From 1fdf475aa141a669af8db6ccc7015f0b725087de Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 30 Nov 2009 12:53:30 -0800
Subject: [PATCH] tcp: tcp_disconnect() should clear window_clamp

NFS can reuse its TCP socket after calling tcp_disconnect().

We noticed window scaling was not negotiated in SYN packet of next
connection request.

Fix is to clear tp->window_clamp in tcp_disconnect().

Reported-by: Krzysztof Oledzki <ole@ans.pl>
Tested-by: Krzysztof Oledzki <ole@ans.pl>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/tcp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f1813bc71088..d7a884c534a6 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2059,6 +2059,7 @@ int tcp_disconnect(struct sock *sk, int flags)
 	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
 	tp->snd_cwnd_cnt = 0;
 	tp->bytes_acked = 0;
+	tp->window_clamp = 0;
 	tcp_set_ca_state(sk, TCP_CA_Open);
 	tcp_clear_retrans(tp);
 	inet_csk_delack_init(sk);