From 7b5ddd26bcf1f72e16e121c02533ee6192a3eea0 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Sat, 8 Jun 2024 17:01:31 -0400 Subject: [PATCH 231/233] bcachefs: Write lock btree node in key cache fills Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit this addresses a key cache coherency bug Signed-off-by: Kent Overstreet Signed-off-by: Alexander Miroshnichenko --- fs/bcachefs/btree_key_cache.c | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-) diff --git a/fs/bcachefs/btree_key_cache.c b/fs/bcachefs/btree_key_cache.c index 4eba2871f289..382f99b774b8 100644 --- a/fs/bcachefs/btree_key_cache.c +++ b/fs/bcachefs/btree_key_cache.c @@ -197,7 +197,9 @@ bkey_cached_reuse(struct btree_key_cache *c) return ck; } -static int btree_key_cache_create(struct btree_trans *trans, struct btree_path *path, +static int btree_key_cache_create(struct btree_trans *trans, + struct btree_path *path, + struct btree_path *ck_path, struct bkey_s_c k) { struct bch_fs *c = trans->c; @@ -217,7 +219,7 @@ static int btree_key_cache_create(struct btree_trans *trans, struct btree_path * 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); + struct bkey_cached *ck = bkey_cached_alloc(trans, ck_path, key_u64s); int ret = PTR_ERR_OR_ZERO(ck); if (ret) return ret; @@ -226,19 +228,19 @@ static int btree_key_cache_create(struct btree_trans *trans, struct btree_path * 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)); + bch2_btree_id_str(ck_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->c.btree_id = ck_path->btree_id; + ck->key.btree_id = ck_path->btree_id; + ck->key.pos = ck_path->pos; ck->flags = 1U << BKEY_CACHED_ACCESSED; if (unlikely(key_u64s > ck->u64s)) { - mark_btree_node_locked_noreset(path, 0, BTREE_NODE_UNLOCKED); + mark_btree_node_locked_noreset(ck_path, 0, BTREE_NODE_UNLOCKED); struct bkey_i *new_k = allocate_dropping_locks(trans, ret, kmalloc(key_u64s * sizeof(u64), _gfp)); @@ -258,22 +260,29 @@ static int btree_key_cache_create(struct btree_trans *trans, struct btree_path * bkey_reassemble(ck->k, k); + ret = bch2_btree_node_lock_write(trans, path, &path_l(path)->b->c); + if (unlikely(ret)) + goto err; + ret = rhashtable_lookup_insert_fast(&bc->table, &ck->hash, bch2_btree_key_cache_params); + + bch2_btree_node_unlock_write(trans, path, path_l(path)->b); + 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); + enum six_lock_type lock_want = __btree_lock_want(ck_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; + btree_path_cached_set(trans, ck_path, ck, (enum btree_node_locked_type) lock_want); + ck_path->uptodate = BTREE_ITER_UPTODATE; return 0; err: bkey_cached_free(bc, ck); - mark_btree_node_locked_noreset(path, 0, BTREE_NODE_UNLOCKED); + mark_btree_node_locked_noreset(ck_path, 0, BTREE_NODE_UNLOCKED); return ret; } @@ -293,6 +302,7 @@ static noinline int btree_key_cache_fill(struct btree_trans *trans, int ret; bch2_trans_iter_init(trans, &iter, ck_path->btree_id, ck_path->pos, + BTREE_ITER_intent| BTREE_ITER_key_cache_fill| BTREE_ITER_cached_nofill); iter.flags &= ~BTREE_ITER_with_journal; @@ -306,7 +316,7 @@ static noinline int btree_key_cache_fill(struct btree_trans *trans, if (unlikely(ret)) goto out; - ret = btree_key_cache_create(trans, ck_path, k); + ret = btree_key_cache_create(trans, btree_iter_path(trans, &iter), ck_path, k); if (ret) goto err; -- 2.45.2