// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "btree_cache.h"
#include "btree_iter.h"
#include "btree_key_cache.h"
#include "btree_locking.h"
#include "btree_update.h"
#include "errcode.h"
#include "error.h"
#include "journal.h"
#include "journal_reclaim.h"
#include "trace.h"
#include <linux/sched/mm.h>
static inline bool btree_uses_pcpu_readers(enum btree_id id)
{
return id == BTREE_ID_subvolumes;
}
static struct kmem_cache *bch2_key_cache;
static int bch2_btree_key_cache_cmp_fn(struct rhashtable_compare_arg *arg,
const void *obj)
{
const struct bkey_cached *ck = obj;
const struct bkey_cached_key *key = arg->key;
return ck->key.btree_id != key->btree_id ||
!bpos_eq(ck->key.pos, key->pos);
}
static const struct rhashtable_params bch2_btree_key_cache_params = {
.head_offset = offsetof(struct bkey_cached, hash),
.key_offset = offsetof(struct bkey_cached, key),
.key_len = sizeof(struct bkey_cached_key),
.obj_cmpfn = bch2_btree_key_cache_cmp_fn,
.automatic_shrinking = true,
};
static inline void btree_path_cached_set(struct btree_trans *trans, struct btree_path *path,
struct bkey_cached *ck,
enum btree_node_locked_type lock_held)
{
path->l[0].lock_seq = six_lock_seq(&ck->c.lock);
path->l[0].b = (void *) ck;
mark_btree_node_locked(trans, path, 0, lock_held);
}
__flatten
inline struct bkey_cached *
bch2_btree_key_cache_find(struct bch_fs *c, enum btree_id btree_id, struct bpos pos)
{
struct bkey_cached_key key = {
.btree_id = btree_id,
.pos = pos,
};
return rhashtable_lookup_fast(&c->btree_key_cache.table, &key,
bch2_btree_key_cache_params);
}
static bool bkey_cached_lock_for_evict(struct bkey_cached *ck)
{
if (!six_trylock_intent(&ck->c.lock))
return false;
if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
six_unlock_intent(&ck->c.lock);
return false;
}
if (!six_trylock_write(&ck->c.lock)) {
six_unlock_intent(&ck->c.lock);
return false;
}
return true;
}
static bool bkey_cached_evict(struct btree_key_cache *c,
struct bkey_cached *ck)
{
bool ret = !rhashtable_remove_fast(&c->table, &ck->hash,
bch2_btree_key_cache_params);
if (ret) {
memset(&ck->key, ~0, sizeof(ck->key));
atomic_long_dec(&c->nr_keys);
}
return ret;
}
static void __bkey_cached_free(struct rcu_pending *pending, struct rcu_head *rcu)
{
struct bch_fs *c = container_of(pending->srcu, struct bch_fs, btree_trans_barrier);
struct bkey_cached *ck = container_of(rcu, struct bkey_cached, rcu);
this_cpu_dec(*c->btree_key_cache.nr_pending);
kmem_cache_free(bch2_key_cache, ck);
}
static void bkey_cached_free(struct btree_key_cache *bc,
struct bkey_cached *ck)
{
kfree(ck->k);
ck->k = NULL;
ck->u64s = 0;
six_unlock_write(&ck->c.lock);
six_unlock_intent(&ck->c.lock);
bool pcpu_readers = ck->c.lock.readers != NULL;
rcu_pending_enqueue(&bc->pending[pcpu_readers], &ck->rcu);
this_cpu_inc(*bc->nr_pending);
}
static struct bkey_cached *__bkey_cached_alloc(unsigned key_u64s, gfp_t gfp)
{
gfp |= __GFP_ACCOUNT|__GFP_RECLAIMABLE;
struct bkey_cached *ck = kmem_cache_zalloc(bch2_key_cache, gfp);
if (unlikely(!ck))
return NULL;
ck->k = kmalloc(key_u64s * sizeof(u64), gfp);
if (unlikely(!ck->k)) {
kmem_cache_free(bch2_key_cache, ck);
return NULL;
}
ck->u64s = key_u64s;
return ck;
}
static struct bkey_cached *
bkey_cached_alloc(struct btree_trans *trans, struct btree_path *path, unsigned key_u64s)
{
struct bch_fs *c = trans->c;
struct btree_key_cache *bc = &c->btree_key_cache;
bool pcpu_readers = btree_uses_pcpu_readers(path->btree_id);
int ret;
struct bkey_cached *ck = container_of_or_null(
rcu_pending_dequeue(&bc->pending[pcpu_readers]),
struct bkey_cached, rcu);
if (ck)
goto lock;
ck = allocate_dropping_locks(trans, ret,
__bkey_cached_alloc(key_u64s, _gfp));
if (ret) {
if (ck)
kfree(ck->k);
kmem_cache_free(bch2_key_cache, ck);
return ERR_PTR(ret);
}
if (ck) {
bch2_btree_lock_init(&ck->c, pcpu_readers ? SIX_LOCK_INIT_PCPU : 0);
ck->c.cached = true;
goto lock;
}
ck = container_of_or_null(rcu_pending_dequeue_from_all(&bc->pending[pcpu_readers]),
struct bkey_cached, rcu);
if (ck)
goto lock;
lock:
six_lock_intent(&ck->c.lock, NULL, NULL);
six_lock_write(&ck->c.lock, NULL, NULL);
return ck;
}
static struct bkey_cached *
bkey_cached_reuse(struct btree_key_cache *c)
{
struct bucket_table *tbl;
struct rhash_head *pos;
struct bkey_cached *ck;
unsigned i;
rcu_read_lock();
tbl = rht_dereference_rcu(c->table.tbl, &c->table);
for (i = 0; i < tbl->size; i++)
rht_for_each_entry_rcu(ck, pos, tbl, i, hash) {
if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags) &&
bkey_cached_lock_for_evict(ck)) {
if (bkey_cached_evict(c, ck))
goto out;
six_unlock_write(&ck->c.lock);
six_unlock_intent(&ck->c.lock);
}
}
ck = NULL;
out:
rcu_read_unlock();
return ck;
}
static int btree_key_cache_create(struct btree_trans *trans, struct btree_path *path,
struct bkey_s_c k)
{
struct bch_fs *c = trans->c;
struct btree_key_cache *bc = &c->btree_key_cache;
/*
* bch2_varint_decode can read past the end of the buffer by at
* most 7 bytes (it won't be used):
*/
unsigned key_u64s = k.k->u64s + 1;
/*
* Allocate some extra space so that the transaction commit path is less
* likely to have to reallocate, since that requires a transaction
* restart:
*/
key_u64s = min(256U, (key_u64s * 3) / 2);
key_u64s = roundup_pow_of_two(key_u64s);
struct bkey_cached *ck = bkey_cached_alloc(trans, path, key_u64s);
int ret = PTR_ERR_OR_ZERO(ck);
if (ret)
return ret;
if (unlikely(!ck)) {
ck = bkey_cached_reuse(bc);
if (unlikely(!ck)) {
bch_err(c, "error allocating memory for key cache item, btree %s",
bch2_btree_id_str(path->btree_id));
return -BCH_ERR_ENOMEM_btree_key_cache_create;
}
}
ck->c.level = 0;
ck->c.btree_id = path->btree_id;
ck->key.btree_id = path->btree_id;
ck->key.pos = path->pos;
ck->flags = 1U << BKEY_CACHED_ACCESSED;
if (unlikely(key_u64s > ck->u64s)) {
mark_btree_node_locked_noreset(path, 0, BTREE_NODE_UNLOCKED);
struct bkey_i *new_k = allocate_dropping_locks(trans, ret,
kmalloc(key_u64s * sizeof(u64), _gfp));
if (unlikely(!new_k)) {
bch_err(trans->c, "error allocating memory for key cache key, btree %s u64s %u",
bch2_btree_id_str(ck->key.btree_id), key_u64s);
ret = -BCH_ERR_ENOMEM_btree_key_cache_fill;
} else if (ret) {
kfree(new_k);
goto err;
}
kfree(ck->k);
ck->k = new_k;
ck->u64s = key_u64s;
}
bkey_reassemble(ck->k, k);
ret = rhashtable_lookup_insert_fast(&bc->table, &ck->hash, bch2_btree_key_cache_params);
if (unlikely(ret)) /* raced with another fill? */
goto err;
atomic_long_inc(&bc->nr_keys);
six_unlock_write(&ck->c.lock);
enum six_lock_type lock_want = __btree_lock_want(path, 0);
if (lock_want == SIX_LOCK_read)
six_lock_downgrade(&ck->c.lock);
btree_path_cached_set(trans, path, ck, (enum btree_node_locked_type) lock_want);
path->uptodate = BTREE_ITER_UPTODATE;
return 0;
err:
bkey_cached_free(bc, ck);
mark_btree_node_locked_noreset(path, 0, BTREE_NODE_UNLOCKED);
return ret;
}
static noinline int btree_key_cache_fill(struct btree_trans *trans,
struct btree_path *ck_path,
unsigned flags)
{
if (flags & BTREE_ITER_cached_nofill) {
ck_path->uptodate = BTREE_ITER_UPTODATE;
return 0;
}
struct bch_fs *c = trans->c;
struct btree_iter iter;
struct bkey_s_c k;
int ret;
bch2_trans_iter_init(trans, &iter, ck_path->btree_id, ck_path->pos,
BTREE_ITER_key_cache_fill|
BTREE_ITER_cached_nofill);
iter.flags &= ~BTREE_ITER_with_journal;
k = bch2_btree_iter_peek_slot(&iter);
ret = bkey_err(k);
if (ret)
goto err;
/* Recheck after btree lookup, before allocating: */
ret = bch2_btree_key_cache_find(c, ck_path->btree_id, ck_path->pos) ? -EEXIST : 0;
if (unlikely(ret))
goto out;
ret = btree_key_cache_create(trans, ck_path, k);
if (ret)
goto err;
out:
/* We're not likely to need this iterator again: */
bch2_set_btree_iter_dontneed(&iter);
err:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
static inline int btree_path_traverse_cached_fast(struct btree_trans *trans,
struct btree_path *path)
{
struct bch_fs *c = trans->c;
struct bkey_cached *ck;
retry:
ck = bch2_btree_key_cache_find(c, path->btree_id, path->pos);
if (!ck)
return -ENOENT;
enum six_lock_type lock_want = __btree_lock_want(path, 0);
int ret = btree_node_lock(trans, path, (void *) ck, 0, lock_want, _THIS_IP_);
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;
}
if (!test_bit(BKEY_CACHED_ACCESSED, &ck->flags))
set_bit(BKEY_CACHED_ACCESSED, &ck->flags);
btree_path_cached_set(trans, path, ck, (enum btree_node_locked_type) lock_want);
path->uptodate = BTREE_ITER_UPTODATE;
return 0;
}
int bch2_btree_path_traverse_cached(struct btree_trans *trans, struct btree_path *path,
unsigned flags)
{
EBUG_ON(path->level);
path->l[1].b = NULL;
int ret;
do {
ret = btree_path_traverse_cached_fast(trans, path);
if (unlikely(ret == -ENOENT))
ret = btree_key_cache_fill(trans, path, flags);
} while (ret == -EEXIST);
if (unlikely(ret)) {
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;
}
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 *) btree_iter_path(trans, &c_iter)->l[0].b;
if (!ck)
goto out;
if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
if (evict)
goto evict;
goto out;
}
if (journal_seq && ck->journal.seq != journal_seq)
goto out;
trans->journal_res.seq = ck->journal.seq;
/*
* If we're at the end of the journal, we really want to free up space
* in the journal right away - we don't want to pin that old journal
* sequence number with a new btree node write, we want to re-journal
* the update
*/
if (ck->journal.seq == journal_last_seq(j))
commit_flags |= BCH_WATERMARK_reclaim;
if (ck->journal.seq != journal_last_seq(j) ||
!test_bit(JOURNAL_space_low, &c->journal.flags))
commit_flags |= BCH_TRANS_COMMIT_no_journal_res;
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,
BCH_TRANS_COMMIT_no_check_rw|
BCH_TRANS_COMMIT_no_enospc|
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,
"flushing key cache: %s", bch2_err_str(ret));
if (ret)
goto out;
bch2_journal_pin_drop(j, &ck->journal);
struct btree_path *path = btree_iter_path(trans, &c_iter);
BUG_ON(!btree_node_locked(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;
unsigned i;
evict:
trans_for_each_path(trans, path2, i)
if (path2 != path)
__bch2_btree_path_unlock(trans, path2);
bch2_btree_node_lock_write_nofail(trans, 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(path, 0, BTREE_NODE_UNLOCKED);
if (bkey_cached_evict(&c->btree_key_cache, ck)) {
bkey_cached_free(&c->btree_key_cache, ck);
} else {
six_unlock_write(&ck->c.lock);
six_unlock_intent(&ck->c.lock);
}
}
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 = lockrestart_do(trans,
btree_key_cache_flush_pos(trans, key, seq,
BCH_TRANS_COMMIT_journal_reclaim, false));
unlock:
srcu_read_unlock(&c->btree_trans_barrier, srcu_idx);
bch2_trans_put(trans);
return ret;
}
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 *) (trans->paths + insert_entry->path)->l[0].b;
struct bkey_i *insert = insert_entry->k;
bool kick_reclaim = false;
BUG_ON(insert->k.u64s > ck->u64s);
bkey_copy(ck->k, insert);
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 btree_key_cache *bc = &c->btree_key_cache;
struct bkey_cached *ck = (void *) path->l[0].b;
/*
* 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);
}
bkey_cached_evict(bc, ck);
bkey_cached_free(bc, ck);
mark_btree_node_locked(trans, path, 0, BTREE_NODE_UNLOCKED);
btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
path->should_be_locked = false;
}
static unsigned long bch2_btree_key_cache_scan(struct shrinker *shrink,
struct shrink_control *sc)
{
struct bch_fs *c = shrink->private_data;
struct btree_key_cache *bc = &c->btree_key_cache;
struct bucket_table *tbl;
struct bkey_cached *ck;
size_t scanned = 0, freed = 0, nr = sc->nr_to_scan;
unsigned iter, start;
int srcu_idx;
srcu_idx = srcu_read_lock(&c->btree_trans_barrier);
rcu_read_lock();
tbl = rht_dereference_rcu(bc->table.tbl, &bc->table);
/*
* Scanning is expensive while a rehash is in progress - most elements
* will be on the new hashtable, if it's in progress
*
* A rehash could still start while we're scanning - that's ok, we'll
* still see most elements.
*/
if (unlikely(tbl->nest)) {
rcu_read_unlock();
srcu_read_unlock(&c->btree_trans_barrier, srcu_idx);
return SHRINK_STOP;
}
iter = bc->shrink_iter;
if (iter >= tbl->size)
iter = 0;
start = iter;
do {
struct rhash_head *pos, *next;
pos = rht_ptr_rcu(&tbl->buckets[iter]);
while (!rht_is_a_nulls(pos)) {
next = rht_dereference_bucket_rcu(pos->next, tbl, iter);
ck = container_of(pos, struct bkey_cached, hash);
if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
bc->skipped_dirty++;
} else if (test_bit(BKEY_CACHED_ACCESSED, &ck->flags)) {
clear_bit(BKEY_CACHED_ACCESSED, &ck->flags);
bc->skipped_accessed++;
} else if (!bkey_cached_lock_for_evict(ck)) {
bc->skipped_lock_fail++;
} else if (bkey_cached_evict(bc, ck)) {
bkey_cached_free(bc, ck);
bc->freed++;
freed++;
} else {
six_unlock_write(&ck->c.lock);
six_unlock_intent(&ck->c.lock);
}
scanned++;
if (scanned >= nr)
goto out;
pos = next;
}
iter++;
if (iter >= tbl->size)
iter = 0;
} while (scanned < nr && iter != start);
out:
bc->shrink_iter = iter;
rcu_read_unlock();
srcu_read_unlock(&c->btree_trans_barrier, srcu_idx);
return freed;
}
static unsigned long bch2_btree_key_cache_count(struct shrinker *shrink,
struct shrink_control *sc)
{
struct bch_fs *c = shrink->private_data;
struct btree_key_cache *bc = &c->btree_key_cache;
long nr = atomic_long_read(&bc->nr_keys) -
atomic_long_read(&bc->nr_dirty);
/*
* Avoid hammering our shrinker too much if it's nearly empty - the
* shrinker code doesn't take into account how big our cache is, if it's
* mostly empty but the system is under memory pressure it causes nasty
* lock contention:
*/
nr -= 128;
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;
struct rhash_head *pos;
LIST_HEAD(items);
unsigned i;
shrinker_free(bc->shrink);
/*
* 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) {
if (tbl->nest) {
/* wait for in progress rehash */
rcu_read_unlock();
mutex_lock(&bc->table.mutex);
mutex_unlock(&bc->table.mutex);
rcu_read_lock();
continue;
}
for (i = 0; i < tbl->size; i++)
while (pos = rht_ptr_rcu(&tbl->buckets[i]), !rht_is_a_nulls(pos)) {
ck = container_of(pos, struct bkey_cached, hash);
BUG_ON(!bkey_cached_evict(bc, ck));
kfree(ck->k);
kmem_cache_free(bch2_key_cache, ck);
}
}
rcu_read_unlock();
}
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);
rcu_pending_exit(&bc->pending[0]);
rcu_pending_exit(&bc->pending[1]);
free_percpu(bc->nr_pending);
}
void bch2_fs_btree_key_cache_init_early(struct btree_key_cache *c)
{
}
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);
struct shrinker *shrink;
bc->nr_pending = alloc_percpu(size_t);
if (!bc->nr_pending)
return -BCH_ERR_ENOMEM_fs_btree_cache_init;
if (rcu_pending_init(&bc->pending[0], &c->btree_trans_barrier, __bkey_cached_free) ||
rcu_pending_init(&bc->pending[1], &c->btree_trans_barrier, __bkey_cached_free))
return -BCH_ERR_ENOMEM_fs_btree_cache_init;
if (rhashtable_init(&bc->table, &bch2_btree_key_cache_params))
return -BCH_ERR_ENOMEM_fs_btree_cache_init;
bc->table_init_done = true;
shrink = shrinker_alloc(0, "%s-btree_key_cache", c->name);
if (!shrink)
return -BCH_ERR_ENOMEM_fs_btree_cache_init;
bc->shrink = shrink;
shrink->count_objects = bch2_btree_key_cache_count;
shrink->scan_objects = bch2_btree_key_cache_scan;
shrink->batch = 1 << 14;
shrink->seeks = 0;
shrink->private_data = c;
shrinker_register(shrink);
return 0;
}
void bch2_btree_key_cache_to_text(struct printbuf *out, struct btree_key_cache *bc)
{
printbuf_tabstop_push(out, 24);
printbuf_tabstop_push(out, 12);
prt_printf(out, "keys:\t%lu\r\n", atomic_long_read(&bc->nr_keys));
prt_printf(out, "dirty:\t%lu\r\n", atomic_long_read(&bc->nr_dirty));
prt_printf(out, "table size:\t%u\r\n", bc->table.tbl->size);
prt_newline(out);
prt_printf(out, "shrinker:\n");
prt_printf(out, "requested_to_free:\t%lu\r\n", bc->requested_to_free);
prt_printf(out, "freed:\t%lu\r\n", bc->freed);
prt_printf(out, "skipped_dirty:\t%lu\r\n", bc->skipped_dirty);
prt_printf(out, "skipped_accessed:\t%lu\r\n", bc->skipped_accessed);
prt_printf(out, "skipped_lock_fail:\t%lu\r\n", bc->skipped_lock_fail);
prt_newline(out);
prt_printf(out, "pending:\t%zu\r\n", per_cpu_sum(bc->nr_pending));
}
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;
}
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