vni_head
hlist_for_each_entry_rcu(node, vni_head(vs, vni), hlist) {
hlist_add_head_rcu(&node->hlist, vni_head(vs, vni));
hlist_add_head_rcu(&node->hlist, vni_head(vs, v->vni));
hlist_add_head_rcu(&node->hlist, vni_head(vs, v->vni));
hlist_add_head_rcu(&node->hlist, vni_head(vs, v->vni));