From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934889Ab1KJD1v (ORCPT ); Wed, 9 Nov 2011 22:27:51 -0500 Received: from cantor2.suse.de ([195.135.220.15]:42418 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934856Ab1KJD1j (ORCPT ); Wed, 9 Nov 2011 22:27:39 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Nov 9 13:27:15 2011 Message-Id: <20111109212715.001132361@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 09 Nov 2011 13:27:45 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Zheng Yan , "David S. Miller" Subject: [143/262] tcp: properly update lost_cnt_hint during shifting In-Reply-To: <20111109212847.GA20838@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Yan, Zheng" [ Upstream commit 1e5289e121372a3494402b1b131b41bfe1cf9b7f ] lost_skb_hint is used by tcp_mark_head_lost() to mark the first unhandled skb. lost_cnt_hint is the number of packets or sacked packets before the lost_skb_hint; When shifting a skb that is before the lost_skb_hint, if tcp_is_fack() is ture, the skb has already been counted in the lost_cnt_hint; if tcp_is_fack() is false, tcp_sacktag_one() will increase the lost_cnt_hint. So tcp_shifted_skb() does not need to adjust the lost_cnt_hint by itself. When shifting a skb that is equal to lost_skb_hint, the shifted packets will not be counted by tcp_mark_head_lost(). So tcp_shifted_skb() should adjust the lost_cnt_hint even tcp_is_fack(tp) is true. Signed-off-by: Zheng Yan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_input.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1380,9 +1380,7 @@ static int tcp_shifted_skb(struct sock * 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)) + if (skb == tp->lost_skb_hint) tp->lost_cnt_hint += pcount; TCP_SKB_CB(prev)->end_seq += shifted;