+++ /dev/null
-// 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,
-};
-
-__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 void bkey_cached_evict(struct btree_key_cache *c,
- struct bkey_cached *ck)
-{
- BUG_ON(rhashtable_remove_fast(&c->table, &ck->hash,
- bch2_btree_key_cache_params));
- memset(&ck->key, ~0, sizeof(ck->key));
-
- atomic_long_dec(&c->nr_keys);
-}
-
-static void bkey_cached_free(struct btree_key_cache *bc,
- struct bkey_cached *ck)
-{
- struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);
-
- BUG_ON(test_bit(BKEY_CACHED_DIRTY, &ck->flags));
-
- ck->btree_trans_barrier_seq =
- start_poll_synchronize_srcu(&c->btree_trans_barrier);
-
- if (ck->c.lock.readers) {
- list_move_tail(&ck->list, &bc->freed_pcpu);
- bc->nr_freed_pcpu++;
- } else {
- list_move_tail(&ck->list, &bc->freed_nonpcpu);
- bc->nr_freed_nonpcpu++;
- }
- atomic_long_inc(&bc->nr_freed);
-
- kfree(ck->k);
- ck->k = NULL;
- ck->u64s = 0;
-
- six_unlock_write(&ck->c.lock);
- six_unlock_intent(&ck->c.lock);
-}
-
-#ifdef __KERNEL__
-static void __bkey_cached_move_to_freelist_ordered(struct btree_key_cache *bc,
- struct bkey_cached *ck)
-{
- struct bkey_cached *pos;
-
- bc->nr_freed_nonpcpu++;
-
- list_for_each_entry_reverse(pos, &bc->freed_nonpcpu, list) {
- if (ULONG_CMP_GE(ck->btree_trans_barrier_seq,
- pos->btree_trans_barrier_seq)) {
- list_move(&ck->list, &pos->list);
- return;
- }
- }
-
- list_move(&ck->list, &bc->freed_nonpcpu);
-}
-#endif
-
-static void bkey_cached_move_to_freelist(struct btree_key_cache *bc,
- struct bkey_cached *ck)
-{
- BUG_ON(test_bit(BKEY_CACHED_DIRTY, &ck->flags));
-
- if (!ck->c.lock.readers) {
-#ifdef __KERNEL__
- struct btree_key_cache_freelist *f;
- bool freed = false;
-
- preempt_disable();
- f = this_cpu_ptr(bc->pcpu_freed);
-
- if (f->nr < ARRAY_SIZE(f->objs)) {
- f->objs[f->nr++] = ck;
- freed = true;
- }
- preempt_enable();
-
- if (!freed) {
- mutex_lock(&bc->lock);
- preempt_disable();
- f = this_cpu_ptr(bc->pcpu_freed);
-
- while (f->nr > ARRAY_SIZE(f->objs) / 2) {
- struct bkey_cached *ck2 = f->objs[--f->nr];
-
- __bkey_cached_move_to_freelist_ordered(bc, ck2);
- }
- preempt_enable();
-
- __bkey_cached_move_to_freelist_ordered(bc, ck);
- mutex_unlock(&bc->lock);
- }
-#else
- mutex_lock(&bc->lock);
- list_move_tail(&ck->list, &bc->freed_nonpcpu);
- bc->nr_freed_nonpcpu++;
- mutex_unlock(&bc->lock);
-#endif
- } else {
- mutex_lock(&bc->lock);
- list_move_tail(&ck->list, &bc->freed_pcpu);
- mutex_unlock(&bc->lock);
- }
-}
-
-static void bkey_cached_free_fast(struct btree_key_cache *bc,
- struct bkey_cached *ck)
-{
- struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);
-
- ck->btree_trans_barrier_seq =
- start_poll_synchronize_srcu(&c->btree_trans_barrier);
-
- list_del_init(&ck->list);
- atomic_long_inc(&bc->nr_freed);
-
- kfree(ck->k);
- ck->k = NULL;
- ck->u64s = 0;
-
- bkey_cached_move_to_freelist(bc, ck);
-
- six_unlock_write(&ck->c.lock);
- six_unlock_intent(&ck->c.lock);
-}
-
-static struct bkey_cached *
-bkey_cached_alloc(struct btree_trans *trans, struct btree_path *path,
- bool *was_new)
-{
- struct bch_fs *c = trans->c;
- struct btree_key_cache *bc = &c->btree_key_cache;
- struct bkey_cached *ck = NULL;
- bool pcpu_readers = btree_uses_pcpu_readers(path->btree_id);
- int ret;
-
- if (!pcpu_readers) {
-#ifdef __KERNEL__
- struct btree_key_cache_freelist *f;
-
- preempt_disable();
- f = this_cpu_ptr(bc->pcpu_freed);
- if (f->nr)
- ck = f->objs[--f->nr];
- preempt_enable();
-
- if (!ck) {
- mutex_lock(&bc->lock);
- preempt_disable();
- f = this_cpu_ptr(bc->pcpu_freed);
-
- while (!list_empty(&bc->freed_nonpcpu) &&
- f->nr < ARRAY_SIZE(f->objs) / 2) {
- ck = list_last_entry(&bc->freed_nonpcpu, struct bkey_cached, list);
- list_del_init(&ck->list);
- bc->nr_freed_nonpcpu--;
- f->objs[f->nr++] = ck;
- }
-
- ck = f->nr ? f->objs[--f->nr] : NULL;
- preempt_enable();
- mutex_unlock(&bc->lock);
- }
-#else
- mutex_lock(&bc->lock);
- if (!list_empty(&bc->freed_nonpcpu)) {
- ck = list_last_entry(&bc->freed_nonpcpu, struct bkey_cached, list);
- list_del_init(&ck->list);
- bc->nr_freed_nonpcpu--;
- }
- mutex_unlock(&bc->lock);
-#endif
- } else {
- mutex_lock(&bc->lock);
- if (!list_empty(&bc->freed_pcpu)) {
- ck = list_last_entry(&bc->freed_pcpu, struct bkey_cached, list);
- list_del_init(&ck->list);
- }
- mutex_unlock(&bc->lock);
- }
-
- if (ck) {
- ret = btree_node_lock_nopath(trans, &ck->c, SIX_LOCK_intent, _THIS_IP_);
- if (unlikely(ret)) {
- bkey_cached_move_to_freelist(bc, ck);
- return ERR_PTR(ret);
- }
-
- path->l[0].b = (void *) ck;
- path->l[0].lock_seq = six_lock_seq(&ck->c.lock);
- mark_btree_node_locked(trans, path, 0, BTREE_NODE_INTENT_LOCKED);
-
- ret = bch2_btree_node_lock_write(trans, path, &ck->c);
- if (unlikely(ret)) {
- btree_node_unlock(trans, path, 0);
- bkey_cached_move_to_freelist(bc, ck);
- return ERR_PTR(ret);
- }
-
- return ck;
- }
-
- ck = allocate_dropping_locks(trans, ret,
- kmem_cache_zalloc(bch2_key_cache, _gfp));
- if (ret) {
- kmem_cache_free(bch2_key_cache, ck);
- return ERR_PTR(ret);
- }
-
- if (!ck)
- return NULL;
-
- INIT_LIST_HEAD(&ck->list);
- bch2_btree_lock_init(&ck->c, pcpu_readers ? SIX_LOCK_INIT_PCPU : 0);
-
- ck->c.cached = true;
- BUG_ON(!six_trylock_intent(&ck->c.lock));
- BUG_ON(!six_trylock_write(&ck->c.lock));
- *was_new = true;
- 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;
-
- mutex_lock(&c->lock);
- 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)) {
- bkey_cached_evict(c, ck);
- goto out;
- }
- }
- ck = NULL;
-out:
- rcu_read_unlock();
- mutex_unlock(&c->lock);
- return ck;
-}
-
-static struct bkey_cached *
-btree_key_cache_create(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;
- bool was_new = false;
-
- ck = bkey_cached_alloc(trans, path, &was_new);
- if (IS_ERR(ck))
- return ck;
-
- 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 ERR_PTR(-BCH_ERR_ENOMEM_btree_key_cache_create);
- }
-
- mark_btree_node_locked(trans, path, 0, BTREE_NODE_INTENT_LOCKED);
- }
-
- ck->c.level = 0;
- ck->c.btree_id = path->btree_id;
- ck->key.btree_id = path->btree_id;
- ck->key.pos = path->pos;
- ck->valid = false;
- ck->flags = 1U << BKEY_CACHED_ACCESSED;
-
- if (unlikely(rhashtable_lookup_insert_fast(&bc->table,
- &ck->hash,
- bch2_btree_key_cache_params))) {
- /* We raced with another fill: */
-
- if (likely(was_new)) {
- six_unlock_write(&ck->c.lock);
- six_unlock_intent(&ck->c.lock);
- kfree(ck);
- } else {
- bkey_cached_free_fast(bc, ck);
- }
-
- mark_btree_node_locked(trans, path, 0, BTREE_NODE_UNLOCKED);
- return NULL;
- }
-
- atomic_long_inc(&bc->nr_keys);
-
- six_unlock_write(&ck->c.lock);
-
- return ck;
-}
-
-static int btree_key_cache_fill(struct btree_trans *trans,
- struct btree_path *ck_path,
- struct bkey_cached *ck)
-{
- struct btree_iter iter;
- struct bkey_s_c k;
- unsigned new_u64s = 0;
- struct bkey_i *new_k = NULL;
- int ret;
-
- k = bch2_bkey_get_iter(trans, &iter, ck->key.btree_id, ck->key.pos,
- BTREE_ITER_KEY_CACHE_FILL|
- BTREE_ITER_CACHED_NOFILL);
- ret = bkey_err(k);
- if (ret)
- goto err;
-
- if (!bch2_btree_node_relock(trans, ck_path, 0)) {
- trace_and_count(trans->c, trans_restart_relock_key_cache_fill, trans, _THIS_IP_, ck_path);
- ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_key_cache_fill);
- goto err;
- }
-
- /*
- * bch2_varint_decode can read past the end of the buffer by at
- * most 7 bytes (it won't be used):
- */
- new_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:
- */
- new_u64s = min(256U, (new_u64s * 3) / 2);
-
- if (new_u64s > ck->u64s) {
- new_u64s = roundup_pow_of_two(new_u64s);
- new_k = kmalloc(new_u64s * sizeof(u64), GFP_NOWAIT|__GFP_NOWARN);
- if (!new_k) {
- bch2_trans_unlock(trans);
-
- new_k = kmalloc(new_u64s * sizeof(u64), GFP_KERNEL);
- if (!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), new_u64s);
- ret = -BCH_ERR_ENOMEM_btree_key_cache_fill;
- goto err;
- }
-
- if (!bch2_btree_node_relock(trans, ck_path, 0)) {
- kfree(new_k);
- trace_and_count(trans->c, trans_restart_relock_key_cache_fill, trans, _THIS_IP_, ck_path);
- ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_key_cache_fill);
- goto err;
- }
-
- ret = bch2_trans_relock(trans);
- if (ret) {
- kfree(new_k);
- goto err;
- }
- }
- }
-
- ret = bch2_btree_node_lock_write(trans, ck_path, &ck_path->l[0].b->c);
- if (ret) {
- kfree(new_k);
- goto err;
- }
-
- if (new_k) {
- kfree(ck->k);
- ck->u64s = new_u64s;
- ck->k = new_k;
- }
-
- bkey_reassemble(ck->k, k);
- ck->valid = true;
- bch2_btree_node_unlock_write(trans, ck_path, ck_path->l[0].b);
-
- /* We're not likely to need this iterator again: */
- set_btree_iter_dontneed(&iter);
-err:
- bch2_trans_iter_exit(trans, &iter);
- return ret;
-}
-
-static noinline int
-bch2_btree_path_traverse_cached_slowpath(struct btree_trans *trans, struct btree_path *path,
- unsigned flags)
-{
- struct bch_fs *c = trans->c;
- struct bkey_cached *ck;
- int ret = 0;
-
- BUG_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) {
- ck = btree_key_cache_create(trans, path);
- ret = PTR_ERR_OR_ZERO(ck);
- if (ret)
- goto err;
- if (!ck)
- goto retry;
-
- mark_btree_node_locked(trans, path, 0, BTREE_NODE_INTENT_LOCKED);
- path->locks_want = 1;
- } 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_);
- if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
- goto err;
-
- BUG_ON(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:
- 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 *) 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;
- }
-
- BUG_ON(!ck->valid);
-
- 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) ||
- j->watermark == BCH_WATERMARK_stripe)
- 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,
- "error 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);
- 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 = 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);
- 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 = shrink->private_data;
- 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:
- */
- scanned += bc->nr_freed_nonpcpu;
-
- 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);
- freed++;
- bc->nr_freed_nonpcpu--;
- }
-
- if (scanned >= nr)
- goto out;
-
- scanned += bc->nr_freed_pcpu;
-
- 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);
- freed++;
- bc->nr_freed_pcpu--;
- }
-
- 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 = 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);
-
- 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
-
- shrinker_free(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
-
- BUG_ON(list_count_nodes(&bc->freed_pcpu) != bc->nr_freed_pcpu);
- BUG_ON(list_count_nodes(&bc->freed_nonpcpu) != bc->nr_freed_nonpcpu);
-
- 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();
-
- 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);
- struct shrinker *shrink;
-
-#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;
-
- shrink = shrinker_alloc(0, "%s-btree_key_cache", c->name);
- if (!shrink)
- return -BCH_ERR_ENOMEM_fs_btree_cache_init;
- bc->shrink = shrink;
- shrink->seeks = 0;
- shrink->count_objects = bch2_btree_key_cache_count;
- shrink->scan_objects = bch2_btree_key_cache_scan;
- shrink->private_data = c;
- shrinker_register(shrink);
- 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;
-}
projects / bcachefs-tools-debian / blobdiff