From patchwork Thu Aug 1 11:06:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Haberland X-Patchwork-Id: 11070515 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9FDF91398 for ; Thu, 1 Aug 2019 11:06:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8EE0A28421 for ; Thu, 1 Aug 2019 11:06:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8086D28563; Thu, 1 Aug 2019 11:06:39 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1612528421 for ; Thu, 1 Aug 2019 11:06:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728217AbfHALGi (ORCPT ); Thu, 1 Aug 2019 07:06:38 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:23302 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729084AbfHALGi (ORCPT ); Thu, 1 Aug 2019 07:06:38 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x71B3R0a046597 for ; Thu, 1 Aug 2019 07:06:37 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2u3v82y7tf-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 01 Aug 2019 07:06:36 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 1 Aug 2019 12:06:34 +0100 Received: from b06avi18626390.portsmouth.uk.ibm.com (9.149.26.192) by e06smtp05.uk.ibm.com (192.168.101.135) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 1 Aug 2019 12:06:32 +0100 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x71B6Ebk18874734 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 1 Aug 2019 11:06:14 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CEDA6AE055; Thu, 1 Aug 2019 11:06:30 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BC935AE053; Thu, 1 Aug 2019 11:06:30 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Thu, 1 Aug 2019 11:06:30 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 20191) id 779F4E0218; Thu, 1 Aug 2019 13:06:30 +0200 (CEST) From: Stefan Haberland To: axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-s390@vger.kernel.org, hoeppner@linux.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.com, gor@linux.ibm.com Subject: [PATCH 1/1] s390/dasd: fix endless loop after read unit address configuration Date: Thu, 1 Aug 2019 13:06:30 +0200 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190801110630.82432-1-sth@linux.ibm.com> References: <20190801110630.82432-1-sth@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19080111-0020-0000-0000-000003594D60 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19080111-0021-0000-0000-000021AD5C01 Message-Id: <20190801110630.82432-2-sth@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-08-01_06:,, 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=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908010116 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP After getting a storage server event that causes the DASD device driver to update its unit address configuration during a device shutdown there is the possibility of an endless loop in the device driver. In the system log there will be ongoing DASD error messages with RC: -19. The reason is that the loop starting the ruac request only terminates when the retry counter is decreased to 0. But in the sleep_on function there are early exit paths that do not decrease the retry counter. Prevent an endless loop by handling those cases separately. Remove the unnecessary do..while loop since the sleep_on function takes care of retries by itself. Fixes: 8e09f21574ea ("[S390] dasd: add hyper PAV support to DASD device driver, part 1") Cc: stable@vger.kernel.org # 2.6.25+ Signed-off-by: Stefan Haberland Reviewed-by: Jan Hoeppner --- drivers/s390/block/dasd_alias.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c index b9ce93e9df89..99f86612f775 100644 --- a/drivers/s390/block/dasd_alias.c +++ b/drivers/s390/block/dasd_alias.c @@ -383,6 +383,20 @@ suborder_not_supported(struct dasd_ccw_req *cqr) char msg_format; char msg_no; + /* + * intrc values ENODEV, ENOLINK and EPERM + * will be optained from sleep_on to indicate that no + * IO operation can be started + */ + if (cqr->intrc == -ENODEV) + return 1; + + if (cqr->intrc == -ENOLINK) + return 1; + + if (cqr->intrc == -EPERM) + return 1; + sense = dasd_get_sense(&cqr->irb); if (!sense) return 0; @@ -447,12 +461,8 @@ static int read_unit_address_configuration(struct dasd_device *device, lcu->flags &= ~NEED_UAC_UPDATE; spin_unlock_irqrestore(&lcu->lock, flags); - do { - rc = dasd_sleep_on(cqr); - if (rc && suborder_not_supported(cqr)) - return -EOPNOTSUPP; - } while (rc && (cqr->retries > 0)); - if (rc) { + rc = dasd_sleep_on(cqr); + if (rc && !suborder_not_supported(cqr)) { spin_lock_irqsave(&lcu->lock, flags); lcu->flags |= NEED_UAC_UPDATE; spin_unlock_irqrestore(&lcu->lock, flags);