From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935825AbdCJJbW (ORCPT ); Fri, 10 Mar 2017 04:31:22 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:41410 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935335AbdCJJbQ (ORCPT ); Fri, 10 Mar 2017 04:31:16 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tejun Heo , Omar Sandoval , Ming Lei , Jens Axboe Subject: [PATCH 4.10 073/167] loop: fix LO_FLAGS_PARTSCAN hang Date: Fri, 10 Mar 2017 10:08:36 +0100 Message-Id: <20170310084001.130882492@linuxfoundation.org> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170310083956.767605269@linuxfoundation.org> References: <20170310083956.767605269@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Omar Sandoval commit e02898b423802b1f3a3aaa7f16e896da069ba8f7 upstream. loop_reread_partitions() needs to do I/O, but we just froze the queue, so we end up waiting forever. This can easily be reproduced with losetup -P. Fix it by moving the reread to after we unfreeze the queue. Fixes: ecdd09597a57 ("block/loop: fix race between I/O and set_status") Reported-by: Tejun Heo Signed-off-by: Omar Sandoval Reviewed-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/loop.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1142,13 +1142,6 @@ loop_set_status(struct loop_device *lo, (info->lo_flags & LO_FLAGS_AUTOCLEAR)) lo->lo_flags ^= LO_FLAGS_AUTOCLEAR; - if ((info->lo_flags & LO_FLAGS_PARTSCAN) && - !(lo->lo_flags & LO_FLAGS_PARTSCAN)) { - lo->lo_flags |= LO_FLAGS_PARTSCAN; - lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; - loop_reread_partitions(lo, lo->lo_device); - } - lo->lo_encrypt_key_size = info->lo_encrypt_key_size; lo->lo_init[0] = info->lo_init[0]; lo->lo_init[1] = info->lo_init[1]; @@ -1163,6 +1156,14 @@ loop_set_status(struct loop_device *lo, exit: blk_mq_unfreeze_queue(lo->lo_queue); + + if (!err && (info->lo_flags & LO_FLAGS_PARTSCAN) && + !(lo->lo_flags & LO_FLAGS_PARTSCAN)) { + lo->lo_flags |= LO_FLAGS_PARTSCAN; + lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; + loop_reread_partitions(lo, lo->lo_device); + } + return err; }