From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6ECABC433F4 for ; Tue, 18 Sep 2018 13:47:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 29CC82146D for ; Tue, 18 Sep 2018 13:47:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 29CC82146D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730082AbeIRTTv (ORCPT ); Tue, 18 Sep 2018 15:19:51 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:36968 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729979AbeIRTTb (ORCPT ); Tue, 18 Sep 2018 15:19:31 -0400 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w8IDd8hS090490 for ; Tue, 18 Sep 2018 09:46:50 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2mk0t0db70-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 18 Sep 2018 09:46:49 -0400 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 18 Sep 2018 14:46:44 +0100 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w8IDkhJu47972582 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 18 Sep 2018 13:46:43 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B0A6711C04C; Tue, 18 Sep 2018 16:46:28 +0100 (BST) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7446011C06E; Tue, 18 Sep 2018 16:46:28 +0100 (BST) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 18 Sep 2018 16:46:28 +0100 (BST) From: Ursula Braun To: davem@davemloft.net Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, raspl@linux.ibm.com, linux-kernel@vger.kernel.org Subject: [PATCH net 2/5] net/smc: remove duplicate mutex_unlock Date: Tue, 18 Sep 2018 15:46:35 +0200 X-Mailer: git-send-email 2.16.4 In-Reply-To: <20180918134638.90271-1-ubraun@linux.ibm.com> References: <20180918134638.90271-1-ubraun@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18091813-4275-0000-0000-000002BBDBCA X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18091813-4276-0000-0000-000037C525C7 Message-Id: <20180918134638.90271-3-ubraun@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-09-18_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1809180139 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For a failing smc_listen_rdma_finish() smc_listen_decline() is called. If fallback is possible, the new socket is already enqueued to be accepted in smc_listen_decline(). Avoid enqueuing a second time afterwards in this case, otherwise the smc_create_lgr_pending lock is released twice: [ 373.463976] WARNING: bad unlock balance detected! [ 373.463978] 4.18.0-rc7+ #123 Tainted: G O [ 373.463979] ------------------------------------- [ 373.463980] kworker/1:1/30 is trying to release lock (smc_create_lgr_pending) at: [ 373.463990] [<000003ff801205fc>] smc_listen_work+0x22c/0x5d0 [smc] [ 373.463991] but there are no more locks to release! [ 373.463991] other info that might help us debug this: [ 373.463993] 2 locks held by kworker/1:1/30: [ 373.463994] #0: 00000000772cbaed ((wq_completion)"events"){+.+.}, at: process_one_work+0x1ec/0x6b0 [ 373.464000] #1: 000000003ad0894a ((work_completion)(&new_smc->smc_listen_work)){+.+.}, at: process_one_work+0x1ec/0x6b0 [ 373.464003] stack backtrace: [ 373.464005] CPU: 1 PID: 30 Comm: kworker/1:1 Kdump: loaded Tainted: G O 4.18.0-rc7uschi+ #123 [ 373.464007] Hardware name: IBM 2827 H43 738 (LPAR) [ 373.464010] Workqueue: events smc_listen_work [smc] [ 373.464011] Call Trace: [ 373.464015] ([<0000000000114100>] show_stack+0x60/0xd8) [ 373.464019] [<0000000000a8c9bc>] dump_stack+0x9c/0xd8 [ 373.464021] [<00000000001dcaf8>] print_unlock_imbalance_bug+0xf8/0x108 [ 373.464022] [<00000000001e045c>] lock_release+0x114/0x4f8 [ 373.464025] [<0000000000aa87fa>] __mutex_unlock_slowpath+0x4a/0x300 [ 373.464027] [<000003ff801205fc>] smc_listen_work+0x22c/0x5d0 [smc] [ 373.464029] [<0000000000197a68>] process_one_work+0x2a8/0x6b0 [ 373.464030] [<0000000000197ec2>] worker_thread+0x52/0x410 [ 373.464033] [<000000000019fd0e>] kthread+0x15e/0x178 [ 373.464035] [<0000000000aaf58a>] kernel_thread_starter+0x6/0xc [ 373.464052] [<0000000000aaf584>] kernel_thread_starter+0x0/0xc [ 373.464054] INFO: lockdep is turned off. Signed-off-by: Ursula Braun --- net/smc/af_smc.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 9c3976bcde46..5c6d30eb4a71 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1153,9 +1153,9 @@ static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact) } /* listen worker: finish RDMA setup */ -static void smc_listen_rdma_finish(struct smc_sock *new_smc, - struct smc_clc_msg_accept_confirm *cclc, - int local_contact) +static int smc_listen_rdma_finish(struct smc_sock *new_smc, + struct smc_clc_msg_accept_confirm *cclc, + int local_contact) { struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK]; int reason_code = 0; @@ -1178,11 +1178,12 @@ static void smc_listen_rdma_finish(struct smc_sock *new_smc, if (reason_code) goto decline; } - return; + return 0; decline: mutex_unlock(&smc_create_lgr_pending); smc_listen_decline(new_smc, reason_code, local_contact); + return reason_code; } /* setup for RDMA connection of server */ @@ -1279,8 +1280,10 @@ static void smc_listen_work(struct work_struct *work) } /* finish worker */ - if (!ism_supported) - smc_listen_rdma_finish(new_smc, &cclc, local_contact); + if (!ism_supported) { + if (smc_listen_rdma_finish(new_smc, &cclc, local_contact)) + return; + } smc_conn_save_peer_info(new_smc, &cclc); mutex_unlock(&smc_create_lgr_pending); smc_listen_out_connected(new_smc); -- 2.16.4