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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 289F1C5ACAE for ; Wed, 11 Sep 2019 17:23:03 +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 EFF8C2067D for ; Wed, 11 Sep 2019 17:23:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EFF8C2067D 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]:54080 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i86Kb-0001Us-UG for qemu-devel@archiver.kernel.org; Wed, 11 Sep 2019 13:23:01 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49356) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i86JR-0000k2-6e for qemu-devel@nongnu.org; Wed, 11 Sep 2019 13:21:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i86JP-0002so-64 for qemu-devel@nongnu.org; Wed, 11 Sep 2019 13:21:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56110) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i86JL-0002qw-Pt; Wed, 11 Sep 2019 13:21:44 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A963010CC1F9; Wed, 11 Sep 2019 17:21:41 +0000 (UTC) Received: from [10.3.116.234] (ovpn-116-234.phx2.redhat.com [10.3.116.234]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B92F0608C2; Wed, 11 Sep 2019 17:21:38 +0000 (UTC) To: Sergio Lopez , qemu-block@nongnu.org References: <20190911161521.59261-1-slp@redhat.com> From: Eric Blake Openpgp: preference=signencrypt Autocrypt: addr=eblake@redhat.com; keydata= xsBNBEvHyWwBCACw7DwsQIh0kAbUXyqhfiKAKOTVu6OiMGffw2w90Ggrp4bdVKmCaEXlrVLU xphBM8mb+wsFkU+pq9YR621WXo9REYVIl0FxKeQo9dyQBZ/XvmUMka4NOmHtFg74nvkpJFCD TUNzmqfcjdKhfFV0d7P/ixKQeZr2WP1xMcjmAQY5YvQ2lUoHP43m8TtpB1LkjyYBCodd+LkV GmCx2Bop1LSblbvbrOm2bKpZdBPjncRNob73eTpIXEutvEaHH72LzpzksfcKM+M18cyRH+nP sAd98xIbVjm3Jm4k4d5oQyE2HwOur+trk2EcxTgdp17QapuWPwMfhaNq3runaX7x34zhABEB AAHNHkVyaWMgQmxha2UgPGVibGFrZUByZWRoYXQuY29tPsLAegQTAQgAJAIbAwULCQgHAwUV CgkICwUWAgMBAAIeAQIXgAUCS8fL9QIZAQAKCRCnoWtKJSdDahBHCACbl/5FGkUqJ89GAjeX RjpAeJtdKhujir0iS4CMSIng7fCiGZ0fNJCpL5RpViSo03Q7l37ss+No+dJI8KtAp6ID+PMz wTJe5Egtv/KGUKSDvOLYJ9WIIbftEObekP+GBpWP2+KbpADsc7EsNd70sYxExD3liwVJYqLc Rw7so1PEIFp+Ni9A1DrBR5NaJBnno2PHzHPTS9nmZVYm/4I32qkLXOcdX0XElO8VPDoVobG6 gELf4v/vIImdmxLh/w5WctUpBhWWIfQDvSOW2VZDOihm7pzhQodr3QP/GDLfpK6wI7exeu3P pfPtqwa06s1pae3ad13mZGzkBdNKs1HEm8x6zsBNBEvHyWwBCADGkMFzFjmmyqAEn5D+Mt4P zPdO8NatsDw8Qit3Rmzu+kUygxyYbz52ZO40WUu7EgQ5kDTOeRPnTOd7awWDQcl1gGBXgrkR pAlQ0l0ReO57Q0eglFydLMi5bkwYhfY+TwDPMh3aOP5qBXkm4qIYSsxb8A+i00P72AqFb9Q7 3weG/flxSPApLYQE5qWGSXjOkXJv42NGS6o6gd4RmD6Ap5e8ACo1lSMPfTpGzXlt4aRkBfvb NCfNsQikLZzFYDLbQgKBA33BDeV6vNJ9Cj0SgEGOkYyed4I6AbU0kIy1hHAm1r6+sAnEdIKj cHi3xWH/UPrZW5flM8Kqo14OTDkI9EtlABEBAAHCwF8EGAEIAAkFAkvHyWwCGwwACgkQp6Fr SiUnQ2q03wgAmRFGDeXzc58NX0NrDijUu0zx3Lns/qZ9VrkSWbNZBFjpWKaeL1fdVeE4TDGm I5mRRIsStjQzc2R9b+2VBUhlAqY1nAiBDv0Qnt+9cLiuEICeUwlyl42YdwpmY0ELcy5+u6wz mK/jxrYOpzXKDwLq5k4X+hmGuSNWWAN3gHiJqmJZPkhFPUIozZUCeEc76pS/IUN72NfprZmF Dp6/QDjDFtfS39bHSWXKVZUbqaMPqlj/z6Ugk027/3GUjHHr8WkeL1ezWepYDY7WSoXwfoAL 2UXYsMAr/uUncSKlfjvArhsej0S4zbqim2ZY6S8aRWw94J3bSvJR+Nwbs34GPTD4Pg== Organization: Red Hat, Inc. Message-ID: Date: Wed, 11 Sep 2019 12:21:37 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190911161521.59261-1-slp@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="hFAeHbL5kqgnixoKp6B13hEFulx533M4S" X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.65]); Wed, 11 Sep 2019 17:21:41 +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: Re: [Qemu-devel] [PATCH] 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 Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --hFAeHbL5kqgnixoKp6B13hEFulx533M4S Content-Type: multipart/mixed; boundary="b2Idtuhv7eN7yK1jMMqbiP7J85w9Xqltp"; protected-headers="v1" From: Eric Blake To: Sergio Lopez , qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, kwolf@redhat.com Message-ID: Subject: Re: [PATCH] nbd/server: attach client channel to the export's AioContext References: <20190911161521.59261-1-slp@redhat.com> In-Reply-To: <20190911161521.59261-1-slp@redhat.com> --b2Idtuhv7eN7yK1jMMqbiP7J85w9Xqltp Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 9/11/19 11:15 AM, Sergio Lopez wrote: > 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. >=20 > 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]. >=20 > 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 in > blk_aio_attached(). >=20 > RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=3D1748253 > Signed-off-by: Sergio Lopez > --- > nbd/server.c | 2 ++ > 1 file changed, 2 insertions(+) I'd like a second opinion from Kevin, but the description makes sense to me. I'm happy to queue this through my NBD tree. Reviewed-by: Eric Blake >=20 > diff --git a/nbd/server.c b/nbd/server.c > index 10faedcfc5..51322e2343 100644 > --- a/nbd/server.c > +++ b/nbd/server.c > @@ -471,6 +471,7 @@ static int nbd_negotiate_handle_export_name(NBDClie= nt *client, > QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); > nbd_export_get(client->exp); > nbd_check_meta_export(client); > + qio_channel_attach_aio_context(client->ioc, client->exp->ctx); > =20 > return 0; > } > @@ -673,6 +674,7 @@ static int nbd_negotiate_handle_info(NBDClient *cli= ent, uint16_t myflags, > QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); > nbd_export_get(client->exp); > nbd_check_meta_export(client); > + qio_channel_attach_aio_context(client->ioc, exp->ctx); > rc =3D 1; > } > return rc; >=20 --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org --b2Idtuhv7eN7yK1jMMqbiP7J85w9Xqltp-- --hFAeHbL5kqgnixoKp6B13hEFulx533M4S Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAl15LSEACgkQp6FrSiUn Q2qQugf/ehAQj008CqKgxDaB0+hm582/EXYTwoM5zcwynlC32/3R/1sP4Go69kHD RGkvYzOsbwEFImNTQcduZEq0N6QAxwwJ5Zl3oi0TPs2O+BLDYTXoWVF+CDyvAThV GZMRz6UYQTc8Oa7pIbBzF0CrN3XayVmT15XX1Y9r9rhCM1r8cWQ1wsM3xlaH9E1N 0aCauofUNKfe2KyZskoKTnff/4iDEGHAL7YKG6EZYXdEs3Z/reSpeGGEBQYH3uZu wYrCXcMfgoR8Kw27Xb/v6meIdVsIod1hxPzkeEcgFjaCjZtKdrNgn8q3MVUBVC2c AcQsQwUoYR2pRrE7guwztsnXGE//bQ== =GgUt -----END PGP SIGNATURE----- --hFAeHbL5kqgnixoKp6B13hEFulx533M4S--