[NETNS]: Add netns refcnt debug for timewait buckets.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/inet_timewait_sock.c

@@ -57,6 +57,7 @@ void inet_twsk_put(struct inet_timewait_sock *tw)
 		printk(KERN_DEBUG "%s timewait_sock %p released\n",
 		       tw->tw_prot->name, tw);
 #endif
+		release_net(twsk_net(tw));
 		kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);
 		module_put(owner);
 	}
@@ -124,7 +125,7 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int stat
 		tw->tw_hash	    = sk->sk_hash;
 		tw->tw_ipv6only	    = 0;
 		tw->tw_prot	    = sk->sk_prot_creator;
-		twsk_net_set(tw, sock_net(sk));
+		twsk_net_set(tw, hold_net(sock_net(sk)));
 		atomic_set(&tw->tw_refcnt, 1);
 		inet_twsk_dead_node_init(tw);
 		__module_get(tw->tw_prot->owner);