From nobody Wed Nov 5 19:59:53 2025 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.zohomail.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; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1536844103195535.2001134968917; Thu, 13 Sep 2018 06:08:23 -0700 (PDT) Received: from localhost ([::1]:42350 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g0RM2-0005GI-4d for importer@patchew.org; Thu, 13 Sep 2018 09:08:18 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46808) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g0R7G-0002Mh-6x for qemu-devel@nongnu.org; Thu, 13 Sep 2018 08:53:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g0R7F-0001uP-F7 for qemu-devel@nongnu.org; Thu, 13 Sep 2018 08:53:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56496) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1g0R7D-0001sX-HP; Thu, 13 Sep 2018 08:52:59 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DBEF788313; Thu, 13 Sep 2018 12:52:58 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-117-67.ams2.redhat.com [10.36.117.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0E32060BE0; Thu, 13 Sep 2018 12:52:56 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Thu, 13 Sep 2018 14:52:09 +0200 Message-Id: <20180913125217.23173-10-kwolf@redhat.com> In-Reply-To: <20180913125217.23173-1-kwolf@redhat.com> References: <20180913125217.23173-1-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Thu, 13 Sep 2018 12:52:58 +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 09/17] block-backend: Add .drained_poll callback 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, famz@redhat.com, slp@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com, pbonzini@redhat.com, jsnow@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RDMRC_1 RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" A bdrv_drain operation must ensure that all parents are quiesced, this includes BlockBackends. Otherwise, callbacks called by requests that are completed on the BDS layer, but not quite yet on the BlockBackend layer could still create new requests. Signed-off-by: Kevin Wolf Reviewed-by: Fam Zheng Reviewed-by: Max Reitz --- block/block-backend.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/block/block-backend.c b/block/block-backend.c index fa120630be..efa8d8011c 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -121,6 +121,7 @@ static void blk_root_inherit_options(int *child_flags, = QDict *child_options, abort(); } static void blk_root_drained_begin(BdrvChild *child); +static bool blk_root_drained_poll(BdrvChild *child); static void blk_root_drained_end(BdrvChild *child); =20 static void blk_root_change_media(BdrvChild *child, bool load); @@ -294,6 +295,7 @@ static const BdrvChildRole child_root =3D { .get_parent_desc =3D blk_root_get_parent_desc, =20 .drained_begin =3D blk_root_drained_begin, + .drained_poll =3D blk_root_drained_poll, .drained_end =3D blk_root_drained_end, =20 .activate =3D blk_root_activate, @@ -2191,6 +2193,13 @@ static void blk_root_drained_begin(BdrvChild *child) } } =20 +static bool blk_root_drained_poll(BdrvChild *child) +{ + BlockBackend *blk =3D child->opaque; + assert(blk->quiesce_counter); + return !!blk->in_flight; +} + static void blk_root_drained_end(BdrvChild *child) { BlockBackend *blk =3D child->opaque; --=20 2.13.6