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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 C1B79C2BA19 for ; Tue, 14 Apr 2020 18:24:35 +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 94014206A2 for ; Tue, 14 Apr 2020 18:24:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LuKQPXTj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 94014206A2 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]:37072 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jOQEc-0008E8-OQ for qemu-devel@archiver.kernel.org; Tue, 14 Apr 2020 14:24:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58184) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jOQDV-0007gb-QP for qemu-devel@nongnu.org; Tue, 14 Apr 2020 14:23:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jOQDU-0005tp-Np for qemu-devel@nongnu.org; Tue, 14 Apr 2020 14:23:25 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:58763 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jOQDU-0005s7-JH for qemu-devel@nongnu.org; Tue, 14 Apr 2020 14:23:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1586888604; 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=GRi6l4DVocR+PjaxpoIaogodDgmsfE+CZ7xpgtyJ0L0=; b=LuKQPXTjJ5c+joFQrbgbdZjmrOBRYyf385Bn+m90sGn1y2gKnHWmUFoTxaokOZCB4wV9SR a2zl6WHYCaPJnMrpDKjKTxBmG3JYLjbmjKjqGbjUhs0J4hIp7fCy8Y5RSc2jyiZCCLfXGL YQb4gc+VH98dU90hMB+XT07gwLsKERY= 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-182-HLA1x867NfejoPmYnDbLWA-1; Tue, 14 Apr 2020 14:23:14 -0400 X-MC-Unique: HLA1x867NfejoPmYnDbLWA-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 D5D49801E53; Tue, 14 Apr 2020 18:23:12 +0000 (UTC) Received: from [10.3.115.59] (ovpn-115-59.phx2.redhat.com [10.3.115.59]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0AC0F5D9CD; Tue, 14 Apr 2020 18:23:11 +0000 (UTC) Subject: Re: [PATCH v4 07/30] qcow2: Document the Extended L2 Entries feature To: Alberto Garcia , qemu-devel@nongnu.org References: <8c88b96f-c6f5-e06c-73e1-56001089a7ca@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <1e6c2a1c-e2b5-609a-72fc-144de466345b@redhat.com> Date: Tue, 14 Apr 2020 13:23:11 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.61 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 , Anton Nefedov , qemu-block@nongnu.org, Max Reitz , Vladimir Sementsov-Ogievskiy , "Denis V . Lunev" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 4/14/20 1:16 PM, Alberto Garcia wrote: > On Thu 09 Apr 2020 05:12:16 PM CEST, Eric Blake wrote: >> Hmm - raw external files are incompatible with backing files. > > Pre-existing, but I just realized that we are not checking that in > qcow2_do_open(), only on _create(). > > I suppose that if we find such an image we should either > > a) Show an error message and abort. > b) Clear the 'raw data file' bit and proceed as if it was unset. I would favor a). Such an image was (hopefully) created externally, and not by qemu; therefore refusing to open it will call attention to the image (and it's creation process) being broken, rather than risking silent corruption of whatever the external process thought it was accomplishing by creating an image like that. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org