From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Yan, Zheng" Subject: [PATCH] tcp: properly update lost_cnt_hint during shifting Date: Wed, 28 Sep 2011 14:38:21 +0800 Message-ID: <4E82C0DD.6010304@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: "netdev@vger.kernel.org" , ilpo.jarvinen@helsinki.fi Return-path: Received: from mga02.intel.com ([134.134.136.20]:50185 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751112Ab1I1GiX (ORCPT ); Wed, 28 Sep 2011 02:38:23 -0400 Sender: netdev-owner@vger.kernel.org List-ID: lost_skb_hint is used by tcp_mark_head_lost() to mark the first unhandled skb. lost_cnt_hint is the number of sacked packets before the lost_skb_hint. tcp_shifted_skb() shouldn't increase lost_cnt_hint when shifting a sacked skb that is before the lost_skb_hint, because packets in it are already counted. Signed-off-by: Zheng Yan --- diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 21fab3e..f712ace 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1390,9 +1390,14 @@ static int tcp_shifted_skb(struct sock *sk, struct sk_buff *skb, BUG_ON(!pcount); /* Tweak before seqno plays */ - if (!tcp_is_fack(tp) && tcp_is_sack(tp) && tp->lost_skb_hint && - !before(TCP_SKB_CB(tp->lost_skb_hint)->seq, TCP_SKB_CB(skb)->seq)) - tp->lost_cnt_hint += pcount; + if (!tcp_is_fack(tp) && tcp_is_sack(tp) && tp->lost_skb_hint) { + if (skb == tp->lost_skb_hint) + tp->lost_cnt_hint += pcount; + else if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) && + before(TCP_SKB_CB(skb)->seq, + TCP_SKB_CB(tp->lost_skb_hint)->seq)) + tp->lost_cnt_hint += pcount; + } TCP_SKB_CB(prev)->end_seq += shifted; TCP_SKB_CB(skb)->seq += shifted;