restore: disable repair mode in post_open()

A disabling repair mode drops SO_REUSEADDR.

We can set SO_REUSEADDR after disabling repair mode, but
a small race window exists in this case.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/sk-inet.h

@@ -33,6 +33,7 @@ struct inet_sk_info {
 int inet_bind(int sk, struct inet_sk_info *);
 int inet_connect(int sk, struct inet_sk_info *);
 
+void tcp_repair_off(int sk);
 void tcp_unlock_all(void);
 void tcp_locked_conn_add(struct inet_sk_info *);
 void tcp_unlock_connections(void);

sk-inet.c

@@ -403,16 +403,23 @@ static int inet_validate_address(InetSkEntry *ie)
 static int post_open_inet_sk(struct file_desc *d, int sk)
 {
 	struct inet_sk_info *ii;
-	int no = 0;
+	int val;
 
 	ii = container_of(d, struct inet_sk_info, d);
 
-	if (!ii->ie->opts->reuseaddr) {
+	/* SO_REUSEADDR is set for all sockets */
+	if (!tcp_connection(ii->ie) && ii->ie->opts->reuseaddr)
+		return 0;
+
 	futex_wait_until(&ii->port->users, 0);
 
-		if (restore_opt(sk, SOL_SOCKET, SO_REUSEADDR, &no))
+	/* Disabling repair mode drops SO_REUSEADDR */
+	if (tcp_connection(ii->ie))
+		tcp_repair_off(sk);
+
+	val = ii->ie->opts->reuseaddr;
+	if (restore_opt(sk, SOL_SOCKET, SO_REUSEADDR, &val))
 		return -1;
-	}
 
 	return 0;
 }

sk-tcp.c

@@ -55,7 +55,7 @@ static int tcp_repair_on(int fd)
 	return ret;
 }
 
-static void tcp_repair_off(int fd)
+void tcp_repair_off(int fd)
 {
 	int aux = 0;
 
@@ -484,7 +484,6 @@ int restore_one_tcp(int fd, struct inet_sk_info *ii)
 	if (restore_tcp_conn_state(fd, ii))
 		return -1;
 
-	tcp_repair_off(fd);
 	return 0;
 }