From nobody Mon Feb 9 12:45:35 2026 Delivered-To: importer@patchew.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=1594398697; cv=none; d=zohomail.com; s=zohoarc; b=hESI2QKgWcKAvrGOQ7sDbQHkD6mtYAgOZhESwyeb7VqOVIY5U8S3+kd2hOrtBz8/90UA9zHSN18fgt3oUok0u5m0M42qQqQgGW76HQEuYSSf4OYCFXpIPrtMOUmO0sYjFqSUrG4bi58C4LYiqBIaDNzndCgywNNL3eliYn9XBAM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1594398697; 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=dc1B8LYnCsufe9nB7fXbVLjIVWlGOxFWG8w0mRSMhwI=; b=I6dp78WiWi+41Xb1ZIBMKTfKmVx/8fJY988FfFNwISo6iCm2b5uKf0TvYg7S22ZWOwtJvy5LG4sPBjcGIZMBFOV62dJfYr+ohFKr/zfPBWXMAYSAVNnkjaWA/cXmsE98EQMgXhXhHpbNT1aCtzGceUKFlRMPIsA4yS+C57wS2qg= 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 1594398697932600.9877215316725; Fri, 10 Jul 2020 09:31:37 -0700 (PDT) Received: from localhost ([::1]:36552 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jtvw0-00017n-M2 for importer@patchew.org; Fri, 10 Jul 2020 12:31:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42770) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jtvfR-0003DD-Hr; Fri, 10 Jul 2020 12:14:29 -0400 Received: from fanzine.igalia.com ([178.60.130.6]:43812) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jtvfJ-0004w4-KX; Fri, 10 Jul 2020 12:14:29 -0400 Received: from [81.0.43.0] (helo=perseus.local) by fanzine.igalia.com with esmtpsa (Cipher TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim) id 1jtvea-0003kB-LG; Fri, 10 Jul 2020 18:13:36 +0200 Received: from berto by perseus.local with local (Exim 4.92) (envelope-from ) id 1jtveL-0001Rc-MU; Fri, 10 Jul 2020 18:13:21 +0200 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=dc1B8LYnCsufe9nB7fXbVLjIVWlGOxFWG8w0mRSMhwI=; b=CRjE45EjildOc5qFyPcWcyPbZBwTJuuEtH7oP+Vc/SbCoI5MGIvP07MxJYJ6RTKBgKTveNvZ+NMFicd3gd+LerPlNqvYqXshZVLUKtYG7pAHDgok6vt+O08R4AxQa0rVCFnhco06auJynP1g2aDk/6eQLoOdeb2nnQ7JWOocMN1xmcn0ryQtGO6kzTmdnDU/LoFxeGjB/c+mbgLgmm1wC6unrh7r+lXy0D16uuK1uAFfCt6Lw+LDACBD8WP05hshvunMbk25zpSjrgEPxAet3QY+nhACKQpye4gmRhQRFu5QuQOmXlzA4MhM2patGtxIhKKkTDp04aFl0h+16L4r5Q==; From: Alberto Garcia To: qemu-devel@nongnu.org Subject: [PATCH v11 33/34] qcow2: Assert that expand_zero_clusters_in_l1() does not support subclusters Date: Fri, 10 Jul 2020 18:13:15 +0200 Message-Id: <15e65112b4144381b4d8c0bdf8fb76b0d813e3d1.1594396418.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 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; Received-SPF: pass client-ip=178.60.130.6; envelope-from=berto@igalia.com; helo=fanzine.igalia.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/10 12:13:35 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x (no timestamps) [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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 , Vladimir Sementsov-Ogievskiy , Alberto Garcia , qemu-block@nongnu.org, Derek Su , Max Reitz 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. This would require transforming all extended L2 entries into normal L2 entries but this is not a simple task and there are no plans to implement this at the moment. Signed-off-by: Alberto Garcia Reviewed-by: Eric Blake Reviewed-by: Max Reitz --- 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 bbf373ad21..81c49ba934 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -2159,6 +2159,9 @@ 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 @@ -2227,7 +2230,8 @@ 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; @@ -2298,6 +2302,8 @@ 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 10eb243164..23add2dfe3 100755 --- a/tests/qemu-iotests/061 +++ b/tests/qemu-iotests/061 @@ -303,6 +303,12 @@ $QEMU_IMG amend -o "compat=3D0.10" "$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 caa53e87cc..57d8c29f0b 100644 --- a/tests/qemu-iotests/061.out +++ b/tests/qemu-iotests/061.out @@ -532,6 +532,11 @@ Format specific information: extended l2: 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