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be9e782df3
We should only be downgrading locks on success - otherwise, our transaction restarts won't be getting the correct locks and we'll livelock. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
1073 lines
26 KiB
C
1073 lines
26 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include "bcachefs.h"
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#include "btree_cache.h"
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#include "btree_iter.h"
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#include "btree_key_cache.h"
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#include "btree_locking.h"
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#include "btree_update.h"
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#include "errcode.h"
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#include "error.h"
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#include "journal.h"
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#include "journal_reclaim.h"
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#include "trace.h"
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#include <linux/sched/mm.h>
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static inline bool btree_uses_pcpu_readers(enum btree_id id)
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{
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return id == BTREE_ID_subvolumes;
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}
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static struct kmem_cache *bch2_key_cache;
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static int bch2_btree_key_cache_cmp_fn(struct rhashtable_compare_arg *arg,
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const void *obj)
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{
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const struct bkey_cached *ck = obj;
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const struct bkey_cached_key *key = arg->key;
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return ck->key.btree_id != key->btree_id ||
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!bpos_eq(ck->key.pos, key->pos);
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}
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static const struct rhashtable_params bch2_btree_key_cache_params = {
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.head_offset = offsetof(struct bkey_cached, hash),
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.key_offset = offsetof(struct bkey_cached, key),
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.key_len = sizeof(struct bkey_cached_key),
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.obj_cmpfn = bch2_btree_key_cache_cmp_fn,
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};
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__flatten
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inline struct bkey_cached *
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bch2_btree_key_cache_find(struct bch_fs *c, enum btree_id btree_id, struct bpos pos)
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{
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struct bkey_cached_key key = {
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.btree_id = btree_id,
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.pos = pos,
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};
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return rhashtable_lookup_fast(&c->btree_key_cache.table, &key,
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bch2_btree_key_cache_params);
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}
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static bool bkey_cached_lock_for_evict(struct bkey_cached *ck)
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{
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if (!six_trylock_intent(&ck->c.lock))
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return false;
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if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
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six_unlock_intent(&ck->c.lock);
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return false;
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}
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if (!six_trylock_write(&ck->c.lock)) {
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six_unlock_intent(&ck->c.lock);
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return false;
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}
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return true;
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}
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static void bkey_cached_evict(struct btree_key_cache *c,
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struct bkey_cached *ck)
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{
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BUG_ON(rhashtable_remove_fast(&c->table, &ck->hash,
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bch2_btree_key_cache_params));
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memset(&ck->key, ~0, sizeof(ck->key));
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atomic_long_dec(&c->nr_keys);
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}
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static void bkey_cached_free(struct btree_key_cache *bc,
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struct bkey_cached *ck)
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{
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struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);
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BUG_ON(test_bit(BKEY_CACHED_DIRTY, &ck->flags));
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ck->btree_trans_barrier_seq =
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start_poll_synchronize_srcu(&c->btree_trans_barrier);
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if (ck->c.lock.readers)
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list_move_tail(&ck->list, &bc->freed_pcpu);
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else
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list_move_tail(&ck->list, &bc->freed_nonpcpu);
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atomic_long_inc(&bc->nr_freed);
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kfree(ck->k);
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ck->k = NULL;
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ck->u64s = 0;
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six_unlock_write(&ck->c.lock);
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six_unlock_intent(&ck->c.lock);
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}
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#ifdef __KERNEL__
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static void __bkey_cached_move_to_freelist_ordered(struct btree_key_cache *bc,
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struct bkey_cached *ck)
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{
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struct bkey_cached *pos;
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list_for_each_entry_reverse(pos, &bc->freed_nonpcpu, list) {
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if (ULONG_CMP_GE(ck->btree_trans_barrier_seq,
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pos->btree_trans_barrier_seq)) {
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list_move(&ck->list, &pos->list);
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return;
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}
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}
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list_move(&ck->list, &bc->freed_nonpcpu);
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}
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#endif
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static void bkey_cached_move_to_freelist(struct btree_key_cache *bc,
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struct bkey_cached *ck)
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{
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BUG_ON(test_bit(BKEY_CACHED_DIRTY, &ck->flags));
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if (!ck->c.lock.readers) {
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#ifdef __KERNEL__
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struct btree_key_cache_freelist *f;
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bool freed = false;
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preempt_disable();
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f = this_cpu_ptr(bc->pcpu_freed);
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if (f->nr < ARRAY_SIZE(f->objs)) {
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f->objs[f->nr++] = ck;
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freed = true;
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}
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preempt_enable();
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if (!freed) {
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mutex_lock(&bc->lock);
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preempt_disable();
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f = this_cpu_ptr(bc->pcpu_freed);
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while (f->nr > ARRAY_SIZE(f->objs) / 2) {
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struct bkey_cached *ck2 = f->objs[--f->nr];
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__bkey_cached_move_to_freelist_ordered(bc, ck2);
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}
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preempt_enable();
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__bkey_cached_move_to_freelist_ordered(bc, ck);
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mutex_unlock(&bc->lock);
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}
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#else
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mutex_lock(&bc->lock);
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list_move_tail(&ck->list, &bc->freed_nonpcpu);
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mutex_unlock(&bc->lock);
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#endif
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} else {
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mutex_lock(&bc->lock);
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list_move_tail(&ck->list, &bc->freed_pcpu);
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mutex_unlock(&bc->lock);
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}
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}
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static void bkey_cached_free_fast(struct btree_key_cache *bc,
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struct bkey_cached *ck)
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{
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struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);
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ck->btree_trans_barrier_seq =
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start_poll_synchronize_srcu(&c->btree_trans_barrier);
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list_del_init(&ck->list);
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atomic_long_inc(&bc->nr_freed);
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kfree(ck->k);
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ck->k = NULL;
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ck->u64s = 0;
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bkey_cached_move_to_freelist(bc, ck);
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six_unlock_write(&ck->c.lock);
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six_unlock_intent(&ck->c.lock);
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}
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static struct bkey_cached *
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bkey_cached_alloc(struct btree_trans *trans, struct btree_path *path,
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bool *was_new)
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{
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struct bch_fs *c = trans->c;
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struct btree_key_cache *bc = &c->btree_key_cache;
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struct bkey_cached *ck = NULL;
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bool pcpu_readers = btree_uses_pcpu_readers(path->btree_id);
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int ret;
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if (!pcpu_readers) {
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#ifdef __KERNEL__
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struct btree_key_cache_freelist *f;
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preempt_disable();
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f = this_cpu_ptr(bc->pcpu_freed);
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if (f->nr)
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ck = f->objs[--f->nr];
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preempt_enable();
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if (!ck) {
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mutex_lock(&bc->lock);
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preempt_disable();
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f = this_cpu_ptr(bc->pcpu_freed);
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while (!list_empty(&bc->freed_nonpcpu) &&
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f->nr < ARRAY_SIZE(f->objs) / 2) {
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ck = list_last_entry(&bc->freed_nonpcpu, struct bkey_cached, list);
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list_del_init(&ck->list);
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f->objs[f->nr++] = ck;
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}
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ck = f->nr ? f->objs[--f->nr] : NULL;
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preempt_enable();
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mutex_unlock(&bc->lock);
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}
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#else
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mutex_lock(&bc->lock);
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if (!list_empty(&bc->freed_nonpcpu)) {
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ck = list_last_entry(&bc->freed_nonpcpu, struct bkey_cached, list);
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list_del_init(&ck->list);
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}
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mutex_unlock(&bc->lock);
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#endif
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} else {
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mutex_lock(&bc->lock);
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if (!list_empty(&bc->freed_pcpu)) {
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ck = list_last_entry(&bc->freed_pcpu, struct bkey_cached, list);
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list_del_init(&ck->list);
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}
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mutex_unlock(&bc->lock);
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}
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if (ck) {
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ret = btree_node_lock_nopath(trans, &ck->c, SIX_LOCK_intent, _THIS_IP_);
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if (unlikely(ret)) {
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bkey_cached_move_to_freelist(bc, ck);
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return ERR_PTR(ret);
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}
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path->l[0].b = (void *) ck;
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path->l[0].lock_seq = six_lock_seq(&ck->c.lock);
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mark_btree_node_locked(trans, path, 0, BTREE_NODE_INTENT_LOCKED);
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ret = bch2_btree_node_lock_write(trans, path, &ck->c);
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if (unlikely(ret)) {
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btree_node_unlock(trans, path, 0);
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bkey_cached_move_to_freelist(bc, ck);
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return ERR_PTR(ret);
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}
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return ck;
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}
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ck = allocate_dropping_locks(trans, ret,
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kmem_cache_zalloc(bch2_key_cache, _gfp));
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if (ret) {
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kmem_cache_free(bch2_key_cache, ck);
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return ERR_PTR(ret);
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}
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if (!ck)
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return NULL;
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INIT_LIST_HEAD(&ck->list);
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bch2_btree_lock_init(&ck->c, pcpu_readers ? SIX_LOCK_INIT_PCPU : 0);
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ck->c.cached = true;
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BUG_ON(!six_trylock_intent(&ck->c.lock));
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BUG_ON(!six_trylock_write(&ck->c.lock));
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*was_new = true;
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return ck;
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}
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static struct bkey_cached *
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bkey_cached_reuse(struct btree_key_cache *c)
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{
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struct bucket_table *tbl;
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struct rhash_head *pos;
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struct bkey_cached *ck;
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unsigned i;
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mutex_lock(&c->lock);
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rcu_read_lock();
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tbl = rht_dereference_rcu(c->table.tbl, &c->table);
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for (i = 0; i < tbl->size; i++)
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rht_for_each_entry_rcu(ck, pos, tbl, i, hash) {
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if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags) &&
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bkey_cached_lock_for_evict(ck)) {
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bkey_cached_evict(c, ck);
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goto out;
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}
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}
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ck = NULL;
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out:
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rcu_read_unlock();
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mutex_unlock(&c->lock);
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return ck;
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}
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static struct bkey_cached *
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btree_key_cache_create(struct btree_trans *trans, struct btree_path *path)
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{
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struct bch_fs *c = trans->c;
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struct btree_key_cache *bc = &c->btree_key_cache;
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struct bkey_cached *ck;
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bool was_new = false;
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ck = bkey_cached_alloc(trans, path, &was_new);
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if (IS_ERR(ck))
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return ck;
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if (unlikely(!ck)) {
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ck = bkey_cached_reuse(bc);
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if (unlikely(!ck)) {
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bch_err(c, "error allocating memory for key cache item, btree %s",
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bch2_btree_id_str(path->btree_id));
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return ERR_PTR(-BCH_ERR_ENOMEM_btree_key_cache_create);
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}
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mark_btree_node_locked(trans, path, 0, BTREE_NODE_INTENT_LOCKED);
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}
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ck->c.level = 0;
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ck->c.btree_id = path->btree_id;
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ck->key.btree_id = path->btree_id;
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ck->key.pos = path->pos;
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ck->valid = false;
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ck->flags = 1U << BKEY_CACHED_ACCESSED;
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if (unlikely(rhashtable_lookup_insert_fast(&bc->table,
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&ck->hash,
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bch2_btree_key_cache_params))) {
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/* We raced with another fill: */
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if (likely(was_new)) {
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six_unlock_write(&ck->c.lock);
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six_unlock_intent(&ck->c.lock);
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kfree(ck);
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} else {
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bkey_cached_free_fast(bc, ck);
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}
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mark_btree_node_locked(trans, path, 0, BTREE_NODE_UNLOCKED);
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return NULL;
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}
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atomic_long_inc(&bc->nr_keys);
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six_unlock_write(&ck->c.lock);
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return ck;
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}
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static int btree_key_cache_fill(struct btree_trans *trans,
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struct btree_path *ck_path,
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struct bkey_cached *ck)
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{
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struct btree_iter iter;
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struct bkey_s_c k;
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unsigned new_u64s = 0;
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struct bkey_i *new_k = NULL;
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int ret;
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k = bch2_bkey_get_iter(trans, &iter, ck->key.btree_id, ck->key.pos,
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BTREE_ITER_KEY_CACHE_FILL|
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BTREE_ITER_CACHED_NOFILL);
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ret = bkey_err(k);
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if (ret)
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goto err;
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if (!bch2_btree_node_relock(trans, ck_path, 0)) {
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trace_and_count(trans->c, trans_restart_relock_key_cache_fill, trans, _THIS_IP_, ck_path);
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ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_key_cache_fill);
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goto err;
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}
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/*
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* bch2_varint_decode can read past the end of the buffer by at
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* most 7 bytes (it won't be used):
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*/
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new_u64s = k.k->u64s + 1;
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/*
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* Allocate some extra space so that the transaction commit path is less
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* likely to have to reallocate, since that requires a transaction
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* restart:
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*/
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new_u64s = min(256U, (new_u64s * 3) / 2);
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if (new_u64s > ck->u64s) {
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new_u64s = roundup_pow_of_two(new_u64s);
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new_k = kmalloc(new_u64s * sizeof(u64), GFP_NOWAIT|__GFP_NOWARN);
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if (!new_k) {
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bch2_trans_unlock(trans);
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new_k = kmalloc(new_u64s * sizeof(u64), GFP_KERNEL);
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if (!new_k) {
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bch_err(trans->c, "error allocating memory for key cache key, btree %s u64s %u",
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bch2_btree_id_str(ck->key.btree_id), new_u64s);
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ret = -BCH_ERR_ENOMEM_btree_key_cache_fill;
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goto err;
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}
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if (!bch2_btree_node_relock(trans, ck_path, 0)) {
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kfree(new_k);
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trace_and_count(trans->c, trans_restart_relock_key_cache_fill, trans, _THIS_IP_, ck_path);
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ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_key_cache_fill);
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goto err;
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}
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ret = bch2_trans_relock(trans);
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if (ret) {
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kfree(new_k);
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goto err;
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}
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}
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}
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ret = bch2_btree_node_lock_write(trans, ck_path, &ck_path->l[0].b->c);
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if (ret) {
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kfree(new_k);
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goto err;
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}
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if (new_k) {
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kfree(ck->k);
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ck->u64s = new_u64s;
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ck->k = new_k;
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}
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bkey_reassemble(ck->k, k);
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ck->valid = true;
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bch2_btree_node_unlock_write(trans, ck_path, ck_path->l[0].b);
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/* We're not likely to need this iterator again: */
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set_btree_iter_dontneed(&iter);
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err:
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bch2_trans_iter_exit(trans, &iter);
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return ret;
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}
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static noinline int
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bch2_btree_path_traverse_cached_slowpath(struct btree_trans *trans, struct btree_path *path,
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unsigned flags)
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{
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struct bch_fs *c = trans->c;
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struct bkey_cached *ck;
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int ret = 0;
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BUG_ON(path->level);
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path->l[1].b = NULL;
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if (bch2_btree_node_relock_notrace(trans, path, 0)) {
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ck = (void *) path->l[0].b;
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goto fill;
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}
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retry:
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ck = bch2_btree_key_cache_find(c, path->btree_id, path->pos);
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if (!ck) {
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ck = btree_key_cache_create(trans, path);
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ret = PTR_ERR_OR_ZERO(ck);
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if (ret)
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goto err;
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if (!ck)
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goto retry;
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mark_btree_node_locked(trans, path, 0, BTREE_NODE_INTENT_LOCKED);
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path->locks_want = 1;
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} else {
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enum six_lock_type lock_want = __btree_lock_want(path, 0);
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ret = btree_node_lock(trans, path, (void *) ck, 0,
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lock_want, _THIS_IP_);
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if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
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goto err;
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BUG_ON(ret);
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if (ck->key.btree_id != path->btree_id ||
|
|
!bpos_eq(ck->key.pos, path->pos)) {
|
|
six_unlock_type(&ck->c.lock, lock_want);
|
|
goto retry;
|
|
}
|
|
|
|
mark_btree_node_locked(trans, path, 0,
|
|
(enum btree_node_locked_type) lock_want);
|
|
}
|
|
|
|
path->l[0].lock_seq = six_lock_seq(&ck->c.lock);
|
|
path->l[0].b = (void *) ck;
|
|
fill:
|
|
path->uptodate = BTREE_ITER_UPTODATE;
|
|
|
|
if (!ck->valid && !(flags & BTREE_ITER_CACHED_NOFILL)) {
|
|
/*
|
|
* Using the underscore version because we haven't set
|
|
* path->uptodate yet:
|
|
*/
|
|
if (!path->locks_want &&
|
|
!__bch2_btree_path_upgrade(trans, path, 1, NULL)) {
|
|
trace_and_count(trans->c, trans_restart_key_cache_upgrade, trans, _THIS_IP_);
|
|
ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_key_cache_upgrade);
|
|
goto err;
|
|
}
|
|
|
|
ret = btree_key_cache_fill(trans, path, ck);
|
|
if (ret)
|
|
goto err;
|
|
|
|
ret = bch2_btree_path_relock(trans, path, _THIS_IP_);
|
|
if (ret)
|
|
goto err;
|
|
|
|
path->uptodate = BTREE_ITER_UPTODATE;
|
|
}
|
|
|
|
if (!test_bit(BKEY_CACHED_ACCESSED, &ck->flags))
|
|
set_bit(BKEY_CACHED_ACCESSED, &ck->flags);
|
|
|
|
BUG_ON(btree_node_locked_type(path, 0) != btree_lock_want(path, 0));
|
|
BUG_ON(path->uptodate);
|
|
|
|
return ret;
|
|
err:
|
|
path->uptodate = BTREE_ITER_NEED_TRAVERSE;
|
|
if (!bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
|
|
btree_node_unlock(trans, path, 0);
|
|
path->l[0].b = ERR_PTR(ret);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
int bch2_btree_path_traverse_cached(struct btree_trans *trans, struct btree_path *path,
|
|
unsigned flags)
|
|
{
|
|
struct bch_fs *c = trans->c;
|
|
struct bkey_cached *ck;
|
|
int ret = 0;
|
|
|
|
EBUG_ON(path->level);
|
|
|
|
path->l[1].b = NULL;
|
|
|
|
if (bch2_btree_node_relock_notrace(trans, path, 0)) {
|
|
ck = (void *) path->l[0].b;
|
|
goto fill;
|
|
}
|
|
retry:
|
|
ck = bch2_btree_key_cache_find(c, path->btree_id, path->pos);
|
|
if (!ck) {
|
|
return bch2_btree_path_traverse_cached_slowpath(trans, path, flags);
|
|
} else {
|
|
enum six_lock_type lock_want = __btree_lock_want(path, 0);
|
|
|
|
ret = btree_node_lock(trans, path, (void *) ck, 0,
|
|
lock_want, _THIS_IP_);
|
|
EBUG_ON(ret && !bch2_err_matches(ret, BCH_ERR_transaction_restart));
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (ck->key.btree_id != path->btree_id ||
|
|
!bpos_eq(ck->key.pos, path->pos)) {
|
|
six_unlock_type(&ck->c.lock, lock_want);
|
|
goto retry;
|
|
}
|
|
|
|
mark_btree_node_locked(trans, path, 0,
|
|
(enum btree_node_locked_type) lock_want);
|
|
}
|
|
|
|
path->l[0].lock_seq = six_lock_seq(&ck->c.lock);
|
|
path->l[0].b = (void *) ck;
|
|
fill:
|
|
if (!ck->valid)
|
|
return bch2_btree_path_traverse_cached_slowpath(trans, path, flags);
|
|
|
|
if (!test_bit(BKEY_CACHED_ACCESSED, &ck->flags))
|
|
set_bit(BKEY_CACHED_ACCESSED, &ck->flags);
|
|
|
|
path->uptodate = BTREE_ITER_UPTODATE;
|
|
EBUG_ON(!ck->valid);
|
|
EBUG_ON(btree_node_locked_type(path, 0) != btree_lock_want(path, 0));
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int btree_key_cache_flush_pos(struct btree_trans *trans,
|
|
struct bkey_cached_key key,
|
|
u64 journal_seq,
|
|
unsigned commit_flags,
|
|
bool evict)
|
|
{
|
|
struct bch_fs *c = trans->c;
|
|
struct journal *j = &c->journal;
|
|
struct btree_iter c_iter, b_iter;
|
|
struct bkey_cached *ck = NULL;
|
|
int ret;
|
|
|
|
bch2_trans_iter_init(trans, &b_iter, key.btree_id, key.pos,
|
|
BTREE_ITER_SLOTS|
|
|
BTREE_ITER_INTENT|
|
|
BTREE_ITER_ALL_SNAPSHOTS);
|
|
bch2_trans_iter_init(trans, &c_iter, key.btree_id, key.pos,
|
|
BTREE_ITER_CACHED|
|
|
BTREE_ITER_INTENT);
|
|
b_iter.flags &= ~BTREE_ITER_WITH_KEY_CACHE;
|
|
|
|
ret = bch2_btree_iter_traverse(&c_iter);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ck = (void *) c_iter.path->l[0].b;
|
|
if (!ck)
|
|
goto out;
|
|
|
|
if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
|
|
if (evict)
|
|
goto evict;
|
|
goto out;
|
|
}
|
|
|
|
BUG_ON(!ck->valid);
|
|
|
|
if (journal_seq && ck->journal.seq != journal_seq)
|
|
goto out;
|
|
|
|
/*
|
|
* Since journal reclaim depends on us making progress here, and the
|
|
* allocator/copygc depend on journal reclaim making progress, we need
|
|
* to be using alloc reserves:
|
|
*/
|
|
ret = bch2_btree_iter_traverse(&b_iter) ?:
|
|
bch2_trans_update(trans, &b_iter, ck->k,
|
|
BTREE_UPDATE_KEY_CACHE_RECLAIM|
|
|
BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|
|
|
BTREE_TRIGGER_NORUN) ?:
|
|
bch2_trans_commit(trans, NULL, NULL,
|
|
BTREE_INSERT_NOCHECK_RW|
|
|
BTREE_INSERT_NOFAIL|
|
|
(ck->journal.seq == journal_last_seq(j)
|
|
? BCH_WATERMARK_reclaim
|
|
: 0)|
|
|
commit_flags);
|
|
|
|
bch2_fs_fatal_err_on(ret &&
|
|
!bch2_err_matches(ret, BCH_ERR_transaction_restart) &&
|
|
!bch2_err_matches(ret, BCH_ERR_journal_reclaim_would_deadlock) &&
|
|
!bch2_journal_error(j), c,
|
|
"error flushing key cache: %s", bch2_err_str(ret));
|
|
if (ret)
|
|
goto out;
|
|
|
|
bch2_journal_pin_drop(j, &ck->journal);
|
|
bch2_journal_preres_put(j, &ck->res);
|
|
|
|
BUG_ON(!btree_node_locked(c_iter.path, 0));
|
|
|
|
if (!evict) {
|
|
if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
|
|
clear_bit(BKEY_CACHED_DIRTY, &ck->flags);
|
|
atomic_long_dec(&c->btree_key_cache.nr_dirty);
|
|
}
|
|
} else {
|
|
struct btree_path *path2;
|
|
evict:
|
|
trans_for_each_path(trans, path2)
|
|
if (path2 != c_iter.path)
|
|
__bch2_btree_path_unlock(trans, path2);
|
|
|
|
bch2_btree_node_lock_write_nofail(trans, c_iter.path, &ck->c);
|
|
|
|
if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
|
|
clear_bit(BKEY_CACHED_DIRTY, &ck->flags);
|
|
atomic_long_dec(&c->btree_key_cache.nr_dirty);
|
|
}
|
|
|
|
mark_btree_node_locked_noreset(c_iter.path, 0, BTREE_NODE_UNLOCKED);
|
|
bkey_cached_evict(&c->btree_key_cache, ck);
|
|
bkey_cached_free_fast(&c->btree_key_cache, ck);
|
|
}
|
|
out:
|
|
bch2_trans_iter_exit(trans, &b_iter);
|
|
bch2_trans_iter_exit(trans, &c_iter);
|
|
return ret;
|
|
}
|
|
|
|
int bch2_btree_key_cache_journal_flush(struct journal *j,
|
|
struct journal_entry_pin *pin, u64 seq)
|
|
{
|
|
struct bch_fs *c = container_of(j, struct bch_fs, journal);
|
|
struct bkey_cached *ck =
|
|
container_of(pin, struct bkey_cached, journal);
|
|
struct bkey_cached_key key;
|
|
struct btree_trans *trans = bch2_trans_get(c);
|
|
int srcu_idx = srcu_read_lock(&c->btree_trans_barrier);
|
|
int ret = 0;
|
|
|
|
btree_node_lock_nopath_nofail(trans, &ck->c, SIX_LOCK_read);
|
|
key = ck->key;
|
|
|
|
if (ck->journal.seq != seq ||
|
|
!test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
|
|
six_unlock_read(&ck->c.lock);
|
|
goto unlock;
|
|
}
|
|
|
|
if (ck->seq != seq) {
|
|
bch2_journal_pin_update(&c->journal, ck->seq, &ck->journal,
|
|
bch2_btree_key_cache_journal_flush);
|
|
six_unlock_read(&ck->c.lock);
|
|
goto unlock;
|
|
}
|
|
six_unlock_read(&ck->c.lock);
|
|
|
|
ret = commit_do(trans, NULL, NULL, 0,
|
|
btree_key_cache_flush_pos(trans, key, seq,
|
|
BTREE_INSERT_JOURNAL_RECLAIM, false));
|
|
unlock:
|
|
srcu_read_unlock(&c->btree_trans_barrier, srcu_idx);
|
|
|
|
bch2_trans_put(trans);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Flush and evict a key from the key cache:
|
|
*/
|
|
int bch2_btree_key_cache_flush(struct btree_trans *trans,
|
|
enum btree_id id, struct bpos pos)
|
|
{
|
|
struct bch_fs *c = trans->c;
|
|
struct bkey_cached_key key = { id, pos };
|
|
|
|
/* Fastpath - assume it won't be found: */
|
|
if (!bch2_btree_key_cache_find(c, id, pos))
|
|
return 0;
|
|
|
|
return btree_key_cache_flush_pos(trans, key, 0, 0, true);
|
|
}
|
|
|
|
bool bch2_btree_insert_key_cached(struct btree_trans *trans,
|
|
unsigned flags,
|
|
struct btree_insert_entry *insert_entry)
|
|
{
|
|
struct bch_fs *c = trans->c;
|
|
struct bkey_cached *ck = (void *) insert_entry->path->l[0].b;
|
|
struct bkey_i *insert = insert_entry->k;
|
|
bool kick_reclaim = false;
|
|
|
|
BUG_ON(insert->k.u64s > ck->u64s);
|
|
|
|
if (likely(!(flags & BTREE_INSERT_JOURNAL_REPLAY))) {
|
|
int difference;
|
|
|
|
BUG_ON(jset_u64s(insert->k.u64s) > trans->journal_preres.u64s);
|
|
|
|
difference = jset_u64s(insert->k.u64s) - ck->res.u64s;
|
|
if (difference > 0) {
|
|
trans->journal_preres.u64s -= difference;
|
|
ck->res.u64s += difference;
|
|
}
|
|
}
|
|
|
|
bkey_copy(ck->k, insert);
|
|
ck->valid = true;
|
|
|
|
if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
|
|
EBUG_ON(test_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags));
|
|
set_bit(BKEY_CACHED_DIRTY, &ck->flags);
|
|
atomic_long_inc(&c->btree_key_cache.nr_dirty);
|
|
|
|
if (bch2_nr_btree_keys_need_flush(c))
|
|
kick_reclaim = true;
|
|
}
|
|
|
|
/*
|
|
* To minimize lock contention, we only add the journal pin here and
|
|
* defer pin updates to the flush callback via ->seq. Be careful not to
|
|
* update ->seq on nojournal commits because we don't want to update the
|
|
* pin to a seq that doesn't include journal updates on disk. Otherwise
|
|
* we risk losing the update after a crash.
|
|
*
|
|
* The only exception is if the pin is not active in the first place. We
|
|
* have to add the pin because journal reclaim drives key cache
|
|
* flushing. The flush callback will not proceed unless ->seq matches
|
|
* the latest pin, so make sure it starts with a consistent value.
|
|
*/
|
|
if (!(insert_entry->flags & BTREE_UPDATE_NOJOURNAL) ||
|
|
!journal_pin_active(&ck->journal)) {
|
|
ck->seq = trans->journal_res.seq;
|
|
}
|
|
bch2_journal_pin_add(&c->journal, trans->journal_res.seq,
|
|
&ck->journal, bch2_btree_key_cache_journal_flush);
|
|
|
|
if (kick_reclaim)
|
|
journal_reclaim_kick(&c->journal);
|
|
return true;
|
|
}
|
|
|
|
void bch2_btree_key_cache_drop(struct btree_trans *trans,
|
|
struct btree_path *path)
|
|
{
|
|
struct bch_fs *c = trans->c;
|
|
struct bkey_cached *ck = (void *) path->l[0].b;
|
|
|
|
BUG_ON(!ck->valid);
|
|
|
|
/*
|
|
* We just did an update to the btree, bypassing the key cache: the key
|
|
* cache key is now stale and must be dropped, even if dirty:
|
|
*/
|
|
if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
|
|
clear_bit(BKEY_CACHED_DIRTY, &ck->flags);
|
|
atomic_long_dec(&c->btree_key_cache.nr_dirty);
|
|
bch2_journal_pin_drop(&c->journal, &ck->journal);
|
|
}
|
|
|
|
ck->valid = false;
|
|
}
|
|
|
|
static unsigned long bch2_btree_key_cache_scan(struct shrinker *shrink,
|
|
struct shrink_control *sc)
|
|
{
|
|
struct bch_fs *c = container_of(shrink, struct bch_fs,
|
|
btree_key_cache.shrink);
|
|
struct btree_key_cache *bc = &c->btree_key_cache;
|
|
struct bucket_table *tbl;
|
|
struct bkey_cached *ck, *t;
|
|
size_t scanned = 0, freed = 0, nr = sc->nr_to_scan;
|
|
unsigned start, flags;
|
|
int srcu_idx;
|
|
|
|
mutex_lock(&bc->lock);
|
|
srcu_idx = srcu_read_lock(&c->btree_trans_barrier);
|
|
flags = memalloc_nofs_save();
|
|
|
|
/*
|
|
* Newest freed entries are at the end of the list - once we hit one
|
|
* that's too new to be freed, we can bail out:
|
|
*/
|
|
list_for_each_entry_safe(ck, t, &bc->freed_nonpcpu, list) {
|
|
if (!poll_state_synchronize_srcu(&c->btree_trans_barrier,
|
|
ck->btree_trans_barrier_seq))
|
|
break;
|
|
|
|
list_del(&ck->list);
|
|
six_lock_exit(&ck->c.lock);
|
|
kmem_cache_free(bch2_key_cache, ck);
|
|
atomic_long_dec(&bc->nr_freed);
|
|
scanned++;
|
|
freed++;
|
|
}
|
|
|
|
if (scanned >= nr)
|
|
goto out;
|
|
|
|
list_for_each_entry_safe(ck, t, &bc->freed_pcpu, list) {
|
|
if (!poll_state_synchronize_srcu(&c->btree_trans_barrier,
|
|
ck->btree_trans_barrier_seq))
|
|
break;
|
|
|
|
list_del(&ck->list);
|
|
six_lock_exit(&ck->c.lock);
|
|
kmem_cache_free(bch2_key_cache, ck);
|
|
atomic_long_dec(&bc->nr_freed);
|
|
scanned++;
|
|
freed++;
|
|
}
|
|
|
|
if (scanned >= nr)
|
|
goto out;
|
|
|
|
rcu_read_lock();
|
|
tbl = rht_dereference_rcu(bc->table.tbl, &bc->table);
|
|
if (bc->shrink_iter >= tbl->size)
|
|
bc->shrink_iter = 0;
|
|
start = bc->shrink_iter;
|
|
|
|
do {
|
|
struct rhash_head *pos, *next;
|
|
|
|
pos = rht_ptr_rcu(rht_bucket(tbl, bc->shrink_iter));
|
|
|
|
while (!rht_is_a_nulls(pos)) {
|
|
next = rht_dereference_bucket_rcu(pos->next, tbl, bc->shrink_iter);
|
|
ck = container_of(pos, struct bkey_cached, hash);
|
|
|
|
if (test_bit(BKEY_CACHED_DIRTY, &ck->flags))
|
|
goto next;
|
|
|
|
if (test_bit(BKEY_CACHED_ACCESSED, &ck->flags))
|
|
clear_bit(BKEY_CACHED_ACCESSED, &ck->flags);
|
|
else if (bkey_cached_lock_for_evict(ck)) {
|
|
bkey_cached_evict(bc, ck);
|
|
bkey_cached_free(bc, ck);
|
|
}
|
|
|
|
scanned++;
|
|
if (scanned >= nr)
|
|
break;
|
|
next:
|
|
pos = next;
|
|
}
|
|
|
|
bc->shrink_iter++;
|
|
if (bc->shrink_iter >= tbl->size)
|
|
bc->shrink_iter = 0;
|
|
} while (scanned < nr && bc->shrink_iter != start);
|
|
|
|
rcu_read_unlock();
|
|
out:
|
|
memalloc_nofs_restore(flags);
|
|
srcu_read_unlock(&c->btree_trans_barrier, srcu_idx);
|
|
mutex_unlock(&bc->lock);
|
|
|
|
return freed;
|
|
}
|
|
|
|
static unsigned long bch2_btree_key_cache_count(struct shrinker *shrink,
|
|
struct shrink_control *sc)
|
|
{
|
|
struct bch_fs *c = container_of(shrink, struct bch_fs,
|
|
btree_key_cache.shrink);
|
|
struct btree_key_cache *bc = &c->btree_key_cache;
|
|
long nr = atomic_long_read(&bc->nr_keys) -
|
|
atomic_long_read(&bc->nr_dirty);
|
|
|
|
return max(0L, nr);
|
|
}
|
|
|
|
void bch2_fs_btree_key_cache_exit(struct btree_key_cache *bc)
|
|
{
|
|
struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);
|
|
struct bucket_table *tbl;
|
|
struct bkey_cached *ck, *n;
|
|
struct rhash_head *pos;
|
|
LIST_HEAD(items);
|
|
unsigned i;
|
|
#ifdef __KERNEL__
|
|
int cpu;
|
|
#endif
|
|
|
|
unregister_shrinker(&bc->shrink);
|
|
|
|
mutex_lock(&bc->lock);
|
|
|
|
/*
|
|
* The loop is needed to guard against racing with rehash:
|
|
*/
|
|
while (atomic_long_read(&bc->nr_keys)) {
|
|
rcu_read_lock();
|
|
tbl = rht_dereference_rcu(bc->table.tbl, &bc->table);
|
|
if (tbl)
|
|
for (i = 0; i < tbl->size; i++)
|
|
rht_for_each_entry_rcu(ck, pos, tbl, i, hash) {
|
|
bkey_cached_evict(bc, ck);
|
|
list_add(&ck->list, &items);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
#ifdef __KERNEL__
|
|
for_each_possible_cpu(cpu) {
|
|
struct btree_key_cache_freelist *f =
|
|
per_cpu_ptr(bc->pcpu_freed, cpu);
|
|
|
|
for (i = 0; i < f->nr; i++) {
|
|
ck = f->objs[i];
|
|
list_add(&ck->list, &items);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
list_splice(&bc->freed_pcpu, &items);
|
|
list_splice(&bc->freed_nonpcpu, &items);
|
|
|
|
mutex_unlock(&bc->lock);
|
|
|
|
list_for_each_entry_safe(ck, n, &items, list) {
|
|
cond_resched();
|
|
|
|
bch2_journal_pin_drop(&c->journal, &ck->journal);
|
|
bch2_journal_preres_put(&c->journal, &ck->res);
|
|
|
|
list_del(&ck->list);
|
|
kfree(ck->k);
|
|
six_lock_exit(&ck->c.lock);
|
|
kmem_cache_free(bch2_key_cache, ck);
|
|
}
|
|
|
|
if (atomic_long_read(&bc->nr_dirty) &&
|
|
!bch2_journal_error(&c->journal) &&
|
|
test_bit(BCH_FS_WAS_RW, &c->flags))
|
|
panic("btree key cache shutdown error: nr_dirty nonzero (%li)\n",
|
|
atomic_long_read(&bc->nr_dirty));
|
|
|
|
if (atomic_long_read(&bc->nr_keys))
|
|
panic("btree key cache shutdown error: nr_keys nonzero (%li)\n",
|
|
atomic_long_read(&bc->nr_keys));
|
|
|
|
if (bc->table_init_done)
|
|
rhashtable_destroy(&bc->table);
|
|
|
|
free_percpu(bc->pcpu_freed);
|
|
}
|
|
|
|
void bch2_fs_btree_key_cache_init_early(struct btree_key_cache *c)
|
|
{
|
|
mutex_init(&c->lock);
|
|
INIT_LIST_HEAD(&c->freed_pcpu);
|
|
INIT_LIST_HEAD(&c->freed_nonpcpu);
|
|
}
|
|
|
|
int bch2_fs_btree_key_cache_init(struct btree_key_cache *bc)
|
|
{
|
|
struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);
|
|
|
|
#ifdef __KERNEL__
|
|
bc->pcpu_freed = alloc_percpu(struct btree_key_cache_freelist);
|
|
if (!bc->pcpu_freed)
|
|
return -BCH_ERR_ENOMEM_fs_btree_cache_init;
|
|
#endif
|
|
|
|
if (rhashtable_init(&bc->table, &bch2_btree_key_cache_params))
|
|
return -BCH_ERR_ENOMEM_fs_btree_cache_init;
|
|
|
|
bc->table_init_done = true;
|
|
|
|
bc->shrink.seeks = 0;
|
|
bc->shrink.count_objects = bch2_btree_key_cache_count;
|
|
bc->shrink.scan_objects = bch2_btree_key_cache_scan;
|
|
if (register_shrinker(&bc->shrink, "%s-btree_key_cache", c->name))
|
|
return -BCH_ERR_ENOMEM_fs_btree_cache_init;
|
|
return 0;
|
|
}
|
|
|
|
void bch2_btree_key_cache_to_text(struct printbuf *out, struct btree_key_cache *c)
|
|
{
|
|
prt_printf(out, "nr_freed:\t%lu", atomic_long_read(&c->nr_freed));
|
|
prt_newline(out);
|
|
prt_printf(out, "nr_keys:\t%lu", atomic_long_read(&c->nr_keys));
|
|
prt_newline(out);
|
|
prt_printf(out, "nr_dirty:\t%lu", atomic_long_read(&c->nr_dirty));
|
|
prt_newline(out);
|
|
}
|
|
|
|
void bch2_btree_key_cache_exit(void)
|
|
{
|
|
kmem_cache_destroy(bch2_key_cache);
|
|
}
|
|
|
|
int __init bch2_btree_key_cache_init(void)
|
|
{
|
|
bch2_key_cache = KMEM_CACHE(bkey_cached, SLAB_RECLAIM_ACCOUNT);
|
|
if (!bch2_key_cache)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|