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=-6.5 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 148F7C2D0DB for ; Thu, 30 Jan 2020 21:55:04 +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 D3A6620708 for ; Thu, 30 Jan 2020 21:55:03 +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="O7a+u0wS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D3A6620708 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]:39840 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ixHmA-0003Vh-Vh for qemu-devel@archiver.kernel.org; Thu, 30 Jan 2020 16:55:03 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:33532) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ixHce-00057T-44 for qemu-devel@nongnu.org; Thu, 30 Jan 2020 16:45:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ixHcc-0004ai-LC for qemu-devel@nongnu.org; Thu, 30 Jan 2020 16:45:11 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:39013 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ixHcc-0004XT-Fp for qemu-devel@nongnu.org; Thu, 30 Jan 2020 16:45:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580420709; 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=zAXK4A1gwm6JGoSTkcy70CJDNhiVlAh1hgkdPBAzHyg=; b=O7a+u0wSJNsYF2fTe03UZTvSmRnVsYmSf7HmdPADShCa+lQ7qghLb1o4ci11m2Cm0NPHED VOEluVzKQ39YnTXT42PiCioNXMmt56iwhRsYGn5hWujNQs51u1iORpZY5oW7FRv+pYZ26a Ov33IunOGXH9D6pYiQscmUejpWXTBFs= 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-177-8LkCqwhtMwO0pXSfMtgB_w-1; Thu, 30 Jan 2020 16:45:07 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4B14573426; Thu, 30 Jan 2020 21:45:06 +0000 (UTC) Received: from localhost (ovpn-204-145.brq.redhat.com [10.40.204.145]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 04F5810018FF; Thu, 30 Jan 2020 21:45:03 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Subject: [PATCH v3 13/21] mirror: Double-check immediately before replacing Date: Thu, 30 Jan 2020 22:44:23 +0100 Message-Id: <20200130214431.333510-14-mreitz@redhat.com> In-Reply-To: <20200130214431.333510-1-mreitz@redhat.com> References: <20200130214431.333510-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-MC-Unique: 8LkCqwhtMwO0pXSfMtgB_w-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII 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: 207.211.31.120 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: Kevin Wolf , Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" There is no guarantee that we can still replace the node we want to replace at the end of the mirror job. Double-check by calling bdrv_recurse_can_replace(). Signed-off-by: Max Reitz Reviewed-by: Vladimir Sementsov-Ogievskiy --- block/mirror.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/block/mirror.c b/block/mirror.c index cacbc70014..447051dbc6 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -700,7 +700,19 @@ static int mirror_exit_common(Job *job) * drain potential other users of the BDS before changing the grap= h. */ assert(s->in_drain); bdrv_drained_begin(target_bs); - bdrv_replace_node(to_replace, target_bs, &local_err); + /* + * Cannot use check_to_replace_node() here, because that would + * check for an op blocker on @to_replace, and we have our own + * there. + */ + if (bdrv_recurse_can_replace(src, to_replace)) { + bdrv_replace_node(to_replace, target_bs, &local_err); + } else { + error_setg(&local_err, "Can no longer replace '%s' by '%s', " + "because it can no longer be guaranteed that doing = so " + "would not lead to an abrupt change of visible data= ", + to_replace->node_name, target_bs->node_name); + } bdrv_drained_end(target_bs); if (local_err) { error_report_err(local_err); --=20 2.24.1