From nobody Mon Feb 9 18:44:12 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; 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 208.118.235.17 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 [208.118.235.17]) by mx.zohomail.com with SMTPS id 152058324673012.855190887333151; Fri, 9 Mar 2018 00:14:06 -0800 (PST) Received: from localhost ([::1]:43728 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1euDAC-00055x-VO for importer@patchew.org; Fri, 09 Mar 2018 03:14:05 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60312) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1euD5q-0001i6-PR for qemu-devel@nongnu.org; Fri, 09 Mar 2018 03:09:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1euD5p-0008OR-Ls for qemu-devel@nongnu.org; Fri, 09 Mar 2018 03:09:34 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:43330 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1euD5j-0008MU-CY; Fri, 09 Mar 2018 03:09:27 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9916876FBA; Fri, 9 Mar 2018 08:09:25 +0000 (UTC) Received: from lemon.usersys.redhat.com (ovpn-12-195.pek2.redhat.com [10.72.12.195]) by smtp.corp.redhat.com (Postfix) with ESMTP id E144010C6EAB; Fri, 9 Mar 2018 08:09:23 +0000 (UTC) From: Fam Zheng To: qemu-devel@nongnu.org Date: Fri, 9 Mar 2018 16:09:08 +0800 Message-Id: <20180309080910.7274-3-famz@redhat.com> In-Reply-To: <20180309080910.7274-1-famz@redhat.com> References: <20180309080910.7274-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 09 Mar 2018 08:09:25 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 09 Mar 2018 08:09:25 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'famz@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH 2/4] block: Fix write flags in bdrv_backing_options 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: Kevin Wolf , qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" When the child in question already has write access, we shouldn't change that just because the parent being open/reopen doesn't need it. But if we are inherenting the flags from a writable parent, we shouldn't copy the BDRV_O_RDWR flag, which is consistent with the BDRV_OPT_READ_ONLY option we set. Signed-off-by: Fam Zheng --- block.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/block.c b/block.c index bedbe208e6..937f9fe159 100644 --- a/block.c +++ b/block.c @@ -997,7 +997,10 @@ static void bdrv_backing_options(int *child_flags, QDi= ct *child_options, int parent_flags, QDict *parent_options, int current_flags) { - int flags =3D parent_flags; + /* write flag should be preserved if the backing file already has it. = This + * is important during reopen, to keep "parallel block jobs" work. */ + int write_flag =3D current_flags & BDRV_O_RDWR; + int flags =3D parent_flags | write_flag; =20 /* The cache mode is inherited unmodified for backing files; except WC= E, * which is only applied on the top level (BlockBackend) */ @@ -1005,9 +1008,13 @@ static void bdrv_backing_options(int *child_flags, Q= Dict *child_options, qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FL= USH); qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE= ); =20 - /* backing files always opened read-only */ - qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on"); - flags &=3D ~BDRV_O_COPY_ON_READ; + + if (!write_flag) { + flags &=3D ~BDRV_O_COPY_ON_READ; + /* backing files always opened read-only */ + qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on"); + flags &=3D ~BDRV_O_RDWR; + } =20 /* snapshot=3Don is handled on the top layer */ flags &=3D ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY); --=20 2.14.3