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Update bcachefs sources to 3c41353bc1 bcachefs: Fix bch2_verify_keylist_sorted
[bcachefs-tools-debian] / libbcachefs / btree_key_cache.c
1
2 #include "bcachefs.h"
3 #include "btree_cache.h"
4 #include "btree_iter.h"
5 #include "btree_key_cache.h"
6 #include "btree_locking.h"
7 #include "btree_update.h"
8 #include "error.h"
9 #include "journal.h"
10 #include "journal_reclaim.h"
11
12 #include <linux/sched/mm.h>
13 #include <trace/events/bcachefs.h>
14
15 static struct kmem_cache *bch2_key_cache;
16
17 static int bch2_btree_key_cache_cmp_fn(struct rhashtable_compare_arg *arg,
18                                        const void *obj)
19 {
20         const struct bkey_cached *ck = obj;
21         const struct bkey_cached_key *key = arg->key;
22
23         return cmp_int(ck->key.btree_id, key->btree_id) ?:
24                 bpos_cmp(ck->key.pos, key->pos);
25 }
26
27 static const struct rhashtable_params bch2_btree_key_cache_params = {
28         .head_offset    = offsetof(struct bkey_cached, hash),
29         .key_offset     = offsetof(struct bkey_cached, key),
30         .key_len        = sizeof(struct bkey_cached_key),
31         .obj_cmpfn      = bch2_btree_key_cache_cmp_fn,
32 };
33
34 __flatten
35 inline struct bkey_cached *
36 bch2_btree_key_cache_find(struct bch_fs *c, enum btree_id btree_id, struct bpos pos)
37 {
38         struct bkey_cached_key key = {
39                 .btree_id       = btree_id,
40                 .pos            = pos,
41         };
42
43         return rhashtable_lookup_fast(&c->btree_key_cache.table, &key,
44                                       bch2_btree_key_cache_params);
45 }
46
47 static bool bkey_cached_lock_for_evict(struct bkey_cached *ck)
48 {
49         if (!six_trylock_intent(&ck->c.lock))
50                 return false;
51
52         if (!six_trylock_write(&ck->c.lock)) {
53                 six_unlock_intent(&ck->c.lock);
54                 return false;
55         }
56
57         if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
58                 six_unlock_write(&ck->c.lock);
59                 six_unlock_intent(&ck->c.lock);
60                 return false;
61         }
62
63         return true;
64 }
65
66 static void bkey_cached_evict(struct btree_key_cache *c,
67                               struct bkey_cached *ck)
68 {
69         BUG_ON(rhashtable_remove_fast(&c->table, &ck->hash,
70                                       bch2_btree_key_cache_params));
71         memset(&ck->key, ~0, sizeof(ck->key));
72
73         atomic_long_dec(&c->nr_keys);
74 }
75
76 static void bkey_cached_free(struct btree_key_cache *bc,
77                              struct bkey_cached *ck)
78 {
79         struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);
80
81         BUG_ON(test_bit(BKEY_CACHED_DIRTY, &ck->flags));
82
83         ck->btree_trans_barrier_seq =
84                 start_poll_synchronize_srcu(&c->btree_trans_barrier);
85
86         list_move_tail(&ck->list, &bc->freed);
87         bc->nr_freed++;
88
89         kfree(ck->k);
90         ck->k           = NULL;
91         ck->u64s        = 0;
92
93         six_unlock_write(&ck->c.lock);
94         six_unlock_intent(&ck->c.lock);
95 }
96
97 static struct bkey_cached *
98 bkey_cached_alloc(struct btree_key_cache *c)
99 {
100         struct bkey_cached *ck;
101
102         ck = kmem_cache_alloc(bch2_key_cache, GFP_NOFS|__GFP_ZERO);
103         if (likely(ck)) {
104                 INIT_LIST_HEAD(&ck->list);
105                 six_lock_init(&ck->c.lock);
106                 BUG_ON(!six_trylock_intent(&ck->c.lock));
107                 BUG_ON(!six_trylock_write(&ck->c.lock));
108                 return ck;
109         }
110
111         return NULL;
112 }
113
114 static struct bkey_cached *
115 bkey_cached_reuse(struct btree_key_cache *c)
116 {
117         struct bucket_table *tbl;
118         struct rhash_head *pos;
119         struct bkey_cached *ck;
120         unsigned i;
121
122         mutex_lock(&c->lock);
123         list_for_each_entry_reverse(ck, &c->freed, list)
124                 if (bkey_cached_lock_for_evict(ck)) {
125                         c->nr_freed--;
126                         list_del(&ck->list);
127                         mutex_unlock(&c->lock);
128                         return ck;
129                 }
130         mutex_unlock(&c->lock);
131
132         rcu_read_lock();
133         tbl = rht_dereference_rcu(c->table.tbl, &c->table);
134         for (i = 0; i < tbl->size; i++)
135                 rht_for_each_entry_rcu(ck, pos, tbl, i, hash) {
136                         if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags) &&
137                             bkey_cached_lock_for_evict(ck)) {
138                                 bkey_cached_evict(c, ck);
139                                 rcu_read_unlock();
140                                 return ck;
141                         }
142                 }
143         rcu_read_unlock();
144
145         return NULL;
146 }
147
148 static struct bkey_cached *
149 btree_key_cache_create(struct btree_key_cache *c,
150                        enum btree_id btree_id,
151                        struct bpos pos)
152 {
153         struct bkey_cached *ck;
154         bool was_new = true;
155
156         ck = bkey_cached_alloc(c);
157
158         if (unlikely(!ck)) {
159                 ck = bkey_cached_reuse(c);
160                 if (unlikely(!ck))
161                         return ERR_PTR(-ENOMEM);
162
163                 was_new = false;
164         }
165
166         ck->c.level             = 0;
167         ck->c.btree_id          = btree_id;
168         ck->key.btree_id        = btree_id;
169         ck->key.pos             = pos;
170         ck->valid               = false;
171         ck->flags               = 1U << BKEY_CACHED_ACCESSED;
172
173         if (unlikely(rhashtable_lookup_insert_fast(&c->table,
174                                           &ck->hash,
175                                           bch2_btree_key_cache_params))) {
176                 /* We raced with another fill: */
177
178                 if (likely(was_new)) {
179                         six_unlock_write(&ck->c.lock);
180                         six_unlock_intent(&ck->c.lock);
181                         kfree(ck);
182                 } else {
183                         mutex_lock(&c->lock);
184                         bkey_cached_free(c, ck);
185                         mutex_unlock(&c->lock);
186                 }
187
188                 return NULL;
189         }
190
191         atomic_long_inc(&c->nr_keys);
192
193         six_unlock_write(&ck->c.lock);
194
195         return ck;
196 }
197
198 static int btree_key_cache_fill(struct btree_trans *trans,
199                                 struct btree_iter *ck_iter,
200                                 struct bkey_cached *ck)
201 {
202         struct btree_iter *iter;
203         struct bkey_s_c k;
204         unsigned new_u64s = 0;
205         struct bkey_i *new_k = NULL;
206         int ret;
207
208         iter = bch2_trans_get_iter(trans, ck->key.btree_id,
209                                    ck->key.pos, BTREE_ITER_SLOTS);
210         k = bch2_btree_iter_peek_slot(iter);
211         ret = bkey_err(k);
212         if (ret)
213                 goto err;
214
215         if (!bch2_btree_node_relock(ck_iter, 0)) {
216                 trace_transaction_restart_ip(trans->ip, _THIS_IP_);
217                 ret = -EINTR;
218                 goto err;
219         }
220
221         /*
222          * bch2_varint_decode can read past the end of the buffer by at
223          * most 7 bytes (it won't be used):
224          */
225         new_u64s = k.k->u64s + 1;
226
227         if (new_u64s > ck->u64s) {
228                 new_u64s = roundup_pow_of_two(new_u64s);
229                 new_k = kmalloc(new_u64s * sizeof(u64), GFP_NOFS);
230                 if (!new_k) {
231                         ret = -ENOMEM;
232                         goto err;
233                 }
234         }
235
236         bch2_btree_node_lock_write(ck_iter->l[0].b, ck_iter);
237         if (new_k) {
238                 kfree(ck->k);
239                 ck->u64s = new_u64s;
240                 ck->k = new_k;
241         }
242
243         bkey_reassemble(ck->k, k);
244         ck->valid = true;
245         bch2_btree_node_unlock_write(ck_iter->l[0].b, ck_iter);
246
247         /* We're not likely to need this iterator again: */
248         set_btree_iter_dontneed(trans, iter);
249 err:
250         bch2_trans_iter_put(trans, iter);
251         return ret;
252 }
253
254 static int bkey_cached_check_fn(struct six_lock *lock, void *p)
255 {
256         struct bkey_cached *ck = container_of(lock, struct bkey_cached, c.lock);
257         const struct btree_iter *iter = p;
258
259         return ck->key.btree_id == iter->btree_id &&
260                 !bpos_cmp(ck->key.pos, iter->pos) ? 0 : -1;
261 }
262
263 __flatten
264 int bch2_btree_iter_traverse_cached(struct btree_iter *iter)
265 {
266         struct btree_trans *trans = iter->trans;
267         struct bch_fs *c = trans->c;
268         struct bkey_cached *ck;
269         int ret = 0;
270
271         BUG_ON(iter->level);
272
273         if (btree_node_locked(iter, 0)) {
274                 ck = (void *) iter->l[0].b;
275                 goto fill;
276         }
277 retry:
278         ck = bch2_btree_key_cache_find(c, iter->btree_id, iter->pos);
279         if (!ck) {
280                 if (iter->flags & BTREE_ITER_CACHED_NOCREATE) {
281                         iter->l[0].b = NULL;
282                         return 0;
283                 }
284
285                 ck = btree_key_cache_create(&c->btree_key_cache,
286                                             iter->btree_id, iter->pos);
287                 ret = PTR_ERR_OR_ZERO(ck);
288                 if (ret)
289                         goto err;
290                 if (!ck)
291                         goto retry;
292
293                 mark_btree_node_locked(iter, 0, SIX_LOCK_intent);
294                 iter->locks_want = 1;
295         } else {
296                 enum six_lock_type lock_want = __btree_lock_want(iter, 0);
297
298                 if (!btree_node_lock((void *) ck, iter->pos, 0, iter, lock_want,
299                                      bkey_cached_check_fn, iter, _THIS_IP_)) {
300                         if (ck->key.btree_id != iter->btree_id ||
301                             bpos_cmp(ck->key.pos, iter->pos)) {
302                                 goto retry;
303                         }
304
305                         trace_transaction_restart_ip(trans->ip, _THIS_IP_);
306                         ret = -EINTR;
307                         goto err;
308                 }
309
310                 if (ck->key.btree_id != iter->btree_id ||
311                     bpos_cmp(ck->key.pos, iter->pos)) {
312                         six_unlock_type(&ck->c.lock, lock_want);
313                         goto retry;
314                 }
315
316                 mark_btree_node_locked(iter, 0, lock_want);
317         }
318
319         iter->l[0].lock_seq     = ck->c.lock.state.seq;
320         iter->l[0].b            = (void *) ck;
321 fill:
322         if (!ck->valid && !(iter->flags & BTREE_ITER_CACHED_NOFILL)) {
323                 if (!btree_node_intent_locked(iter, 0))
324                         bch2_btree_iter_upgrade(iter, 1);
325                 if (!btree_node_intent_locked(iter, 0)) {
326                         trace_transaction_restart_ip(trans->ip, _THIS_IP_);
327                         ret = -EINTR;
328                         goto err;
329                 }
330
331                 ret = btree_key_cache_fill(trans, iter, ck);
332                 if (ret)
333                         goto err;
334         }
335
336         if (!test_bit(BKEY_CACHED_ACCESSED, &ck->flags))
337                 set_bit(BKEY_CACHED_ACCESSED, &ck->flags);
338
339         iter->uptodate = BTREE_ITER_NEED_PEEK;
340
341         if (!(iter->flags & BTREE_ITER_INTENT))
342                 bch2_btree_iter_downgrade(iter);
343         else if (!iter->locks_want) {
344                 if (!__bch2_btree_iter_upgrade(iter, 1))
345                         ret = -EINTR;
346         }
347
348         return ret;
349 err:
350         if (ret != -EINTR) {
351                 btree_node_unlock(iter, 0);
352                 iter->flags |= BTREE_ITER_ERROR;
353                 iter->l[0].b = BTREE_ITER_NO_NODE_ERROR;
354         }
355         return ret;
356 }
357
358 static int btree_key_cache_flush_pos(struct btree_trans *trans,
359                                      struct bkey_cached_key key,
360                                      u64 journal_seq,
361                                      unsigned commit_flags,
362                                      bool evict)
363 {
364         struct bch_fs *c = trans->c;
365         struct journal *j = &c->journal;
366         struct btree_iter *c_iter = NULL, *b_iter = NULL;
367         struct bkey_cached *ck = NULL;
368         int ret;
369
370         b_iter = bch2_trans_get_iter(trans, key.btree_id, key.pos,
371                                      BTREE_ITER_SLOTS|
372                                      BTREE_ITER_INTENT);
373         c_iter = bch2_trans_get_iter(trans, key.btree_id, key.pos,
374                                      BTREE_ITER_CACHED|
375                                      BTREE_ITER_CACHED_NOFILL|
376                                      BTREE_ITER_CACHED_NOCREATE|
377                                      BTREE_ITER_INTENT);
378 retry:
379         ret = bch2_btree_iter_traverse(c_iter);
380         if (ret)
381                 goto err;
382
383         ck = (void *) c_iter->l[0].b;
384         if (!ck ||
385             (journal_seq && ck->journal.seq != journal_seq))
386                 goto out;
387
388         if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
389                 if (!evict)
390                         goto out;
391                 goto evict;
392         }
393
394         /*
395          * Since journal reclaim depends on us making progress here, and the
396          * allocator/copygc depend on journal reclaim making progress, we need
397          * to be using alloc reserves:
398          * */
399         ret   = bch2_btree_iter_traverse(b_iter) ?:
400                 bch2_trans_update(trans, b_iter, ck->k, BTREE_TRIGGER_NORUN) ?:
401                 bch2_trans_commit(trans, NULL, NULL,
402                                   BTREE_INSERT_NOUNLOCK|
403                                   BTREE_INSERT_NOCHECK_RW|
404                                   BTREE_INSERT_NOFAIL|
405                                   BTREE_INSERT_USE_RESERVE|
406                                   (ck->journal.seq == journal_last_seq(j)
407                                    ? BTREE_INSERT_JOURNAL_RESERVED
408                                    : 0)|
409                                   commit_flags);
410 err:
411         if (ret == -EINTR)
412                 goto retry;
413
414         if (ret == -EAGAIN)
415                 goto out;
416
417         if (ret) {
418                 bch2_fs_fatal_err_on(!bch2_journal_error(j), c,
419                         "error flushing key cache: %i", ret);
420                 goto out;
421         }
422
423         bch2_journal_pin_drop(j, &ck->journal);
424         bch2_journal_preres_put(j, &ck->res);
425
426         BUG_ON(!btree_node_locked(c_iter, 0));
427
428         if (!evict) {
429                 if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
430                         clear_bit(BKEY_CACHED_DIRTY, &ck->flags);
431                         atomic_long_dec(&c->btree_key_cache.nr_dirty);
432                 }
433         } else {
434 evict:
435                 BUG_ON(!btree_node_intent_locked(c_iter, 0));
436
437                 mark_btree_node_unlocked(c_iter, 0);
438                 c_iter->l[0].b = NULL;
439
440                 six_lock_write(&ck->c.lock, NULL, NULL);
441
442                 if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
443                         clear_bit(BKEY_CACHED_DIRTY, &ck->flags);
444                         atomic_long_dec(&c->btree_key_cache.nr_dirty);
445                 }
446
447                 bkey_cached_evict(&c->btree_key_cache, ck);
448
449                 mutex_lock(&c->btree_key_cache.lock);
450                 bkey_cached_free(&c->btree_key_cache, ck);
451                 mutex_unlock(&c->btree_key_cache.lock);
452         }
453 out:
454         bch2_trans_iter_put(trans, b_iter);
455         bch2_trans_iter_put(trans, c_iter);
456         return ret;
457 }
458
459 int bch2_btree_key_cache_journal_flush(struct journal *j,
460                                 struct journal_entry_pin *pin, u64 seq)
461 {
462         struct bch_fs *c = container_of(j, struct bch_fs, journal);
463         struct bkey_cached *ck =
464                 container_of(pin, struct bkey_cached, journal);
465         struct bkey_cached_key key;
466         struct btree_trans trans;
467         int ret = 0;
468
469         int srcu_idx = srcu_read_lock(&c->btree_trans_barrier);
470
471         six_lock_read(&ck->c.lock, NULL, NULL);
472         key = ck->key;
473
474         if (ck->journal.seq != seq ||
475             !test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
476                 six_unlock_read(&ck->c.lock);
477                 goto unlock;
478         }
479         six_unlock_read(&ck->c.lock);
480
481         bch2_trans_init(&trans, c, 0, 0);
482         ret = btree_key_cache_flush_pos(&trans, key, seq,
483                                   BTREE_INSERT_JOURNAL_RECLAIM, false);
484         bch2_trans_exit(&trans);
485 unlock:
486         srcu_read_unlock(&c->btree_trans_barrier, srcu_idx);
487
488         return ret;
489 }
490
491 /*
492  * Flush and evict a key from the key cache:
493  */
494 int bch2_btree_key_cache_flush(struct btree_trans *trans,
495                                enum btree_id id, struct bpos pos)
496 {
497         struct bch_fs *c = trans->c;
498         struct bkey_cached_key key = { id, pos };
499
500         /* Fastpath - assume it won't be found: */
501         if (!bch2_btree_key_cache_find(c, id, pos))
502                 return 0;
503
504         return btree_key_cache_flush_pos(trans, key, 0, 0, true);
505 }
506
507 bool bch2_btree_insert_key_cached(struct btree_trans *trans,
508                                   struct btree_iter *iter,
509                                   struct bkey_i *insert)
510 {
511         struct bch_fs *c = trans->c;
512         struct bkey_cached *ck = (void *) iter->l[0].b;
513         bool kick_reclaim = false;
514
515         BUG_ON(insert->u64s > ck->u64s);
516
517         if (likely(!(trans->flags & BTREE_INSERT_JOURNAL_REPLAY))) {
518                 int difference;
519
520                 BUG_ON(jset_u64s(insert->u64s) > trans->journal_preres.u64s);
521
522                 difference = jset_u64s(insert->u64s) - ck->res.u64s;
523                 if (difference > 0) {
524                         trans->journal_preres.u64s      -= difference;
525                         ck->res.u64s                    += difference;
526                 }
527         }
528
529         bkey_copy(ck->k, insert);
530         ck->valid = true;
531
532         if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
533                 set_bit(BKEY_CACHED_DIRTY, &ck->flags);
534                 atomic_long_inc(&c->btree_key_cache.nr_dirty);
535
536                 if (bch2_nr_btree_keys_need_flush(c))
537                         kick_reclaim = true;
538         }
539
540         bch2_journal_pin_update(&c->journal, trans->journal_res.seq,
541                                 &ck->journal, bch2_btree_key_cache_journal_flush);
542
543         if (kick_reclaim)
544                 journal_reclaim_kick(&c->journal);
545         return true;
546 }
547
548 #ifdef CONFIG_BCACHEFS_DEBUG
549 void bch2_btree_key_cache_verify_clean(struct btree_trans *trans,
550                                enum btree_id id, struct bpos pos)
551 {
552         BUG_ON(bch2_btree_key_cache_find(trans->c, id, pos));
553 }
554 #endif
555
556 static unsigned long bch2_btree_key_cache_scan(struct shrinker *shrink,
557                                            struct shrink_control *sc)
558 {
559         struct bch_fs *c = container_of(shrink, struct bch_fs,
560                                         btree_key_cache.shrink);
561         struct btree_key_cache *bc = &c->btree_key_cache;
562         struct bucket_table *tbl;
563         struct bkey_cached *ck, *t;
564         size_t scanned = 0, freed = 0, nr = sc->nr_to_scan;
565         unsigned start, flags;
566         int srcu_idx;
567
568         /* Return -1 if we can't do anything right now */
569         if (sc->gfp_mask & __GFP_FS)
570                 mutex_lock(&bc->lock);
571         else if (!mutex_trylock(&bc->lock))
572                 return -1;
573
574         srcu_idx = srcu_read_lock(&c->btree_trans_barrier);
575         flags = memalloc_nofs_save();
576
577         /*
578          * Newest freed entries are at the end of the list - once we hit one
579          * that's too new to be freed, we can bail out:
580          */
581         list_for_each_entry_safe(ck, t, &bc->freed, list) {
582                 if (!poll_state_synchronize_srcu(&c->btree_trans_barrier,
583                                                  ck->btree_trans_barrier_seq))
584                         break;
585
586                 list_del(&ck->list);
587                 kmem_cache_free(bch2_key_cache, ck);
588                 bc->nr_freed--;
589                 scanned++;
590                 freed++;
591         }
592
593         if (scanned >= nr)
594                 goto out;
595
596         rcu_read_lock();
597         tbl = rht_dereference_rcu(bc->table.tbl, &bc->table);
598         if (bc->shrink_iter >= tbl->size)
599                 bc->shrink_iter = 0;
600         start = bc->shrink_iter;
601
602         do {
603                 struct rhash_head *pos, *next;
604
605                 pos = rht_ptr_rcu(rht_bucket(tbl, bc->shrink_iter));
606
607                 while (!rht_is_a_nulls(pos)) {
608                         next = rht_dereference_bucket_rcu(pos->next, tbl, bc->shrink_iter);
609                         ck = container_of(pos, struct bkey_cached, hash);
610
611                         if (test_bit(BKEY_CACHED_DIRTY, &ck->flags))
612                                 goto next;
613
614                         if (test_bit(BKEY_CACHED_ACCESSED, &ck->flags))
615                                 clear_bit(BKEY_CACHED_ACCESSED, &ck->flags);
616                         else if (bkey_cached_lock_for_evict(ck)) {
617                                 bkey_cached_evict(bc, ck);
618                                 bkey_cached_free(bc, ck);
619                         }
620
621                         scanned++;
622                         if (scanned >= nr)
623                                 break;
624 next:
625                         pos = next;
626                 }
627
628                 bc->shrink_iter++;
629                 if (bc->shrink_iter >= tbl->size)
630                         bc->shrink_iter = 0;
631         } while (scanned < nr && bc->shrink_iter != start);
632
633         rcu_read_unlock();
634 out:
635         memalloc_nofs_restore(flags);
636         srcu_read_unlock(&c->btree_trans_barrier, srcu_idx);
637         mutex_unlock(&bc->lock);
638
639         return freed;
640 }
641
642 static unsigned long bch2_btree_key_cache_count(struct shrinker *shrink,
643                                             struct shrink_control *sc)
644 {
645         struct bch_fs *c = container_of(shrink, struct bch_fs,
646                                         btree_key_cache.shrink);
647         struct btree_key_cache *bc = &c->btree_key_cache;
648
649         return atomic_long_read(&bc->nr_keys);
650 }
651
652 void bch2_fs_btree_key_cache_exit(struct btree_key_cache *bc)
653 {
654         struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);
655         struct bucket_table *tbl;
656         struct bkey_cached *ck, *n;
657         struct rhash_head *pos;
658         unsigned i;
659
660         if (bc->shrink.list.next)
661                 unregister_shrinker(&bc->shrink);
662
663         mutex_lock(&bc->lock);
664
665         rcu_read_lock();
666         tbl = rht_dereference_rcu(bc->table.tbl, &bc->table);
667         for (i = 0; i < tbl->size; i++)
668                 rht_for_each_entry_rcu(ck, pos, tbl, i, hash) {
669                         bkey_cached_evict(bc, ck);
670                         list_add(&ck->list, &bc->freed);
671                 }
672         rcu_read_unlock();
673
674         list_for_each_entry_safe(ck, n, &bc->freed, list) {
675                 cond_resched();
676
677                 bch2_journal_pin_drop(&c->journal, &ck->journal);
678                 bch2_journal_preres_put(&c->journal, &ck->res);
679
680                 list_del(&ck->list);
681                 kfree(ck->k);
682                 kmem_cache_free(bch2_key_cache, ck);
683         }
684
685         BUG_ON(atomic_long_read(&bc->nr_dirty) && !bch2_journal_error(&c->journal));
686         BUG_ON(atomic_long_read(&bc->nr_keys));
687
688         mutex_unlock(&bc->lock);
689
690         if (bc->table_init_done)
691                 rhashtable_destroy(&bc->table);
692 }
693
694 void bch2_fs_btree_key_cache_init_early(struct btree_key_cache *c)
695 {
696         mutex_init(&c->lock);
697         INIT_LIST_HEAD(&c->freed);
698 }
699
700 int bch2_fs_btree_key_cache_init(struct btree_key_cache *c)
701 {
702         int ret;
703
704         ret = rhashtable_init(&c->table, &bch2_btree_key_cache_params);
705         if (ret)
706                 return ret;
707
708         c->table_init_done = true;
709
710         c->shrink.seeks                 = 1;
711         c->shrink.count_objects         = bch2_btree_key_cache_count;
712         c->shrink.scan_objects          = bch2_btree_key_cache_scan;
713         return register_shrinker(&c->shrink);
714 }
715
716 void bch2_btree_key_cache_to_text(struct printbuf *out, struct btree_key_cache *c)
717 {
718         pr_buf(out, "nr_freed:\t%zu\n", c->nr_freed);
719         pr_buf(out, "nr_keys:\t%zu\n",  atomic_long_read(&c->nr_keys));
720         pr_buf(out, "nr_dirty:\t%zu\n", atomic_long_read(&c->nr_dirty));
721 }
722
723 void bch2_btree_key_cache_exit(void)
724 {
725         if (bch2_key_cache)
726                 kmem_cache_destroy(bch2_key_cache);
727 }
728
729 int __init bch2_btree_key_cache_init(void)
730 {
731         bch2_key_cache = KMEM_CACHE(bkey_cached, 0);
732         if (!bch2_key_cache)
733                 return -ENOMEM;
734
735         return 0;
736 }