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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 50FD5C433C1 for ; Fri, 26 Mar 2021 15:18:43 +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 B9846619D3 for ; Fri, 26 Mar 2021 15:18:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B9846619D3 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]:35748 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lPoET-0002sJ-KC for qemu-devel@archiver.kernel.org; Fri, 26 Mar 2021 11:18:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40812) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lPoDY-0002EU-Iu for qemu-devel@nongnu.org; Fri, 26 Mar 2021 11:17:44 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:27705) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lPoDX-0007Rf-0a for qemu-devel@nongnu.org; Fri, 26 Mar 2021 11:17:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616771861; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NwxxaWw3HP9jYnutJktHjBXk/gexBEkh1O6qDRYd3XM=; b=UYNm81SBKzvvIxmOroWhJymMe3kT2LsBb7hrPAFnoqw1o8Ov2foueMiPGyjLzUx8e2J5id fgUvsGRWJtLmm/T8U1wZv48MdhoKB7cMck8KBkVuwy4nueciQ+5VOD/QddOzTSC+p0Ujy2 nZoxzvnUsRkjlo/Rd7YreGvoSK/3FLA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-323-PHhpnNPpO22kNISPlCy21A-1; Fri, 26 Mar 2021 11:17:39 -0400 X-MC-Unique: PHhpnNPpO22kNISPlCy21A-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AAB3084E20A; Fri, 26 Mar 2021 15:17:38 +0000 (UTC) Received: from [10.3.114.231] (ovpn-114-231.phx2.redhat.com [10.3.114.231]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 485AB5D9E3; Fri, 26 Mar 2021 15:17:38 +0000 (UTC) Subject: Re: [PATCH v2 2/2] iotests/244: Test preallocation for data-file-raw To: Max Reitz , qemu-block@nongnu.org References: <20210326145509.163455-1-mreitz@redhat.com> <20210326145509.163455-3-mreitz@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <1c5b2174-8ce4-e20c-8e0c-f03ac6e1d5ce@redhat.com> Date: Fri, 26 Mar 2021 10:17:37 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210326145509.163455-3-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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 , Alberto Garcia , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 3/26/21 9:55 AM, Max Reitz wrote: > Three test cases: > (1) Adding a qcow2 (metadata) file to an existing data file, see whether > we can read the existing data through the qcow2 image. > (2) Append data to the data file, grow the qcow2 image accordingly, see > whether we can read the new data through the qcow2 image. > (3) At runtime, add a backing image to a freshly created qcow2 image > with an external data file (with data-file-raw). Reading data from > the qcow2 image must return the same result as reading data from the > data file, so everything in the backing image must be ignored. > (This did not use to be the case, because without the L2 tables > preallocated, all clusters would appear as unallocated, and so the > qcow2 driver would fall through to the backing file.) > > Signed-off-by: Max Reitz > --- > tests/qemu-iotests/244 | 104 +++++++++++++++++++++++++++++++++++++ > tests/qemu-iotests/244.out | 59 +++++++++++++++++++++ > 2 files changed, 163 insertions(+) > > + > +# We cannot use qemu-img to create the qcow2 image, because it would > +# clear the data file. Use the blockdev-create job instead, which will > +# only format the qcow2 image file. Well, perhaps we could use qemu-img to create a qcow2 pointing to a temporary file, then rewrite it to point to the real data file, but that feels hackish, and your approach worked. And besides, while we have qemu-img rebase -u to rewrite the backing file, I don't know if we have a similar qemu-img command for rewriting the data file. Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org