From nobody Tue Apr 15 11:33:47 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.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; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1552051083341375.7045679203003; Fri, 8 Mar 2019 05:18:03 -0800 (PST) Received: from localhost ([127.0.0.1]:42923 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h2FNt-0006iy-8u for importer@patchew.org; Fri, 08 Mar 2019 08:17:57 -0500 Received: from eggs.gnu.org ([209.51.188.92]:59937) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h2F5z-0000FQ-JX for qemu-devel@nongnu.org; Fri, 08 Mar 2019 07:59:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h2F5t-0008C9-JA for qemu-devel@nongnu.org; Fri, 08 Mar 2019 07:59:24 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35628) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1h2F5j-0006Tu-AC; Fri, 08 Mar 2019 07:59:11 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8D30E5D61A; Fri, 8 Mar 2019 12:59:02 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-117-27.ams2.redhat.com [10.36.117.27]) by smtp.corp.redhat.com (Postfix) with ESMTP id 660CF5D786; Fri, 8 Mar 2019 12:59:00 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 8 Mar 2019 13:58:06 +0100 Message-Id: <20190308125823.32535-17-kwolf@redhat.com> In-Reply-To: <20190308125823.32535-1-kwolf@redhat.com> References: <20190308125823.32535-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 08 Mar 2019 12:59:02 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 16/33] qcow2: Prepare qcow2_get_cluster_type() for external data file X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" Signed-off-by: Kevin Wolf --- block/qcow2.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/block/qcow2.h b/block/qcow2.h index 7a34bd0c53..8fe2d55005 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -521,7 +521,15 @@ static inline QCow2ClusterType qcow2_get_cluster_type(= BlockDriverState *bs, } return QCOW2_CLUSTER_ZERO_PLAIN; } else if (!(l2_entry & L2E_OFFSET_MASK)) { - return QCOW2_CLUSTER_UNALLOCATED; + /* Offset 0 generally means unallocated, but it is ambiguous with + * external data files because 0 is a valid offset there. However,= all + * clusters in external data files always have refcount 1, so we c= an + * rely on QCOW_OFLAG_COPIED to disambiguate. */ + if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) { + return QCOW2_CLUSTER_NORMAL; + } else { + return QCOW2_CLUSTER_UNALLOCATED; + } } else { return QCOW2_CLUSTER_NORMAL; } --=20 2.20.1