From nobody Sun Feb 8 15:01:57 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.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; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1584470226; cv=none; d=zohomail.com; s=zohoarc; b=NC1B4E33/P2qtB0nPAlNgEr8zevv5BQPcftXMdiniruVoGgouv1lrcCT8MEDL9eXkhUNx4Z0PeZDL8ofYVss9x4PLAG8iPWv9d49I4SlH3bzrF01JBHIJ1vhnpaKMTSuEODdjxegU1s37Wf8P66CgpMQwz11UvULERnB78gBKaA= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1584470226; 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; bh=C0eALyg6t8kHhqoCkYLe5gXMSMiybsgvLwFsI8EfjjI=; b=FzjpS/ZiwwMQ33m2YMizjE8yaANC5su0KrLNf3l1zfRgabIh5PbAY9AujJV8IYQXARNHL9xlfTHsvUincsxkr7jSegJXQhbF5EPMkIXETioqWmaeOmcTPONeCc6Sz6jehY28BUR3VVKirQXpHbSblspKQAHrDP+0fkHR+tDd+2Y= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1584470226134511.5770223879191; Tue, 17 Mar 2020 11:37:06 -0700 (PDT) Received: from localhost ([::1]:39482 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jEH5M-0006KE-VB for importer@patchew.org; Tue, 17 Mar 2020 14:37:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48870) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jEGmy-0003W8-Bi for qemu-devel@nongnu.org; Tue, 17 Mar 2020 14:18:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jEGmv-00009s-A2 for qemu-devel@nongnu.org; Tue, 17 Mar 2020 14:18:04 -0400 Received: from fanzine.igalia.com ([178.60.130.6]:58013) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1jEGmu-0005yB-43; Tue, 17 Mar 2020 14:18:01 -0400 Received: from [81.0.35.138] (helo=perseus.local) by fanzine.igalia.com with esmtpsa (Cipher TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim) id 1jEGmD-00015A-4V; Tue, 17 Mar 2020 19:17:17 +0100 Received: from berto by perseus.local with local (Exim 4.92) (envelope-from ) id 1jEGlw-0006Ov-Uz; Tue, 17 Mar 2020 19:17:00 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=C0eALyg6t8kHhqoCkYLe5gXMSMiybsgvLwFsI8EfjjI=; b=Us9bL0NBDkov6frBccZz/YTvQdgQ+ViKkF6Xc4JKeHbpjnsUxnJWm5X4pVzvCE6pq49NR1OoCq4WrITqGV4Y0p+emAT7jdH3U52XtKiS8XSLkk1Q4ViXC3z4py1NrM6RqG3W3qdeAZNFXgToE+nFZDbeqtGkFKgLt2JzZykB5gSrGzW71LSbzrZ7CYvK/VMoevRYoDlNqTwlPPqafjeXgowx4ApIZX/B0lBL2PICn3PSPZbwJfDmXW9upDEj7p3498Yu9XkaJR6fYXbY7ACQzaHFiSw9v5wu32HerYE9ELSCU2HkrVjH63fY5j7+A3YrT4L1V2aleiqKzOalq1zKoQ==; From: Alberto Garcia To: qemu-devel@nongnu.org Subject: [PATCH v4 27/30] qcow2: Assert that expand_zero_clusters_in_l1() does not support subclusters Date: Tue, 17 Mar 2020 19:16:24 +0100 Message-Id: <5cc70489bfeb7d2f8f6c8a113dc530cab504db9e.1584468723.git.berto@igalia.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] [fuzzy] X-Received-From: 178.60.130.6 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 , Anton Nefedov , Alberto Garcia , qemu-block@nongnu.org, Max Reitz , Vladimir Sementsov-Ogievskiy , "Denis V . Lunev" Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" This function is only used by qcow2_expand_zero_clusters() to downgrade a qcow2 image to a previous version. It is however not possible to downgrade an image with extended L2 entries because older versions of qcow2 do not have this feature. Signed-off-by: Alberto Garcia --- block/qcow2-cluster.c | 8 +++++++- tests/qemu-iotests/061 | 6 ++++++ tests/qemu-iotests/061.out | 5 +++++ 3 files changed, 18 insertions(+), 1 deletion(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 1f471db98c..125d2852f6 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -2039,6 +2039,9 @@ static int expand_zero_clusters_in_l1(BlockDriverStat= e *bs, uint64_t *l1_table, int ret; int i, j; =20 + /* qcow2_downgrade() is not allowed in images with subclusters */ + assert(!has_subclusters(s)); + slice_size2 =3D s->l2_slice_size * l2_entry_size(s); n_slices =3D s->cluster_size / slice_size2; =20 @@ -2107,7 +2110,8 @@ static int expand_zero_clusters_in_l1(BlockDriverStat= e *bs, uint64_t *l1_table, if (cluster_type =3D=3D QCOW2_CLUSTER_ZERO_PLAIN) { if (!bs->backing) { /* not backed; therefore we can simply deallocate = the - * cluster */ + * cluster. No need to call set_l2_bitmap(), this + * function doesn't support images with subcluster= s. */ set_l2_entry(s, l2_slice, j, 0); l2_dirty =3D true; continue; @@ -2178,6 +2182,8 @@ static int expand_zero_clusters_in_l1(BlockDriverStat= e *bs, uint64_t *l1_table, } else { set_l2_entry(s, l2_slice, j, offset); } + /* No need to call set_l2_bitmap() after set_l2_entry() be= cause + * this function doesn't support images with subclusters. = */ l2_dirty =3D true; } =20 diff --git a/tests/qemu-iotests/061 b/tests/qemu-iotests/061 index 36b040491f..66bfd23179 100755 --- a/tests/qemu-iotests/061 +++ b/tests/qemu-iotests/061 @@ -266,6 +266,12 @@ $QEMU_IMG amend -o "compat=3D0.10" "$TEST_IMG" _img_info --format-specific _check_test_img =20 +echo +echo "=3D=3D=3D Testing version downgrade with extended L2 entries =3D=3D= =3D" +echo +_make_test_img -o "compat=3D1.1,extended_l2=3Don" 64M +$QEMU_IMG amend -o "compat=3D0.10" "$TEST_IMG" + echo echo "=3D=3D=3D Try changing the external data file =3D=3D=3D" echo diff --git a/tests/qemu-iotests/061.out b/tests/qemu-iotests/061.out index 8b3091a412..5d009867a2 100644 --- a/tests/qemu-iotests/061.out +++ b/tests/qemu-iotests/061.out @@ -498,6 +498,11 @@ Format specific information: corrupt: false No errors were found on the image. =20 +=3D=3D=3D Testing version downgrade with extended L2 entries =3D=3D=3D + +Formatting 'TEST_DIR/t.IMGFMT', fmt=3DIMGFMT size=3D67108864 +qemu-img: Cannot downgrade an image with incompatible features 0x10 set + =3D=3D=3D Try changing the external data file =3D=3D=3D =20 Formatting 'TEST_DIR/t.IMGFMT', fmt=3DIMGFMT size=3D67108864 --=20 2.20.1