inet: Restore SO_REUSEADDR in case of rollback

tcp_repair_off implicitly modifies SO_REUSEADDR option
inside the kernel (thanks avagin@ for pointing this
feature out) thus if we are to rollback and restore
the former settings of socket -- don't forget to
repair this particular one.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/sk-inet.h

@@ -30,6 +30,7 @@ struct inet_sk_desc {
 	unsigned short		shutdown;
 
 	int rfd;
+	int cpt_reuseaddr;
 	struct list_head rlist;
 };
 

sk-inet.c

@@ -295,6 +295,7 @@ static int do_dump_one_inet_fd(int lfd, u32 id, const struct fd_parms *p, int fa
 	show_one_inet("Dumping", sk);
 	show_one_inet_img("Dumped", &ie);
 	sk->sd.already_dumped = 1;
+	sk->cpt_reuseaddr = skopts.reuseaddr;
 
 	switch (proto) {
 	case IPPROTO_TCP:

sk-tcp.c

@@ -157,6 +157,13 @@ static void tcp_unlock_one(struct inet_sk_desc *sk)
 		pr_perror("Failed to unlock TCP connection");
 
 	tcp_repair_off(sk->rfd);
+
+	/*
+	 * tcp_repair_off modifies SO_REUSEADDR so
+	 * don't forget to restore original value.
+	 */
+	restore_opt(sk->rfd, SOL_SOCKET, SO_REUSEADDR, &sk->cpt_reuseaddr);
+
 	close(sk->rfd);
 }