From nobody Tue Apr 15 14:50:24 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 1537889844979774.7092281759088; Tue, 25 Sep 2018 08:37:24 -0700 (PDT) Received: from localhost ([::1]:53768 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g4pOt-0003BA-Oy for importer@patchew.org; Tue, 25 Sep 2018 11:37:23 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45483) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g4p5M-0001co-5R for qemu-devel@nongnu.org; Tue, 25 Sep 2018 11:17:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g4p5L-00062Z-75 for qemu-devel@nongnu.org; Tue, 25 Sep 2018 11:17:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34126) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1g4p5D-0005u9-Kq; Tue, 25 Sep 2018 11:17:03 -0400 Received: from smtp.corp.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DE01330026A8; Tue, 25 Sep 2018 15:17:02 +0000 (UTC) Received: from localhost (unknown [10.40.205.127]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6E0D730912F5; Tue, 25 Sep 2018 15:17:02 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Tue, 25 Sep 2018 17:15:31 +0200 Message-Id: <20180925151541.18932-33-mreitz@redhat.com> In-Reply-To: <20180925151541.18932-1-mreitz@redhat.com> References: <20180925151541.18932-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.26 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Tue, 25 Sep 2018 15:17:02 +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] [PULL 32/42] 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: Kevin Wolf , Peter Maydell , qemu-devel@nongnu.org, Max Reitz 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" From: Kevin Wolf 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 14a1b7ac6a..4e7d08ac3a 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, @@ -2189,6 +2191,13 @@ 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 2.17.1