From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8BA2C5DF60 for ; Fri, 8 Nov 2019 08:54:41 +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 74190214DA for ; Fri, 8 Nov 2019 08:54:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Vi6PtecY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 74190214DA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50720 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iT02S-0006fr-Kx for qemu-devel@archiver.kernel.org; Fri, 08 Nov 2019 03:54:40 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:58831) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iT01Y-0005kU-Ag for qemu-devel@nongnu.org; Fri, 08 Nov 2019 03:53:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iT01X-0007cL-9a for qemu-devel@nongnu.org; Fri, 08 Nov 2019 03:53:44 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:29237 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iT01X-0007cB-6T for qemu-devel@nongnu.org; Fri, 08 Nov 2019 03:53:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573203222; 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=GzxLFzL+9LXuE6dWeSgWf1dukfXzVPj1WHJ1jYgYL1E=; b=Vi6PtecY3/WcGH6Wi4r7sORkgOKd6eiIhaEt78tQwOvIbJxgMnuoC8yw7vdM3bGK9vcRqv 5cgPQ3T5z2f6oOWfixgglRwlUjyeZGP4I9FhzLfYjfNoA1mTdjOhw2Dec3C7isxGBanmvU sse35jV/Bh5auEbY0DoOwazicUWDsLI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-380-bq8Gi9NINium1zIHimzYyQ-1; Fri, 08 Nov 2019 03:53:39 -0500 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 57A58107ACC3; Fri, 8 Nov 2019 08:53:38 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-116-227.ams2.redhat.com [10.36.116.227]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1AE85600C9; Fri, 8 Nov 2019 08:53:36 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PATCH 1/2] block: Remove 'backing': null from bs->{explicit_, }options Date: Fri, 8 Nov 2019 09:53:11 +0100 Message-Id: <20191108085312.27049-2-kwolf@redhat.com> In-Reply-To: <20191108085312.27049-1-kwolf@redhat.com> References: <20191108085312.27049-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: bq8Gi9NINium1zIHimzYyQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.61 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: kwolf@redhat.com, pkrempa@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" bs->options and bs->explicit_options shouldn't contain any options for child nodes. bdrv_open_inherited() takes care to remove any options that match a child name after opening the image and the same is done when reopening. However, we miss the case of 'backing': null, which is a child option, but results in no child being created. This means that a 'backing': null remains in bs->options and bs->explicit_options. A typical use for 'backing': null is in live snapshots: blockdev-add for the qcow2 overlay makes sure not to open the backing file (because it is already opened and blockdev-snapshot will attach it). After doing a blockdev-snapshot, bs->options and bs->explicit_options become inconsistent with the actual state (bs has a backing file now, but the options still say null). On the next occasion that the image is reopened, e.g. switching it from read-write to read-only when another snapshot is taken, the option will take effect again and the node incorrectly loses its backing file. Fix bdrv_open_inherited() to remove the 'backing' option from bs->options and bs->explicit_options even for the case where it specifies that no backing file is wanted. Reported-by: Peter Krempa Signed-off-by: Kevin Wolf --- block.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block.c b/block.c index dad5a3d8e0..74ba9acb08 100644 --- a/block.c +++ b/block.c @@ -3019,6 +3019,8 @@ static BlockDriverState *bdrv_open_inherit(const char= *filename, "use \"backing\": null instead"); } flags |=3D BDRV_O_NO_BACKING; + qdict_del(bs->explicit_options, "backing"); + qdict_del(bs->options, "backing"); qdict_del(options, "backing"); } =20 --=20 2.20.1