From patchwork Mon Mar 6 16:21:55 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 9607087 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 283F1601D2 for ; Mon, 6 Mar 2017 16:25:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2125627D8D for ; Mon, 6 Mar 2017 16:25:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1638C28173; Mon, 6 Mar 2017 16:25:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id BF2CB27D8D for ; Mon, 6 Mar 2017 16:25:13 +0000 (UTC) Received: from localhost ([::1]:44802 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ckvRg-0004WC-PX for patchwork-qemu-devel@patchwork.kernel.org; Mon, 06 Mar 2017 11:25:12 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54546) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ckvP4-0002U1-FD for qemu-devel@nongnu.org; Mon, 06 Mar 2017 11:22:31 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ckvP3-0001A0-HR for qemu-devel@nongnu.org; Mon, 06 Mar 2017 11:22:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43976) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ckvP1-00017b-66; Mon, 06 Mar 2017 11:22:27 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 51635D59BF; Mon, 6 Mar 2017 16:22:27 +0000 (UTC) Received: from noname.redhat.com (ovpn-116-180.ams2.redhat.com [10.36.116.180]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v26GMJmt031063; Mon, 6 Mar 2017 11:22:25 -0500 From: Kevin Wolf To: qemu-block@nongnu.org Date: Mon, 6 Mar 2017 17:21:55 +0100 Message-Id: <1488817322-11397-4-git-send-email-kwolf@redhat.com> In-Reply-To: <1488817322-11397-1-git-send-email-kwolf@redhat.com> References: <1488817322-11397-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 06 Mar 2017 16:22:27 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 03/10] mirror: Fix permissions for removing mirror_top_bs 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, jcody@redhat.com, famz@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP mirror_top_bs takes write permissions on its backing file, which can make it impossible to attach that backing file node to another parent. However, this is exactly what needs to be done in order to remove mirror_top_bs from the backing chain. So give up the write permission first. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake --- block/mirror.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/block/mirror.c b/block/mirror.c index c9185b3..001b5f0 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -566,8 +566,10 @@ static void mirror_exit(BlockJob *job, void *opaque) /* Remove the mirror filter driver from the graph. Before this, get rid of * the blockers on the intermediate nodes so that the resulting state is - * valid. */ + * valid. Also give up permissions on mirror_top_bs->backing, which might + * block the removal. */ block_job_remove_all_bdrv(job); + bdrv_child_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL); bdrv_replace_in_backing_chain(mirror_top_bs, backing_bs(mirror_top_bs)); /* We just changed the BDS the job BB refers to (with either or both of the @@ -1234,6 +1236,7 @@ fail: block_job_unref(&s->common); } + bdrv_child_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL); bdrv_replace_in_backing_chain(mirror_top_bs, backing_bs(mirror_top_bs)); }