From nobody Sat Feb 7 23:36:47 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.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 1536337801184781.2494878812919; Fri, 7 Sep 2018 09:30:01 -0700 (PDT) Received: from localhost ([::1]:39521 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fyJdw-0002Jh-4m for importer@patchew.org; Fri, 07 Sep 2018 12:30:00 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53472) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fyJQg-0006M1-RV for qemu-devel@nongnu.org; Fri, 07 Sep 2018 12:16:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fyJQa-0004MI-Sj for qemu-devel@nongnu.org; Fri, 07 Sep 2018 12:16:16 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53674 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fyJQM-0003m9-7i; Fri, 07 Sep 2018 12:16:00 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 07CBA4025082; Fri, 7 Sep 2018 16:15:56 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-116-56.ams2.redhat.com [10.36.116.56]) by smtp.corp.redhat.com (Postfix) with ESMTP id E53442156889; Fri, 7 Sep 2018 16:15:50 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 7 Sep 2018 18:15:14 +0200 Message-Id: <20180907161520.26349-9-kwolf@redhat.com> In-Reply-To: <20180907161520.26349-1-kwolf@redhat.com> References: <20180907161520.26349-1-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Fri, 07 Sep 2018 16:15:56 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Fri, 07 Sep 2018 16:15:56 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'kwolf@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH 08/14] 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 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 --- 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