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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 40D94C2BBFD for ; Mon, 13 Apr 2020 18:14:00 +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 120DD20735 for ; Mon, 13 Apr 2020 18:14:00 +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="K4EkRtNz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 120DD20735 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]:47394 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jO3ap-0000aV-AT for qemu-devel@archiver.kernel.org; Mon, 13 Apr 2020 14:13:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47822) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jO3YN-0005vR-RM for qemu-devel@nongnu.org; Mon, 13 Apr 2020 14:11:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jO3YM-0006gi-JV for qemu-devel@nongnu.org; Mon, 13 Apr 2020 14:11:27 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:26434 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jO3YM-0006gI-FS for qemu-devel@nongnu.org; Mon, 13 Apr 2020 14:11:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1586801485; 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=Q5uvgEP4puIuPF2gcjkc0NuwoM1oY3H0l3UmQIM5Pro=; b=K4EkRtNzUQw0+phcBLADLiiS7JCV4CfJ8DCsJIZpnFWPsQoJMu04L89f6aJ3kloCSZ7jzs YNJjCsCL37D3eX57AaTD8za7t9PplJrF+4ae7Geb36D3CR8JULaQpvZh7BqPXXM51TBOo3 B6O1/B6FNlKdCY+fGgdQI1zBqjo3hok= 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-33-qdzgkNKJNrua49LFsKBkTw-1; Mon, 13 Apr 2020 14:11:20 -0400 X-MC-Unique: qdzgkNKJNrua49LFsKBkTw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 30E7418CA240; Mon, 13 Apr 2020 18:11:19 +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 8B08218A85; Mon, 13 Apr 2020 18:11:18 +0000 (UTC) Subject: Re: [PATCH for-5.0] qcow2: Add incompatibility note between backing files and raw external data files To: Alberto Garcia , qemu-devel@nongnu.org References: <20200410121816.8334-1-berto@igalia.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <1f31551c-2ac1-ac5b-01c4-005cca2cb2af@redhat.com> Date: Mon, 13 Apr 2020 13:11:16 -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: <20200410121816.8334-1-berto@igalia.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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 , qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 4/10/20 7:18 AM, Alberto Garcia wrote: > Backing files and raw external data files are mutually exclusive. > The documentation of the raw external data bit (in autoclear_features) > already indicates that, but we should also mention it on the other > side. > > Suggested-by: Eric Blake > Signed-off-by: Alberto Garcia > --- > docs/interop/qcow2.txt | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt > index 640e0eca40..298a031310 100644 > --- a/docs/interop/qcow2.txt > +++ b/docs/interop/qcow2.txt > @@ -25,6 +25,9 @@ The first cluster of a qcow2 image contains the file header: > is stored (NB: The string is not null terminated). 0 if the > image doesn't have a backing file. > > + Note: backing files are incompatible with raw external data > + files (auto-clear feature bit 1). > + > 16 - 19: backing_file_size > Length of the backing file name in bytes. Must not be > longer than 1023 bytes. Undefined if the image doesn't have > Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org