diff options
Diffstat (limited to 'fs/bcachefs/btree_cache.c')
| -rw-r--r-- | fs/bcachefs/btree_cache.c | 941 |
1 files changed, 941 insertions, 0 deletions
diff --git a/fs/bcachefs/btree_cache.c b/fs/bcachefs/btree_cache.c new file mode 100644 index 000000000000..f9afae6c710d --- /dev/null +++ b/fs/bcachefs/btree_cache.c @@ -0,0 +1,941 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "bcachefs.h" +#include "btree_cache.h" +#include "btree_io.h" +#include "btree_iter.h" +#include "btree_locking.h" +#include "debug.h" +#include "extents.h" +#include "trace.h" + +#include <linux/prefetch.h> + +#define DEF_BTREE_ID(kwd, val, name) name, + +const char * const bch2_btree_ids[] = { + DEFINE_BCH_BTREE_IDS() + NULL +}; + +#undef DEF_BTREE_ID + +void bch2_recalc_btree_reserve(struct bch_fs *c) +{ + unsigned i, reserve = 16; + + if (!c->btree_roots[0].b) + reserve += 8; + + for (i = 0; i < BTREE_ID_NR; i++) + if (c->btree_roots[i].b) + reserve += min_t(unsigned, 1, + c->btree_roots[i].b->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_data_free(struct bch_fs *c, struct btree *b) +{ + EBUG_ON(btree_node_write_in_flight(b)); + + kvpfree(b->data, btree_bytes(c)); + b->data = NULL; + bch2_btree_keys_free(b); +} + +static void btree_node_data_free(struct bch_fs *c, struct btree *b) +{ + struct btree_cache *bc = &c->btree_cache; + + __btree_node_data_free(c, b); + bc->used--; + list_move(&b->list, &bc->freed); +} + +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 PTR_HASH(&b->key) == *v ? 0 : 1; +} + +static const struct rhashtable_params bch_btree_cache_params = { + .head_offset = offsetof(struct btree, hash), + .key_offset = offsetof(struct btree, key.v), + .key_len = sizeof(struct bch_extent_ptr), + .obj_cmpfn = bch2_btree_cache_cmp_fn, +}; + +static void btree_node_data_alloc(struct bch_fs *c, struct btree *b, gfp_t gfp) +{ + struct btree_cache *bc = &c->btree_cache; + + b->data = kvpmalloc(btree_bytes(c), gfp); + if (!b->data) + goto err; + + if (bch2_btree_keys_alloc(b, btree_page_order(c), gfp)) + goto err; + + bc->used++; + list_move(&b->list, &bc->freeable); + return; +err: + kvpfree(b->data, btree_bytes(c)); + b->data = NULL; + list_move(&b->list, &bc->freed); +} + +static struct btree *btree_node_mem_alloc(struct bch_fs *c, gfp_t gfp) +{ + struct btree *b = kzalloc(sizeof(struct btree), gfp); + if (!b) + return NULL; + + bkey_extent_init(&b->key); + six_lock_init(&b->lock); + lockdep_set_novalidate_class(&b->lock); + INIT_LIST_HEAD(&b->list); + INIT_LIST_HEAD(&b->write_blocked); + + btree_node_data_alloc(c, b, gfp); + return b->data ? b : NULL; +} + +/* Btree in memory cache - hash table */ + +void bch2_btree_node_hash_remove(struct btree_cache *bc, struct btree *b) +{ + rhashtable_remove_fast(&bc->table, &b->hash, bch_btree_cache_params); + + /* Cause future lookups for this node to fail: */ + bkey_i_to_extent(&b->key)->v._data[0] = 0; +} + +int __bch2_btree_node_hash_insert(struct btree_cache *bc, struct btree *b) +{ + 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->level = level; + b->btree_id = id; + + mutex_lock(&bc->lock); + ret = __bch2_btree_node_hash_insert(bc, b); + if (!ret) + list_add(&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) +{ + return rhashtable_lookup_fast(&bc->table, &PTR_HASH(k), + 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); + + if (!six_trylock_intent(&b->lock)) + return -ENOMEM; + + if (!six_trylock_write(&b->lock)) + goto out_unlock_intent; + + if (btree_node_noevict(b)) + goto out_unlock; + + if (!btree_node_may_write(b)) + goto out_unlock; + + if (btree_node_dirty(b) || + btree_node_write_in_flight(b) || + btree_node_read_in_flight(b)) { + if (!flush) + goto out_unlock; + + wait_on_bit_io(&b->flags, BTREE_NODE_read_in_flight, + TASK_UNINTERRUPTIBLE); + + /* + * 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 (verify_btree_ondisk(c)) + bch2_btree_node_write(c, b, SIX_LOCK_intent); + else + __bch2_btree_node_write(c, b, SIX_LOCK_read); + + /* wait for any in flight btree write */ + btree_node_wait_on_io(b); + } +out: + if (PTR_HASH(&b->key) && !ret) + trace_btree_node_reap(c, b); + return ret; +out_unlock: + six_unlock_write(&b->lock); +out_unlock_intent: + six_unlock_intent(&b->lock); + ret = -ENOMEM; + 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 = container_of(shrink, struct bch_fs, + btree_cache.shrink); + struct btree_cache *bc = &c->btree_cache; + struct btree *b, *t; + unsigned long nr = sc->nr_to_scan; + unsigned long can_free; + unsigned long touched = 0; + unsigned long freed = 0; + unsigned i; + + if (btree_shrinker_disabled(c)) + return SHRINK_STOP; + + /* Return -1 if we can't do anything right now */ + if (sc->gfp_mask & __GFP_IO) + mutex_lock(&bc->lock); + else if (!mutex_trylock(&bc->lock)) + return -1; + + /* + * 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: + */ + nr /= btree_pages(c); + 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) { + touched++; + + if (freed >= nr) + break; + + if (++i > 3 && + !btree_node_reclaim(c, b)) { + btree_node_data_free(c, b); + six_unlock_write(&b->lock); + six_unlock_intent(&b->lock); + freed++; + } + } +restart: + list_for_each_entry_safe(b, t, &bc->live, list) { + touched++; + + if (freed >= nr) { + /* Save position */ + if (&t->list != &bc->live) + list_move_tail(&bc->live, &t->list); + break; + } + + if (!btree_node_accessed(b) && + !btree_node_reclaim(c, b)) { + /* can't call bch2_btree_node_hash_remove under lock */ + freed++; + if (&t->list != &bc->live) + list_move_tail(&bc->live, &t->list); + + btree_node_data_free(c, b); + mutex_unlock(&bc->lock); + + bch2_btree_node_hash_remove(bc, b); + six_unlock_write(&b->lock); + six_unlock_intent(&b->lock); + + if (freed >= nr) + goto out; + + if (sc->gfp_mask & __GFP_IO) + mutex_lock(&bc->lock); + else if (!mutex_trylock(&bc->lock)) + goto out; + goto restart; + } else + clear_btree_node_accessed(b); + } + + mutex_unlock(&bc->lock); +out: + return (unsigned long) freed * btree_pages(c); +} + +static unsigned long bch2_btree_cache_count(struct shrinker *shrink, + struct shrink_control *sc) +{ + struct bch_fs *c = container_of(shrink, struct bch_fs, + btree_cache.shrink); + struct btree_cache *bc = &c->btree_cache; + + if (btree_shrinker_disabled(c)) + return 0; + + return btree_cache_can_free(bc) * btree_pages(c); +} + +void bch2_fs_btree_cache_exit(struct bch_fs *c) +{ + struct btree_cache *bc = &c->btree_cache; + struct btree *b; + unsigned i; + + if (bc->shrink.list.next) + unregister_shrinker(&bc->shrink); + + mutex_lock(&bc->lock); + +#ifdef CONFIG_BCACHEFS_DEBUG + if (c->verify_data) + list_move(&c->verify_data->list, &bc->live); + + kvpfree(c->verify_ondisk, btree_bytes(c)); +#endif + + for (i = 0; i < BTREE_ID_NR; i++) + if (c->btree_roots[i].b) + list_add(&c->btree_roots[i].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)); + + if (btree_node_dirty(b)) + bch2_btree_complete_write(c, b, btree_current_write(b)); + clear_btree_node_dirty(b); + + btree_node_data_free(c, b); + } + + while (!list_empty(&bc->freed)) { + b = list_first_entry(&bc->freed, struct btree, list); + list_del(&b->list); + kfree(b); + } + + mutex_unlock(&bc->lock); + + 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; + unsigned i; + int ret = 0; + + pr_verbose_init(c->opts, ""); + + ret = rhashtable_init(&bc->table, &bch_btree_cache_params); + if (ret) + goto out; + + bc->table_init_done = true; + + bch2_recalc_btree_reserve(c); + + for (i = 0; i < bc->reserve; i++) + if (!btree_node_mem_alloc(c, GFP_KERNEL)) { + ret = -ENOMEM; + goto out; + } + + list_splice_init(&bc->live, &bc->freeable); + +#ifdef CONFIG_BCACHEFS_DEBUG + mutex_init(&c->verify_lock); + + c->verify_ondisk = kvpmalloc(btree_bytes(c), GFP_KERNEL); + if (!c->verify_ondisk) { + ret = -ENOMEM; + goto out; + } + + c->verify_data = btree_node_mem_alloc(c, GFP_KERNEL); + if (!c->verify_data) { + ret = -ENOMEM; + goto out; + } + + list_del_init(&c->verify_data->list); +#endif + + bc->shrink.count_objects = bch2_btree_cache_count; + bc->shrink.scan_objects = bch2_btree_cache_scan; + bc->shrink.seeks = 4; + bc->shrink.batch = btree_pages(c) * 2; + register_shrinker(&bc->shrink, "%s/btree_cache", c->name); +out: + pr_verbose_init(c->opts, "ret %i", ret); + return ret; +} + +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); +} + +/* + * 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 bch_fs *c) +{ + struct btree_cache *bc = &c->btree_cache; + + if (bc->alloc_lock == current) { + trace_btree_node_cannibalize_unlock(c); + bc->alloc_lock = NULL; + closure_wake_up(&bc->alloc_wait); + } +} + +int bch2_btree_cache_cannibalize_lock(struct bch_fs *c, struct closure *cl) +{ + 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_btree_node_cannibalize_lock_fail(c); + return -ENOMEM; + } + + 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_btree_node_cannibalize_lock_fail(c); + return -EAGAIN; + +success: + trace_btree_node_cannibalize_lock(c); + 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 bch_fs *c) +{ + struct btree_cache *bc = &c->btree_cache; + struct btree *b; + u64 start_time = local_clock(); + + mutex_lock(&bc->lock); + + /* + * 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(b, &bc->freeable, list) + if (!btree_node_reclaim(c, b)) + goto out_unlock; + + /* + * 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, &bc->freed, list) + if (!btree_node_reclaim(c, b)) { + btree_node_data_alloc(c, b, __GFP_NOWARN|GFP_NOIO); + if (b->data) + goto out_unlock; + + six_unlock_write(&b->lock); + six_unlock_intent(&b->lock); + goto err; + } + + b = btree_node_mem_alloc(c, __GFP_NOWARN|GFP_NOIO); + if (!b) + goto err; + + BUG_ON(!six_trylock_intent(&b->lock)); + BUG_ON(!six_trylock_write(&b->lock)); +out_unlock: + BUG_ON(btree_node_hashed(b)); + BUG_ON(btree_node_write_in_flight(b)); + + list_del_init(&b->list); + mutex_unlock(&bc->lock); +out: + b->flags = 0; + b->written = 0; + b->nsets = 0; + b->sib_u64s[0] = 0; + b->sib_u64s[1] = 0; + b->whiteout_u64s = 0; + b->uncompacted_whiteout_u64s = 0; + bch2_btree_keys_init(b, &c->expensive_debug_checks); + + bch2_time_stats_update(&c->times[BCH_TIME_btree_node_mem_alloc], + start_time); + + return b; +err: + /* Try to cannibalize another cached btree node: */ + if (bc->alloc_lock == current) { + b = btree_node_cannibalize(c); + list_del_init(&b->list); + mutex_unlock(&bc->lock); + + bch2_btree_node_hash_remove(bc, b); + + trace_btree_node_cannibalize(c); + goto out; + } + + mutex_unlock(&bc->lock); + return ERR_PTR(-ENOMEM); +} + +/* Slowpath, don't want it inlined into btree_iter_traverse() */ +static noinline struct btree *bch2_btree_node_fill(struct bch_fs *c, + struct btree_iter *iter, + const struct bkey_i *k, + unsigned level, + enum six_lock_type lock_type, + bool sync) +{ + struct btree_cache *bc = &c->btree_cache; + struct btree *b; + + /* + * Parent node must be locked, else we could read in a btree node that's + * been freed: + */ + BUG_ON(!btree_node_locked(iter, level + 1)); + BUG_ON(level >= BTREE_MAX_DEPTH); + + b = bch2_btree_node_mem_alloc(c); + if (IS_ERR(b)) + return b; + + bkey_copy(&b->key, k); + if (bch2_btree_node_hash_insert(bc, b, level, iter->btree_id)) { + /* raced with another fill: */ + + /* mark as unhashed... */ + bkey_i_to_extent(&b->key)->v._data[0] = 0; + + mutex_lock(&bc->lock); + list_add(&b->list, &bc->freeable); + mutex_unlock(&bc->lock); + + six_unlock_write(&b->lock); + six_unlock_intent(&b->lock); + return NULL; + } + + /* + * If the btree node wasn't cached, we can't drop our lock on + * the parent until after it's added to the cache - because + * otherwise we could race with a btree_split() freeing the node + * we're trying to lock. + * + * But the deadlock described below doesn't exist in this case, + * so it's safe to not drop the parent lock until here: + */ + if (btree_node_read_locked(iter, level + 1)) + btree_node_unlock(iter, level + 1); + + bch2_btree_node_read(c, b, sync); + + six_unlock_write(&b->lock); + + if (!sync) { + six_unlock_intent(&b->lock); + return NULL; + } + + if (lock_type == SIX_LOCK_read) + six_lock_downgrade(&b->lock); + + return b; +} + +/** + * bch_btree_node_get - find a btree node in the cache and lock it, reading it + * in from disk if necessary. + * + * If IO is necessary and running under generic_make_request, returns -EAGAIN. + * + * The btree node will have either a read or a write lock held, depending on + * the @write parameter. + */ +struct btree *bch2_btree_node_get(struct bch_fs *c, struct btree_iter *iter, + const struct bkey_i *k, unsigned level, + enum six_lock_type lock_type, + bool may_drop_locks) +{ + struct btree_cache *bc = &c->btree_cache; + struct btree *b; + struct bset_tree *t; + + /* + * XXX: locking optimization + * + * we can make the locking looser here - caller can drop lock on parent + * node before locking child node (and potentially blocking): we just + * have to have bch2_btree_node_fill() call relock on the parent and + * return -EINTR if that fails + */ + EBUG_ON(!btree_node_locked(iter, level + 1)); + EBUG_ON(level >= BTREE_MAX_DEPTH); +retry: + rcu_read_lock(); + b = btree_cache_find(bc, k); + rcu_read_unlock(); + + 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(c, iter, k, level, lock_type, true); + + /* We raced and found the btree node in the cache */ + if (!b) + goto retry; + + if (IS_ERR(b)) + return b; + } else { + /* + * There's a potential deadlock with splits and insertions into + * interior nodes we have to avoid: + * + * The other thread might be holding an intent lock on the node + * we want, and they want to update its parent node so they're + * going to upgrade their intent lock on the parent node to a + * write lock. + * + * But if we're holding a read lock on the parent, and we're + * trying to get the intent lock they're holding, we deadlock. + * + * So to avoid this we drop the read locks on parent nodes when + * we're starting to take intent locks - and handle the race. + * + * The race is that they might be about to free the node we + * want, and dropping our read lock on the parent node lets them + * update the parent marking the node we want as freed, and then + * free it: + * + * To guard against this, btree nodes are evicted from the cache + * when they're freed - and PTR_HASH() is zeroed out, which we + * check for after we lock the node. + * + * Then, bch2_btree_node_relock() on the parent will fail - because + * the parent was modified, when the pointer to the node we want + * was removed - and we'll bail out: + */ + if (btree_node_read_locked(iter, level + 1)) + btree_node_unlock(iter, level + 1); + + if (!btree_node_lock(b, k->k.p, level, iter, + lock_type, may_drop_locks)) + return ERR_PTR(-EINTR); + + if (unlikely(PTR_HASH(&b->key) != PTR_HASH(k) || + b->level != level || + race_fault())) { + six_unlock_type(&b->lock, lock_type); + if (bch2_btree_node_relock(iter, level + 1)) + goto retry; + + return ERR_PTR(-EINTR); + } + } + + wait_on_bit_io(&b->flags, BTREE_NODE_read_in_flight, + TASK_UNINTERRUPTIBLE); + + 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->lock, lock_type); + return ERR_PTR(-EIO); + } + + EBUG_ON(b->btree_id != iter->btree_id || + BTREE_NODE_LEVEL(b->data) != level || + bkey_cmp(b->data->max_key, k->k.p)); + + return b; +} + +struct btree *bch2_btree_node_get_sibling(struct bch_fs *c, + struct btree_iter *iter, + struct btree *b, + bool may_drop_locks, + enum btree_node_sibling sib) +{ + struct btree *parent; + struct btree_node_iter node_iter; + struct bkey_packed *k; + BKEY_PADDED(k) tmp; + struct btree *ret = NULL; + unsigned level = b->level; + + parent = btree_iter_node(iter, level + 1); + if (!parent) + return NULL; + + if (!bch2_btree_node_relock(iter, level + 1)) + goto out_upgrade; + + node_iter = iter->l[parent->level].iter; + + k = bch2_btree_node_iter_peek_all(&node_iter, parent); + BUG_ON(bkey_cmp_left_packed(parent, k, &b->key.k.p)); + + k = sib == btree_prev_sib + ? bch2_btree_node_iter_prev(&node_iter, parent) + : (bch2_btree_node_iter_advance(&node_iter, parent), + bch2_btree_node_iter_peek(&node_iter, parent)); + if (!k) + goto out; + + bch2_bkey_unpack(parent, &tmp.k, k); + + ret = bch2_btree_node_get(c, iter, &tmp.k, level, + SIX_LOCK_intent, may_drop_locks); + + if (PTR_ERR_OR_ZERO(ret) == -EINTR && may_drop_locks) { + struct btree_iter *linked; + + if (!bch2_btree_node_relock(iter, level + 1)) + goto out_upgrade; + + /* + * We might have got -EINTR because trylock failed, and we're + * holding other locks that would cause us to deadlock: + */ + for_each_linked_btree_iter(iter, linked) + if (btree_iter_cmp(iter, linked) < 0) + __bch2_btree_iter_unlock(linked); + + if (sib == btree_prev_sib) + btree_node_unlock(iter, level); + + ret = bch2_btree_node_get(c, iter, &tmp.k, level, + SIX_LOCK_intent, may_drop_locks); + + /* + * before btree_iter_relock() calls btree_iter_verify_locks(): + */ + if (btree_lock_want(iter, level + 1) == BTREE_NODE_UNLOCKED) + btree_node_unlock(iter, level + 1); + + if (!bch2_btree_node_relock(iter, level)) { + btree_iter_set_dirty(iter, BTREE_ITER_NEED_RELOCK); + + if (!IS_ERR(ret)) { + six_unlock_intent(&ret->lock); + ret = ERR_PTR(-EINTR); + } + } + + bch2_btree_iter_relock(iter); + } +out: + if (btree_lock_want(iter, level + 1) == BTREE_NODE_UNLOCKED) + btree_node_unlock(iter, level + 1); + + bch2_btree_iter_verify_locks(iter); + + BUG_ON((!may_drop_locks || !IS_ERR(ret)) && + (iter->uptodate >= BTREE_ITER_NEED_RELOCK || + !btree_node_locked(iter, level))); + + if (!IS_ERR_OR_NULL(ret)) { + struct btree *n1 = ret, *n2 = b; + + if (sib != btree_prev_sib) + swap(n1, n2); + + BUG_ON(bkey_cmp(btree_type_successor(n1->btree_id, + n1->key.k.p), + n2->data->min_key)); + } + + return ret; +out_upgrade: + if (may_drop_locks) + bch2_btree_iter_upgrade(iter, level + 2, true); + ret = ERR_PTR(-EINTR); + goto out; +} + +void bch2_btree_node_prefetch(struct bch_fs *c, struct btree_iter *iter, + const struct bkey_i *k, unsigned level) +{ + struct btree_cache *bc = &c->btree_cache; + struct btree *b; + + BUG_ON(!btree_node_locked(iter, level + 1)); + BUG_ON(level >= BTREE_MAX_DEPTH); + + rcu_read_lock(); + b = btree_cache_find(bc, k); + rcu_read_unlock(); + + if (b) + return; + + bch2_btree_node_fill(c, iter, k, level, SIX_LOCK_read, false); +} + +int bch2_print_btree_node(struct bch_fs *c, struct btree *b, + char *buf, size_t len) +{ + const struct bkey_format *f = &b->format; + struct bset_stats stats; + char ptrs[100]; + + memset(&stats, 0, sizeof(stats)); + + bch2_val_to_text(c, BKEY_TYPE_BTREE, ptrs, sizeof(ptrs), + bkey_i_to_s_c(&b->key)); + bch2_btree_keys_stats(b, &stats); + + return scnprintf(buf, len, + "l %u %llu:%llu - %llu:%llu:\n" + " ptrs: %s\n" + " format: u64s %u fields %u %u %u %u %u\n" + " unpack fn len: %u\n" + " bytes used %zu/%zu (%zu%% full)\n" + " sib u64s: %u, %u (merge threshold %zu)\n" + " nr packed keys %u\n" + " nr unpacked keys %u\n" + " floats %zu\n" + " failed unpacked %zu\n" + " failed prev %zu\n" + " failed overflow %zu\n", + b->level, + b->data->min_key.inode, + b->data->min_key.offset, + b->data->max_key.inode, + b->data->max_key.offset, + ptrs, + f->key_u64s, + f->bits_per_field[0], + f->bits_per_field[1], + f->bits_per_field[2], + f->bits_per_field[3], + f->bits_per_field[4], + 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], + BTREE_FOREGROUND_MERGE_THRESHOLD(c), + b->nr.packed_keys, + b->nr.unpacked_keys, + stats.floats, + stats.failed_unpacked, + stats.failed_prev, + stats.failed_overflow); +} |