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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MSGID_FROM_MTA_HEADER,NICE_REPLY_A,SIGNED_OFF_BY, 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 92B4CC433E2 for ; Fri, 11 Sep 2020 09:14:58 +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 AC99A21D6C for ; Fri, 11 Sep 2020 09:14:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=virtuozzo.com header.i=@virtuozzo.com header.b="OJC0N7Uv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AC99A21D6C Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59328 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kGf8y-0007Sy-GI for qemu-devel@archiver.kernel.org; Fri, 11 Sep 2020 05:14:56 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42512) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kGf8G-0006yZ-Nz; Fri, 11 Sep 2020 05:14:12 -0400 Received: from mail-eopbgr60117.outbound.protection.outlook.com ([40.107.6.117]:13134 helo=EUR04-DB3-obe.outbound.protection.outlook.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kGf8D-0006pu-GW; Fri, 11 Sep 2020 05:14:11 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=n6ndzkQHa07YUzP34Cm6wEQ2IO9N4PhiYz4fICnYrgwEubI/unqo5zUSTE+PRxgCFZEE/OQouUrXe5/U1a6G8UryaKCXJ5e+a2lkw82ziu4Qr7NwGinXVF18LzVPJ/5xCX9zTMGzUH1SIXQ2ff9o5YClCKZh18Bx9m0IhFyo0Eu/fidRe06WPcFQxEGa/+k1MMVV9KgmITg/VEwoUySDsxGGuopAPty4fmaQ7bUdZ9TeYm3wgzH2nB8p9KvJkzQhUwJwfKxJEaIBW8OYHVVBiQu6K7rLodfnwfkiWO7eQwU8ZTkvXqyR/m8J5vSpOH43znvzQhI/7ij00mMvlK+12w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=YO9X1TGFSGlMlkCgKM8zJ2h5/EnHqkJAMXc+cn0OHAQ=; b=DMcbBaV4v2Wo/PPZeOS+UpDmNCbxZh2XK1/EbosCSDvxYia9d58M7JM+vD8Mc7RFBU/ekqNx/TI4c2cE0R3/N8ayF06PkP034P0SqpfR3Wn886TBCK5EeInHk5vb3awdyjdbwgNcGu3wC4LIGGMlTHL4LaumUAho4HINfBdiPl2J4zQ08TSeZXjlUe/slMg0/u3Qr1LlIv15l+vsfl44QPnfg8vW/Y514xPyscC1W60CSWEOG68VDHCZ+2O0jAxkn/lRet0o5CfRcWHARTkr7LLK2kDSh37pD9xGoMriikFnFrx0WllFFLHMnnm0F/4U2wOnRT32TsBgrCDBzbn6hw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=virtuozzo.com; dmarc=pass action=none header.from=virtuozzo.com; dkim=pass header.d=virtuozzo.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=virtuozzo.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=YO9X1TGFSGlMlkCgKM8zJ2h5/EnHqkJAMXc+cn0OHAQ=; b=OJC0N7UvUv6A9xHnDRJ5ttm2L+zhE+01Z/S5Wx2kUl4hHjFXACsIhyJfQYjs9VbKI6Knyo/Pn1445ZfuZvZP4nBHuSG5/8wo1PL0HraOoKhec3brW59PMU7f20DlfVo0wZURwrBX76IKLhDCtU4V/410nWkqhtHhgxSNEKDNYdg= Authentication-Results: redhat.com; dkim=none (message not signed) header.d=none;redhat.com; dmarc=none action=none header.from=virtuozzo.com; Received: from AM7PR08MB5494.eurprd08.prod.outlook.com (2603:10a6:20b:dc::15) by AM5PR0801MB1651.eurprd08.prod.outlook.com (2603:10a6:203:39::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3370.16; Fri, 11 Sep 2020 09:14:04 +0000 Received: from AM7PR08MB5494.eurprd08.prod.outlook.com ([fe80::b179:9641:7589:d692]) by AM7PR08MB5494.eurprd08.prod.outlook.com ([fe80::b179:9641:7589:d692%7]) with mapi id 15.20.3348.019; Fri, 11 Sep 2020 09:14:04 +0000 Subject: Re: [PATCH v3 1/2] qcow2: Report BDRV_BLOCK_ZERO more accurately in bdrv_co_block_status() To: Alberto Garcia , qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, Kevin Wolf , Max Reitz References: <104cbe2dfac940e4c5ca0a7e2eb22a0245e206f7.1599759873.git.berto@igalia.com> From: Vladimir Sementsov-Ogievskiy Message-ID: <3c60aece-51a5-c281-ebb1-f384d2ea244e@virtuozzo.com> Date: Fri, 11 Sep 2020 12:14:02 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 In-Reply-To: <104cbe2dfac940e4c5ca0a7e2eb22a0245e206f7.1599759873.git.berto@igalia.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: AM0PR03CA0029.eurprd03.prod.outlook.com (2603:10a6:208:14::42) To AM7PR08MB5494.eurprd08.prod.outlook.com (2603:10a6:20b:dc::15) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.100.5] (185.215.60.150) by AM0PR03CA0029.eurprd03.prod.outlook.com (2603:10a6:208:14::42) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3370.16 via Frontend Transport; Fri, 11 Sep 2020 09:14:03 +0000 X-Originating-IP: [185.215.60.150] X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 274a108b-d3ad-435a-3461-08d856330766 X-MS-TrafficTypeDiagnostic: AM5PR0801MB1651: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:6790; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: CDKwtlE7cdzkTru31IYVDM3QXLIouJPcj4D5HZl1KyE1xvR1Zqin3WZ2SZoSRmpa7gG3eJZTWXFJAYU7QtmlJphBMQHIObF0c3b1nG67zyJZHglXONILrtpVj9O4ASzFRwXKRLYP9kHaZYMasRQn38EENNvvhPUxmGF1SPQAD25fO6ja8lDwbAH3vPV8p9aFU0+pPESGLwQpAoOdPM8D8Zewf3fXeP3/IxvKbWJ8C6Z9erX00cSQ0qBNEdfFZoB0Yku5NnhIUokyRw7IV+JUODWl+ORMRcjpb+7XUA9Pi4ahZWzNNr90n/BnUVmHB2f1C/uNlLzNfB7YE/1AQsJR6Zl+LNBMKDzZqjysOn0fKCILXTiWA6eIfj8UezCnOyXg X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:AM7PR08MB5494.eurprd08.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(376002)(346002)(366004)(39840400004)(396003)(136003)(4326008)(2906002)(956004)(83380400001)(2616005)(36756003)(54906003)(5660300002)(31686004)(6486002)(66556008)(86362001)(316002)(16576012)(8936002)(66476007)(66946007)(31696002)(478600001)(52116002)(26005)(16526019)(8676002)(186003)(43740500002); DIR:OUT; SFP:1102; X-MS-Exchange-AntiSpam-MessageData: 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 X-OriginatorOrg: virtuozzo.com X-MS-Exchange-CrossTenant-Network-Message-Id: 274a108b-d3ad-435a-3461-08d856330766 X-MS-Exchange-CrossTenant-AuthSource: AM7PR08MB5494.eurprd08.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Sep 2020 09:14:04.1668 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 0bc7f26d-0264-416e-a6fc-8352af79c58f X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 1ZtgzTGTTuu92sPoa1bqN2K2JIauLLZyAyHWqb6fMNP6yL2XL3TkukUy8zLObMqCcg/JD5lMv8A2hFEG0d9uqBZhLml0qc+jYMWYarf7dQc= X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM5PR0801MB1651 Received-SPF: pass client-ip=40.107.6.117; envelope-from=vsementsov@virtuozzo.com; helo=EUR04-DB3-obe.outbound.protection.outlook.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/11 05:14:05 X-ACL-Warn: Detected OS = Windows NT kernel [generic] [fuzzy] X-Spam_score_int: -63 X-Spam_score: -6.4 X-Spam_bar: ------ X-Spam_report: (-6.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, MSGID_FROM_MTA_HEADER=0.001, NICE_REPLY_A=-3.576, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_PASS=-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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 10.09.2020 20:46, Alberto Garcia wrote: > If a BlockDriverState supports backing files but has none then any > unallocated area reads back as zeroes. > > bdrv_co_block_status() is only reporting this is if want_zero is true, > but this is an inexpensive test and there is no reason not to do it in > all cases. > > Suggested-by: Vladimir Sementsov-Ogievskiy > Signed-off-by: Alberto Garcia Reviewed-by: Vladimir Sementsov-Ogievskiy > --- > block/io.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/block/io.c b/block/io.c > index ad3a51ed53..1b0ae29610 100644 > --- a/block/io.c > +++ b/block/io.c > @@ -2408,16 +2408,16 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs, > > if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) { > ret |= BDRV_BLOCK_ALLOCATED; > - } else if (want_zero && bs->drv->supports_backing) { > - if (bs->backing) { > + } else if (bs->drv->supports_backing) { > + if (!bs->backing) { > + ret |= BDRV_BLOCK_ZERO; > + } else if (want_zero) { > BlockDriverState *bs2 = bs->backing->bs; > int64_t size2 = bdrv_getlength(bs2); > > if (size2 >= 0 && offset >= size2) { > ret |= BDRV_BLOCK_ZERO; > } > - } else { > - ret |= BDRV_BLOCK_ZERO; > } > } > > -- Best regards, Vladimir