From patchwork Thu Sep 12 11:00:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergio Lopez X-Patchwork-Id: 1161530 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 ozlabs.org (Postfix) with ESMTPS id 46TbV52Jykz9s00 for ; Thu, 12 Sep 2019 21:03:25 +1000 (AEST) Received: from localhost ([::1]:60990 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i8Msl-0001Fu-3d for incoming@patchwork.ozlabs.org; Thu, 12 Sep 2019 07:03:23 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33882) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i8Ms6-0001A0-ON for qemu-devel@nongnu.org; Thu, 12 Sep 2019 07:02:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i8Ms5-0000mC-Js for qemu-devel@nongnu.org; Thu, 12 Sep 2019 07:02:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32994) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i8Ms1-0000kT-7v; Thu, 12 Sep 2019 07:02:37 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ACFC818C4274; Thu, 12 Sep 2019 11:02:35 +0000 (UTC) Received: from dritchie.redhat.com (unknown [10.33.36.24]) by smtp.corp.redhat.com (Postfix) with ESMTP id CF14D5D713; Thu, 12 Sep 2019 11:02:31 +0000 (UTC) From: Sergio Lopez To: qemu-block@nongnu.org Date: Thu, 12 Sep 2019 13:00:33 +0200 Message-Id: <20190912110032.26395-1-slp@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.62]); Thu, 12 Sep 2019 11:02:35 +0000 (UTC) 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] [PATCH v2] nbd/server: attach client channel to the export's AioContext 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, Sergio Lopez Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" On creation, the export's AioContext is set to the same one as the BlockBackend, while the AioContext in the client QIOChannel is left untouched. As a result, when using data-plane, nbd_client_receive_next_request() schedules coroutines in the IOThread AioContext, while the client's QIOChannel is serviced from the main_loop, potentially triggering the assertion at qio_channel_restart_[read|write]. To fix this, as soon we have the export corresponding to the client, we call qio_channel_attach_aio_context() to attach the QIOChannel context to the export's AioContext. This matches with the logic at blk_aio_attached(). RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1748253 Signed-off-by: Sergio Lopez Reviewed-by: Eric Blake --- Changelog v2: - Attach the channel once after negotiation completes, avoiding duplication. (thanks Kevin Wolf). --- nbd/server.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/nbd/server.c b/nbd/server.c index 28c3c8be85..31d624e146 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1297,6 +1297,11 @@ static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp) return ret; } + /* Attach the channel to the same AioContext as the export */ + if (client->exp && client->exp->ctx) { + qio_channel_attach_aio_context(client->ioc, client->exp->ctx); + } + assert(!client->optlen); trace_nbd_negotiate_success();