From patchwork Thu Dec 13 13:59:41 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herton Ronaldo Krzesinski X-Patchwork-Id: 206443 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id 53A382C0097 for ; Fri, 14 Dec 2012 23:58:29 +1100 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1TjUqF-0003hv-2E; Fri, 14 Dec 2012 12:58:15 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1Tj9Y8-00072r-M5 for kernel-team@lists.ubuntu.com; Thu, 13 Dec 2012 14:14:08 +0000 Received: from 200.139.123.215.dynamic.adsl.gvt.net.br ([200.139.123.215] helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1Tj9Y7-0004py-42; Thu, 13 Dec 2012 14:14:07 +0000 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 216/241] tcp: fix retransmission in repair mode Date: Thu, 13 Dec 2012 11:59:41 -0200 Message-Id: <1355407206-17100-217-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1355407206-17100-1-git-send-email-herton.krzesinski@canonical.com> References: <1355407206-17100-1-git-send-email-herton.krzesinski@canonical.com> X-Mailman-Approved-At: Fri, 14 Dec 2012 12:58:12 +0000 Cc: Andrey Vagin , Pavel Emelyanov , Hideaki YOSHIFUJI , James Morris , "David S. Miller" , Alexey Kuznetsov , Patrick McHardy X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com 3.5.7.2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Vagin commit ec34232575083fd0f43d3a101e8ebb041b203761 upstream. Currently if a socket was repaired with a few packet in a write queue, a kernel bug may be triggered: kernel BUG at net/ipv4/tcp_output.c:2330! RIP: 0010:[] tcp_retransmit_skb+0x5ff/0x610 According to the initial realization v3.4-rc2-963-gc0e88ff, all skb-s should look like already posted. This patch fixes code according with this sentence. Here are three points, which were not done in the initial patch: 1. A tcp send head should not be changed 2. Initialize TSO state of a skb 3. Reset the retransmission time This patch moves logic from tcp_sendmsg to tcp_write_xmit. A packet passes the ussual way, but isn't sent to network. This patch solves all described problems and handles tcp_sendpages. Cc: Pavel Emelyanov Cc: "David S. Miller" Cc: Alexey Kuznetsov Cc: James Morris Cc: Hideaki YOSHIFUJI Cc: Patrick McHardy Signed-off-by: Andrey Vagin Acked-by: Pavel Emelyanov Signed-off-by: David S. Miller [ herton: adjust context ] Signed-off-by: Herton Ronaldo Krzesinski --- net/ipv4/tcp.c | 4 ++-- net/ipv4/tcp_output.c | 4 ++++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index d758741..34b23da 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1180,7 +1180,7 @@ new_segment: wait_for_sndbuf: set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); wait_for_memory: - if (copied && likely(!tp->repair)) + if (copied) tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) @@ -1191,7 +1191,7 @@ wait_for_memory: } out: - if (copied && likely(!tp->repair)) + if (copied) tcp_push(sk, flags, mss_now, tp->nonagle); release_sock(sk); return copied; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 90b10d0..305aafe 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1784,6 +1784,9 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, tso_segs = tcp_init_tso_segs(sk, skb, mss_now); BUG_ON(!tso_segs); + if (unlikely(tp->repair) && tp->repair_queue == TCP_SEND_QUEUE) + goto repair; /* Skip network transmission */ + cwnd_quota = tcp_cwnd_test(tp, skb); if (!cwnd_quota) break; @@ -1817,6 +1820,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, if (unlikely(tcp_transmit_skb(sk, skb, 1, gfp))) break; +repair: /* Advance the send_head. This one is sent out. * This call will increment packets_out. */