RDS: TCP: Simplify reconnect to avoid duelling reconnnect attempts

When reconnecting, the peer with the smaller IP address will initiate
the reconnect, to avoid needless duelling SYN issues.

Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/threads.c b/net/rds/threads.c
index e8f0941..bc97d67 100644
--- a/net/rds/threads.c
+++ b/net/rds/threads.c
@@ -125,6 +125,11 @@
 	  conn, &conn->c_laddr, &conn->c_faddr,
 	  cp->cp_reconnect_jiffies);
 
+	/* let peer with smaller addr initiate reconnect, to avoid duels */
+	if (conn->c_trans->t_type == RDS_TRANS_TCP &&
+	    conn->c_laddr > conn->c_faddr)
+		return;
+
 	set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags);
 	if (cp->cp_reconnect_jiffies == 0) {
 		cp->cp_reconnect_jiffies = rds_sysctl_reconnect_min_jiffies;