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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 32E8CC433DF for ; Tue, 19 May 2020 21:50:44 +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 E34E92072C for ; Tue, 19 May 2020 21:50:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dukIO9+j" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E34E92072C 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]:54778 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jbA8J-0003So-1L for qemu-devel@archiver.kernel.org; Tue, 19 May 2020 17:50:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40174) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jbA7b-0002Wi-3U for qemu-devel@nongnu.org; Tue, 19 May 2020 17:49:59 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:48884 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jbA7a-0002G2-AU for qemu-devel@nongnu.org; Tue, 19 May 2020 17:49:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589924997; 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=xYuxmNc6NRNemLa5lQX72UyN3962WPDQJnA6AsNosVA=; b=dukIO9+jdNmIPg7JKMXIfJVo02SqQ+5yVfyZwYs2mn0eV9iNSI0WvodJtK8em6aUPUFieW tdpQnvyceVvhZJ8j1mDL32JYtXg3pW9z+8Sr5Hj+VDJ0HuM22dAvyslahgVgvQ7OV6+Dwr CUCcwpuAFPxETIGyJEslOfwYuyKJtmA= 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-485-pEnaLDFROAK2oY1Dp-9dvQ-1; Tue, 19 May 2020 17:49:55 -0400 X-MC-Unique: pEnaLDFROAK2oY1Dp-9dvQ-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 80950872FE0; Tue, 19 May 2020 21:49:54 +0000 (UTC) Received: from [10.3.112.88] (ovpn-112-88.phx2.redhat.com [10.3.112.88]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CECDC1001B07; Tue, 19 May 2020 21:49:50 +0000 (UTC) Subject: Re: [PATCH v2 5/5] iotests: add commit top->base cases to 274 To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org References: <20200519195501.29071-1-vsementsov@virtuozzo.com> <20200519195501.29071-6-vsementsov@virtuozzo.com> <506b90f3-2d40-168f-14f9-f5ab30c80535@virtuozzo.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <0fc27063-98de-f1db-8981-e47e07049465@redhat.com> Date: Tue, 19 May 2020 16:49:50 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <506b90f3-2d40-168f-14f9-f5ab30c80535@virtuozzo.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.120; envelope-from=eblake@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/19 17:21:19 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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: kwolf@redhat.com, fam@euphon.net, qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com, den@openvz.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 5/19/20 4:25 PM, Vladimir Sementsov-Ogievskiy wrote: >> $ ./qemu-img map --output=json top.qcow2 >> [{ "start": 0, "length": 1048576, "depth": 2, "zero": false, "data": >> true, "offset": 327680}, >> { "start": 1048576, "length": 1048576, "depth": 0, "zero": true, >> "data": false}] >> >> I think what we really want is: >> >> [{ "start": 0, "length": 1048576, "depth": 2, "zero": false, "data": >> true, "offset": 327680}, >> { "start": 1048576, "length": 1048576, "depth": 1, "zero": true, >> "data": false}] >> >> because then we would be _accurately_ reporting that the zeroes that >> we read from 1m-2m come _because_ we read from mid (beyond EOF), which >> is different from our current answer that the zeroes come from top >> (they don't, because top deferred to mid). > > Right. This is exactly the logic which I bring to block_status_above and > is_allocated_above by this series > > If we fix up qemu-img map output to correctly report zeroes beyond EOF > from the correct layer, will that also fix up the bug we are seeing in > qemu-img commit? >> > > No it will not fix it, because img_map has own implementation of > block_status_above - get_block_status function in qemu-img.c, which goes > through backing chain by itself, and is used only in img_map (not in > img_convert). But you are right that it should be fixed too. You are in a maze of twisty passages, all alike ;) [Hope neither of us is eaten by a grue by the time we get this series in] -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org