diff options
Diffstat (limited to 'libbcachefs/btree_cache.c')
| -rw-r--r-- | libbcachefs/btree_cache.c | 1211 |
1 files changed, 0 insertions, 1211 deletions
diff --git a/libbcachefs/btree_cache.c b/libbcachefs/btree_cache.c deleted file mode 100644 index 8e2488a4..00000000 --- a/libbcachefs/btree_cache.c +++ /dev/null @@ -1,1211 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 - -#include "bcachefs.h" -#include "bkey_buf.h" -#include "btree_cache.h" -#include "btree_io.h" -#include "btree_iter.h" -#include "btree_locking.h" -#include "debug.h" -#include "errcode.h" -#include "error.h" -#include "journal.h" -#include "trace.h" - -#include <linux/prefetch.h> -#include <linux/sched/mm.h> - -const char * const bch2_btree_node_flags[] = { -#define x(f) #f, - BTREE_FLAGS() -#undef x - NULL -}; - -void bch2_recalc_btree_reserve(struct bch_fs *c) -{ - unsigned i, reserve = 16; - - if (!c->btree_roots_known[0].b) - reserve += 8; - - for (i = 0; i < btree_id_nr_alive(c); i++) { - struct btree_root *r = bch2_btree_id_root(c, i); - - if (r->b) - reserve += min_t(unsigned, 1, r->b->c.level) * 8; - } - - c->btree_cache.reserve = reserve; -} - -static inline unsigned btree_cache_can_free(struct btree_cache *bc) -{ - return max_t(int, 0, bc->used - bc->reserve); -} - -static void btree_node_to_freedlist(struct btree_cache *bc, struct btree *b) -{ - if (b->c.lock.readers) - list_move(&b->list, &bc->freed_pcpu); - else - list_move(&b->list, &bc->freed_nonpcpu); -} - -static void btree_node_data_free(struct bch_fs *c, struct btree *b) -{ - struct btree_cache *bc = &c->btree_cache; - - EBUG_ON(btree_node_write_in_flight(b)); - - clear_btree_node_just_written(b); - - kvpfree(b->data, btree_bytes(c)); - b->data = NULL; -#ifdef __KERNEL__ - kvfree(b->aux_data); -#else - munmap(b->aux_data, btree_aux_data_bytes(b)); -#endif - b->aux_data = NULL; - - bc->used--; - - btree_node_to_freedlist(bc, b); -} - -static int bch2_btree_cache_cmp_fn(struct rhashtable_compare_arg *arg, - const void *obj) -{ - const struct btree *b = obj; - const u64 *v = arg->key; - - return b->hash_val == *v ? 0 : 1; -} - -static const struct rhashtable_params bch_btree_cache_params = { - .head_offset = offsetof(struct btree, hash), - .key_offset = offsetof(struct btree, hash_val), - .key_len = sizeof(u64), - .obj_cmpfn = bch2_btree_cache_cmp_fn, -}; - -static int btree_node_data_alloc(struct bch_fs *c, struct btree *b, gfp_t gfp) -{ - BUG_ON(b->data || b->aux_data); - - b->data = kvpmalloc(btree_bytes(c), gfp); - if (!b->data) - return -BCH_ERR_ENOMEM_btree_node_mem_alloc; -#ifdef __KERNEL__ - b->aux_data = kvmalloc(btree_aux_data_bytes(b), gfp); -#else - b->aux_data = mmap(NULL, btree_aux_data_bytes(b), - PROT_READ|PROT_WRITE|PROT_EXEC, - MAP_PRIVATE|MAP_ANONYMOUS, 0, 0); - if (b->aux_data == MAP_FAILED) - b->aux_data = NULL; -#endif - if (!b->aux_data) { - kvpfree(b->data, btree_bytes(c)); - b->data = NULL; - return -BCH_ERR_ENOMEM_btree_node_mem_alloc; - } - - return 0; -} - -static struct btree *__btree_node_mem_alloc(struct bch_fs *c, gfp_t gfp) -{ - struct btree *b; - - b = kzalloc(sizeof(struct btree), gfp); - if (!b) - return NULL; - - bkey_btree_ptr_init(&b->key); - INIT_LIST_HEAD(&b->list); - INIT_LIST_HEAD(&b->write_blocked); - b->byte_order = ilog2(btree_bytes(c)); - return b; -} - -struct btree *__bch2_btree_node_mem_alloc(struct bch_fs *c) -{ - struct btree_cache *bc = &c->btree_cache; - struct btree *b; - - b = __btree_node_mem_alloc(c, GFP_KERNEL); - if (!b) - return NULL; - - if (btree_node_data_alloc(c, b, GFP_KERNEL)) { - kfree(b); - return NULL; - } - - bch2_btree_lock_init(&b->c, 0); - - bc->used++; - list_add(&b->list, &bc->freeable); - return b; -} - -/* Btree in memory cache - hash table */ - -void bch2_btree_node_hash_remove(struct btree_cache *bc, struct btree *b) -{ - int ret = rhashtable_remove_fast(&bc->table, &b->hash, bch_btree_cache_params); - - BUG_ON(ret); - - /* Cause future lookups for this node to fail: */ - b->hash_val = 0; -} - -int __bch2_btree_node_hash_insert(struct btree_cache *bc, struct btree *b) -{ - BUG_ON(b->hash_val); - b->hash_val = btree_ptr_hash_val(&b->key); - - return rhashtable_lookup_insert_fast(&bc->table, &b->hash, - bch_btree_cache_params); -} - -int bch2_btree_node_hash_insert(struct btree_cache *bc, struct btree *b, - unsigned level, enum btree_id id) -{ - int ret; - - b->c.level = level; - b->c.btree_id = id; - - mutex_lock(&bc->lock); - ret = __bch2_btree_node_hash_insert(bc, b); - if (!ret) - list_add_tail(&b->list, &bc->live); - mutex_unlock(&bc->lock); - - return ret; -} - -__flatten -static inline struct btree *btree_cache_find(struct btree_cache *bc, - const struct bkey_i *k) -{ - u64 v = btree_ptr_hash_val(k); - - return rhashtable_lookup_fast(&bc->table, &v, bch_btree_cache_params); -} - -/* - * this version is for btree nodes that have already been freed (we're not - * reaping a real btree node) - */ -static int __btree_node_reclaim(struct bch_fs *c, struct btree *b, bool flush) -{ - struct btree_cache *bc = &c->btree_cache; - int ret = 0; - - lockdep_assert_held(&bc->lock); -wait_on_io: - if (b->flags & ((1U << BTREE_NODE_dirty)| - (1U << BTREE_NODE_read_in_flight)| - (1U << BTREE_NODE_write_in_flight))) { - if (!flush) - return -BCH_ERR_ENOMEM_btree_node_reclaim; - - /* XXX: waiting on IO with btree cache lock held */ - bch2_btree_node_wait_on_read(b); - bch2_btree_node_wait_on_write(b); - } - - if (!six_trylock_intent(&b->c.lock)) - return -BCH_ERR_ENOMEM_btree_node_reclaim; - - if (!six_trylock_write(&b->c.lock)) - goto out_unlock_intent; - - /* recheck under lock */ - if (b->flags & ((1U << BTREE_NODE_read_in_flight)| - (1U << BTREE_NODE_write_in_flight))) { - if (!flush) - goto out_unlock; - six_unlock_write(&b->c.lock); - six_unlock_intent(&b->c.lock); - goto wait_on_io; - } - - if (btree_node_noevict(b) || - btree_node_write_blocked(b) || - btree_node_will_make_reachable(b)) - goto out_unlock; - - if (btree_node_dirty(b)) { - if (!flush) - goto out_unlock; - /* - * Using the underscore version because we don't want to compact - * bsets after the write, since this node is about to be evicted - * - unless btree verify mode is enabled, since it runs out of - * the post write cleanup: - */ - if (bch2_verify_btree_ondisk) - bch2_btree_node_write(c, b, SIX_LOCK_intent, - BTREE_WRITE_cache_reclaim); - else - __bch2_btree_node_write(c, b, - BTREE_WRITE_cache_reclaim); - - six_unlock_write(&b->c.lock); - six_unlock_intent(&b->c.lock); - goto wait_on_io; - } -out: - if (b->hash_val && !ret) - trace_and_count(c, btree_cache_reap, c, b); - return ret; -out_unlock: - six_unlock_write(&b->c.lock); -out_unlock_intent: - six_unlock_intent(&b->c.lock); - ret = -BCH_ERR_ENOMEM_btree_node_reclaim; - goto out; -} - -static int btree_node_reclaim(struct bch_fs *c, struct btree *b) -{ - return __btree_node_reclaim(c, b, false); -} - -static int btree_node_write_and_reclaim(struct bch_fs *c, struct btree *b) -{ - return __btree_node_reclaim(c, b, true); -} - -static unsigned long bch2_btree_cache_scan(struct shrinker *shrink, - struct shrink_control *sc) -{ - struct bch_fs *c = shrink->private_data; - struct btree_cache *bc = &c->btree_cache; - struct btree *b, *t; - unsigned long nr = sc->nr_to_scan; - unsigned long can_free = 0; - unsigned long freed = 0; - unsigned long touched = 0; - unsigned i, flags; - unsigned long ret = SHRINK_STOP; - bool trigger_writes = atomic_read(&bc->dirty) + nr >= - bc->used * 3 / 4; - - if (bch2_btree_shrinker_disabled) - return SHRINK_STOP; - - mutex_lock(&bc->lock); - flags = memalloc_nofs_save(); - - /* - * It's _really_ critical that we don't free too many btree nodes - we - * have to always leave ourselves a reserve. The reserve is how we - * guarantee that allocating memory for a new btree node can always - * succeed, so that inserting keys into the btree can always succeed and - * IO can always make forward progress: - */ - can_free = btree_cache_can_free(bc); - nr = min_t(unsigned long, nr, can_free); - - i = 0; - list_for_each_entry_safe(b, t, &bc->freeable, list) { - /* - * Leave a few nodes on the freeable list, so that a btree split - * won't have to hit the system allocator: - */ - if (++i <= 3) - continue; - - touched++; - - if (touched >= nr) - goto out; - - if (!btree_node_reclaim(c, b)) { - btree_node_data_free(c, b); - six_unlock_write(&b->c.lock); - six_unlock_intent(&b->c.lock); - freed++; - } - } -restart: - list_for_each_entry_safe(b, t, &bc->live, list) { - touched++; - - if (btree_node_accessed(b)) { - clear_btree_node_accessed(b); - } else if (!btree_node_reclaim(c, b)) { - freed++; - btree_node_data_free(c, b); - - bch2_btree_node_hash_remove(bc, b); - six_unlock_write(&b->c.lock); - six_unlock_intent(&b->c.lock); - - if (freed == nr) - goto out_rotate; - } else if (trigger_writes && - btree_node_dirty(b) && - !btree_node_will_make_reachable(b) && - !btree_node_write_blocked(b) && - six_trylock_read(&b->c.lock)) { - list_move(&bc->live, &b->list); - mutex_unlock(&bc->lock); - __bch2_btree_node_write(c, b, BTREE_WRITE_cache_reclaim); - six_unlock_read(&b->c.lock); - if (touched >= nr) - goto out_nounlock; - mutex_lock(&bc->lock); - goto restart; - } - - if (touched >= nr) - break; - } -out_rotate: - if (&t->list != &bc->live) - list_move_tail(&bc->live, &t->list); -out: - mutex_unlock(&bc->lock); -out_nounlock: - ret = freed; - memalloc_nofs_restore(flags); - trace_and_count(c, btree_cache_scan, sc->nr_to_scan, can_free, ret); - return ret; -} - -static unsigned long bch2_btree_cache_count(struct shrinker *shrink, - struct shrink_control *sc) -{ - struct bch_fs *c = shrink->private_data; - struct btree_cache *bc = &c->btree_cache; - - if (bch2_btree_shrinker_disabled) - return 0; - - return btree_cache_can_free(bc); -} - -void bch2_fs_btree_cache_exit(struct bch_fs *c) -{ - struct btree_cache *bc = &c->btree_cache; - struct btree *b; - unsigned i, flags; - - shrinker_free(bc->shrink); - - /* vfree() can allocate memory: */ - flags = memalloc_nofs_save(); - mutex_lock(&bc->lock); - - if (c->verify_data) - list_move(&c->verify_data->list, &bc->live); - - kvpfree(c->verify_ondisk, btree_bytes(c)); - - for (i = 0; i < btree_id_nr_alive(c); i++) { - struct btree_root *r = bch2_btree_id_root(c, i); - - if (r->b) - list_add(&r->b->list, &bc->live); - } - - list_splice(&bc->freeable, &bc->live); - - while (!list_empty(&bc->live)) { - b = list_first_entry(&bc->live, struct btree, list); - - BUG_ON(btree_node_read_in_flight(b) || - btree_node_write_in_flight(b)); - - btree_node_data_free(c, b); - } - - BUG_ON(!bch2_journal_error(&c->journal) && - atomic_read(&c->btree_cache.dirty)); - - list_splice(&bc->freed_pcpu, &bc->freed_nonpcpu); - - while (!list_empty(&bc->freed_nonpcpu)) { - b = list_first_entry(&bc->freed_nonpcpu, struct btree, list); - list_del(&b->list); - six_lock_exit(&b->c.lock); - kfree(b); - } - - mutex_unlock(&bc->lock); - memalloc_nofs_restore(flags); - - if (bc->table_init_done) - rhashtable_destroy(&bc->table); -} - -int bch2_fs_btree_cache_init(struct bch_fs *c) -{ - struct btree_cache *bc = &c->btree_cache; - struct shrinker *shrink; - unsigned i; - int ret = 0; - - ret = rhashtable_init(&bc->table, &bch_btree_cache_params); - if (ret) - goto err; - - bc->table_init_done = true; - - bch2_recalc_btree_reserve(c); - - for (i = 0; i < bc->reserve; i++) - if (!__bch2_btree_node_mem_alloc(c)) - goto err; - - list_splice_init(&bc->live, &bc->freeable); - - mutex_init(&c->verify_lock); - - shrink = shrinker_alloc(0, "%s-btree_cache", c->name); - if (!shrink) - goto err; - bc->shrink = shrink; - shrink->count_objects = bch2_btree_cache_count; - shrink->scan_objects = bch2_btree_cache_scan; - shrink->seeks = 4; - shrink->private_data = c; - shrinker_register(shrink); - - return 0; -err: - return -BCH_ERR_ENOMEM_fs_btree_cache_init; -} - -void bch2_fs_btree_cache_init_early(struct btree_cache *bc) -{ - mutex_init(&bc->lock); - INIT_LIST_HEAD(&bc->live); - INIT_LIST_HEAD(&bc->freeable); - INIT_LIST_HEAD(&bc->freed_pcpu); - INIT_LIST_HEAD(&bc->freed_nonpcpu); -} - -/* - * We can only have one thread cannibalizing other cached btree nodes at a time, - * or we'll deadlock. We use an open coded mutex to ensure that, which a - * cannibalize_bucket() will take. This means every time we unlock the root of - * the btree, we need to release this lock if we have it held. - */ -void bch2_btree_cache_cannibalize_unlock(struct btree_trans *trans) -{ - struct bch_fs *c = trans->c; - struct btree_cache *bc = &c->btree_cache; - - if (bc->alloc_lock == current) { - trace_and_count(c, btree_cache_cannibalize_unlock, trans); - bc->alloc_lock = NULL; - closure_wake_up(&bc->alloc_wait); - } -} - -int bch2_btree_cache_cannibalize_lock(struct btree_trans *trans, struct closure *cl) -{ - struct bch_fs *c = trans->c; - struct btree_cache *bc = &c->btree_cache; - struct task_struct *old; - - old = cmpxchg(&bc->alloc_lock, NULL, current); - if (old == NULL || old == current) - goto success; - - if (!cl) { - trace_and_count(c, btree_cache_cannibalize_lock_fail, trans); - return -BCH_ERR_ENOMEM_btree_cache_cannibalize_lock; - } - - closure_wait(&bc->alloc_wait, cl); - - /* Try again, after adding ourselves to waitlist */ - old = cmpxchg(&bc->alloc_lock, NULL, current); - if (old == NULL || old == current) { - /* We raced */ - closure_wake_up(&bc->alloc_wait); - goto success; - } - - trace_and_count(c, btree_cache_cannibalize_lock_fail, trans); - return -BCH_ERR_btree_cache_cannibalize_lock_blocked; - -success: - trace_and_count(c, btree_cache_cannibalize_lock, trans); - return 0; -} - -static struct btree *btree_node_cannibalize(struct bch_fs *c) -{ - struct btree_cache *bc = &c->btree_cache; - struct btree *b; - - list_for_each_entry_reverse(b, &bc->live, list) - if (!btree_node_reclaim(c, b)) - return b; - - while (1) { - list_for_each_entry_reverse(b, &bc->live, list) - if (!btree_node_write_and_reclaim(c, b)) - return b; - - /* - * Rare case: all nodes were intent-locked. - * Just busy-wait. - */ - WARN_ONCE(1, "btree cache cannibalize failed\n"); - cond_resched(); - } -} - -struct btree *bch2_btree_node_mem_alloc(struct btree_trans *trans, bool pcpu_read_locks) -{ - struct bch_fs *c = trans->c; - struct btree_cache *bc = &c->btree_cache; - struct list_head *freed = pcpu_read_locks - ? &bc->freed_pcpu - : &bc->freed_nonpcpu; - struct btree *b, *b2; - u64 start_time = local_clock(); - unsigned flags; - - flags = memalloc_nofs_save(); - mutex_lock(&bc->lock); - - /* - * We never free struct btree itself, just the memory that holds the on - * disk node. Check the freed list before allocating a new one: - */ - list_for_each_entry(b, freed, list) - if (!btree_node_reclaim(c, b)) { - list_del_init(&b->list); - goto got_node; - } - - b = __btree_node_mem_alloc(c, GFP_NOWAIT|__GFP_NOWARN); - if (!b) { - mutex_unlock(&bc->lock); - bch2_trans_unlock(trans); - b = __btree_node_mem_alloc(c, GFP_KERNEL); - if (!b) - goto err; - mutex_lock(&bc->lock); - } - - bch2_btree_lock_init(&b->c, pcpu_read_locks ? SIX_LOCK_INIT_PCPU : 0); - - BUG_ON(!six_trylock_intent(&b->c.lock)); - BUG_ON(!six_trylock_write(&b->c.lock)); -got_node: - - /* - * btree_free() doesn't free memory; it sticks the node on the end of - * the list. Check if there's any freed nodes there: - */ - list_for_each_entry(b2, &bc->freeable, list) - if (!btree_node_reclaim(c, b2)) { - swap(b->data, b2->data); - swap(b->aux_data, b2->aux_data); - btree_node_to_freedlist(bc, b2); - six_unlock_write(&b2->c.lock); - six_unlock_intent(&b2->c.lock); - goto got_mem; - } - - mutex_unlock(&bc->lock); - - if (btree_node_data_alloc(c, b, GFP_NOWAIT|__GFP_NOWARN)) { - bch2_trans_unlock(trans); - if (btree_node_data_alloc(c, b, GFP_KERNEL|__GFP_NOWARN)) - goto err; - } - - mutex_lock(&bc->lock); - bc->used++; -got_mem: - mutex_unlock(&bc->lock); - - BUG_ON(btree_node_hashed(b)); - BUG_ON(btree_node_dirty(b)); - BUG_ON(btree_node_write_in_flight(b)); -out: - b->flags = 0; - b->written = 0; - b->nsets = 0; - b->sib_u64s[0] = 0; - b->sib_u64s[1] = 0; - b->whiteout_u64s = 0; - bch2_btree_keys_init(b); - set_btree_node_accessed(b); - - bch2_time_stats_update(&c->times[BCH_TIME_btree_node_mem_alloc], - start_time); - - memalloc_nofs_restore(flags); - return b; -err: - mutex_lock(&bc->lock); - - /* Try to cannibalize another cached btree node: */ - if (bc->alloc_lock == current) { - b2 = btree_node_cannibalize(c); - clear_btree_node_just_written(b2); - bch2_btree_node_hash_remove(bc, b2); - - if (b) { - swap(b->data, b2->data); - swap(b->aux_data, b2->aux_data); - btree_node_to_freedlist(bc, b2); - six_unlock_write(&b2->c.lock); - six_unlock_intent(&b2->c.lock); - } else { - b = b2; - list_del_init(&b->list); - } - - mutex_unlock(&bc->lock); - - trace_and_count(c, btree_cache_cannibalize, trans); - goto out; - } - - mutex_unlock(&bc->lock); - memalloc_nofs_restore(flags); - return ERR_PTR(-BCH_ERR_ENOMEM_btree_node_mem_alloc); -} - -/* Slowpath, don't want it inlined into btree_iter_traverse() */ -static noinline struct btree *bch2_btree_node_fill(struct btree_trans *trans, - struct btree_path *path, - const struct bkey_i *k, - enum btree_id btree_id, - unsigned level, - enum six_lock_type lock_type, - bool sync) -{ - struct bch_fs *c = trans->c; - struct btree_cache *bc = &c->btree_cache; - struct btree *b; - u32 seq; - - BUG_ON(level + 1 >= BTREE_MAX_DEPTH); - /* - * Parent node must be locked, else we could read in a btree node that's - * been freed: - */ - if (path && !bch2_btree_node_relock(trans, path, level + 1)) { - trace_and_count(c, trans_restart_relock_parent_for_fill, trans, _THIS_IP_, path); - return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_fill_relock)); - } - - b = bch2_btree_node_mem_alloc(trans, level != 0); - - if (bch2_err_matches(PTR_ERR_OR_ZERO(b), ENOMEM)) { - trans->memory_allocation_failure = true; - trace_and_count(c, trans_restart_memory_allocation_failure, trans, _THIS_IP_, path); - return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_fill_mem_alloc_fail)); - } - - if (IS_ERR(b)) - return b; - - bkey_copy(&b->key, k); - if (bch2_btree_node_hash_insert(bc, b, level, btree_id)) { - /* raced with another fill: */ - - /* mark as unhashed... */ - b->hash_val = 0; - - mutex_lock(&bc->lock); - list_add(&b->list, &bc->freeable); - mutex_unlock(&bc->lock); - - six_unlock_write(&b->c.lock); - six_unlock_intent(&b->c.lock); - return NULL; - } - - set_btree_node_read_in_flight(b); - - six_unlock_write(&b->c.lock); - seq = six_lock_seq(&b->c.lock); - six_unlock_intent(&b->c.lock); - - /* Unlock before doing IO: */ - if (path && sync) - bch2_trans_unlock_noassert(trans); - - bch2_btree_node_read(trans, b, sync); - - if (!sync) - return NULL; - - if (path) { - int ret = bch2_trans_relock(trans) ?: - bch2_btree_path_relock_intent(trans, path); - if (ret) { - BUG_ON(!trans->restarted); - return ERR_PTR(ret); - } - } - - if (!six_relock_type(&b->c.lock, lock_type, seq)) { - if (path) - trace_and_count(c, trans_restart_relock_after_fill, trans, _THIS_IP_, path); - return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_relock_after_fill)); - } - - return b; -} - -static noinline void btree_bad_header(struct bch_fs *c, struct btree *b) -{ - struct printbuf buf = PRINTBUF; - - if (c->curr_recovery_pass <= BCH_RECOVERY_PASS_check_allocations) - return; - - prt_printf(&buf, - "btree node header doesn't match ptr\n" - "btree %s level %u\n" - "ptr: ", - bch2_btree_id_str(b->c.btree_id), b->c.level); - bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&b->key)); - - prt_printf(&buf, "\nheader: btree %s level %llu\n" - "min ", - bch2_btree_id_str(BTREE_NODE_ID(b->data)), - BTREE_NODE_LEVEL(b->data)); - bch2_bpos_to_text(&buf, b->data->min_key); - - prt_printf(&buf, "\nmax "); - bch2_bpos_to_text(&buf, b->data->max_key); - - bch2_fs_inconsistent(c, "%s", buf.buf); - printbuf_exit(&buf); -} - -static inline void btree_check_header(struct bch_fs *c, struct btree *b) -{ - if (b->c.btree_id != BTREE_NODE_ID(b->data) || - b->c.level != BTREE_NODE_LEVEL(b->data) || - !bpos_eq(b->data->max_key, b->key.k.p) || - (b->key.k.type == KEY_TYPE_btree_ptr_v2 && - !bpos_eq(b->data->min_key, - bkey_i_to_btree_ptr_v2(&b->key)->v.min_key))) - btree_bad_header(c, b); -} - -static struct btree *__bch2_btree_node_get(struct btree_trans *trans, struct btree_path *path, - const struct bkey_i *k, unsigned level, - enum six_lock_type lock_type, - unsigned long trace_ip) -{ - struct bch_fs *c = trans->c; - struct btree_cache *bc = &c->btree_cache; - struct btree *b; - struct bset_tree *t; - bool need_relock = false; - int ret; - - EBUG_ON(level >= BTREE_MAX_DEPTH); -retry: - b = btree_cache_find(bc, k); - if (unlikely(!b)) { - /* - * We must have the parent locked to call bch2_btree_node_fill(), - * else we could read in a btree node from disk that's been - * freed: - */ - b = bch2_btree_node_fill(trans, path, k, path->btree_id, - level, lock_type, true); - need_relock = true; - - /* We raced and found the btree node in the cache */ - if (!b) - goto retry; - - if (IS_ERR(b)) - return b; - } else { - if (btree_node_read_locked(path, level + 1)) - btree_node_unlock(trans, path, level + 1); - - ret = btree_node_lock(trans, path, &b->c, level, lock_type, trace_ip); - if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) - return ERR_PTR(ret); - - BUG_ON(ret); - - if (unlikely(b->hash_val != btree_ptr_hash_val(k) || - b->c.level != level || - race_fault())) { - six_unlock_type(&b->c.lock, lock_type); - if (bch2_btree_node_relock(trans, path, level + 1)) - goto retry; - - trace_and_count(c, trans_restart_btree_node_reused, trans, trace_ip, path); - return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_lock_node_reused)); - } - - /* avoid atomic set bit if it's not needed: */ - if (!btree_node_accessed(b)) - set_btree_node_accessed(b); - } - - if (unlikely(btree_node_read_in_flight(b))) { - u32 seq = six_lock_seq(&b->c.lock); - - six_unlock_type(&b->c.lock, lock_type); - bch2_trans_unlock(trans); - need_relock = true; - - bch2_btree_node_wait_on_read(b); - - /* - * should_be_locked is not set on this path yet, so we need to - * relock it specifically: - */ - if (!six_relock_type(&b->c.lock, lock_type, seq)) - goto retry; - } - - if (unlikely(need_relock)) { - ret = bch2_trans_relock(trans) ?: - bch2_btree_path_relock_intent(trans, path); - if (ret) { - six_unlock_type(&b->c.lock, lock_type); - return ERR_PTR(ret); - } - } - - prefetch(b->aux_data); - - for_each_bset(b, t) { - void *p = (u64 *) b->aux_data + t->aux_data_offset; - - prefetch(p + L1_CACHE_BYTES * 0); - prefetch(p + L1_CACHE_BYTES * 1); - prefetch(p + L1_CACHE_BYTES * 2); - } - - if (unlikely(btree_node_read_error(b))) { - six_unlock_type(&b->c.lock, lock_type); - return ERR_PTR(-EIO); - } - - EBUG_ON(b->c.btree_id != path->btree_id); - EBUG_ON(BTREE_NODE_LEVEL(b->data) != level); - btree_check_header(c, b); - - return b; -} - -/** - * bch2_btree_node_get - find a btree node in the cache and lock it, reading it - * in from disk if necessary. - * - * @trans: btree transaction object - * @path: btree_path being traversed - * @k: pointer to btree node (generally KEY_TYPE_btree_ptr_v2) - * @level: level of btree node being looked up (0 == leaf node) - * @lock_type: SIX_LOCK_read or SIX_LOCK_intent - * @trace_ip: ip of caller of btree iterator code (i.e. caller of bch2_btree_iter_peek()) - * - * The btree node will have either a read or a write lock held, depending on - * the @write parameter. - * - * Returns: btree node or ERR_PTR() - */ -struct btree *bch2_btree_node_get(struct btree_trans *trans, struct btree_path *path, - const struct bkey_i *k, unsigned level, - enum six_lock_type lock_type, - unsigned long trace_ip) -{ - struct bch_fs *c = trans->c; - struct btree *b; - struct bset_tree *t; - int ret; - - EBUG_ON(level >= BTREE_MAX_DEPTH); - - b = btree_node_mem_ptr(k); - - /* - * Check b->hash_val _before_ calling btree_node_lock() - this might not - * be the node we want anymore, and trying to lock the wrong node could - * cause an unneccessary transaction restart: - */ - if (unlikely(!c->opts.btree_node_mem_ptr_optimization || - !b || - b->hash_val != btree_ptr_hash_val(k))) - return __bch2_btree_node_get(trans, path, k, level, lock_type, trace_ip); - - if (btree_node_read_locked(path, level + 1)) - btree_node_unlock(trans, path, level + 1); - - ret = btree_node_lock(trans, path, &b->c, level, lock_type, trace_ip); - if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) - return ERR_PTR(ret); - - BUG_ON(ret); - - if (unlikely(b->hash_val != btree_ptr_hash_val(k) || - b->c.level != level || - race_fault())) { - six_unlock_type(&b->c.lock, lock_type); - if (bch2_btree_node_relock(trans, path, level + 1)) - return __bch2_btree_node_get(trans, path, k, level, lock_type, trace_ip); - - trace_and_count(c, trans_restart_btree_node_reused, trans, trace_ip, path); - return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_lock_node_reused)); - } - - if (unlikely(btree_node_read_in_flight(b))) { - six_unlock_type(&b->c.lock, lock_type); - return __bch2_btree_node_get(trans, path, k, level, lock_type, trace_ip); - } - - prefetch(b->aux_data); - - for_each_bset(b, t) { - void *p = (u64 *) b->aux_data + t->aux_data_offset; - - prefetch(p + L1_CACHE_BYTES * 0); - prefetch(p + L1_CACHE_BYTES * 1); - prefetch(p + L1_CACHE_BYTES * 2); - } - - /* avoid atomic set bit if it's not needed: */ - if (!btree_node_accessed(b)) - set_btree_node_accessed(b); - - if (unlikely(btree_node_read_error(b))) { - six_unlock_type(&b->c.lock, lock_type); - return ERR_PTR(-EIO); - } - - EBUG_ON(b->c.btree_id != path->btree_id); - EBUG_ON(BTREE_NODE_LEVEL(b->data) != level); - btree_check_header(c, b); - - return b; -} - -struct btree *bch2_btree_node_get_noiter(struct btree_trans *trans, - const struct bkey_i *k, - enum btree_id btree_id, - unsigned level, - bool nofill) -{ - struct bch_fs *c = trans->c; - struct btree_cache *bc = &c->btree_cache; - struct btree *b; - struct bset_tree *t; - int ret; - - EBUG_ON(level >= BTREE_MAX_DEPTH); - - if (c->opts.btree_node_mem_ptr_optimization) { - b = btree_node_mem_ptr(k); - if (b) - goto lock_node; - } -retry: - b = btree_cache_find(bc, k); - if (unlikely(!b)) { - if (nofill) - goto out; - - b = bch2_btree_node_fill(trans, NULL, k, btree_id, - level, SIX_LOCK_read, true); - - /* We raced and found the btree node in the cache */ - if (!b) - goto retry; - - if (IS_ERR(b) && - !bch2_btree_cache_cannibalize_lock(trans, NULL)) - goto retry; - - if (IS_ERR(b)) - goto out; - } else { -lock_node: - ret = btree_node_lock_nopath(trans, &b->c, SIX_LOCK_read, _THIS_IP_); - if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) - return ERR_PTR(ret); - - BUG_ON(ret); - - if (unlikely(b->hash_val != btree_ptr_hash_val(k) || - b->c.btree_id != btree_id || - b->c.level != level)) { - six_unlock_read(&b->c.lock); - goto retry; - } - } - - /* XXX: waiting on IO with btree locks held: */ - __bch2_btree_node_wait_on_read(b); - - prefetch(b->aux_data); - - for_each_bset(b, t) { - void *p = (u64 *) b->aux_data + t->aux_data_offset; - - prefetch(p + L1_CACHE_BYTES * 0); - prefetch(p + L1_CACHE_BYTES * 1); - prefetch(p + L1_CACHE_BYTES * 2); - } - - /* avoid atomic set bit if it's not needed: */ - if (!btree_node_accessed(b)) - set_btree_node_accessed(b); - - if (unlikely(btree_node_read_error(b))) { - six_unlock_read(&b->c.lock); - b = ERR_PTR(-EIO); - goto out; - } - - EBUG_ON(b->c.btree_id != btree_id); - EBUG_ON(BTREE_NODE_LEVEL(b->data) != level); - btree_check_header(c, b); -out: - bch2_btree_cache_cannibalize_unlock(trans); - return b; -} - -int bch2_btree_node_prefetch(struct btree_trans *trans, - struct btree_path *path, - const struct bkey_i *k, - enum btree_id btree_id, unsigned level) -{ - struct bch_fs *c = trans->c; - struct btree_cache *bc = &c->btree_cache; - struct btree *b; - - BUG_ON(trans && !btree_node_locked(path, level + 1)); - BUG_ON(level >= BTREE_MAX_DEPTH); - - b = btree_cache_find(bc, k); - if (b) - return 0; - - b = bch2_btree_node_fill(trans, path, k, btree_id, - level, SIX_LOCK_read, false); - return PTR_ERR_OR_ZERO(b); -} - -void bch2_btree_node_evict(struct btree_trans *trans, const struct bkey_i *k) -{ - struct bch_fs *c = trans->c; - struct btree_cache *bc = &c->btree_cache; - struct btree *b; - - b = btree_cache_find(bc, k); - if (!b) - return; -wait_on_io: - /* not allowed to wait on io with btree locks held: */ - - /* XXX we're called from btree_gc which will be holding other btree - * nodes locked - */ - __bch2_btree_node_wait_on_read(b); - __bch2_btree_node_wait_on_write(b); - - btree_node_lock_nopath_nofail(trans, &b->c, SIX_LOCK_intent); - btree_node_lock_nopath_nofail(trans, &b->c, SIX_LOCK_write); - - if (btree_node_dirty(b)) { - __bch2_btree_node_write(c, b, BTREE_WRITE_cache_reclaim); - six_unlock_write(&b->c.lock); - six_unlock_intent(&b->c.lock); - goto wait_on_io; - } - - BUG_ON(btree_node_dirty(b)); - - mutex_lock(&bc->lock); - btree_node_data_free(c, b); - bch2_btree_node_hash_remove(bc, b); - mutex_unlock(&bc->lock); - - six_unlock_write(&b->c.lock); - six_unlock_intent(&b->c.lock); -} - -const char *bch2_btree_id_str(enum btree_id btree) -{ - return btree < BTREE_ID_NR ? __bch2_btree_ids[btree] : "(unknown)"; -} - -void bch2_btree_pos_to_text(struct printbuf *out, struct bch_fs *c, const struct btree *b) -{ - prt_printf(out, "%s level %u/%u\n ", - bch2_btree_id_str(b->c.btree_id), - b->c.level, - bch2_btree_id_root(c, b->c.btree_id)->level); - bch2_bkey_val_to_text(out, c, bkey_i_to_s_c(&b->key)); -} - -void bch2_btree_node_to_text(struct printbuf *out, struct bch_fs *c, const struct btree *b) -{ - struct bset_stats stats; - - memset(&stats, 0, sizeof(stats)); - - bch2_btree_keys_stats(b, &stats); - - prt_printf(out, "l %u ", b->c.level); - bch2_bpos_to_text(out, b->data->min_key); - prt_printf(out, " - "); - bch2_bpos_to_text(out, b->data->max_key); - prt_printf(out, ":\n" - " ptrs: "); - bch2_val_to_text(out, c, bkey_i_to_s_c(&b->key)); - prt_newline(out); - - prt_printf(out, - " format: "); - bch2_bkey_format_to_text(out, &b->format); - - prt_printf(out, - " unpack fn len: %u\n" - " bytes used %zu/%zu (%zu%% full)\n" - " sib u64s: %u, %u (merge threshold %u)\n" - " nr packed keys %u\n" - " nr unpacked keys %u\n" - " floats %zu\n" - " failed unpacked %zu\n", - b->unpack_fn_len, - b->nr.live_u64s * sizeof(u64), - btree_bytes(c) - sizeof(struct btree_node), - b->nr.live_u64s * 100 / btree_max_u64s(c), - b->sib_u64s[0], - b->sib_u64s[1], - c->btree_foreground_merge_threshold, - b->nr.packed_keys, - b->nr.unpacked_keys, - stats.floats, - stats.failed); -} - -void bch2_btree_cache_to_text(struct printbuf *out, const struct bch_fs *c) -{ - prt_printf(out, "nr nodes:\t\t%u\n", c->btree_cache.used); - prt_printf(out, "nr dirty:\t\t%u\n", atomic_read(&c->btree_cache.dirty)); - prt_printf(out, "cannibalize lock:\t%p\n", c->btree_cache.alloc_lock); -} |