From nobody Wed Feb 11 05:11:17 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 149191370583764.2678891374303; Tue, 11 Apr 2017 05:28:25 -0700 (PDT) Received: from localhost ([::1]:39030 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxuuG-0005H3-FO for importer@patchew.org; Tue, 11 Apr 2017 08:28:24 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39104) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxush-00041b-Nl for qemu-devel@nongnu.org; Tue, 11 Apr 2017 08:26:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cxusg-0003oz-Os for qemu-devel@nongnu.org; Tue, 11 Apr 2017 08:26:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35369) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cxusg-0003nl-Ig for qemu-devel@nongnu.org; Tue, 11 Apr 2017 08:26:46 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 93F91C04BD24; Tue, 11 Apr 2017 12:26:45 +0000 (UTC) Received: from lemon.redhat.com (ovpn-8-27.pek2.redhat.com [10.72.8.27]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8EDA28764D; Tue, 11 Apr 2017 12:26:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 93F91C04BD24 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=famz@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 93F91C04BD24 From: Fam Zheng To: qemu-devel@nongnu.org Date: Tue, 11 Apr 2017 20:26:23 +0800 Message-Id: <20170411122632.14050-3-famz@redhat.com> In-Reply-To: <20170411122632.14050-1-famz@redhat.com> References: <20170411122632.14050-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Tue, 11 Apr 2017 12:26:45 +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] [PULL 02/11] block: Quiesce old aio context during bdrv_set_aio_context 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: Peter Maydell , famz@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The fact that the bs->aio_context is changing can confuse the dataplane iothread, because of the now fine granularity aio context lock. bdrv_drain should rather be a bdrv_drained_begin/end pair, but since bs->aio_context is changing, we can just use aio_disable_external and bdrv_parent_drained_begin. Reported-by: Ed Swierk Signed-off-by: Fam Zheng Acked-by: Stefan Hajnoczi Reviewed-by: Stefan Hajnoczi Reviewed-by: Kevin Wolf --- block.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/block.c b/block.c index b8a3011..a995a8e 100644 --- a/block.c +++ b/block.c @@ -4396,11 +4396,12 @@ void bdrv_attach_aio_context(BlockDriverState *bs, =20 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) { - AioContext *ctx; + AioContext *ctx =3D bdrv_get_aio_context(bs); =20 + aio_disable_external(ctx); + bdrv_parent_drained_begin(bs); bdrv_drain(bs); /* ensure there are no in-flight requests */ =20 - ctx =3D bdrv_get_aio_context(bs); while (aio_poll(ctx, false)) { /* wait for all bottom halves to execute */ } @@ -4412,6 +4413,8 @@ void bdrv_set_aio_context(BlockDriverState *bs, AioCo= ntext *new_context) */ aio_context_acquire(new_context); bdrv_attach_aio_context(bs, new_context); + bdrv_parent_drained_end(bs); + aio_enable_external(ctx); aio_context_release(new_context); } =20 --=20 2.9.3