From: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Date: Thu, 30 Jun 2016 23:11:17 +0000 (-0700)
Subject: RDS: TCP: Simplify reconnect to avoid duelling reconnnect attempts
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=8315011ad67670691545ed394968435f0a0bb29e;p=deliverable%2Flinux.git

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/connection.c b/net/rds/connection.c
index 1b0c2a783b5e..19a4fee5f4dd 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -355,9 +355,7 @@ void rds_conn_shutdown(struct rds_conn_path *cp)
 	rcu_read_lock();
 	if (!hlist_unhashed(&conn->c_hash_node)) {
 		rcu_read_unlock();
-		if (conn->c_trans->t_type != RDS_TRANS_TCP ||
-		    cp->cp_outgoing == 1)
-			rds_queue_reconnect(cp);
+		rds_queue_reconnect(cp);
 	} else {
 		rcu_read_unlock();
 	}
diff --git a/net/rds/threads.c b/net/rds/threads.c
index e8f0941f0548..bc97d67f29cc 100644
--- a/net/rds/threads.c
+++ b/net/rds/threads.c
@@ -125,6 +125,11 @@ void rds_queue_reconnect(struct rds_conn_path *cp)
 	  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;