From patchwork Tue Oct 9 04:57:27 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "jeff.liu" X-Patchwork-Id: 190202 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id D74DF2C00D6 for ; Tue, 9 Oct 2012 15:58:48 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752045Ab2JIE6q (ORCPT ); Tue, 9 Oct 2012 00:58:46 -0400 Received: from acsinet15.oracle.com ([141.146.126.227]:22788 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750952Ab2JIE6o (ORCPT ); Tue, 9 Oct 2012 00:58:44 -0400 Received: from acsinet22.oracle.com (acsinet22.oracle.com [141.146.126.238]) by acsinet15.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id q994wfTG001429 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 9 Oct 2012 04:58:42 GMT Received: from acsmt358.oracle.com (acsmt358.oracle.com [141.146.40.158]) by acsinet22.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id q994wfF9008993 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 9 Oct 2012 04:58:41 GMT Received: from abhmt102.oracle.com (abhmt102.oracle.com [141.146.116.54]) by acsmt358.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id q994wfdN024248; Mon, 8 Oct 2012 23:58:41 -0500 Received: from [192.168.1.102] (/123.119.96.149) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 08 Oct 2012 21:58:40 -0700 Message-ID: <5073AEB7.9060309@oracle.com> Date: Tue, 09 Oct 2012 12:57:27 +0800 From: Jeff Liu Reply-To: jeff.liu@oracle.com Organization: Oracle User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.28) Gecko/20120313 Thunderbird/3.1.20 MIME-Version: 1.0 To: rds-devel@oss.oracle.com CC: Venkat Venkatsubra , davem@davemloft.net, Dan Carpenter , James Morris , netdev@vger.kernel.org Subject: [PATCH v2] RDS: fix rds-ping spinlock recursion X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hello, This is the revised patch for fixing rds-ping spinlock recursion according to Venkat's suggestions. RDS ping/pong over TCP feature has been broken for years(2.6.39 to 3.6.0) since we have to set TCP cork and call kernel_sendmsg() between ping/pong which both need to lock "struct sock *sk". However, this lock has already been hold before rds_tcp_data_ready() callback is triggerred. As a result, we always facing spinlock resursion which would resulting in system panic. Given that RDS ping is only used to test the connectivity and not for serious performance measurements, we can queue the pong transmit to rds_wq as a delayed response. Reported-by: Dan Carpenter CC: Venkat Venkatsubra CC: David S. Miller CC: James Morris Signed-off-by: Jie Liu --- net/rds/send.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/rds/send.c b/net/rds/send.c index 96531d4..88eace5 100644 --- a/net/rds/send.c +++ b/net/rds/send.c @@ -1122,7 +1122,7 @@ rds_send_pong(struct rds_connection *conn, __be16 dport) rds_stats_inc(s_send_pong); if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags)) - rds_send_xmit(conn); + queue_delayed_work(rds_wq, &conn->c_send_w, 0); rds_message_put(rm); return 0;