From patchwork Tue Feb 1 14:42:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hanna Czenczek X-Patchwork-Id: 12731924 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 76013C433EF for ; Tue, 1 Feb 2022 15:43:57 +0000 (UTC) Received: from localhost ([::1]:44922 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nEvK0-0001il-Gd for qemu-devel@archiver.kernel.org; Tue, 01 Feb 2022 10:43:56 -0500 Received: from eggs.gnu.org ([209.51.188.92]:37384) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nEuRS-0002mJ-Bq for qemu-devel@nongnu.org; Tue, 01 Feb 2022 09:47:37 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:28363) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nEuRL-00031Y-1I for qemu-devel@nongnu.org; Tue, 01 Feb 2022 09:47:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643726636; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dvtPQCatEZe0xC82XXY+CMWfvD5GlCP7wXvXV1nBZkQ=; b=HQaFKMFEV1ms6r1zEsgWlTmYznoRs9XLoBRGyVwss7m9s8/8Vc+g1ZH3/hQHxuqsK0WVXk djnBBAUAj4YnHA84QEr4sN5yTKz86x1CFRGu3iHwKrOU5KGsD2jr/tutRv7jt/oiNhiHna WVQMCUaRebWpREF+ZMcJ3DYGgbC0ObI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-62-ndr_zvQhMgWcOAjH7FMaig-1; Tue, 01 Feb 2022 09:43:50 -0500 X-MC-Unique: ndr_zvQhMgWcOAjH7FMaig-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 78AB1640A3; Tue, 1 Feb 2022 14:43:48 +0000 (UTC) Received: from localhost (unknown [10.39.193.129]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1F75370D31; Tue, 1 Feb 2022 14:43:47 +0000 (UTC) From: Hanna Reitz To: qemu-block@nongnu.org Subject: [PULL 14/24] qcow2: simple case support for downgrading of qcow2 images with zstd Date: Tue, 1 Feb 2022 15:42:23 +0100 Message-Id: <20220201144233.617021-15-hreitz@redhat.com> In-Reply-To: <20220201144233.617021-1-hreitz@redhat.com> References: <20220201144233.617021-1-hreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=hreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=hreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.081, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Peter Maydell , Hanna Reitz , Richard Henderson , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Vladimir Sementsov-Ogievskiy If image doesn't have any compressed cluster we can easily switch to zlib compression, which may allow to downgrade the image. That's mostly needed to support IMGOPTS='compression_type=zstd' in some iotests which do qcow2 downgrade. While being here also fix checkpatch complain against '#' in printf formatting. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Max Reitz Message-Id: <20211223160144.1097696-13-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz --- block/qcow2.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 56 insertions(+), 2 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index d509016756..c8115e1cba 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -5279,6 +5279,38 @@ static int qcow2_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, return bs->drv->bdrv_co_preadv_part(bs, offset, qiov->size, qiov, 0, 0); } +static int qcow2_has_compressed_clusters(BlockDriverState *bs) +{ + int64_t offset = 0; + int64_t bytes = bdrv_getlength(bs); + + if (bytes < 0) { + return bytes; + } + + while (bytes != 0) { + int ret; + QCow2SubclusterType type; + unsigned int cur_bytes = MIN(INT_MAX, bytes); + uint64_t host_offset; + + ret = qcow2_get_host_offset(bs, offset, &cur_bytes, &host_offset, + &type); + if (ret < 0) { + return ret; + } + + if (type == QCOW2_SUBCLUSTER_COMPRESSED) { + return 1; + } + + offset += cur_bytes; + bytes -= cur_bytes; + } + + return 0; +} + /* * Downgrades an image's version. To achieve this, any incompatible features * have to be removed. @@ -5336,9 +5368,10 @@ static int qcow2_downgrade(BlockDriverState *bs, int target_version, * the first place; if that happens nonetheless, returning -ENOTSUP is the * best thing to do anyway */ - if (s->incompatible_features) { + if (s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION) { error_setg(errp, "Cannot downgrade an image with incompatible features " - "%#" PRIx64 " set", s->incompatible_features); + "0x%" PRIx64 " set", + s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION); return -ENOTSUP; } @@ -5356,6 +5389,27 @@ static int qcow2_downgrade(BlockDriverState *bs, int target_version, return ret; } + if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) { + ret = qcow2_has_compressed_clusters(bs); + if (ret < 0) { + error_setg(errp, "Failed to check block status"); + return -EINVAL; + } + if (ret) { + error_setg(errp, "Cannot downgrade an image with zstd compression " + "type and existing compressed clusters"); + return -ENOTSUP; + } + /* + * No compressed clusters for now, so just chose default zlib + * compression. + */ + s->incompatible_features &= ~QCOW2_INCOMPAT_COMPRESSION; + s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; + } + + assert(s->incompatible_features == 0); + s->qcow_version = target_version; ret = qcow2_update_header(bs); if (ret < 0) {