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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 7E190ECE58E for ; Thu, 10 Oct 2019 12:33:05 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 561AD214E0 for ; Thu, 10 Oct 2019 12:33:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 561AD214E0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37332 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iIXct-0004te-V6 for qemu-devel@archiver.kernel.org; Thu, 10 Oct 2019 08:33:03 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52191) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iIWra-0007E8-Ci for qemu-devel@nongnu.org; Thu, 10 Oct 2019 07:44:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iIWrW-0008OF-D3 for qemu-devel@nongnu.org; Thu, 10 Oct 2019 07:44:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59582) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iIWrS-0008Mi-Ol; Thu, 10 Oct 2019 07:44:03 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 04B44308FE8F; Thu, 10 Oct 2019 11:44:02 +0000 (UTC) Received: from localhost (unknown [10.36.118.5]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9AF3510098FB; Thu, 10 Oct 2019 11:44:01 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Subject: [PULL 27/36] iotests: Disable 125 on broken XFS versions Date: Thu, 10 Oct 2019 13:42:51 +0200 Message-Id: <20191010114300.7746-28-mreitz@redhat.com> In-Reply-To: <20191010114300.7746-1-mreitz@redhat.com> References: <20191010114300.7746-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Thu, 10 Oct 2019 11:44:02 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Peter Maydell , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" And by that I mean all XFS versions, as far as I can tell. All details are in the comment below. We never noticed this problem because we only read the first number from qemu-img info's "disk size" output -- and that is effectively useless, because qemu-img prints a human-readable value (which generally includes a decimal point). That will be fixed in the next patch. Signed-off-by: Max Reitz Message-id: 20190925183231.11196-3-mreitz@redhat.com Reviewed-by: Eric Blake Signed-off-by: Max Reitz --- tests/qemu-iotests/125 | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/tests/qemu-iotests/125 b/tests/qemu-iotests/125 index df328a63a6..0ef51f1e21 100755 --- a/tests/qemu-iotests/125 +++ b/tests/qemu-iotests/125 @@ -49,6 +49,46 @@ if [ -z "$TEST_IMG_FILE" ]; then TEST_IMG_FILE=3D$TEST_IMG fi =20 +# Test whether we are running on a broken XFS version. There is this +# bug: + +# $ rm -f foo +# $ touch foo +# $ block_size=3D4096 # Your FS's block size +# $ fallocate -o $((block_size / 2)) -l $block_size foo +# $ LANG=3DC xfs_bmap foo | grep hole +# 1: [8..15]: hole +# +# The problem is that the XFS driver rounds down the offset and +# rounds up the length to the block size, but independently. As +# such, it only allocates the first block in the example above, +# even though it should allocate the first two blocks (because our +# request is to fallocate something that touches both the first +# two blocks). +# +# This means that when you then write to the beginning of the +# second block, the disk usage of the first two blocks grows. +# +# That is precisely what fallocate() promises, though: That when you +# write to an area that you have fallocated, no new blocks will have +# to be allocated. + +touch "$TEST_IMG_FILE" +# Assuming there is no FS with a block size greater than 64k +fallocate -o 65535 -l 2 "$TEST_IMG_FILE" +len0=3D$(get_image_size_on_host) + +# Write to something that in theory we have just fallocated +# (Thus, the on-disk size should not increase) +poke_file "$TEST_IMG_FILE" 65536 42 +len1=3D$(get_image_size_on_host) + +if [ $len1 -gt $len0 ]; then + _notrun "the test filesystem's fallocate() is broken" +fi + +rm -f "$TEST_IMG_FILE" + # Generally, we create some image with or without existing preallocation= and # then resize it. Then we write some data into the image and verify that= its # size does not change if we have used preallocation. --=20 2.21.0