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=-9.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=unavailable 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 5F763C43381 for ; Thu, 21 Feb 2019 04:14:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A8EB2070B for ; Thu, 21 Feb 2019 04:14:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="KQMahG9T" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727349AbfBUEOk (ORCPT ); Wed, 20 Feb 2019 23:14:40 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:45252 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727162AbfBUEOj (ORCPT ); Wed, 20 Feb 2019 23:14:39 -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 x1L4E8qw056565; Thu, 21 Feb 2019 04:14:35 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2018-07-02; bh=kLciAT+AyzRLAoa7LpOuXSr3oO5lyoPSVcEHLqmqO5o=; b=KQMahG9TjCbehGGe6D2iVH4BsJ2aXpc459im7IIjl0YYZ1watJLMkToGH4+Z35uZr5xz 2cae4KLFM5C8d1O8lEicjzWjw/5rGrDI9dJYMJIIdWuV5MUZNJ4Ktw1H7i909LakDxuT ToOSGMatBQIlK+5Nuhr4KAyGYbe+CrK22Qh2XOv1b3yCbkwl+mjFBbSyebSqOtQDbEkr 2dLp0WqWv6rMDrEd13JJ1U7i+IQevPlQGcqFkTF9s2se0Q3MF7HyCPwRK6hRd0pK17aI 3fsD6kT0n2H/au7sS44uMP+PHIwbQIBkOclua5JhTFRZP61Xrc7djjC+P1h97Cydap5M yQ== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2130.oracle.com with ESMTP id 2qp9xu5m7a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 21 Feb 2019 04:14:34 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x1L4EYY6007259 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 21 Feb 2019 04:14:34 GMT Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x1L4EXPe015674; Thu, 21 Feb 2019 04:14:34 GMT Received: from linux.cn.oracle.com (/10.182.69.106) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 20 Feb 2019 20:14:33 -0800 From: Dongli Zhang To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: axboe@kernel.dk, jack@suse.cz Subject: [PATCH 2/2] loop: set GENHD_FL_NO_PART_SCAN after blkdev_reread_part() Date: Thu, 21 Feb 2019 12:17:35 +0800 Message-Id: <1550722655-15102-3-git-send-email-dongli.zhang@oracle.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1550722655-15102-1-git-send-email-dongli.zhang@oracle.com> References: <1550722655-15102-1-git-send-email-dongli.zhang@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9173 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 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=8.0.1-1810050000 definitions=main-1902210031 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 0da03cab87e6 ("loop: Fix deadlock when calling blkdev_reread_part()") moves blkdev_reread_part() out of the loop_ctl_mutex. However, GENHD_FL_NO_PART_SCAN is set before __blkdev_reread_part(). As a result, __blkdev_reread_part() will fail the check of GENHD_FL_NO_PART_SCAN and will not rescan the loop device to delete all partitions. Below are steps to reproduce the issue: step1 # dd if=/dev/zero of=tmp.raw bs=1M count=100 step2 # losetup -P /dev/loop0 tmp.raw step3 # parted /dev/loop0 mklabel gpt step4 # parted -a none -s /dev/loop0 mkpart primary 64s 1 step5 # losetup -d /dev/loop0 Step5 will not be able to delete /dev/loop0p1 (introduced by step4) and there is below kernel warning message: [ 464.414043] __loop_clr_fd: partition scan of loop0 failed (rc=-22) This patch sets GENHD_FL_NO_PART_SCAN after blkdev_reread_part(). Fixes: 0da03cab87e6 ("loop: Fix deadlock when calling blkdev_reread_part()") Signed-off-by: Dongli Zhang --- drivers/block/loop.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 7908673..736e55b 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1034,6 +1034,15 @@ loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer, return err; } +static void loop_disable_partscan(struct loop_device *lo) +{ + mutex_lock(&loop_ctl_mutex); + lo->lo_flags = 0; + if (!part_shift) + lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN; + mutex_unlock(&loop_ctl_mutex); +} + static int __loop_clr_fd(struct loop_device *lo, bool release) { struct file *filp = NULL; @@ -1096,9 +1105,6 @@ static int __loop_clr_fd(struct loop_device *lo, bool release) partscan = lo->lo_flags & LO_FLAGS_PARTSCAN && bdev; lo_number = lo->lo_number; - lo->lo_flags = 0; - if (!part_shift) - lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN; loop_unprepare_queue(lo); out_unlock: mutex_unlock(&loop_ctl_mutex); @@ -1121,6 +1127,9 @@ static int __loop_clr_fd(struct loop_device *lo, bool release) /* Device is gone, no point in returning error */ err = 0; } + + loop_disable_partscan(lo); + /* * Need not hold loop_ctl_mutex to fput backing file. * Calling fput holding loop_ctl_mutex triggers a circular -- 2.7.4