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=-12.4 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 53DB6C433DF for ; Wed, 19 Aug 2020 18:34:50 +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 134B720658 for ; Wed, 19 Aug 2020 18:34:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LOooT4l4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 134B720658 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]:39896 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k8SvB-0001qE-8s for qemu-devel@archiver.kernel.org; Wed, 19 Aug 2020 14:34:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60834) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k8Ssp-00061g-Hr for qemu-devel@nongnu.org; Wed, 19 Aug 2020 14:32:23 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:29770 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1k8Ssm-0002IX-SS for qemu-devel@nongnu.org; Wed, 19 Aug 2020 14:32:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597861939; 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=jrOtYn0fox3vyYzno7Xye2AttQFAgnnkiAUYE6107Qc=; b=LOooT4l4BK5AnM08bxAs8dIgKWnv8MFr+NJ7833m6FhtHrY80fMQ5LNox1LzvIev+PHw4K VKiX9V1POs/goUtZcNUfOWM814uLwBli83wZnBmnGt+flsfUOeI0oHCPIDsp70CGIo1YkH It136Az86IN8614IXfyRIE9uOJd2mys= 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-505-aWneYDt4MKOB68HMNy-Hcw-1; Wed, 19 Aug 2020 14:32:12 -0400 X-MC-Unique: aWneYDt4MKOB68HMNy-Hcw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 37DA581C478; Wed, 19 Aug 2020 18:31:46 +0000 (UTC) Received: from [10.3.112.136] (ovpn-112-136.phx2.redhat.com [10.3.112.136]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D75EC5C1D0; Wed, 19 Aug 2020 18:31:45 +0000 (UTC) Subject: Re: [RFC PATCH 04/22] block/export: Add BlockExport infrastructure and block-export-add To: Kevin Wolf , qemu-block@nongnu.org References: <20200813162935.210070-1-kwolf@redhat.com> <20200813162935.210070-5-kwolf@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <3573ab66-884e-d237-cd5e-12bd67b05d8c@redhat.com> Date: Wed, 19 Aug 2020 13:31:45 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200813162935.210070-5-kwolf@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0.002 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.81; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/19 01:46:53 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, 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_H2=-1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 8/13/20 11:29 AM, Kevin Wolf wrote: > We want to have a common set of commands for all types of block exports. > Currently, this is only NBD, but we're going to add more types. > > This patch adds the basic BlockExport and BlockExportDriver structs and > a QMP command block-export-add that creates a new export based on the > given BlockExportOptions. > > qmp_nbd_server_add() becomes a wrapper around qmp_block_export_add(). > > Signed-off-by: Kevin Wolf > --- Seeing if I can spot anything beyond Max's fine points: > +++ b/qapi/block-export.json > @@ -170,3 +170,12 @@ > 'nbd': 'BlockExportOptionsNbd' > } } > > +## > +# @block-export-add: > +# > +# Creates a new block export. > +# > +# Since: 5.2 > +## > +{ 'command': 'block-export-add', > + 'data': 'BlockExportOptions', 'boxed': true } So if I read patch 3 correctly, the difference between nbd-server-add and block-export-add is that the latter includes a "type":"nbd" member. (If we ever play with allowing a default discriminator value in QAPI, we could declare the default for "type" to be NBD, and then the two would be identical - except that since you are adding a new command designed to extend to more than just nbd, I don't think keeping nbd as default makes sense) > +++ b/block/export/export.c > +void qmp_nbd_server_add(BlockExportOptionsNbd *arg, Error **errp) > +{ > + BlockExportOptions export = { > + .type = BLOCK_EXPORT_TYPE_NBD, > + .u.nbd = *arg, > + }; > + qmp_block_export_add(&export, errp); > +} And indeed, this matches that analysis. > @@ -217,6 +220,8 @@ void qmp_nbd_server_add(BlockExportOptionsNbd *arg, Error **errp) > > out: > aio_context_release(aio_context); > + /* TODO Remove the cast: Move to server.c which can access fields of exp */ > + return (BlockExport*) exp; Should this use container_of()? Ah, the TODO says you want to, but can't because exp is an opaque type in this file... > } > > void qmp_nbd_server_remove(const char *name, > diff --git a/nbd/server.c b/nbd/server.c > index bee2ef8bd1..774325dbe5 100644 > --- a/nbd/server.c > +++ b/nbd/server.c > @@ -18,6 +18,8 @@ > */ > > #include "qemu/osdep.h" > + > +#include "block/export.h" > #include "qapi/error.h" > #include "qemu/queue.h" > #include "trace.h" > @@ -80,6 +82,7 @@ struct NBDRequestData { > }; > > struct NBDExport { > + BlockExport common; ...but at least the cast is accurate. Overall, the idea looks sane. I'm happy if you want to move blockdev-nbd.c out of the top level. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org