bcachefs: New helper __bch2_btree_insert_keys_interior()

Consolidate common parts of bch2_btree_insert_keys_interior() and
btree_split_insert_keys() - prep work for adding some new topology
assertions.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_update_interior.c

@@ -1154,6 +1154,27 @@ static void bch2_insert_fixup_btree_ptr(struct btree_update *as, struct btree *b
 	set_btree_node_need_write(b);
 }
 
+static void
+__bch2_btree_insert_keys_interior(struct btree_update *as, struct btree *b,
+				  struct btree_iter *iter, struct keylist *keys,
+				  struct btree_node_iter node_iter)
+{
+	struct bkey_i *insert = bch2_keylist_front(keys);
+	struct bkey_packed *k;
+
+	BUG_ON(btree_node_type(b) != BKEY_TYPE_btree);
+
+	while ((k = bch2_btree_node_iter_prev_all(&node_iter, b)) &&
+	       (bkey_cmp_left_packed(b, k, &insert->k.p) >= 0))
+		;
+
+	while (!bch2_keylist_empty(keys)) {
+		bch2_insert_fixup_btree_ptr(as, b, iter,
+				bch2_keylist_front(keys), &node_iter);
+		bch2_keylist_pop_front(keys);
+	}
+}
+
 /*
  * Move keys from n1 (original replacement node, now lower node) to n2 (higher
  * node)
@@ -1284,16 +1305,9 @@ static void btree_split_insert_keys(struct btree_update *as, struct btree *b,
 	struct bkey_packed *src, *dst, *n;
 	struct bset *i;
 
-	BUG_ON(btree_node_type(b) != BKEY_TYPE_btree);
-
 	bch2_btree_node_iter_init(&node_iter, b, &k->k.p);
 
-	while (!bch2_keylist_empty(keys)) {
-		k = bch2_keylist_front(keys);
-
-		bch2_insert_fixup_btree_ptr(as, b, iter, k, &node_iter);
-		bch2_keylist_pop_front(keys);
-	}
+	__bch2_btree_insert_keys_interior(as, b, iter, keys, node_iter);
 
 	/*
 	 * We can't tolerate whiteouts here - with whiteouts there can be
@@ -1439,24 +1453,8 @@ bch2_btree_insert_keys_interior(struct btree_update *as, struct btree *b,
 				struct btree_iter *iter, struct keylist *keys)
 {
 	struct btree_iter *linked;
-	struct btree_node_iter node_iter;
-	struct bkey_i *insert = bch2_keylist_front(keys);
-	struct bkey_packed *k;
-
-	/* Don't screw up @iter's position: */
-	node_iter = iter->l[b->c.level].iter;
-
-	/*
-	 * btree_split(), btree_gc_coalesce() will insert keys before
-	 * the iterator's current position - they know the keys go in
-	 * the node the iterator points to:
-	 */
-	while ((k = bch2_btree_node_iter_prev_all(&node_iter, b)) &&
-	       (bkey_cmp_left_packed(b, k, &insert->k.p) >= 0))
-		;
 
-	for_each_keylist_key(keys, insert)
-		bch2_insert_fixup_btree_ptr(as, b, iter, insert, &node_iter);
+	__bch2_btree_insert_keys_interior(as, b, iter, keys, iter->l[b->c.level].iter);
 
 	btree_update_updated_node(as, b);