From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id D6F23C433EF for ; Mon, 7 Feb 2022 17:54:28 +0000 (UTC) Received: from localhost ([::1]:37640 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nH8Db-0002c9-Oj for qemu-devel@archiver.kernel.org; Mon, 07 Feb 2022 12:54:27 -0500 Received: from eggs.gnu.org ([209.51.188.92]:36314) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nH7bO-0003l0-B3 for qemu-devel@nongnu.org; Mon, 07 Feb 2022 12:15:00 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:45261) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nH7bI-0004Bh-U0 for qemu-devel@nongnu.org; Mon, 07 Feb 2022 12:14:57 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644254092; 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: in-reply-to:in-reply-to:references:references; bh=YyNGPDMGS9oQHw1NTjwhW/9ckOh0yg7JwyQovGpBIks=; b=e9Eh49QG7kcUN6xY5DpKpELyBYpErjU4IQ7/kte8Kq1GKBRhWlc9KFdPq2eSJnd8w5U8C+ uoGMy4Ms6iBUiwoGaHpWGKcI4nsoeR3//Wkj3hL3SWOwrkIGWWNgd0CeX0QSZn6yF4SfaA itFXPCyfBGrOkgHuHdCiHbXYA4ye5tE= 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-218-zrJNCltvNEGYypbx4V34cw-1; Mon, 07 Feb 2022 12:14:48 -0500 X-MC-Unique: zrJNCltvNEGYypbx4V34cw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A091181440E; Mon, 7 Feb 2022 17:14:44 +0000 (UTC) Received: from redhat.com (unknown [10.39.193.223]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 80EE72ED9C; Mon, 7 Feb 2022 17:14:39 +0000 (UTC) Date: Mon, 7 Feb 2022 18:14:37 +0100 From: Kevin Wolf To: Emanuele Giuseppe Esposito Subject: Re: [PATCH v6 09/33] block: introduce assert_bdrv_graph_writable Message-ID: References: <20220121170544.2049944-1-eesposit@redhat.com> <20220121170544.2049944-10-eesposit@redhat.com> MIME-Version: 1.0 In-Reply-To: <20220121170544.2049944-10-eesposit@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@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, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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: Fam Zheng , qemu-devel@nongnu.org, "Denis V. Lunev" , Eric Blake , qemu-block@nongnu.org, Juan Quintela , Daniel Henrique Barboza , Markus Armbruster , Richard Henderson , Greg Kurz , "Dr. David Alan Gilbert" , =?iso-8859-1?Q?C=E9dric?= Le Goater , Stefan Hajnoczi , John Snow , David Gibson , Eduardo Habkost , Vladimir Sementsov-Ogievskiy , Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , Hanna Reitz , qemu-ppc@nongnu.org, Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 21.01.2022 um 18:05 hat Emanuele Giuseppe Esposito geschrieben: > We want to be sure that the functions that write the child and > parent list of a bs are under BQL and drain. > > BQL prevents from concurrent writings from the GS API, while > drains protect from I/O. > > TODO: drains are missing in some functions using this assert. > Therefore a proper assertion will fail. Because adding drains > requires additional discussions, they will be added in future > series. > > Signed-off-by: Emanuele Giuseppe Esposito > diff --git a/block/io.c b/block/io.c > index cb095deeec..3be08cad29 100644 > --- a/block/io.c > +++ b/block/io.c > @@ -734,6 +734,17 @@ void bdrv_drain_all(void) > bdrv_drain_all_end(); > } > > +void assert_bdrv_graph_writable(BlockDriverState *bs) > +{ > + /* > + * TODO: this function is incomplete. Because the users of this > + * assert lack the necessary drains, check only for BQL. > + * Once the necessary drains are added, > + * assert also for qatomic_read(&bs->quiesce_counter) > 0 > + */ > + assert(qemu_in_main_thread()); > +} This looks like a trivial function that could easily be static inline. Kevin