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 9A38FC3ABB2 for ; Wed, 28 May 2025 06:11:26 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uKA0M-0003gj-RG; Wed, 28 May 2025 02:11:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uKA0I-0003gE-RK for qemu-devel@nongnu.org; Wed, 28 May 2025 02:11:07 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uKA0F-0001Od-KB for qemu-devel@nongnu.org; Wed, 28 May 2025 02:11:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1748412662; 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=APQEGYqPTd5AKjX8aZTXGo++DT571wQerKqkm3AODg8=; b=h3f8iDshonbeJWjZKUS8W0pyfLu3IgFb5+VOr+2ju1ROmlof+qUfYcD+0ZaWO82hk53cOl 9Oc75TYVDDW3179HMFl73izocX0tKYwsRGpzvhfzrcLsrnr1YNQhdO/A7yAbk51va6+bdL KyT7okZvow8DQqhYxcKmKGRZDz7Xv40= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-215-VjL6SCpnOnajVwhk062i7w-1; Wed, 28 May 2025 02:11:00 -0400 X-MC-Unique: VjL6SCpnOnajVwhk062i7w-1 X-Mimecast-MFC-AGG-ID: VjL6SCpnOnajVwhk062i7w_1748412659 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 91D67180045B; Wed, 28 May 2025 06:10:59 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.2]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 10BEB1956095; Wed, 28 May 2025 06:10:59 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 5475C21E6768; Wed, 28 May 2025 08:10:56 +0200 (CEST) From: Markus Armbruster To: Eric Blake Cc: "Richard W.M. Jones" , qemu-devel@nongnu.org, qemu-block@nongnu.org, Vladimir Sementsov-Ogievskiy , Kevin Wolf , Hanna Reitz Subject: Re: [PATCH v2 1/4] nbd: Add multi-conn option In-Reply-To: (Eric Blake's message of "Tue, 27 May 2025 17:01:18 -0500") References: <20250428185246.492388-6-eblake@redhat.com> <20250428185246.492388-7-eblake@redhat.com> <877c33qzzn.fsf@pond.sub.org> <20250429091422.GG1450@redhat.com> <87wmb3jkoh.fsf@pond.sub.org> <20250429111958.GI1450@redhat.com> <87o6wfnqzj.fsf@pond.sub.org> Date: Wed, 28 May 2025 08:10:56 +0200 Message-ID: <87ecw9jmdr.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -49 X-Spam_score: -5.0 X-Spam_bar: ----- X-Spam_report: (-5.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-2.907, 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, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, 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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Eric Blake writes: > On Tue, Apr 29, 2025 at 01:31:44PM +0200, Markus Armbruster wrote: >> > In the context of qemu that might suggest having separate >> > multi_conn_requested and multi_conn fields, where the latter can be >> > queried over QMP to find out what is actually going on. Could even >> > add multi_conn_max to allow MAX_MULTI_CONN constant to be read out. >> >> You decide what to do with my feedback :) > > I've got a local patch that adds the ability for > query-named-block-nodes (and query-block) to output image-specific > information for NBD that includes how many connections are actually in > use. But now I've got a QMP question: > > My patch, as written, makes the output look like this: > > "format-specific": {"mode": "extended", "type": "nbd", "connections": 1}}, > > by changing block-core.json like this (partial patch shown): > > @@ -208,10 +223,12 @@ > # > # @file: Since 8.0 > # > +# @nbd: Since 10.1 > +# > # Since: 1.7 > ## > { 'enum': 'ImageInfoSpecificKind', > - 'data': [ 'qcow2', 'vmdk', 'luks', 'rbd', 'file' ] } > + 'data': [ 'qcow2', 'vmdk', 'luks', 'rbd', 'file', 'nbd' ] } > > ## > # @ImageInfoSpecificQCow2Wrapper: > @@ -284,7 +301,8 @@ > 'luks': 'ImageInfoSpecificLUKSWrapper', > 'rbd': 'ImageInfoSpecificRbdWrapper', > - 'file': 'ImageInfoSpecificFileWrapper' > + 'file': 'ImageInfoSpecificFileWrapper', > + 'nbd': 'ImageInfoSpecificNbd' > } } > > But that is different from all of the other image modes, where the > output looks more like: > > "format-specific": {"type": "rbd", "data": {"encryption-format":"..."}}}, > > note the extra layer of nesting, due to historical reasons of being > added in a time when the QMP generator was not as nice on supporting > flatter union-style coding. Correct, this is an artifact of development history, specifically "simple" unions and their elimination. > Must I create an ImageInfoSpecificNbdWrapper type, with the sole > purpose of having the same (pointless, IMO) "data":{} wrapper as all > the other branches of the union type, or am I okay with my addition > using the flatter style? I dislike these wrappers, possibly more than is reasonable. Still, I think local consistency is more important. Precedence: commit 7f36a50ab4e (block/file: Add file-specific image info) added a new branch with a wrapper well after we eliminated "simple" unions. I think you should add the silly wrapper.