bcachefs: fix btree iterators when btree depth == 3

3 files changed, 23 insertions, 10 deletions

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index ee463f36823c..93689542cf8c 100644
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -510,11 +510,15 @@ static inline void __btree_iter_advance(struct btree_iter *iter)
  */
 static void btree_iter_verify_new_node(struct btree_iter *iter, struct btree *b)
 {
+	struct btree *parent;
 	bool parent_locked;
 	struct bkey_packed *k;
 
-	if (!IS_ENABLED(CONFIG_BCACHEFS_DEBUG) ||
-	    !iter->nodes[b->level + 1])
+	if (!IS_ENABLED(CONFIG_BCACHEFS_DEBUG))
+		return;
+
+	parent = btree_node_parent(iter, b);
+	if (!parent)
 		return;
 
 	parent_locked = btree_node_locked(iter, b->level + 1);
@@ -523,11 +527,10 @@ static void btree_iter_verify_new_node(struct btree_iter *iter, struct btree *b)
 		return;
 
 	k = bch2_btree_node_iter_peek_all(&iter->node_iters[b->level + 1],
-					 iter->nodes[b->level + 1]);
+					  parent);
 	if (!k ||
 	    bkey_deleted(k) ||
-	    bkey_cmp_left_packed(iter->nodes[b->level + 1],
-				 k, &b->key.k.p)) {
+	    bkey_cmp_left_packed(parent, k, &b->key.k.p)) {
 		char buf[100];
 		struct bkey uk = bkey_unpack_key(b, k);
 
@@ -902,7 +905,8 @@ int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter)
 	 * btree_iter_lock_root() comes next and that it can't fail
 	 */
 	while (iter->level > depth_want) {
-		int ret = iter->nodes[iter->level]
+		int ret = iter->level < BTREE_MAX_DEPTH &&
+			iter->nodes[iter->level]
 			? btree_iter_down(iter)
 			: btree_iter_lock_root(iter, depth_want);
 		if (unlikely(ret)) {
diff --git a/fs/bcachefs/btree_iter.h b/fs/bcachefs/btree_iter.h
index 8feb2a574e29..75105dd3d1f7 100644
--- a/fs/bcachefs/btree_iter.h
+++ b/fs/bcachefs/btree_iter.h
@@ -73,6 +73,14 @@ struct btree_iter {
 	struct btree_iter	*next;
 };
 
+static inline struct btree *btree_node_parent(struct btree_iter *iter,
+					      struct btree *b)
+{
+	unsigned level = b->level + 1;
+
+	return level < BTREE_MAX_DEPTH ? iter->nodes[level] : NULL;
+}
+
 static inline bool btree_iter_linked(const struct btree_iter *iter)
 {
 	return iter->next != iter;
diff --git a/fs/bcachefs/btree_update_interior.c b/fs/bcachefs/btree_update_interior.c
index 41d78eb480bc..56708ea61770 100644
--- a/fs/bcachefs/btree_update_interior.c
+++ b/fs/bcachefs/btree_update_interior.c
@@ -393,6 +393,7 @@ static struct btree *bch2_btree_node_alloc(struct btree_update *as, unsigned lev
 	struct bch_fs *c = as->c;
 	struct btree *b;
 
+	BUG_ON(level >= BTREE_MAX_DEPTH);
 	BUG_ON(!as->reserve->nr);
 
 	b = as->reserve->b[--as->reserve->nr];
@@ -1344,7 +1345,7 @@ static void btree_split(struct btree_update *as, struct btree *b,
 			struct btree_iter *iter, struct keylist *keys)
 {
 	struct bch_fs *c = as->c;
-	struct btree *parent = iter->nodes[b->level + 1];
+	struct btree *parent = btree_node_parent(iter, b);
 	struct btree *n1, *n2 = NULL, *n3 = NULL;
 	u64 start_time = local_clock();
 
@@ -1600,7 +1601,7 @@ retry:
 
 	b = iter->nodes[iter->level];
 
-	parent = iter->nodes[b->level + 1];
+	parent = btree_node_parent(iter, b);
 	if (!parent)
 		return 0;
 
@@ -1737,7 +1738,7 @@ static int __btree_node_rewrite(struct bch_fs *c, struct btree_iter *iter,
 				struct btree *b, unsigned flags,
 				struct closure *cl)
 {
-	struct btree *n, *parent = iter->nodes[b->level + 1];
+	struct btree *n, *parent = btree_node_parent(iter, b);
 	struct btree_update *as;
 
 	as = bch2_btree_update_start(c, iter->btree_id,
@@ -1869,7 +1870,7 @@ static void __bch2_btree_node_update_key(struct bch_fs *c,
 
 	btree_interior_update_add_node_reference(as, b);
 
-	parent = iter->nodes[b->level + 1];
+	parent = btree_node_parent(iter, b);
 	if (parent) {
 		if (new_hash) {
 			bkey_copy(&new_hash->key, &new_key->k_i);