From nobody Sun Feb 8 18:24:35 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=1593792832; cv=none; d=zohomail.com; s=zohoarc; b=nN2bLzQTnuqnGON5xC5km+Jl5lPAjIRALda4S9Q/jMrlK+JC1VIBmWIeP15FDYwkoSqh89UgjSOTV4grTwDqLMUh+C5C3xIvVYy517jj/wzrEsL3qkpXa+qc6CmwurPQDri0DJzFIfoGwYqZep8R7NXA4SFvDQphHc6l4rYb9Jw= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1593792832; 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=LY/et2AdwdNh1S7gB98XcKaWu4e2Wpe6nEn2bXOs7rA=; b=Ap5V0img3RUUoi0fBDDPKJksBxcktgxltqYs1QyXJw8T8fuFNiHhzeSFCHhiJfyIFsVcdIV5fSsRMMALIVdnh/x1iSIdcirdZagExCyjKcmz3xIwsdeFJafpfB4x6s2Fe/evAmSQCl+amer0iwkV/7QB4RryS7hQPdKyFPkWUV4= 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 1593792832149774.5800452266894; Fri, 3 Jul 2020 09:13:52 -0700 (PDT) Received: from localhost ([::1]:43584 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jrOJy-000492-Uf for importer@patchew.org; Fri, 03 Jul 2020 12:13:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59244) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jrO5t-0003lE-Cn; Fri, 03 Jul 2020 11:59:17 -0400 Received: from fanzine.igalia.com ([178.60.130.6]:41855) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jrO5m-0007TP-T6; Fri, 03 Jul 2020 11:59:16 -0400 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 1jrO5P-0001Sn-KM; Fri, 03 Jul 2020 17:58:47 +0200 Received: from berto by perseus.local with local (Exim 4.92) (envelope-from ) id 1jrO52-0007Qg-Hc; Fri, 03 Jul 2020 17:58:24 +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=LY/et2AdwdNh1S7gB98XcKaWu4e2Wpe6nEn2bXOs7rA=; b=cnqiYyQc8kbgfG4FWnwS65mvbqQ183cqMi/XZ45JiiOUkiQLwkccnT/fAhgA+06Iti7taiWz0ZK0OiFE6B1VepGkDemqw3Rj0M5d/S1JUxUSQ+FTufErgof7fjFk8Czl5QBbLRyc3W03QZO2IcTMhtkVM3og7Z9jVlgVKoFEBRHs0AvQTtWYnoBUetdDa3M+sD4piYy7KWQKxQ98NEkkB7xuzKda9046tvJ63GUIbXuWgviF2Bg9fAA7jf/XpQLyD8kz+u6r7FUih5i2WRFShb7eUkzynhN4wCvrm/v7X5dCiJteywHzzy4qCEFUQ8dMifGv9+9L6MyU1gilEx0kkA==; From: Alberto Garcia To: qemu-devel@nongnu.org Subject: [PATCH v10 32/34] qcow2: Allow preallocation and backing files if extended_l2 is set Date: Fri, 3 Jul 2020 17:58:18 +0200 Message-Id: <87cb87b541ceccc8a6df66da0001a29e20077115.1593791819.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 = 2020/07/03 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" Traditional qcow2 images don't allow preallocation if a backing file is set. This is because once a cluster is allocated there is no way to tell that its data should be read from the backing file. Extended L2 entries have individual allocation bits for each subcluster, and therefore it is perfectly possible to have an allocated cluster with all its subclusters unallocated. Signed-off-by: Alberto Garcia Reviewed-by: Eric Blake Reviewed-by: Max Reitz --- block/qcow2.c | 7 ++++--- tests/qemu-iotests/206.out | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index 3dfb56ccca..06e5c53b70 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -3451,10 +3451,11 @@ qcow2_co_create(BlockdevCreateOptions *create_optio= ns, Error **errp) qcow2_opts->preallocation =3D PREALLOC_MODE_OFF; } if (qcow2_opts->has_backing_file && - qcow2_opts->preallocation !=3D PREALLOC_MODE_OFF) + qcow2_opts->preallocation !=3D PREALLOC_MODE_OFF && + !qcow2_opts->extended_l2) { - error_setg(errp, "Backing file and preallocation cannot be used at= " - "the same time"); + error_setg(errp, "Backing file and preallocation can only be used = at " + "the same time if extended_l2 is on"); ret =3D -EINVAL; goto out; } diff --git a/tests/qemu-iotests/206.out b/tests/qemu-iotests/206.out index 363c5abe35..a100849fcb 100644 --- a/tests/qemu-iotests/206.out +++ b/tests/qemu-iotests/206.out @@ -203,7 +203,7 @@ Job failed: Different refcount widths than 16 bits requ= ire compatibility level 1 =3D=3D=3D Invalid backing file options =3D=3D=3D {"execute": "blockdev-create", "arguments": {"job-id": "job0", "options": = {"backing-file": "/dev/null", "driver": "qcow2", "file": "node0", "prealloc= ation": "full", "size": 67108864}}} {"return": {}} -Job failed: Backing file and preallocation cannot be used at the same time +Job failed: Backing file and preallocation can only be used at the same ti= me if extended_l2 is on {"execute": "job-dismiss", "arguments": {"id": "job0"}} {"return": {}} =20 --=20 2.20.1