_discard_work);
486                 schedule_work(&ja->discard_work);
487         }
488 }
489
490 static void journal_reclaim(struct cache_set *c)
491 {
492         struct bkey *k = &c->journal.key;
493         struct cache *ca;
494         uint64_t last_seq;
495         unsigned iter, n = 0;
496         atomic_t p;
497
498         atomic_long_inc(&c->reclaim);
499
500         while (!atomic_read(&fifo_front(&c->journal.pin)))
501                 fifo_pop(&c->journal.pin, p);
502
503         last_seq = last_seq(&c->journal);
504
505         /* Update last_idx */
506
507         for_each_cache(ca, c, iter) {
508                 struct journal_device *ja = &ca->journal;
509
510                 while (ja->last_idx != ja->cur_idx &&
511                        ja->seq[ja->last_idx] < last_seq)
512                         ja->last_idx = (ja->last_idx + 1) %
513                                 ca->sb.njournal_buckets;
514         }
515
516         for_each_cache(ca, c, iter)
517                 do_journal_discard(ca);
518
519         if (c->journal.blocks_free)
520                 goto out;
521
522         /*
523          * Allocate:
524          * XXX: Sort by free journal space
525          */
526
527         for_each_cache(ca, c, iter) {
528                 struct journal_device *ja = &ca->journal;
529                 unsigned next = (ja->cur_idx + 1) % ca->sb.njournal_buckets;
530
531                 /* No space available on this device */
532                 if (next == ja->discard_idx)
533                         continue;
534
535                 ja->cur_idx = next;
536                 k->ptr[n++] = MAKE_PTR(0,
537                                   bucket_to_sector(c, ca->sb.d[ja->cur_idx]),
538                                   ca->sb.nr_this_dev);
539         }
540
541         bkey_init(k);
542         SET_KEY_PTRS(k, n);
543
544         if (n)
545                 c->journal.blocks_free = c->sb.bucket_size >> c->block_bits;
546 out:
547         if (!journal_full(&c->journal))
548                 __closure_wake_up(&c->journal.wait);
549 }
550
551 void bch_journal_next(struct journal *j)
552 {
553         atomic_t p = { 1 };
554
555         j->cur = (j->cur == j->w)
556                 ? &j->w[1]
557                 : &j->w[0];
558
559         /*
560          * The fifo_push() needs to happen at the same time as j->seq is
561          * incremented for last_seq() to be calculated correctly
562          */
563         BUG_ON(!fifo_push(&j->pin, p));
564         atomic_set(&fifo_back(&j->pin), 1);
565
566         j->cur->data->seq       = ++j->seq;
567         j->cur->dirty           = false;
568         j->cur->need_write      = false;
569         j->cur->data->keys      = 0;
570
571         if (fifo_full(&j->pin))
572                 pr_debug("journal_pin full (%zu)", fifo_used(&j->pin));
573 }
574
575 static void journal_write_endio(struct bio *bio)
576 {
577         struct journal_write *w = bio->bi_private;
578
579         cache_set_err_on(bio->bi_status, w->c, "journal io error");
580         closure_put(&w->c->journal.io);
581 }
582
583 static void journal_write(struct closure *);
584
585 static void journal_write_done(struct closure *cl)
586 {
587         struct journal *j = container_of(cl, struct journal, io);
588         struct journal_write *w = (j->cur == j->w)
589                 ? &j->w[1]
590                 : &j->w[0];
591
592         __closure_wake_up(&w->wait);
593         continue_at_nobarrier(cl, journal_write, system_wq);
594 }
595
596 static void journal_write_unlock(struct closure *cl)
597 {
598         struct cache_set *c = container_of(cl, struct cache_set, journal.io);
599
600         c->journal.io_in_flight = 0;
601         spin_unlock(&c->journal.lock);
602 }
603
604 static void journal_write_unlocked(struct closure *cl)
605         __releases(c->journal.lock)
606 {
607         struct cache_set *c = container_of(cl, struct cache_set, journal.io);
608         struct cache *ca;
609         struct journal_write *w = c->journal.cur;
610         struct bkey *k = &c->journal.key;
611         unsigned i, sectors = set_blocks(w->data, block_bytes(c)) *
612                 c->sb.block_size;
613
614         struct bio *bio;
615         struct bio_list list;
616         bio_list_init(&list);
617
618         if (!w->need_write) {
619                 closure_return_with_destructor(cl, journal_write_unlock);
620                 return;
621         } else if (journal_full(&c->journal)) {
622                 journal_reclaim(c);
623                 spin_unlock(&c->journal.lock);
624
625                 btree_flush_write(c);
626                 continue_at(cl, journal_write, system_wq);
627                 return;
628         }
629
630         c->journal.blocks_free -= set_blocks(w->data, block_bytes(c));
631
632         w->data->btree_level = c->root->level;
633
634         bkey_copy(&w->data->btree_root, &c->root->key);
635         bkey_copy(&w->data->uuid_bucket, &c->uuid_bucket);
636
637         for_each_cache(ca, c, i)
638                 w->data->prio_bucket[ca->sb.nr_this_dev] = ca->prio_buckets[0];
639
640         w->data->magic          = jset_magic(&c->sb);
641         w->data->version        = BCACHE_JSET_VERSION;
642         w->data->last_seq       = last_seq(&c->journal);
643         w->data->csum           = csum_set(w->data);
644
645         for (i = 0; i < KEY_PTRS(k); i++) {
646                 ca = PTR_CACHE(c, k, i);
647                 bio = &ca->journal.bio;
648
649                 atomic_long_add(sectors, &ca->meta_sectors_written);
650
651                 bio_reset(bio);
652                 bio->bi_iter.bi_sector  = PTR_OFFSET(k, i);
653                 bio_set_dev(bio, ca->bdev);
654                 bio->bi_iter.bi_size = sectors << 9;
655
656                 bio->bi_end_io  = journal_write_endio;
657                 bio->bi_private = w;
658                 bio_set_op_attrs(bio, REQ_OP_WRITE,
659                                  REQ_SYNC|REQ_META|REQ_PREFLUSH|REQ_FUA);
660                 bch_bio_map(bio, w->data);
661
662                 trace_bcache_journal_write(bio);
663                 bio_list_add(&list, bio);
664
665                 SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + sectors);
666
667                 ca->journal.seq[ca->journal.cur_idx] = w->data->seq;
668         }
669
670         atomic_dec_bug(&fifo_back(&c->journal.pin));
671         bch_journal_next(&c->journal);
672         journal_reclaim(c);
673
674         spin_unlock(&c->journal.lock);
675
676         while ((bio = bio_list_pop(&list)))
677                 closure_bio_submit(bio, cl);
678
679         continue_at(cl, journal_write_done, NULL);
680 }
681
682 static void journal_write(struct closure *cl)
683 {
684         struct cache_set *c = container_of(cl, struct cache_set, journal.io);
685
686         spin_lock(&c->journal.lock);
687         journal_write_unlocked(cl);
688 }
689
690 static void journal_try_write(struct cache_set *c)
691         __releases(c->journal.lock)
692 {
693         struct closure *cl = &c->journal.io;
694         struct journal_write *w = c->journal.cur;
695
696         w->need_write = true;
697
698         if (!c->journal.io_in_flight) {
699                 c->journal.io_in_flight = 1;
700                 closure_call(cl, journal_write_unlocked, NULL, &c->cl);
701         } else {
702                 spin_unlock(&c->journal.lock);
703         }
704 }
705
706 static struct journal_write *journal_wait_for_write(struct cache_set *c,
707                                                     unsigned nkeys)
708 {
709         size_t sectors;
710         struct closure cl;
711         bool wait = false;
712
713         closure_init_stack(&cl);
714
715         spin_lock(&c->journal.lock);
716
717         while (1) {
718                 struct journal_write *w = c->journal.cur;
719
720                 sectors = __set_blocks(w->data, w->data->keys + nkeys,
721                                        block_bytes(c)) * c->sb.block_size;
722
723                 if (sectors <= min_t(size_t,
724                                      c->journal.blocks_free * c->sb.block_size,
725                                      PAGE_SECTORS << JSET_BITS))
726                         return w;
727
728                 if (wait)
729                         closure_wait(&c->journal.wait, &cl);
730
731                 if (!journal_full(&c->journal)) {
732                         if (wait)
733                                 trace_bcache_journal_entry_full(c);
734
735                         /*
736                          * XXX: If we were inserting so many keys that they
737                          * won't fit in an _empty_ journal write, we'll
738                          * deadlock. For now, handle this in
739                          * bch_keylist_realloc() - but something to think about.
740                          */
741                         BUG_ON(!w->data->keys);
742
743                         journal_try_write(c); /* unlocks */
744                 } else {
745                         if (wait)
746                                 trace_bcache_journal_full(c);
747
748                         journal_reclaim(c);
749                         spin_unlock(&c->journal.lock);
750
751                         btree_flush_write(c);
752                 }
753
754                 closure_sync(&cl);
755                 spin_lock(&c->journal.lock);
756                 wait = true;
757         }
758 }
759
760 static void journal_write_work(struct work_struct *work)
761 {
762         struct cache_set *c = container_of(to_delayed_work(work),
763                                            struct cache_set,
764                                            journal.work);
765         spin_lock(&c->journal.lock);
766         if (c->journal.cur->dirty)
767                 journal_try_write(c);
768         else
769                 spin_unlock(&c->journal.lock);
770 }
771
772 /*
773  * Entry point to the journalling code - bio_insert() and btree_invalidate()
774  * pass bch_journal() a list of keys to be journalled, and then
775  * bch_journal() hands those same keys off to btree_insert_async()
776  */
777
778 atomic_t *bch_journal(struct cache_set *c,
779                       struct keylist *keys,
780                       struct closure *parent)
781 {
782         struct journal_write *w;
783         atomic_t *ret;
784
785         if (!CACHE_SYNC(&c->sb))
786                 return NULL;
787
788         w = journal_wait_for_write(c, bch_keylist_nkeys(keys));
789
790         memcpy(bset_bkey_last(w->data), keys->keys, bch_keylist_bytes(keys));
791         w->data->keys += bch_keylist_nkeys(keys);
792
793         ret = &fifo_back(&c->journal.pin);
794         atomic_inc(ret);
795
796         if (parent) {
797                 closure_wait(&w->wait, parent);
798                 journal_try_write(c);
799         } else if (!w->dirty) {
800                 w->dirty = true;
801                 schedule_delayed_work(&c->journal.work,
802                                       msecs_to_jiffies(c->journal_delay_ms));
803                 spin_unlock(&c->journal.lock);
804         } else {
805                 spin_unlock(&c->journal.lock);
806         }
807
808
809         return ret;
810 }
811
812 void bch_journal_meta(struct cache_set *c, struct closure *cl)
813 {
814         struct keylist keys;
815         atomic_t *ref;
816
817         bch_keylist_init(&keys);
818
819         ref = bch_journal(c, &keys, cl);
820         if (ref)
821                 atomic_dec_bug(ref);
822 }
823
824 void bch_journal_free(struct cache_set *c)
825 {
826         free_pages((unsigned long) c->journal.w[1].data, JSET_BITS);
827         free_pages((unsigned long) c->journal.w[0].data, JSET_BITS);
828         free_fifo(&c->journal.pin);
829 }
830
831 int bch_journal_alloc(struct cache_set *c)
832 {
833         struct journal *j = &c->journal;
834
835         spin_lock_init(&j->lock);
836         INIT_DELAYED_WORK(&j->work, journal_write_work);
837
838         c->journal_delay_ms = 100;
839
840         j->w[0].c = c;
841         j->w[1].c = c;
842
843         if (!(init_heap(&c->flush_btree, 128, GFP_KERNEL)) ||
844             !(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)) ||
845             !(j->w[0].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS)) ||
846             !(j->w[1].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS)))
847                 return -ENOMEM;
848
849         return 0;
850 }