From nobody Thu Dec 18 13:29:16 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1566231995; cv=none; d=zoho.com; s=zohoarc; b=I7mG70ZdwM2IQIEbIuCwSLTzGHbvI+Mw6b8Ljj3TTHTrN7THweO7QTR13nxImCYM4/msRjxizv7C4+zZPlA0N4rdbzhafZ5RwRTJqbNuxhwREswAYJfRZQ3wdfBbnyzZHQiMvGUz93q1heO6usv8BRk64bdNK8a4aejOzPVmNDs= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1566231995; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=OqxOtTMl2ldt22V36ap9skjpSUVtinpYKMeAyFYEKew=; b=LESpAB5Ks7JDe5v6hq89zvbc18+4LCP+BOehqmSVMidRzJZdA3lAyAmvlECwamMBPleC8lrdJAAPoqUzHTIYBKyEaKCmD6K8ADVpSCLoAHDcokyXg2nXUarAr1804LuzuQEcFur30EhpIHSKFWJISbLNs8i+cOVtU7Qg5FkdfNM= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1566231995983888.1714551923103; Mon, 19 Aug 2019 09:26:35 -0700 (PDT) Received: from localhost ([::1]:55292 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hzkUK-0004Uo-DX for importer@patchew.org; Mon, 19 Aug 2019 12:26:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35401) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hzkLv-00031T-Tu for qemu-devel@nongnu.org; Mon, 19 Aug 2019 12:17:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hzkLu-0006Le-Eq for qemu-devel@nongnu.org; Mon, 19 Aug 2019 12:17:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60586) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hzkLs-0006KE-3l; Mon, 19 Aug 2019 12:17:48 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6CA0E4628B; Mon, 19 Aug 2019 16:17:47 +0000 (UTC) Received: from localhost (ovpn-204-64.brq.redhat.com [10.40.204.64]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 118A860BE2; Mon, 19 Aug 2019 16:17:44 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Mon, 19 Aug 2019 18:17:13 +0200 Message-Id: <20190819161723.7746-8-mreitz@redhat.com> In-Reply-To: <20190819161723.7746-1-mreitz@redhat.com> References: <20190819161723.7746-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Mon, 19 Aug 2019 16:17:47 +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] [PULL 07/17] 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 , Peter Maydell , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" 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 Message-id: 20190724171239.8764-7-mreitz@redhat.com Reviewed-by: Maxim Levitsky 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 ea3b42fdac..7c5a4859f7 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -4632,6 +4632,33 @@ static ImageInfoSpecific *qcow2_get_specific_info(Bl= ockDriverState *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) { @@ -5187,7 +5214,7 @@ 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