From patchwork Tue Feb 8 15:36:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Emanuele Giuseppe Esposito X-Patchwork-Id: 1589977 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=hqDyYwGv; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4JtT7S49y6z9s09 for ; Wed, 9 Feb 2022 03:32:18 +1100 (AEDT) Received: from localhost ([::1]:52092 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nHTPY-0000Q9-N8 for incoming@patchwork.ozlabs.org; Tue, 08 Feb 2022 11:32:12 -0500 Received: from eggs.gnu.org ([209.51.188.92]:47080) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nHSYP-0000Ib-3x for qemu-devel@nongnu.org; Tue, 08 Feb 2022 10:37:20 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:26763) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nHSYD-0002e0-Kl for qemu-devel@nongnu.org; Tue, 08 Feb 2022 10:37:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644334624; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=w2tBAWxKc13b0G4VpXQRinZ9kc2SVuxYbfgKU6+nyAw=; b=hqDyYwGvm2uxRPt2DqaTfqo5r1XT2SOQwPsKmkmVL7AqUR0ZZxETVr8ZeuTujvDi/85GPp 0kh/6vuyjErLmiKBMI1C9aGtfleEcDC00AlM0l1qsadJCCzVAYQuZCJoQAf0pZoRH19XIE h+21OmfhA49JZwDssDHO5WwNOFGSvvA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-433-jqQxXrQlM_e1mGVkMU0Jew-1; Tue, 08 Feb 2022 10:37:00 -0500 X-MC-Unique: jqQxXrQlM_e1mGVkMU0Jew-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id AB5371898291; Tue, 8 Feb 2022 15:36:59 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id E81157D475; Tue, 8 Feb 2022 15:36:58 +0000 (UTC) From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [PATCH 1/6] block/io.c: fix bdrv_child_cb_drained_begin invocations from a coroutine Date: Tue, 8 Feb 2022 10:36:50 -0500 Message-Id: <20220208153655.1251658-2-eesposit@redhat.com> In-Reply-To: <20220208153655.1251658-1-eesposit@redhat.com> References: <20220208153655.1251658-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eesposit@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.129.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01, T_SPF_TEMPERROR=0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , Vladimir Sementsov-Ogievskiy , Emanuele Giuseppe Esposito , qemu-devel@nongnu.org, Hanna Reitz , Stefan Hajnoczi , Paolo Bonzini , John Snow Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Using bdrv_do_drained_begin_quiesce() in bdrv_child_cb_drained_begin() is not a good idea: the callback might be called when running a drain in a coroutine, and bdrv_drained_begin_poll() does not handle that case, resulting in assertion failure. Instead, bdrv_do_drained_begin with no recursion and poll will accomplish the same thing (invoking bdrv_do_drained_begin_quiesce) but will firstly check if we are already in a coroutine, and exit from that via bdrv_co_yield_to_drain(). Signed-off-by: Emanuele Giuseppe Esposito Reviewed-by: Stefan Hajnoczi --- block.c | 2 +- block/io.c | 7 ++++++- include/block/block-io.h | 8 +++++--- 3 files changed, 12 insertions(+), 5 deletions(-) diff --git a/block.c b/block.c index e42a99d2af..4551eba2aa 100644 --- a/block.c +++ b/block.c @@ -1203,7 +1203,7 @@ static char *bdrv_child_get_parent_desc(BdrvChild *c) static void bdrv_child_cb_drained_begin(BdrvChild *child) { BlockDriverState *bs = child->opaque; - bdrv_do_drained_begin_quiesce(bs, NULL, false); + bdrv_drained_begin_no_poll(bs); } static bool bdrv_child_cb_drained_poll(BdrvChild *child) diff --git a/block/io.c b/block/io.c index 683a32c955..d3ee3e1a7c 100644 --- a/block/io.c +++ b/block/io.c @@ -425,7 +425,7 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs, } } -void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, +static void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, BdrvChild *parent, bool ignore_bds_parents) { assert(!qemu_in_coroutine()); @@ -487,6 +487,11 @@ void bdrv_subtree_drained_begin(BlockDriverState *bs) bdrv_do_drained_begin(bs, true, NULL, false, true); } +void bdrv_drained_begin_no_poll(BlockDriverState *bs) +{ + bdrv_do_drained_begin(bs, false, NULL, false, false); +} + /** * This function does not poll, nor must any of its recursively called * functions. The *drained_end_counter pointee will be incremented diff --git a/include/block/block-io.h b/include/block/block-io.h index 7c04bc3049..48d3442970 100644 --- a/include/block/block-io.h +++ b/include/block/block-io.h @@ -308,13 +308,15 @@ bool bdrv_drain_poll(BlockDriverState *bs, bool recursive, void bdrv_drained_begin(BlockDriverState *bs); /** - * bdrv_do_drained_begin_quiesce: + * bdrv_drained_begin_no_poll: * * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already * running requests to complete. + * Same as bdrv_drained_begin(), but do not poll for the subgraph to + * actually become unquiesced. Therefore, no graph changes will occur + * with this function. */ -void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, - BdrvChild *parent, bool ignore_bds_parents); +void bdrv_drained_begin_no_poll(BlockDriverState *bs); /** * Like bdrv_drained_begin, but recursively begins a quiesced section for