From nobody Tue Feb 10 05:44:10 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 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 [209.51.188.17]) by mx.zohomail.com with SMTPS id 1582022737108229.26321396542664; Tue, 18 Feb 2020 02:45:37 -0800 (PST) Received: from localhost ([::1]:60750 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j40Nk-0004RB-3z for importer@patchew.org; Tue, 18 Feb 2020 05:45:36 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52252) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j40E3-0001qn-1J for qemu-devel@nongnu.org; Tue, 18 Feb 2020 05:35:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j40E1-0007Ui-Ey for qemu-devel@nongnu.org; Tue, 18 Feb 2020 05:35:34 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:60088 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 1j40E0-0007UV-UI for qemu-devel@nongnu.org; Tue, 18 Feb 2020 05:35:33 -0500 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-284-s6GvOgoVNs63w4D90gI1jg-1; Tue, 18 Feb 2020 05:35:30 -0500 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id E3005107ACC4; Tue, 18 Feb 2020 10:35:29 +0000 (UTC) Received: from localhost (unknown [10.36.118.17]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5BDC719756; Tue, 18 Feb 2020 10:35:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582022132; 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=DyB6BovZ7Zn3dfeO8Kv6XtQqu8cYsm8l7mSVBQ/IEDVuPXFbBGniptfvHNQ1xpYG6XJc9K 0l0USVPjDHcA2iUfWS2WqPK0uU4JraanCeOfDfbproRoTWS4+GGaCagYddJToSGG8oWEzR Jqsj9BiDlI7j82LGAx1J0Fc9UQlAwmk= From: Max Reitz To: qemu-block@nongnu.org Subject: [PATCH v4 11/19] mirror: Double-check immediately before replacing Date: Tue, 18 Feb 2020 11:34:46 +0100 Message-Id: <20200218103454.296704-12-mreitz@redhat.com> In-Reply-To: <20200218103454.296704-1-mreitz@redhat.com> References: <20200218103454.296704-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: s6GvOgoVNs63w4D90gI1jg-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] 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: Kevin Wolf , Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" 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