From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:56868) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hL40B-0002XI-IW for qemu-devel@nongnu.org; Mon, 29 Apr 2019 06:59:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hL3zk-0000vo-Cw for qemu-devel@nongnu.org; Mon, 29 Apr 2019 06:59:15 -0400 From: Kevin Wolf Date: Mon, 29 Apr 2019 12:57:41 +0200 Message-Id: <20190429105741.31033-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH] qcow2: Fix qcow2_make_empty() with external data file List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, mreitz@redhat.com, qemu-stable@nongnu.org, qemu-devel@nongnu.org make_completely_empty() is an optimisated path for bdrv_make_empty() where completely new metadata is created inside the image file instead of going through all clusters and discarding them. For an external data file, however, we actually need to do discard operations on the data file; just overwriting the qcow2 file doesn't get rid of the data. The necessary slow path with an explicit discard operation already exists for other cases. Use it for external data files, too. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf --- block/qcow2.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/qcow2.c b/block/qcow2.c index 7fbef97aab..097fde56f9 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -4384,7 +4384,8 @@ static int qcow2_make_empty(BlockDriverState *bs) =20 if (s->qcow_version >=3D 3 && !s->snapshots && !s->nb_bitmaps && 3 + l1_clusters <=3D s->refcount_block_size && - s->crypt_method_header !=3D QCOW_CRYPT_LUKS) { + s->crypt_method_header !=3D QCOW_CRYPT_LUKS && + !has_data_file(bs)) { /* The following function only works for qcow2 v3 images (it * requires the dirty flag) and only as long as there are no * features that reserve extra clusters (such as snapshots, --=20 2.20.1 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=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 5EC76C43219 for ; Mon, 29 Apr 2019 11:00:27 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2F3A220673 for ; Mon, 29 Apr 2019 11:00:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F3A220673 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 ([127.0.0.1]:55739 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hL41K-0002x4-Ei for qemu-devel@archiver.kernel.org; Mon, 29 Apr 2019 07:00:26 -0400 Received: from eggs.gnu.org ([209.51.188.92]:56868) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hL40B-0002XI-IW for qemu-devel@nongnu.org; Mon, 29 Apr 2019 06:59:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hL3zk-0000vo-Cw for qemu-devel@nongnu.org; Mon, 29 Apr 2019 06:59:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:25549) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hL3yl-0000Jk-UA; Mon, 29 Apr 2019 06:57:48 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A5E1085A03; Mon, 29 Apr 2019 10:57:46 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-116-63.ams2.redhat.com [10.36.116.63]) by smtp.corp.redhat.com (Postfix) with ESMTP id 44816608C2; Mon, 29 Apr 2019 10:57:45 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Mon, 29 Apr 2019 12:57:41 +0200 Message-Id: <20190429105741.31033-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Mon, 29 Apr 2019 10:57:46 +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] qcow2: Fix qcow2_make_empty() with external data file X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-devel@nongnu.org, qemu-stable@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="UTF-8" Message-ID: <20190429105741.L_CkzN1tVe_ERVxRjpOQfHLrL5vb1FU40WI5_mZi2ec@z> make_completely_empty() is an optimisated path for bdrv_make_empty() where completely new metadata is created inside the image file instead of going through all clusters and discarding them. For an external data file, however, we actually need to do discard operations on the data file; just overwriting the qcow2 file doesn't get rid of the data. The necessary slow path with an explicit discard operation already exists for other cases. Use it for external data files, too. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf --- block/qcow2.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/qcow2.c b/block/qcow2.c index 7fbef97aab..097fde56f9 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -4384,7 +4384,8 @@ static int qcow2_make_empty(BlockDriverState *bs) =20 if (s->qcow_version >=3D 3 && !s->snapshots && !s->nb_bitmaps && 3 + l1_clusters <=3D s->refcount_block_size && - s->crypt_method_header !=3D QCOW_CRYPT_LUKS) { + s->crypt_method_header !=3D QCOW_CRYPT_LUKS && + !has_data_file(bs)) { /* The following function only works for qcow2 v3 images (it * requires the dirty flag) and only as long as there are no * features that reserve extra clusters (such as snapshots, --=20 2.20.1