[PATCH 2/3 resend] TCP_DEFER_ACCEPT updates - dont retxmt synack

[Patrick McManus <mcmanus@ducksong.com>]

commit 95dea62ad7004a1de84e1f38c1b5243e1cb0d554
Author: Patrick McManus <mcmanus@ducksong.com>
Date:   Sat Feb 23 15:59:22 2008 -0500

    a socket in LISTEN that had completed its 3 way handshake, but not notified
    userspace because of SO_DEFER_ACCEPT, would retransmit the already
    acked syn-ack during the time it was waiting for the first data byte
    from the peer.
    
    Signed-off-by: Patrick McManus <mcmanus@ducksong.com>
    Acked-by: Eric Dumazet <dada1@cosmosbay.com>

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 03cc323..3380d04 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -461,8 +461,9 @@ void inet_csk_reqsk_queue_prune(struct sock *parent,
 		reqp=&lopt->syn_table[i];
 		while ((req = *reqp) != NULL) {
 			if (time_after_eq(now, req->expires)) {
-				if ((req->retrans < (inet_rsk(req)->acked ? max_retries : thresh))
-				    && !req->rsk_ops->rtx_syn_ack(parent, req, NULL)) {
+				if ((req->retrans < (inet_rsk(req)->acked ? max_retries : thresh)) &&
+				    (inet_rsk(req)->acked ||
+				     !req->rsk_ops->rtx_syn_ack(parent, req, NULL))) {
 					unsigned long timeo;
 
 					if (req->retrans++ == 0)