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 B8550C4CEC4 for ; Wed, 18 Sep 2019 09:58:09 +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 8DE0A218AF for ; Wed, 18 Sep 2019 09:58:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8DE0A218AF 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]:56790 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iAWiu-0007BK-Lj for qemu-devel@archiver.kernel.org; Wed, 18 Sep 2019 05:58:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59362) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iAWdJ-0001LM-Gu for qemu-devel@nongnu.org; Wed, 18 Sep 2019 05:52:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iAWdI-0005ni-As for qemu-devel@nongnu.org; Wed, 18 Sep 2019 05:52:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58772) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iAWdF-0005kb-Ka; Wed, 18 Sep 2019 05:52:17 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EF96C46288; Wed, 18 Sep 2019 09:52:16 +0000 (UTC) Received: from localhost (ovpn-116-168.ams2.redhat.com [10.36.116.168]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7270A5C219; Wed, 18 Sep 2019 09:52:13 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Wed, 18 Sep 2019 11:51:42 +0200 Message-Id: <20190918095144.955-7-mreitz@redhat.com> In-Reply-To: <20190918095144.955-1-mreitz@redhat.com> References: <20190918095144.955-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 18 Sep 2019 09:52:17 +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 6/8] block: Let format drivers pass @exact 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 , Fam Zheng , qemu-devel@nongnu.org, Maxim Levitsky , Stefan Hajnoczi , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" When truncating a format node, the @exact parameter is generally handled simply by virtue of the format storing the new size in the image metadata. Such formats do not need to pass on the parameter to their file nodes. There are exceptions, though: - raw and crypto cannot store the image size, and thus must pass on @exact. - When using qcow2 with an external data file, it just makes sense to keep its size in sync with the qcow2 virtual disk (because the external data file is the virtual disk). Therefore, we should pass @exact when truncating it. Signed-off-by: Max Reitz --- block/crypto.c | 2 +- block/qcow2.c | 15 ++++++++++++++- block/raw-format.c | 2 +- 3 files changed, 16 insertions(+), 3 deletions(-) diff --git a/block/crypto.c b/block/crypto.c index e5a1a2cdf3..24823835c1 100644 --- a/block/crypto.c +++ b/block/crypto.c @@ -311,7 +311,7 @@ block_crypto_co_truncate(BlockDriverState *bs, int64_= t offset, bool exact, =20 offset +=3D payload_offset; =20 - return bdrv_co_truncate(bs->file, offset, false, prealloc, errp); + return bdrv_co_truncate(bs->file, offset, exact, prealloc, errp); } =20 static void block_crypto_close(BlockDriverState *bs) diff --git a/block/qcow2.c b/block/qcow2.c index 157b9b75d9..4ef19dd29a 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -3822,6 +3822,13 @@ static int coroutine_fn qcow2_co_truncate(BlockDri= verState *bs, int64_t offset, if ((last_cluster + 1) * s->cluster_size < old_file_size) { Error *local_err =3D NULL; =20 + /* + * Do not pass @exact here: It will not help the user if + * we get an error here just because they wanted to shrink + * their qcow2 image (on a block device) with qemu-img. + * (And on the qcow2 layer, the @exact requirement is + * always fulfilled, so there is no need to pass it on.) + */ bdrv_co_truncate(bs->file, (last_cluster + 1) * s->cluster_s= ize, false, PREALLOC_MODE_OFF, &local_err); if (local_err) { @@ -3840,7 +3847,12 @@ static int coroutine_fn qcow2_co_truncate(BlockDri= verState *bs, int64_t offset, switch (prealloc) { case PREALLOC_MODE_OFF: if (has_data_file(bs)) { - ret =3D bdrv_co_truncate(s->data_file, offset, false, preall= oc, errp); + /* + * If the caller wants an exact resize, the external data + * file should be resized to the exact target size, too, + * so we pass @exact here. + */ + ret =3D bdrv_co_truncate(s->data_file, offset, exact, preall= oc, errp); if (ret < 0) { goto fail; } @@ -3925,6 +3937,7 @@ static int coroutine_fn qcow2_co_truncate(BlockDriv= erState *bs, int64_t offset, /* Allocate the data area */ new_file_size =3D allocation_start + nb_new_data_clusters * s->cluster_size; + /* Image file grows, so @exact does not matter */ ret =3D bdrv_co_truncate(bs->file, new_file_size, false, preallo= c, errp); if (ret < 0) { error_prepend(errp, "Failed to resize underlying file: "); diff --git a/block/raw-format.c b/block/raw-format.c index 57d84d0bae..3a76ec7dd2 100644 --- a/block/raw-format.c +++ b/block/raw-format.c @@ -387,7 +387,7 @@ static int coroutine_fn raw_co_truncate(BlockDriverSt= ate *bs, int64_t offset, =20 s->size =3D offset; offset +=3D s->offset; - return bdrv_co_truncate(bs->file, offset, false, prealloc, errp); + return bdrv_co_truncate(bs->file, offset, exact, prealloc, errp); } =20 static void raw_eject(BlockDriverState *bs, bool eject_flag) --=20 2.21.0