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=-7.0 required=3.0 tests=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 24196C04AAF for ; Tue, 21 May 2019 19:18:42 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F19E2217D7 for ; Tue, 21 May 2019 19:18:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F19E2217D7 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 ([127.0.0.1]:58214 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hTAHZ-0000i5-4P for qemu-devel@archiver.kernel.org; Tue, 21 May 2019 15:18:41 -0400 Received: from eggs.gnu.org ([209.51.188.92]:46795) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hTAFv-0007v1-94 for qemu-devel@nongnu.org; Tue, 21 May 2019 15:17:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hTAFu-0000DV-BM for qemu-devel@nongnu.org; Tue, 21 May 2019 15:16:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52050) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hTAFr-0000B6-Nt; Tue, 21 May 2019 15:16:55 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 71C3F5D61C; Tue, 21 May 2019 19:16:48 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-117-63.ams2.redhat.com [10.36.117.63]) by smtp.corp.redhat.com (Postfix) with ESMTP id 613DC6013B; Tue, 21 May 2019 19:16:45 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Tue, 21 May 2019 21:16:37 +0200 Message-Id: <20190521191638.32713-2-kwolf@redhat.com> In-Reply-To: <20190521191638.32713-1-kwolf@redhat.com> References: <20190521191638.32713-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Tue, 21 May 2019 19:16:55 +0000 (UTC) Content-Transfer-Encoding: quoted-printable 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 1/2] block: Drain source node in bdrv_replace_node() 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: kwolf@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Instead of just asserting that no requests are in flight in bdrv_replace_node(), which is a requirement that most callers ignore, we can just drain the source node right there. This fixes at least starting a commit job while I/O is active on the backing chain, but probably other callers, too. Having requests in flight on the target node isn't a problem because the target just gets new parents, but the call path of running requests isn't modified. So we can just drop this assertion without a replacement. Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=3D1711643 Signed-off-by: Kevin Wolf --- block.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/block.c b/block.c index cb11537029..75f370dbba 100644 --- a/block.c +++ b/block.c @@ -4021,13 +4021,13 @@ void bdrv_replace_node(BlockDriverState *from, Bl= ockDriverState *to, uint64_t perm =3D 0, shared =3D BLK_PERM_ALL; int ret; =20 - assert(!atomic_read(&from->in_flight)); - assert(!atomic_read(&to->in_flight)); - /* Make sure that @from doesn't go away until we have successfully a= ttached * all of its parents to @to. */ bdrv_ref(from); =20 + assert(qemu_get_current_aio_context() =3D=3D qemu_get_aio_context())= ; + bdrv_drained_begin(from); + /* Put all parents into @list and calculate their cumulative permiss= ions */ QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) { assert(c->bs =3D=3D from); @@ -4068,6 +4068,7 @@ void bdrv_replace_node(BlockDriverState *from, Bloc= kDriverState *to, =20 out: g_slist_free(list); + bdrv_drained_end(from); bdrv_unref(from); } =20 --=20 2.20.1