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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=no 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 816AFC43603 for ; Mon, 9 Dec 2019 23:13:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53331206D5 for ; Mon, 9 Dec 2019 23:13:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="bnN78Mx1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727109AbfLIXN2 (ORCPT ); Mon, 9 Dec 2019 18:13:28 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:60540 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726743AbfLIXN1 (ORCPT ); Mon, 9 Dec 2019 18:13:27 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xB9N9N7v005846; Mon, 9 Dec 2019 23:13:10 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=to : cc : subject : from : references : date : in-reply-to : message-id : mime-version : content-type; s=corp-2019-08-05; bh=XByPhQ/GK+1qe7eG/ANSprBhc5tw+oXQP23irQKqo9E=; b=bnN78Mx15gz3HKX9NF8lqUe34sEVPOsmrbfmlPa2P5iGp5yzqK2qdjfz70MLYiFI0IgA mERbIxdn03HbpgrJ50r5ISj7Y2UjtAPK6HyifY/uaDJ6pXD/oKGxKdQvASHWRZM4a5b3 Js4TLaB2bQ0CEJUgXdvp4Nlp0KWy9bLU6rxHnusluHf7u2P3mbpPJtsJzoym5K0Ra2lG lYCxbthMUTHDH1BxKK79TTR32L2Kma9/HYcQF9UEo6DHRbYKhHU104FSHa8r+1bv5hjX SiFvmYzXEzb+OGMo8vhrK4fT4A1CJDtaETmb/nlhOd4Ud1IOvKMwNbgBNcYVekgnmS40 5w== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2130.oracle.com with ESMTP id 2wrw4myjgq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 09 Dec 2019 23:13:10 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xB9N9UmS053443; Mon, 9 Dec 2019 23:11:10 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3030.oracle.com with ESMTP id 2wsv8arn0a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 09 Dec 2019 23:11:09 +0000 Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id xB9NB3qx010457; Mon, 9 Dec 2019 23:11:03 GMT Received: from ca-mkp.ca.oracle.com (/10.159.214.123) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 09 Dec 2019 15:11:02 -0800 To: "wubo \(T\)" Cc: Lee Duncan , "cleech\@redhat.com" , "jejb\@linux.ibm.com" , "martin.petersen\@oracle.com" , "open-iscsi\@googlegroups.com" , "linux-scsi\@vger.kernel.org" , "linux-kernel\@vger.kernel.org" , Ulrich Windl , Mingfangsen , "liuzhiqiang \(I\)" Subject: Re: [PATCH V4] scsi: avoid potential deadlock in iscsi_if_rx func From: "Martin K. Petersen" Organization: Oracle Corporation References: Date: Mon, 09 Dec 2019 18:11:00 -0500 In-Reply-To: (wubo's message of "Wed, 20 Nov 2019 13:26:17 +0000") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1.92 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9466 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=912 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-1912090182 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9466 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=976 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-1912090182 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org wubo, > In iscsi_if_rx func, after receiving one request through > iscsi_if_recv_msg func, iscsi_if_send_reply will be called to try to > reply the request in do-loop. If the return of iscsi_if_send_reply > func return -EAGAIN all the time, one deadlock will occur. > > For example, a client only send msg without calling recvmsg func, then > it will result in the watchdog soft lockup. The details are given as > follows, > Signed-off-by: Bo Wu > Reviewed-by: Zhiqiang Liu > Reviewed-by: Lee Duncan I haven't seen a Reviewed-by: from Lee on this patch. -- Martin K. Petersen Oracle Linux Engineering