From patchwork Wed Aug 7 14:46:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 11082321 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 49E8D13AC for ; Wed, 7 Aug 2019 14:49:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3691B286E6 for ; Wed, 7 Aug 2019 14:49:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2A2A928678; Wed, 7 Aug 2019 14:49:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id AC0D228789 for ; Wed, 7 Aug 2019 14:49:33 +0000 (UTC) Received: from localhost ([::1]:42048 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hvNFt-0008MS-1t for patchwork-qemu-devel@patchwork.kernel.org; Wed, 07 Aug 2019 10:49:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44097) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hvNDC-0004Vs-GR for qemu-devel@nongnu.org; Wed, 07 Aug 2019 10:46:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hvNDB-0005Qq-FA for qemu-devel@nongnu.org; Wed, 07 Aug 2019 10:46:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45664) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hvND8-0005Np-SI; Wed, 07 Aug 2019 10:46:43 -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 2DBD5309321C; Wed, 7 Aug 2019 14:46:42 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-117-121.ams2.redhat.com [10.36.117.121]) by smtp.corp.redhat.com (Postfix) with ESMTP id 76FC85D717; Wed, 7 Aug 2019 14:46:40 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Wed, 7 Aug 2019 16:46:27 +0200 Message-Id: <20190807144628.4988-3-kwolf@redhat.com> In-Reply-To: <20190807144628.4988-1-kwolf@redhat.com> References: <20190807144628.4988-1-kwolf@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-4.5.16 (mx1.redhat.com [10.5.110.45]); Wed, 07 Aug 2019 14:46:42 +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 2/3] mirror: Keep mirror_top_bs drained after dropping permissions 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, vsementsov@virtuozzo.com, den@virtuozzo.com, qemu-devel@nongnu.org, mreitz@redhat.com, dplotnikov@virtuozzo.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP mirror_top_bs is currently implicitly drained through its connection to the source or the target node. However, the drain section for target_bs ends early after moving mirror_top_bs from src to target_bs, so that requests can already be restarted while mirror_top_bs is still present in the chain, but has dropped all permissions and therefore runs into an assertion failure like this: qemu-system-x86_64: block/io.c:1634: bdrv_co_write_req_prepare: Assertion `child->perm & BLK_PERM_WRITE' failed. Keep mirror_top_bs drained until all graph changes have completed. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz --- block/mirror.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/block/mirror.c b/block/mirror.c index 9f5c59ece1..642d6570cc 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -656,7 +656,10 @@ static int mirror_exit_common(Job *job) s->target = NULL; /* We don't access the source any more. Dropping any WRITE/RESIZE is - * required before it could become a backing file of target_bs. */ + * required before it could become a backing file of target_bs. Not having + * these permissions any more means that we can't allow any new requests on + * mirror_top_bs from now on, so keep it drained. */ + bdrv_drained_begin(mirror_top_bs); bs_opaque->stop = true; bdrv_child_refresh_perms(mirror_top_bs, mirror_top_bs->backing, &error_abort); @@ -724,6 +727,7 @@ static int mirror_exit_common(Job *job) bs_opaque->job = NULL; bdrv_drained_end(src); + bdrv_drained_end(mirror_top_bs); s->in_drain = false; bdrv_unref(mirror_top_bs); bdrv_unref(src);