From patchwork Thu Dec 31 16:28:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauricio Faria de Oliveira X-Patchwork-Id: 11994255 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A4D58C433E0 for ; Thu, 31 Dec 2020 16:29:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69CD1223E0 for ; Thu, 31 Dec 2020 16:29:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727371AbgLaQ3d (ORCPT ); Thu, 31 Dec 2020 11:29:33 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:35395 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726642AbgLaQ3d (ORCPT ); Thu, 31 Dec 2020 11:29:33 -0500 Received: from mail-qk1-f197.google.com ([209.85.222.197]) by youngberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kv0ol-0007F8-KT for linux-block@vger.kernel.org; Thu, 31 Dec 2020 16:28:51 +0000 Received: by mail-qk1-f197.google.com with SMTP id p21so14902425qke.6 for ; Thu, 31 Dec 2020 08:28:51 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=LC15KHp3+IKj1GNX+EAQR0lktZ2fCbra0Gw7Q4HqdPc=; b=ayedqpQX3f0fq37rlpwPLfkyidhf1hw5RO4CCjFqpO9bPeDfr780PQB7EHH+iyy2zG loMCKIKk9iP485ZkfEACr591thpM0FzJFIB5D8doswsZ50WbSWYBO3D5jcYKUm3BeuHB GNBXWiy4lDVGSxXUbeBtdewaRKC3grA7ujuB/0eWo7l8iIcjMUBnxTgxeNra6MfGrv9f fqHolYqrY6eCzu9lRbr9nIgmI4QBUmcawTqgkbe8Od798Awq6dkHgWemJ5YT7hAQPiRz TgzEDlAddmJLsHGT9W5mCoAikvoTqF1iTKFI6gbabF7KCxXbkgMI+Yapk39D0ftET9BT b98Q== X-Gm-Message-State: AOAM533jRrXjt13097JNZXn471WnV8zQdkw0Y4L33ntC8us39FqLK+3i DDbE7j0YFkWSM8NA4kGdPh3BAxmExuqdXi9wZ4NRhMskknbggn1kVvfFj4EkXaYCeT1+z79Vtev 710taOcsAOmUvL6rLsNfJA2RPjFGaTIA305A+dXt5 X-Received: by 2002:a37:e504:: with SMTP id e4mr60302733qkg.201.1609432130524; Thu, 31 Dec 2020 08:28:50 -0800 (PST) X-Google-Smtp-Source: ABdhPJx7ha4/x40h9YZS51HZ85CqYZmKhDeWDnBOuH0K8FRFJH0wUAhEO74nxnAGjWSygnFd93keCA== X-Received: by 2002:a37:e504:: with SMTP id e4mr60302725qkg.201.1609432130315; Thu, 31 Dec 2020 08:28:50 -0800 (PST) Received: from localhost.localdomain ([201.82.34.122]) by smtp.gmail.com with ESMTPSA id p23sm31302772qtu.53.2020.12.31.08.28.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 31 Dec 2020 08:28:49 -0800 (PST) From: Mauricio Faria de Oliveira To: Jens Axboe Cc: linux-block@vger.kernel.org Subject: [PATCH] loop: fix I/O error on fsync() in detached loop devices Date: Thu, 31 Dec 2020 13:28:45 -0300 Message-Id: <20201231162845.1853347-1-mfo@canonical.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org There's an I/O error on fsync() in a detached loop device if it has been previously attached. The issue is write cache is enabled in the attach path in loop_configure() but it isn't disabled in the detach path; thus it remains enabled in the block device regardless of whether it is attached or not. Now fsync() can get an I/O request that will just be failed later in loop_queue_rq() as device's state is not 'Lo_bound'. So, disable write cache in the detach path. Test-case: # DEV=/dev/loop7 # IMG=/tmp/image # truncate --size 1M $IMG # losetup $DEV $IMG # losetup -d $DEV Before: # strace -e fsync parted -s $DEV print 2>&1 | grep fsync fsync(3) = -1 EIO (Input/output error) Warning: Error fsyncing/closing /dev/loop7: Input/output error [ 982.529929] blk_update_request: I/O error, dev loop7, sector 0 op 0x1:(WRITE) flags 0x800 phys_seg 0 prio class 0 After: # strace -e fsync parted -s $DEV print 2>&1 | grep fsync fsync(3) = 0 Signed-off-by: Mauricio Faria de Oliveira Co-developed-by: Eric Desrochers Signed-off-by: Eric Desrochers Tested-by: Gabriel Krisman Bertazi --- drivers/block/loop.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index e5ff328f0917..49517482e061 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1212,6 +1212,9 @@ static int __loop_clr_fd(struct loop_device *lo, bool release) goto out_unlock; } + if (!(lo->lo_flags & LO_FLAGS_READ_ONLY) && filp->f_op->fsync) + blk_queue_write_cache(lo->lo_queue, false, false); + /* freeze request queue during the transition */ blk_mq_freeze_queue(lo->lo_queue);