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=-6.8 required=3.0 tests=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 6DF8DC31E5B for ; Tue, 18 Jun 2019 16:21:49 +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 440C820B1F for ; Tue, 18 Jun 2019 16:21:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 440C820B1F 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]:59500 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hdGrk-0007d0-Gf for qemu-devel@archiver.kernel.org; Tue, 18 Jun 2019 12:21:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56330) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hdFxm-0008T1-Qx for qemu-devel@nongnu.org; Tue, 18 Jun 2019 11:24:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hdFxh-0000zS-7I for qemu-devel@nongnu.org; Tue, 18 Jun 2019 11:23:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38372) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hdFxY-0000lF-Qf; Tue, 18 Jun 2019 11:23:44 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ED34D30001D8; Tue, 18 Jun 2019 15:23:35 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-116-185.ams2.redhat.com [10.36.116.185]) by smtp.corp.redhat.com (Postfix) with ESMTP id 199C719492; Tue, 18 Jun 2019 15:23:34 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Tue, 18 Jun 2019 17:23:14 +0200 Message-Id: <20190618152318.24953-11-kwolf@redhat.com> In-Reply-To: <20190618152318.24953-1-kwolf@redhat.com> References: <20190618152318.24953-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Tue, 18 Jun 2019 15:23:35 +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 10/14] block: Fix order in bdrv_replace_child() 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, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Max Reitz We have to start by applying the permission restrictions to new_bs before we can loosen them on old_bs. See the comment for the explanation. Signed-off-by: Max Reitz Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- block.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/block.c b/block.c index 013369851b..b7d4149c2f 100644 --- a/block.c +++ b/block.c @@ -2240,6 +2240,19 @@ static void bdrv_replace_child(BdrvChild *child, B= lockDriverState *new_bs) =20 bdrv_replace_child_noperm(child, new_bs); =20 + /* + * Start with the new node's permissions. If @new_bs is a (direct + * or indirect) child of @old_bs, we must complete the permission + * update on @new_bs before we loosen the restrictions on @old_bs. + * Otherwise, bdrv_check_perm() on @old_bs would re-initiate + * updating the permissions of @new_bs, and thus not purely loosen + * restrictions. + */ + if (new_bs) { + bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm); + bdrv_set_perm(new_bs, perm, shared_perm); + } + if (old_bs) { /* Update permissions for old node. This is guaranteed to succee= d * because we're just taking a parent away, so we're loosening @@ -2252,11 +2265,6 @@ static void bdrv_replace_child(BdrvChild *child, B= lockDriverState *new_bs) * node moves back to the main AioContext */ bdrv_try_set_aio_context(old_bs, qemu_get_aio_context(), NULL); } - - if (new_bs) { - bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm); - bdrv_set_perm(new_bs, perm, shared_perm); - } } =20 /* --=20 2.20.1