+ if (rt6->rt6i_flags & RTF_CACHE) {
+ rt6_do_update_pmtu(rt6, mtu);
+ } else {
+ const struct in6_addr *daddr, *saddr;
+ struct rt6_info *nrt6;
+
+ if (iph) {
+ daddr = &iph->daddr;
+ saddr = &iph->saddr;
+ } else if (sk) {
+ daddr = &sk->sk_v6_daddr;
+ saddr = &inet6_sk(sk)->saddr;
+ } else {
+ return;
+ }
+ nrt6 = ip6_rt_cache_alloc(rt6, daddr, saddr);
+ if (nrt6) {
+ rt6_do_update_pmtu(nrt6, mtu);
+
+ /* ip6_ins_rt(nrt6) will bump the
+ * rt6->rt6i_node->fn_sernum
+ * which will fail the next rt6_check() and
+ * invalidate the sk->sk_dst_cache.
+ */
+ ip6_ins_rt(nrt6);
+ }