bcachefs: refactor bch2_btree_node_prefetch()

3 files changed, 22 insertions, 34 deletions

diff --git a/fs/bcachefs/btree_cache.c b/fs/bcachefs/btree_cache.c
index 798f7be00cec..e347368e7afc 100644
--- a/fs/bcachefs/btree_cache.c
+++ b/fs/bcachefs/btree_cache.c
@@ -577,10 +577,11 @@ err:
 
 /* 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)
+				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;
@@ -590,6 +591,7 @@ static noinline struct btree *bch2_btree_node_fill(struct bch_fs *c,
 	 * 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))
@@ -623,9 +625,15 @@ static noinline struct btree *bch2_btree_node_fill(struct bch_fs *c,
 	if (btree_node_read_locked(iter, level + 1))
 		btree_node_unlock(iter, level + 1);
 
-	bch2_btree_node_read(c, b, true);
+	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);
 
@@ -670,7 +678,7 @@ retry:
 		 * 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);
+		b = bch2_btree_node_fill(c, iter, k, level, lock_type, true);
 
 		/* We raced and found the btree node in the cache */
 		if (!b)
@@ -855,12 +863,13 @@ out_upgrade:
 	goto out;
 }
 
-void bch2_btree_node_prefetch(struct bch_fs *c, const struct bkey_i *k,
-			      unsigned level, enum btree_id btree_id)
+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();
@@ -870,27 +879,7 @@ void bch2_btree_node_prefetch(struct bch_fs *c, const struct bkey_i *k,
 	if (b)
 		return;
 
-	b = bch2_btree_node_mem_alloc(c);
-	if (IS_ERR(b))
-		return;
-
-	bkey_copy(&b->key, k);
-	if (bch2_btree_node_hash_insert(bc, b, level, 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);
-		goto out;
-	}
-
-	bch2_btree_node_read(c, b, false);
-out:
-	six_unlock_write(&b->lock);
-	six_unlock_intent(&b->lock);
+	bch2_btree_node_fill(c, iter, k, level, SIX_LOCK_read, false);
 }
 
 int bch2_print_btree_node(struct bch_fs *c, struct btree *b,
diff --git a/fs/bcachefs/btree_cache.h b/fs/bcachefs/btree_cache.h
index 43109d086479..a89183996a4f 100644
--- a/fs/bcachefs/btree_cache.h
+++ b/fs/bcachefs/btree_cache.h
@@ -29,8 +29,8 @@ struct btree *bch2_btree_node_get_sibling(struct bch_fs *, struct btree_iter *,
 					  struct btree *, bool,
 					  enum btree_node_sibling);
 
-void bch2_btree_node_prefetch(struct bch_fs *, const struct bkey_i *,
-			      unsigned, enum btree_id);
+void bch2_btree_node_prefetch(struct bch_fs *, struct btree_iter *,
+			      const struct bkey_i *, unsigned);
 
 void bch2_fs_btree_cache_exit(struct bch_fs *);
 int bch2_fs_btree_cache_init(struct bch_fs *);
diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index 09f360712a23..3ad9f8f275f5 100644
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -834,9 +834,8 @@ static void btree_iter_prefetch(struct btree_iter *iter)
 			break;
 
 		bch2_bkey_unpack(l->b, &tmp.k, k);
-		bch2_btree_node_prefetch(iter->c, &tmp.k,
-					 iter->level - 1,
-					 iter->btree_id);
+		bch2_btree_node_prefetch(iter->c, iter, &tmp.k,
+					 iter->level - 1);
 	}
 
 	if (!was_locked)