From nobody Mon Sep 22 23:44:55 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 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 [209.51.188.17]) by mx.zohomail.com with SMTPS id 1647265782669155.81551499478132; Mon, 14 Mar 2022 06:49:42 -0700 (PDT) Received: from localhost ([::1]:60460 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nTl4w-000679-KA for importer@patchew.org; Mon, 14 Mar 2022 09:49:42 -0400 Received: from eggs.gnu.org ([209.51.188.92]:37868) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nTkbP-0001Jj-3o for qemu-devel@nongnu.org; Mon, 14 Mar 2022 09:19:11 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:38088) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nTkbL-0006XZ-Hz for qemu-devel@nongnu.org; Mon, 14 Mar 2022 09:19:09 -0400 Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-636-vX2TlG__MQy3C2rH0tvpIw-1; Mon, 14 Mar 2022 09:19:05 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1C18480158E; Mon, 14 Mar 2022 13:19:05 +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 CB8741686D; Mon, 14 Mar 2022 13:19:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647263946; 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=ML8EyUfiYt5tFNjQrNSkx8Cc5L6+V2QPZKONCh3xuWI=; b=Rmfcuw8o4p1LkUlBErAbvmzhqa66SlQ377FEu43UWMPSNp/JH/FStBdncaOWPUBERpE4Ks ISAONn4keCZLyDfTQVeg1Nf1iRDaDIzDsHn7iqnlSIc4Nb4pb+/2dWKZaahHhtidvKNP2G ygm3wr3l2aO2mBOUVLjia5dPEA8D92o= X-MC-Unique: vX2TlG__MQy3C2rH0tvpIw-1 From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [PATCH v2 03/10] block/io.c: fix bdrv_child_cb_drained_begin invocations from a coroutine Date: Mon, 14 Mar 2022 09:18:47 -0400 Message-Id: <20220314131854.2202651-4-eesposit@redhat.com> In-Reply-To: <20220314131854.2202651-1-eesposit@redhat.com> References: <20220314131854.2202651-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 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 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.133.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1647265784686100001 Content-Type: text/plain; charset="utf-8" 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 --- block.c | 2 +- block/io.c | 8 +++++++- include/block/block-io.h | 20 +++++++++++--------- 3 files changed, 19 insertions(+), 11 deletions(-) diff --git a/block.c b/block.c index 718e4cae8b..372f16f4a0 100644 --- a/block.c +++ b/block.c @@ -1211,7 +1211,7 @@ static char *bdrv_child_get_parent_desc(BdrvChild *c) static void bdrv_child_cb_drained_begin(BdrvChild *child) { BlockDriverState *bs =3D child->opaque; - bdrv_do_drained_begin_quiesce(bs, NULL, false); + bdrv_drained_begin_no_poll(bs); } =20 static bool bdrv_child_cb_drained_poll(BdrvChild *child) diff --git a/block/io.c b/block/io.c index e446782ae0..e77861c464 100644 --- a/block/io.c +++ b/block/io.c @@ -523,7 +523,7 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDr= iverState *bs, } } =20 -void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, +static void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, BdrvChild *parent, bool ignore_bds_pare= nts) { IO_OR_GS_CODE(); @@ -587,6 +587,12 @@ void bdrv_subtree_drained_begin(BlockDriverState *bs) bdrv_do_drained_begin(bs, true, NULL, false, true); } =20 +void bdrv_drained_begin_no_poll(BlockDriverState *bs) +{ + IO_CODE(); + 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 5e3f346806..9135b648bf 100644 --- a/include/block/block-io.h +++ b/include/block/block-io.h @@ -226,6 +226,17 @@ int coroutine_fn bdrv_co_copy_range(BdrvChild *src, in= t64_t src_offset, int64_t bytes, BdrvRequestFlags read_f= lags, BdrvRequestFlags write_flags); =20 +/** + * 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_drained_begin_no_poll(BlockDriverState *bs); + /** * bdrv_drained_end_no_poll: * @@ -332,15 +343,6 @@ bool bdrv_drain_poll(BlockDriverState *bs, bool recurs= ive, */ void bdrv_drained_begin(BlockDriverState *bs); =20 -/** - * bdrv_do_drained_begin_quiesce: - * - * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already - * running requests to complete. - */ -void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, - BdrvChild *parent, bool ignore_bds_pare= nts); - /** * Like bdrv_drained_begin, but recursively begins a quiesced section for * exclusive access to all child nodes as well. --=20 2.31.1