mutex_lock(&c->pending_node_rewrites_lock);
list_add(&a->list, &c->pending_node_rewrites);
mutex_unlock(&c->pending_node_rewrites_lock);
mutex_lock(&c->pending_node_rewrites_lock);
list_add(&a->list, &c->pending_node_rewrites);
mutex_unlock(&c->pending_node_rewrites_lock);