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 4BFF7C5478C for ; Mon, 4 Mar 2024 10:49:32 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rh5sc-0001tz-58; Mon, 04 Mar 2024 05:49:10 -0500 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 1rh5sa-0001tR-M6 for qemu-devel@nongnu.org; Mon, 04 Mar 2024 05:49:08 -0500 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 1rh5sV-00050E-Uf for qemu-devel@nongnu.org; Mon, 04 Mar 2024 05:49:08 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1709549343; 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=5r7OrzhRlKRkE5WLQ/StS72wkl+VKB3T4fPjQFBAPlo=; b=eZPHvM0Xv+gN6aOc4JkUn23q/t2oqwooSoXjO4JfF7oeV8FlAaS5eccKR7uNsPY5SivEdD DqZ953v3AMwWhTvymWksHDO8e7imm3/4G7URrAieuuWxpx/TLKiAVmEs0ebV8Xs+UdXzdG 0rDjb+WyzTzxR5Mfulchgm0jtnxPLpE= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-31-AsFrqwdRMnSMY8VHBQZQJQ-1; Mon, 04 Mar 2024 05:48:58 -0500 X-MC-Unique: AsFrqwdRMnSMY8VHBQZQJQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id 589762806400; Mon, 4 Mar 2024 10:48:58 +0000 (UTC) Received: from redhat.com (unknown [10.39.193.83]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6ADD52026D06; Mon, 4 Mar 2024 10:48:55 +0000 (UTC) Date: Mon, 4 Mar 2024 11:48:54 +0100 From: Kevin Wolf To: Vladimir Sementsov-Ogievskiy Cc: Markus Armbruster , Fiona Ebner , qemu-devel@nongnu.org, qemu-block@nongnu.org, eblake@redhat.com, hreitz@redhat.com, jsnow@redhat.com, den@virtuozzo.com, t.lamprecht@proxmox.com, alexander.ivanov@virtuozzo.com, pkrempa@redhat.com Subject: Re: [PATCH v2 00/10] mirror: allow switching from background to active mode Message-ID: References: <20231009094619.469668-1-f.ebner@proxmox.com> <993bfa5d-1a91-4b32-9bd8-165b7abba4f0@proxmox.com> <99dd287b-816b-4f4f-b156-32f94bbb62c2@yandex-team.ru> <87o7gbyy8w.fsf@pond.sub.org> <87cywqn84g.fsf@pond.sub.org> <1310efb0-e211-46f5-b166-d7d529507a43@yandex-team.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1310efb0-e211-46f5-b166-d7d529507a43@yandex-team.ru> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -26 X-Spam_score: -2.7 X-Spam_bar: -- X-Spam_report: (-2.7 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.589, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Am 28.02.2024 um 19:07 hat Vladimir Sementsov-Ogievskiy geschrieben: > On 03.11.23 18:56, Markus Armbruster wrote: > > Kevin Wolf writes: > > > > > Am 03.11.2023 um 10:36 hat Markus Armbruster geschrieben: > > > > Vladimir Sementsov-Ogievskiy writes: > > > > > > > > > On 11.10.23 13:18, Fiona Ebner wrote: > > > > > > Am 10.10.23 um 19:55 schrieb Vladimir Sementsov-Ogievskiy: > > > > > > > On 09.10.23 12:46, Fiona Ebner wrote: > > > > > > > > Initially, I tried to go for a more general 'job-change' command, but > > > > > > > > I couldn't figure out a way to avoid mutual inclusion between > > > > > > > > block-core.json and job.json. > > > > > > > > > > > > > > > What is the problem with it? I still think that job-change would be better. > > > > > > > > > > > > > If going for job-change in job.json, the dependencies would be > > > > > > job-change -> JobChangeOptions -> JobChangeOptionsMirror -> MirrorCopyMode > > > > > > query-jobs -> JobInfo -> JobInfoMirror > > > > > > and we can't include block-core.json in job.json, because an inclusion > > > > > > loop gives a build error. > > > > Let me try to understand this. > > > > > > > > Command job-change needs its argument type JobChangeOptions. > > > > > > > > JobChangeOptions is a union, and JobChangeOptionsMirror is one of its > > > > branches. > > > > > > > > JobChangeOptionsMirror needs MirrorCopyMode from block-core.json. > > > > > > > > block-core.json needs job.json for JobType and JobStatus. > > > > > > > > > > Could be made to work by moving MirrorCopyMode (and > > > > > > JobChangeOptionsMirror, JobInfoMirror) to job.json or some place that > > > > > > can be included by both job.json and block-core.json. Moving the > > > > > > type-specific definitions to the general job.json didn't feel right to > > > > > > me. Including another file with type-specific definitions in job.json > > > > > > feels slightly less wrong, but still not quite right and I didn't want > > > > > > to create a new file just for MirrorCopyMode (and > > > > > > JobChangeOptionsMirror, JobInfoMirror). > > > > > > And going further and moving all mirror-related things to a separate > > > > > > file would require moving along things like NewImageMode with it or > > > > > > create yet another file for such general things used by multiple block-jobs. > > > > > > If preferred, I can try and go with some version of the above. > > > > > > > > > > > OK, I see the problem. Seems, that all requires some good refactoring. But that's a preexisting big work, and should not hold up your series. I'm OK to proceed with block-job-change. > > > > Saving ourselves some internal refactoring is a poor excuse for > > > > undesirable external interfaces. > > > I'm not sure how undesirable it is. We have block-job-* commands for > > > pretty much every other operation, so it's only consistent to have > > > block-job-change, too. > > Is the job abstraction a failure? > > > > We have > > > > block-job- command since job- command since > > ----------------------------------------------------- > > block-job-set-speed 1.1 > > block-job-cancel 1.1 job-cancel 3.0 > > block-job-pause 1.3 job-pause 3.0 > > block-job-resume 1.3 job-resume 3.0 > > block-job-complete 1.3 job-complete 3.0 > > block-job-dismiss 2.12 job-dismiss 3.0 > > block-job-finalize 2.12 job-finalize 3.0 > > block-job-change 8.2 > > query-block-jobs 1.1 query-jobs > > > > I was under the impression that we added the (more general) job- > > commands to replace the (less general) block-job commands, and we're > > keeping the latter just for compatibility. Am I mistaken? > > > > Which one should be used? > > > > Why not deprecate the one that shouldn't be used? > > > > The addition of block-job-change without even trying to do job-change > > makes me wonder: have we given up on the job- interface? > > > > I'm okay with giving up on failures. All I want is clarity. Right now, > > I feel thoroughly confused about the status block-jobs and jobs, and how > > they're related. > > Hi! I didn't notice, that the series was finally merged. > > About the APIs, I think, of course we should deprecate block-job-* API, because we already have jobs which are not block-jobs, so we can't deprecate job-* API. > > So I suggest a plan: > > 1. Add job-change command simply in block-core.json, as a simple copy > of block-job-change, to not care with resolving inclusion loops. > (ha we could simply name our block-job-change to be job-change and > place it in block-core.json, but now is too late) > > 2. Support changing speed in a new job-chage command. (or both in > block-job-change and job-change, keeping them equal) It should be both block-job-change and job-change. Having job-change in block-core.json rather than job.json is ugly, but if Markus doesn't complain, why would I. > 3. Deprecate block-job-* APIs > > 4. Wait 3 releases > > 5. Drop block-job-* APIs I consider these strictly optional. We don't really have strong reasons to deprecate these commands (they are just thin wrappers), and I think libvirt still uses block-job-* in some places. We also need to check if the interfaces are really the same. For example, JobInfo is only a small subset of BlockJobInfo. Some things could be added to JobInfo, other things like BlockDeviceIoStatus don't really have a place there, so we would have to introduce job type specific data in query-jobs first. I'm sure it's all doable, but it might be more work than your list above would make you think. > 6. Move all job-related stuff to job.json, drop `{ 'include': > 'job.json' }` from block-core.json, and instead include > block-core.json into job.json Of course, this cleanup assumes that steps 3.-5. are really implemented. If not, you would end up moving a lot more block related things to job.json than after them. Kevin