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 X-Spam-Level: X-Spam-Status: No, score=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B64D9C47083 for ; Wed, 2 Jun 2021 11:58:02 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 30CE761360 for ; Wed, 2 Jun 2021 11:58:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 30CE761360 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50342 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1loPVZ-0005dX-1O for qemu-devel@archiver.kernel.org; Wed, 02 Jun 2021 07:58:01 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43100) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1loPUt-0004rd-Ms for qemu-devel@nongnu.org; Wed, 02 Jun 2021 07:57:19 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:25462) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1loPUr-0008Aq-RK for qemu-devel@nongnu.org; Wed, 02 Jun 2021 07:57:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622635037; 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=gCIm1c2hKWwFLpLwL6eAz7Q7j0gsqHhUxSJXuIBGZJY=; b=DtRDaeqbffjjicA+uCvCWLGq3D30rBn1I3Halt0vwMzbCKxUsbbiZkZoP+GbN3lTaJ9mph cnuHSnxarDwNnfIvRBfb33kncPCxrKlqC2gnWEtPAvVipgJ28AGaJtRUmX1B8U7BDjrbMT jqmC2wUkn3DMyLhi9/23/7nWGed6yZ4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-386-uc6yXrDJNn2HFa90P4CuJA-1; Wed, 02 Jun 2021 07:57:13 -0400 X-MC-Unique: uc6yXrDJNn2HFa90P4CuJA-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 D5E3E8015F8; Wed, 2 Jun 2021 11:57:12 +0000 (UTC) Received: from redhat.com (ovpn-114-240.ams2.redhat.com [10.36.114.240]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1A2F860E3A; Wed, 2 Jun 2021 11:57:06 +0000 (UTC) Date: Wed, 2 Jun 2021 13:57:05 +0200 From: Kevin Wolf To: Sergio Lopez Subject: Re: [PATCH v2 0/2] nbd/server: Quiesce server on drained section Message-ID: References: <20210602060552.17433-1-slp@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210602060552.17433-1-slp@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 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: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.371, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, qemu-devel@nongnu.org, Max Reitz , Nir Soffer Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 02.06.2021 um 08:05 hat Sergio Lopez geschrieben: > Before switching between AioContexts we need to make sure that we're > fully quiesced ("nb_requests == 0" for every client) when entering the > drained section. Otherwise, coroutines may be run in the wrong context > after the switch, leading to a number of critical issues. > > To accomplish this, we add ".drained_poll" to BlockDevOps and use it > in the NBD server, along with ".drained_being" and "drained_end", to > coordinate the quiescing of the server while entering a drained > section. > > v2: > - Use a bool for the value returned by .drained_poll [Kevin] > - Change .drained_poll comment to reflect that the returned boolean > value will be true if the device is still busy, or false otherwise > - Drop yield_co_list and use recv_coroutine and read_yielding [Kevin] > - Return "true" or "false" in nbd_drained_poll [Kevin] > - Fix grammar in the commit message of patch 2 [Eric] Thanks, applied to the block branch. Kevin