From patchwork Fri Jul 3 15:58:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alberto Garcia X-Patchwork-Id: 11642211 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 12DD0912 for ; Fri, 3 Jul 2020 16:09:43 +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 DE4D2217BA for ; Fri, 3 Jul 2020 16:09:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="Ejj+wLEL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE4D2217BA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=igalia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:57042 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jrOFy-0006Pe-2P for patchwork-qemu-devel@patchwork.kernel.org; Fri, 03 Jul 2020 12:09:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59198) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jrO5q-0003dA-Nt; Fri, 03 Jul 2020 11:59:14 -0400 Received: from fanzine.igalia.com ([178.60.130.6]:41791) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jrO5l-0007SL-9j; Fri, 03 Jul 2020 11:59:14 -0400 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=XKJZ8yyqhlVSk84jmRYI3Yd+Y6Hi+Lfy6XSaI9F5REg=; b=Ejj+wLELDOEWRBuYnNGPwORF9XACAT4J+E4ARbbGYMg8pW8evGDFzUj2U371rbA2JDp5pCxAGEoDjURwQqb9OOfpl3AoniJ3lD25g5kxUS92s8AonFUyowQKlQc2h1xvtvlDRJfVfYge/tSn0D2ErSEJnoKE1jYc/iM+zBFeiYuyI0vou4gVNAPzEkZ7qV144JDF1bHijsff/kYJ/0H2WlDiK75AON1kZqw+A/G76od6Xf2RjcxT+bfGrNhE3tkFuwfuJQTXyouImy9F2Y8DKAWG7m25+HErV8+TakN7ORzCKgla5Y3gjumJL1dn4e5d3d3cytUNUP3I7rRencUSpw==; Received: from [81.0.49.0] (helo=perseus.local) by fanzine.igalia.com with esmtpsa (Cipher TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim) id 1jrO5L-0001Rk-Vj; Fri, 03 Jul 2020 17:58:44 +0200 Received: from berto by perseus.local with local (Exim 4.92) (envelope-from ) id 1jrO52-0007Qj-IW; Fri, 03 Jul 2020 17:58:24 +0200 From: Alberto Garcia To: qemu-devel@nongnu.org Subject: [PATCH v10 33/34] qcow2: Assert that expand_zero_clusters_in_l1() does not support subclusters Date: Fri, 3 Jul 2020 17:58:19 +0200 Message-Id: <85378aabb27575eb1dc853213c0bd7176ed4bd1a.1593791819.git.berto@igalia.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 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 = 2020/07/03 11:21:00 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=_AUTOLEARN 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" 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(BlockDriverState *bs, uint64_t *l1_table, int ret; int i, j; + /* qcow2_downgrade() is not allowed in images with subclusters */ + assert(!has_subclusters(s)); + slice_size2 = s->l2_slice_size * l2_entry_size(s); n_slices = s->cluster_size / slice_size2; @@ -2227,7 +2230,8 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, if (cluster_type == 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 subclusters. */ set_l2_entry(s, l2_slice, j, 0); l2_dirty = true; continue; @@ -2298,6 +2302,8 @@ static int expand_zero_clusters_in_l1(BlockDriverState *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() because + * this function doesn't support images with subclusters. */ l2_dirty = true; } 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 @@ $QEMU_IMG amend -o "compat=0.10" "$TEST_IMG" _img_info --format-specific _check_test_img +echo +echo "=== Testing version downgrade with extended L2 entries ===" +echo +_make_test_img -o "compat=1.1,extended_l2=on" 64M +$QEMU_IMG amend -o "compat=0.10" "$TEST_IMG" + echo echo "=== Try changing the external data file ===" echo diff --git a/tests/qemu-iotests/061.out b/tests/qemu-iotests/061.out index f618259d47..a139d4f1fe 100644 --- a/tests/qemu-iotests/061.out +++ b/tests/qemu-iotests/061.out @@ -528,6 +528,11 @@ Format specific information: extended l2: false No errors were found on the image. +=== Testing version downgrade with extended L2 entries === + +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 +qemu-img: Cannot downgrade an image with incompatible features 0x10 set + === Try changing the external data file === Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864