[TCP]: Never TSO defer under periods of congestion.

Congestion window recover after loss depends upon the fact
that if we have a full MSS sized frame at the head of the
send queue, we will send it.  TSO deferral can defeat the
ACK clocking necessary to exit cleanly from recovery.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index fd3ce38184ae..e041d057ec86 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -909,6 +909,9 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
         if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)
                 return 0;
 
+        if (tp->ca_state != TCP_CA_Open)
+                return 0;
+
         in_flight = tcp_packets_in_flight(tp);
 
         BUG_ON(tcp_skb_pcount(skb) <= 1 ||