814 lines · c
1// SPDX-License-Identifier: GPL-2.02 3#include "bcachefs.h"4#include "btree_cache.h"5#include "btree_iter.h"6#include "btree_key_cache.h"7#include "btree_locking.h"8#include "btree_update.h"9#include "errcode.h"10#include "error.h"11#include "journal.h"12#include "journal_reclaim.h"13#include "trace.h"14 15#include <linux/sched/mm.h>16 17static inline bool btree_uses_pcpu_readers(enum btree_id id)18{19 return id == BTREE_ID_subvolumes;20}21 22static struct kmem_cache *bch2_key_cache;23 24static int bch2_btree_key_cache_cmp_fn(struct rhashtable_compare_arg *arg,25 const void *obj)26{27 const struct bkey_cached *ck = obj;28 const struct bkey_cached_key *key = arg->key;29 30 return ck->key.btree_id != key->btree_id ||31 !bpos_eq(ck->key.pos, key->pos);32}33 34static const struct rhashtable_params bch2_btree_key_cache_params = {35 .head_offset = offsetof(struct bkey_cached, hash),36 .key_offset = offsetof(struct bkey_cached, key),37 .key_len = sizeof(struct bkey_cached_key),38 .obj_cmpfn = bch2_btree_key_cache_cmp_fn,39 .automatic_shrinking = true,40};41 42static inline void btree_path_cached_set(struct btree_trans *trans, struct btree_path *path,43 struct bkey_cached *ck,44 enum btree_node_locked_type lock_held)45{46 path->l[0].lock_seq = six_lock_seq(&ck->c.lock);47 path->l[0].b = (void *) ck;48 mark_btree_node_locked(trans, path, 0, lock_held);49}50 51__flatten52inline struct bkey_cached *53bch2_btree_key_cache_find(struct bch_fs *c, enum btree_id btree_id, struct bpos pos)54{55 struct bkey_cached_key key = {56 .btree_id = btree_id,57 .pos = pos,58 };59 60 return rhashtable_lookup_fast(&c->btree_key_cache.table, &key,61 bch2_btree_key_cache_params);62}63 64static bool bkey_cached_lock_for_evict(struct bkey_cached *ck)65{66 if (!six_trylock_intent(&ck->c.lock))67 return false;68 69 if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {70 six_unlock_intent(&ck->c.lock);71 return false;72 }73 74 if (!six_trylock_write(&ck->c.lock)) {75 six_unlock_intent(&ck->c.lock);76 return false;77 }78 79 return true;80}81 82static bool bkey_cached_evict(struct btree_key_cache *c,83 struct bkey_cached *ck)84{85 bool ret = !rhashtable_remove_fast(&c->table, &ck->hash,86 bch2_btree_key_cache_params);87 if (ret) {88 memset(&ck->key, ~0, sizeof(ck->key));89 atomic_long_dec(&c->nr_keys);90 }91 92 return ret;93}94 95static void __bkey_cached_free(struct rcu_pending *pending, struct rcu_head *rcu)96{97 struct bch_fs *c = container_of(pending->srcu, struct bch_fs, btree_trans_barrier);98 struct bkey_cached *ck = container_of(rcu, struct bkey_cached, rcu);99 100 this_cpu_dec(*c->btree_key_cache.nr_pending);101 kmem_cache_free(bch2_key_cache, ck);102}103 104static void bkey_cached_free(struct btree_key_cache *bc,105 struct bkey_cached *ck)106{107 kfree(ck->k);108 ck->k = NULL;109 ck->u64s = 0;110 111 six_unlock_write(&ck->c.lock);112 six_unlock_intent(&ck->c.lock);113 114 bool pcpu_readers = ck->c.lock.readers != NULL;115 rcu_pending_enqueue(&bc->pending[pcpu_readers], &ck->rcu);116 this_cpu_inc(*bc->nr_pending);117}118 119static struct bkey_cached *__bkey_cached_alloc(unsigned key_u64s, gfp_t gfp)120{121 gfp |= __GFP_ACCOUNT|__GFP_RECLAIMABLE;122 123 struct bkey_cached *ck = kmem_cache_zalloc(bch2_key_cache, gfp);124 if (unlikely(!ck))125 return NULL;126 ck->k = kmalloc(key_u64s * sizeof(u64), gfp);127 if (unlikely(!ck->k)) {128 kmem_cache_free(bch2_key_cache, ck);129 return NULL;130 }131 ck->u64s = key_u64s;132 return ck;133}134 135static struct bkey_cached *136bkey_cached_alloc(struct btree_trans *trans, struct btree_path *path, unsigned key_u64s)137{138 struct bch_fs *c = trans->c;139 struct btree_key_cache *bc = &c->btree_key_cache;140 bool pcpu_readers = btree_uses_pcpu_readers(path->btree_id);141 int ret;142 143 struct bkey_cached *ck = container_of_or_null(144 rcu_pending_dequeue(&bc->pending[pcpu_readers]),145 struct bkey_cached, rcu);146 if (ck)147 goto lock;148 149 ck = allocate_dropping_locks(trans, ret,150 __bkey_cached_alloc(key_u64s, _gfp));151 if (ret) {152 if (ck)153 kfree(ck->k);154 kmem_cache_free(bch2_key_cache, ck);155 return ERR_PTR(ret);156 }157 158 if (ck) {159 bch2_btree_lock_init(&ck->c, pcpu_readers ? SIX_LOCK_INIT_PCPU : 0);160 ck->c.cached = true;161 goto lock;162 }163 164 ck = container_of_or_null(rcu_pending_dequeue_from_all(&bc->pending[pcpu_readers]),165 struct bkey_cached, rcu);166 if (ck)167 goto lock;168lock:169 six_lock_intent(&ck->c.lock, NULL, NULL);170 six_lock_write(&ck->c.lock, NULL, NULL);171 return ck;172}173 174static struct bkey_cached *175bkey_cached_reuse(struct btree_key_cache *c)176{177 struct bucket_table *tbl;178 struct rhash_head *pos;179 struct bkey_cached *ck;180 unsigned i;181 182 rcu_read_lock();183 tbl = rht_dereference_rcu(c->table.tbl, &c->table);184 for (i = 0; i < tbl->size; i++)185 rht_for_each_entry_rcu(ck, pos, tbl, i, hash) {186 if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags) &&187 bkey_cached_lock_for_evict(ck)) {188 if (bkey_cached_evict(c, ck))189 goto out;190 six_unlock_write(&ck->c.lock);191 six_unlock_intent(&ck->c.lock);192 }193 }194 ck = NULL;195out:196 rcu_read_unlock();197 return ck;198}199 200static int btree_key_cache_create(struct btree_trans *trans, struct btree_path *path,201 struct bkey_s_c k)202{203 struct bch_fs *c = trans->c;204 struct btree_key_cache *bc = &c->btree_key_cache;205 206 /*207 * bch2_varint_decode can read past the end of the buffer by at208 * most 7 bytes (it won't be used):209 */210 unsigned key_u64s = k.k->u64s + 1;211 212 /*213 * Allocate some extra space so that the transaction commit path is less214 * likely to have to reallocate, since that requires a transaction215 * restart:216 */217 key_u64s = min(256U, (key_u64s * 3) / 2);218 key_u64s = roundup_pow_of_two(key_u64s);219 220 struct bkey_cached *ck = bkey_cached_alloc(trans, path, key_u64s);221 int ret = PTR_ERR_OR_ZERO(ck);222 if (ret)223 return ret;224 225 if (unlikely(!ck)) {226 ck = bkey_cached_reuse(bc);227 if (unlikely(!ck)) {228 bch_err(c, "error allocating memory for key cache item, btree %s",229 bch2_btree_id_str(path->btree_id));230 return -BCH_ERR_ENOMEM_btree_key_cache_create;231 }232 }233 234 ck->c.level = 0;235 ck->c.btree_id = path->btree_id;236 ck->key.btree_id = path->btree_id;237 ck->key.pos = path->pos;238 ck->flags = 1U << BKEY_CACHED_ACCESSED;239 240 if (unlikely(key_u64s > ck->u64s)) {241 mark_btree_node_locked_noreset(path, 0, BTREE_NODE_UNLOCKED);242 243 struct bkey_i *new_k = allocate_dropping_locks(trans, ret,244 kmalloc(key_u64s * sizeof(u64), _gfp));245 if (unlikely(!new_k)) {246 bch_err(trans->c, "error allocating memory for key cache key, btree %s u64s %u",247 bch2_btree_id_str(ck->key.btree_id), key_u64s);248 ret = -BCH_ERR_ENOMEM_btree_key_cache_fill;249 } else if (ret) {250 kfree(new_k);251 goto err;252 }253 254 kfree(ck->k);255 ck->k = new_k;256 ck->u64s = key_u64s;257 }258 259 bkey_reassemble(ck->k, k);260 261 ret = rhashtable_lookup_insert_fast(&bc->table, &ck->hash, bch2_btree_key_cache_params);262 if (unlikely(ret)) /* raced with another fill? */263 goto err;264 265 atomic_long_inc(&bc->nr_keys);266 six_unlock_write(&ck->c.lock);267 268 enum six_lock_type lock_want = __btree_lock_want(path, 0);269 if (lock_want == SIX_LOCK_read)270 six_lock_downgrade(&ck->c.lock);271 btree_path_cached_set(trans, path, ck, (enum btree_node_locked_type) lock_want);272 path->uptodate = BTREE_ITER_UPTODATE;273 return 0;274err:275 bkey_cached_free(bc, ck);276 mark_btree_node_locked_noreset(path, 0, BTREE_NODE_UNLOCKED);277 278 return ret;279}280 281static noinline int btree_key_cache_fill(struct btree_trans *trans,282 struct btree_path *ck_path,283 unsigned flags)284{285 if (flags & BTREE_ITER_cached_nofill) {286 ck_path->uptodate = BTREE_ITER_UPTODATE;287 return 0;288 }289 290 struct bch_fs *c = trans->c;291 struct btree_iter iter;292 struct bkey_s_c k;293 int ret;294 295 bch2_trans_iter_init(trans, &iter, ck_path->btree_id, ck_path->pos,296 BTREE_ITER_key_cache_fill|297 BTREE_ITER_cached_nofill);298 iter.flags &= ~BTREE_ITER_with_journal;299 k = bch2_btree_iter_peek_slot(&iter);300 ret = bkey_err(k);301 if (ret)302 goto err;303 304 /* Recheck after btree lookup, before allocating: */305 ret = bch2_btree_key_cache_find(c, ck_path->btree_id, ck_path->pos) ? -EEXIST : 0;306 if (unlikely(ret))307 goto out;308 309 ret = btree_key_cache_create(trans, ck_path, k);310 if (ret)311 goto err;312out:313 /* We're not likely to need this iterator again: */314 bch2_set_btree_iter_dontneed(&iter);315err:316 bch2_trans_iter_exit(trans, &iter);317 return ret;318}319 320static inline int btree_path_traverse_cached_fast(struct btree_trans *trans,321 struct btree_path *path)322{323 struct bch_fs *c = trans->c;324 struct bkey_cached *ck;325retry:326 ck = bch2_btree_key_cache_find(c, path->btree_id, path->pos);327 if (!ck)328 return -ENOENT;329 330 enum six_lock_type lock_want = __btree_lock_want(path, 0);331 332 int ret = btree_node_lock(trans, path, (void *) ck, 0, lock_want, _THIS_IP_);333 if (ret)334 return ret;335 336 if (ck->key.btree_id != path->btree_id ||337 !bpos_eq(ck->key.pos, path->pos)) {338 six_unlock_type(&ck->c.lock, lock_want);339 goto retry;340 }341 342 if (!test_bit(BKEY_CACHED_ACCESSED, &ck->flags))343 set_bit(BKEY_CACHED_ACCESSED, &ck->flags);344 345 btree_path_cached_set(trans, path, ck, (enum btree_node_locked_type) lock_want);346 path->uptodate = BTREE_ITER_UPTODATE;347 return 0;348}349 350int bch2_btree_path_traverse_cached(struct btree_trans *trans, struct btree_path *path,351 unsigned flags)352{353 EBUG_ON(path->level);354 355 path->l[1].b = NULL;356 357 int ret;358 do {359 ret = btree_path_traverse_cached_fast(trans, path);360 if (unlikely(ret == -ENOENT))361 ret = btree_key_cache_fill(trans, path, flags);362 } while (ret == -EEXIST);363 364 if (unlikely(ret)) {365 path->uptodate = BTREE_ITER_NEED_TRAVERSE;366 if (!bch2_err_matches(ret, BCH_ERR_transaction_restart)) {367 btree_node_unlock(trans, path, 0);368 path->l[0].b = ERR_PTR(ret);369 }370 }371 return ret;372}373 374static int btree_key_cache_flush_pos(struct btree_trans *trans,375 struct bkey_cached_key key,376 u64 journal_seq,377 unsigned commit_flags,378 bool evict)379{380 struct bch_fs *c = trans->c;381 struct journal *j = &c->journal;382 struct btree_iter c_iter, b_iter;383 struct bkey_cached *ck = NULL;384 int ret;385 386 bch2_trans_iter_init(trans, &b_iter, key.btree_id, key.pos,387 BTREE_ITER_slots|388 BTREE_ITER_intent|389 BTREE_ITER_all_snapshots);390 bch2_trans_iter_init(trans, &c_iter, key.btree_id, key.pos,391 BTREE_ITER_cached|392 BTREE_ITER_intent);393 b_iter.flags &= ~BTREE_ITER_with_key_cache;394 395 ret = bch2_btree_iter_traverse(&c_iter);396 if (ret)397 goto out;398 399 ck = (void *) btree_iter_path(trans, &c_iter)->l[0].b;400 if (!ck)401 goto out;402 403 if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {404 if (evict)405 goto evict;406 goto out;407 }408 409 if (journal_seq && ck->journal.seq != journal_seq)410 goto out;411 412 trans->journal_res.seq = ck->journal.seq;413 414 /*415 * If we're at the end of the journal, we really want to free up space416 * in the journal right away - we don't want to pin that old journal417 * sequence number with a new btree node write, we want to re-journal418 * the update419 */420 if (ck->journal.seq == journal_last_seq(j))421 commit_flags |= BCH_WATERMARK_reclaim;422 423 if (ck->journal.seq != journal_last_seq(j) ||424 !test_bit(JOURNAL_space_low, &c->journal.flags))425 commit_flags |= BCH_TRANS_COMMIT_no_journal_res;426 427 ret = bch2_btree_iter_traverse(&b_iter) ?:428 bch2_trans_update(trans, &b_iter, ck->k,429 BTREE_UPDATE_key_cache_reclaim|430 BTREE_UPDATE_internal_snapshot_node|431 BTREE_TRIGGER_norun) ?:432 bch2_trans_commit(trans, NULL, NULL,433 BCH_TRANS_COMMIT_no_check_rw|434 BCH_TRANS_COMMIT_no_enospc|435 commit_flags);436 437 bch2_fs_fatal_err_on(ret &&438 !bch2_err_matches(ret, BCH_ERR_transaction_restart) &&439 !bch2_err_matches(ret, BCH_ERR_journal_reclaim_would_deadlock) &&440 !bch2_journal_error(j), c,441 "flushing key cache: %s", bch2_err_str(ret));442 if (ret)443 goto out;444 445 bch2_journal_pin_drop(j, &ck->journal);446 447 struct btree_path *path = btree_iter_path(trans, &c_iter);448 BUG_ON(!btree_node_locked(path, 0));449 450 if (!evict) {451 if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {452 clear_bit(BKEY_CACHED_DIRTY, &ck->flags);453 atomic_long_dec(&c->btree_key_cache.nr_dirty);454 }455 } else {456 struct btree_path *path2;457 unsigned i;458evict:459 trans_for_each_path(trans, path2, i)460 if (path2 != path)461 __bch2_btree_path_unlock(trans, path2);462 463 bch2_btree_node_lock_write_nofail(trans, path, &ck->c);464 465 if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {466 clear_bit(BKEY_CACHED_DIRTY, &ck->flags);467 atomic_long_dec(&c->btree_key_cache.nr_dirty);468 }469 470 mark_btree_node_locked_noreset(path, 0, BTREE_NODE_UNLOCKED);471 if (bkey_cached_evict(&c->btree_key_cache, ck)) {472 bkey_cached_free(&c->btree_key_cache, ck);473 } else {474 six_unlock_write(&ck->c.lock);475 six_unlock_intent(&ck->c.lock);476 }477 }478out:479 bch2_trans_iter_exit(trans, &b_iter);480 bch2_trans_iter_exit(trans, &c_iter);481 return ret;482}483 484int bch2_btree_key_cache_journal_flush(struct journal *j,485 struct journal_entry_pin *pin, u64 seq)486{487 struct bch_fs *c = container_of(j, struct bch_fs, journal);488 struct bkey_cached *ck =489 container_of(pin, struct bkey_cached, journal);490 struct bkey_cached_key key;491 struct btree_trans *trans = bch2_trans_get(c);492 int srcu_idx = srcu_read_lock(&c->btree_trans_barrier);493 int ret = 0;494 495 btree_node_lock_nopath_nofail(trans, &ck->c, SIX_LOCK_read);496 key = ck->key;497 498 if (ck->journal.seq != seq ||499 !test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {500 six_unlock_read(&ck->c.lock);501 goto unlock;502 }503 504 if (ck->seq != seq) {505 bch2_journal_pin_update(&c->journal, ck->seq, &ck->journal,506 bch2_btree_key_cache_journal_flush);507 six_unlock_read(&ck->c.lock);508 goto unlock;509 }510 six_unlock_read(&ck->c.lock);511 512 ret = lockrestart_do(trans,513 btree_key_cache_flush_pos(trans, key, seq,514 BCH_TRANS_COMMIT_journal_reclaim, false));515unlock:516 srcu_read_unlock(&c->btree_trans_barrier, srcu_idx);517 518 bch2_trans_put(trans);519 return ret;520}521 522bool bch2_btree_insert_key_cached(struct btree_trans *trans,523 unsigned flags,524 struct btree_insert_entry *insert_entry)525{526 struct bch_fs *c = trans->c;527 struct bkey_cached *ck = (void *) (trans->paths + insert_entry->path)->l[0].b;528 struct bkey_i *insert = insert_entry->k;529 bool kick_reclaim = false;530 531 BUG_ON(insert->k.u64s > ck->u64s);532 533 bkey_copy(ck->k, insert);534 535 if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {536 EBUG_ON(test_bit(BCH_FS_clean_shutdown, &c->flags));537 set_bit(BKEY_CACHED_DIRTY, &ck->flags);538 atomic_long_inc(&c->btree_key_cache.nr_dirty);539 540 if (bch2_nr_btree_keys_need_flush(c))541 kick_reclaim = true;542 }543 544 /*545 * To minimize lock contention, we only add the journal pin here and546 * defer pin updates to the flush callback via ->seq. Be careful not to547 * update ->seq on nojournal commits because we don't want to update the548 * pin to a seq that doesn't include journal updates on disk. Otherwise549 * we risk losing the update after a crash.550 *551 * The only exception is if the pin is not active in the first place. We552 * have to add the pin because journal reclaim drives key cache553 * flushing. The flush callback will not proceed unless ->seq matches554 * the latest pin, so make sure it starts with a consistent value.555 */556 if (!(insert_entry->flags & BTREE_UPDATE_nojournal) ||557 !journal_pin_active(&ck->journal)) {558 ck->seq = trans->journal_res.seq;559 }560 bch2_journal_pin_add(&c->journal, trans->journal_res.seq,561 &ck->journal, bch2_btree_key_cache_journal_flush);562 563 if (kick_reclaim)564 journal_reclaim_kick(&c->journal);565 return true;566}567 568void bch2_btree_key_cache_drop(struct btree_trans *trans,569 struct btree_path *path)570{571 struct bch_fs *c = trans->c;572 struct btree_key_cache *bc = &c->btree_key_cache;573 struct bkey_cached *ck = (void *) path->l[0].b;574 575 /*576 * We just did an update to the btree, bypassing the key cache: the key577 * cache key is now stale and must be dropped, even if dirty:578 */579 if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {580 clear_bit(BKEY_CACHED_DIRTY, &ck->flags);581 atomic_long_dec(&c->btree_key_cache.nr_dirty);582 bch2_journal_pin_drop(&c->journal, &ck->journal);583 }584 585 bkey_cached_evict(bc, ck);586 bkey_cached_free(bc, ck);587 588 mark_btree_node_locked(trans, path, 0, BTREE_NODE_UNLOCKED);589 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);590 path->should_be_locked = false;591}592 593static unsigned long bch2_btree_key_cache_scan(struct shrinker *shrink,594 struct shrink_control *sc)595{596 struct bch_fs *c = shrink->private_data;597 struct btree_key_cache *bc = &c->btree_key_cache;598 struct bucket_table *tbl;599 struct bkey_cached *ck;600 size_t scanned = 0, freed = 0, nr = sc->nr_to_scan;601 unsigned iter, start;602 int srcu_idx;603 604 srcu_idx = srcu_read_lock(&c->btree_trans_barrier);605 rcu_read_lock();606 607 tbl = rht_dereference_rcu(bc->table.tbl, &bc->table);608 609 /*610 * Scanning is expensive while a rehash is in progress - most elements611 * will be on the new hashtable, if it's in progress612 *613 * A rehash could still start while we're scanning - that's ok, we'll614 * still see most elements.615 */616 if (unlikely(tbl->nest)) {617 rcu_read_unlock();618 srcu_read_unlock(&c->btree_trans_barrier, srcu_idx);619 return SHRINK_STOP;620 }621 622 iter = bc->shrink_iter;623 if (iter >= tbl->size)624 iter = 0;625 start = iter;626 627 do {628 struct rhash_head *pos, *next;629 630 pos = rht_ptr_rcu(&tbl->buckets[iter]);631 632 while (!rht_is_a_nulls(pos)) {633 next = rht_dereference_bucket_rcu(pos->next, tbl, iter);634 ck = container_of(pos, struct bkey_cached, hash);635 636 if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {637 bc->skipped_dirty++;638 } else if (test_bit(BKEY_CACHED_ACCESSED, &ck->flags)) {639 clear_bit(BKEY_CACHED_ACCESSED, &ck->flags);640 bc->skipped_accessed++;641 } else if (!bkey_cached_lock_for_evict(ck)) {642 bc->skipped_lock_fail++;643 } else if (bkey_cached_evict(bc, ck)) {644 bkey_cached_free(bc, ck);645 bc->freed++;646 freed++;647 } else {648 six_unlock_write(&ck->c.lock);649 six_unlock_intent(&ck->c.lock);650 }651 652 scanned++;653 if (scanned >= nr)654 goto out;655 656 pos = next;657 }658 659 iter++;660 if (iter >= tbl->size)661 iter = 0;662 } while (scanned < nr && iter != start);663out:664 bc->shrink_iter = iter;665 666 rcu_read_unlock();667 srcu_read_unlock(&c->btree_trans_barrier, srcu_idx);668 669 return freed;670}671 672static unsigned long bch2_btree_key_cache_count(struct shrinker *shrink,673 struct shrink_control *sc)674{675 struct bch_fs *c = shrink->private_data;676 struct btree_key_cache *bc = &c->btree_key_cache;677 long nr = atomic_long_read(&bc->nr_keys) -678 atomic_long_read(&bc->nr_dirty);679 680 /*681 * Avoid hammering our shrinker too much if it's nearly empty - the682 * shrinker code doesn't take into account how big our cache is, if it's683 * mostly empty but the system is under memory pressure it causes nasty684 * lock contention:685 */686 nr -= 128;687 688 return max(0L, nr);689}690 691void bch2_fs_btree_key_cache_exit(struct btree_key_cache *bc)692{693 struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);694 struct bucket_table *tbl;695 struct bkey_cached *ck;696 struct rhash_head *pos;697 LIST_HEAD(items);698 unsigned i;699 700 shrinker_free(bc->shrink);701 702 /*703 * The loop is needed to guard against racing with rehash:704 */705 while (atomic_long_read(&bc->nr_keys)) {706 rcu_read_lock();707 tbl = rht_dereference_rcu(bc->table.tbl, &bc->table);708 if (tbl) {709 if (tbl->nest) {710 /* wait for in progress rehash */711 rcu_read_unlock();712 mutex_lock(&bc->table.mutex);713 mutex_unlock(&bc->table.mutex);714 rcu_read_lock();715 continue;716 }717 for (i = 0; i < tbl->size; i++)718 while (pos = rht_ptr_rcu(&tbl->buckets[i]), !rht_is_a_nulls(pos)) {719 ck = container_of(pos, struct bkey_cached, hash);720 BUG_ON(!bkey_cached_evict(bc, ck));721 kfree(ck->k);722 kmem_cache_free(bch2_key_cache, ck);723 }724 }725 rcu_read_unlock();726 }727 728 if (atomic_long_read(&bc->nr_dirty) &&729 !bch2_journal_error(&c->journal) &&730 test_bit(BCH_FS_was_rw, &c->flags))731 panic("btree key cache shutdown error: nr_dirty nonzero (%li)\n",732 atomic_long_read(&bc->nr_dirty));733 734 if (atomic_long_read(&bc->nr_keys))735 panic("btree key cache shutdown error: nr_keys nonzero (%li)\n",736 atomic_long_read(&bc->nr_keys));737 738 if (bc->table_init_done)739 rhashtable_destroy(&bc->table);740 741 rcu_pending_exit(&bc->pending[0]);742 rcu_pending_exit(&bc->pending[1]);743 744 free_percpu(bc->nr_pending);745}746 747void bch2_fs_btree_key_cache_init_early(struct btree_key_cache *c)748{749}750 751int bch2_fs_btree_key_cache_init(struct btree_key_cache *bc)752{753 struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);754 struct shrinker *shrink;755 756 bc->nr_pending = alloc_percpu(size_t);757 if (!bc->nr_pending)758 return -BCH_ERR_ENOMEM_fs_btree_cache_init;759 760 if (rcu_pending_init(&bc->pending[0], &c->btree_trans_barrier, __bkey_cached_free) ||761 rcu_pending_init(&bc->pending[1], &c->btree_trans_barrier, __bkey_cached_free))762 return -BCH_ERR_ENOMEM_fs_btree_cache_init;763 764 if (rhashtable_init(&bc->table, &bch2_btree_key_cache_params))765 return -BCH_ERR_ENOMEM_fs_btree_cache_init;766 767 bc->table_init_done = true;768 769 shrink = shrinker_alloc(0, "%s-btree_key_cache", c->name);770 if (!shrink)771 return -BCH_ERR_ENOMEM_fs_btree_cache_init;772 bc->shrink = shrink;773 shrink->count_objects = bch2_btree_key_cache_count;774 shrink->scan_objects = bch2_btree_key_cache_scan;775 shrink->batch = 1 << 14;776 shrink->seeks = 0;777 shrink->private_data = c;778 shrinker_register(shrink);779 return 0;780}781 782void bch2_btree_key_cache_to_text(struct printbuf *out, struct btree_key_cache *bc)783{784 printbuf_tabstop_push(out, 24);785 printbuf_tabstop_push(out, 12);786 787 prt_printf(out, "keys:\t%lu\r\n", atomic_long_read(&bc->nr_keys));788 prt_printf(out, "dirty:\t%lu\r\n", atomic_long_read(&bc->nr_dirty));789 prt_printf(out, "table size:\t%u\r\n", bc->table.tbl->size);790 prt_newline(out);791 prt_printf(out, "shrinker:\n");792 prt_printf(out, "requested_to_free:\t%lu\r\n", bc->requested_to_free);793 prt_printf(out, "freed:\t%lu\r\n", bc->freed);794 prt_printf(out, "skipped_dirty:\t%lu\r\n", bc->skipped_dirty);795 prt_printf(out, "skipped_accessed:\t%lu\r\n", bc->skipped_accessed);796 prt_printf(out, "skipped_lock_fail:\t%lu\r\n", bc->skipped_lock_fail);797 prt_newline(out);798 prt_printf(out, "pending:\t%zu\r\n", per_cpu_sum(bc->nr_pending));799}800 801void bch2_btree_key_cache_exit(void)802{803 kmem_cache_destroy(bch2_key_cache);804}805 806int __init bch2_btree_key_cache_init(void)807{808 bch2_key_cache = KMEM_CACHE(bkey_cached, SLAB_RECLAIM_ACCOUNT);809 if (!bch2_key_cache)810 return -ENOMEM;811 812 return 0;813}814