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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 E5EE1C76186 for ; Wed, 24 Jul 2019 17:14:20 +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 C120021911 for ; Wed, 24 Jul 2019 17:14:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C120021911 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]:53634 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hqKqJ-0000ah-ET for qemu-devel@archiver.kernel.org; Wed, 24 Jul 2019 13:14:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49635) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hqKp7-0004Mr-Sh for qemu-devel@nongnu.org; Wed, 24 Jul 2019 13:13:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hqKp6-0005Up-N9 for qemu-devel@nongnu.org; Wed, 24 Jul 2019 13:13:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54318) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hqKp4-0005Hm-8i; Wed, 24 Jul 2019 13:13:02 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 994F9C03D478; Wed, 24 Jul 2019 17:13:01 +0000 (UTC) Received: from localhost (ovpn-204-115.brq.redhat.com [10.40.204.115]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 13AD919C70; Wed, 24 Jul 2019 17:13:00 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Wed, 24 Jul 2019 19:12:34 +0200 Message-Id: <20190724171239.8764-7-mreitz@redhat.com> In-Reply-To: <20190724171239.8764-1-mreitz@redhat.com> References: <20190724171239.8764-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Wed, 24 Jul 2019 17:13:01 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 06/11] qcow2: Fix .bdrv_has_zero_init() 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 , Stefano Garzarella , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" If a qcow2 file is preallocated, it can no longer guarantee that it initially appears as filled with zeroes. So implement .bdrv_has_zero_init() by checking whether the file is preallocated; if so, forward the call to the underlying storage node, except for when it is encrypted: Encrypted preallocated images always return effectively random data, so .bdrv_has_zero_init() must always return 0 for them. .bdrv_has_zero_init_truncate() can remain bdrv_has_zero_init_1(), because it presupposes PREALLOC_MODE_OFF. Reported-by: Stefano Garzarella Signed-off-by: Max Reitz --- block/qcow2.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/block/qcow2.c b/block/qcow2.c index 5c40f54d64..b4e73aa443 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -4631,6 +4631,33 @@ static ImageInfoSpecific *qcow2_get_specific_info(= BlockDriverState *bs, return spec_info; } =20 +static int qcow2_has_zero_init(BlockDriverState *bs) +{ + BDRVQcow2State *s =3D bs->opaque; + bool preallocated; + + if (qemu_in_coroutine()) { + qemu_co_mutex_lock(&s->lock); + } + /* + * Check preallocation status: Preallocated images have all L2 + * tables allocated, nonpreallocated images have none. It is + * therefore enough to check the first one. + */ + preallocated =3D s->l1_size > 0 && s->l1_table[0] !=3D 0; + if (qemu_in_coroutine()) { + qemu_co_mutex_unlock(&s->lock); + } + + if (!preallocated) { + return 1; + } else if (bs->encrypted) { + return 0; + } else { + return bdrv_has_zero_init(s->data_file->bs); + } +} + static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) { @@ -5186,7 +5213,7 @@ BlockDriver bdrv_qcow2 =3D { .bdrv_child_perm =3D bdrv_format_default_perms, .bdrv_co_create_opts =3D qcow2_co_create_opts, .bdrv_co_create =3D qcow2_co_create, - .bdrv_has_zero_init =3D bdrv_has_zero_init_1, + .bdrv_has_zero_init =3D qcow2_has_zero_init, .bdrv_has_zero_init_truncate =3D bdrv_has_zero_init_1, .bdrv_co_block_status =3D qcow2_co_block_status, =20 --=20 2.21.0