From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id E0E84C8B for ; Tue, 27 Aug 2019 00:30:11 +0000 (UTC) Received: from mail-qt1-f195.google.com (mail-qt1-f195.google.com [209.85.160.195]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 26CA0887 for ; Tue, 27 Aug 2019 00:30:09 +0000 (UTC) Received: by mail-qt1-f195.google.com with SMTP id b11so19725281qtp.10 for ; Mon, 26 Aug 2019 17:30:09 -0700 (PDT) MIME-Version: 1.0 References: <20190826230206.GC28066@mit.edu> In-Reply-To: <20190826230206.GC28066@mit.edu> From: Dmitry Vyukov Date: Mon, 26 Aug 2019 17:29:53 -0700 Message-ID: To: "Theodore Y. Ts'o" Content-Type: text/plain; charset="UTF-8" Cc: Joel Fernandes , Barret Rhoden , ksummit , Greg Kroah-Hartman , Jonathan Nieder , Tomasz Figa , Han-Wen Nienhuys , Theodore Tso , David Rientjes , Dmitry Torokhov Subject: Re: [Ksummit-discuss] Allowing something Change-Id (or something like it) in kernel commits List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Aug 26, 2019 at 4:02 PM Theodore Y. Ts'o wrote: > > On Mon, Aug 26, 2019 at 02:35:33PM -0700, Doug Anderson wrote: > > * This requires extra tooling that I think nobody will adopt. People > > today already (accidentally) adopt Change-Id in the non-discardable > > portion. I think it would be easier to get everyone currently > > removing Change-Id to start including it again than it will be to get > > everyone to change their tools to move it to the discardable portion. > > The reason why people Change-Id's exist in commits today is because of > tooling which is distributed as part of Gerrit. That's why people are > deeply suspicious of any solution that involves Change-Id in the > non-discarded portion --- because the majority of Gerrit servers up > until now are behind corporate firewalls and since Gerrit servers have > robots.txt files, most Change-Id tend to be useless. > > If we come up with new tooling which is more useful, people will use > it. If it's not useful and doesn't makes life easier, people won't. > > > > On Mon, Aug 26, 2019 at 03:06:43PM -0700, Doug Anderson wrote: > > 2. If, as I expect, Change-Id as part of the patch stays NAKed then I > > will modify the tools I use to post upstream (currently patman) to > > encode the Change-Id. My naive proposal would be: > > > > Message-Id: ChangeId-YYYY-MMDD-HHMMSS-PatchNum > > > > If I try this and it works for me then I will post out and suggest > > that any other like-minded people encode Change-Id into Message-Id in > > a similar way. > > ... and I would expect patches with this would get NACK'ed because > they would be just as useless as Change-Id's are perceived to be > today. People who are gaming the rules will tend not to looked upon > favorably; the same will apply to their patches. > > BTW, the Message-Id you've listed above is not legal, per RFC-5322. A > msg-id has to look like a e-mail address (left-hand-side@example.com). > So something like this is legal as a message id: > > I3268f9036512c4378cde1da37e0612b43ed4d384@linux-review.googlesource.com > > ... and indeed, that's more useful, because it tells us how to > interpret I3268f9036512c4378cde1da37e0612b43ed4d384 --- it's a > Change-Id assigned by the linux-review.googlesource.com Gerrit server. > > In contrast a bare "I3268f9036512c4378cde1da37e0612b43ed4d384" is > going to be presumed to be useless. And in fact, a Google search for > this ID returns *nothing*. Yet visiting the link > https://linux-review.googlesource.com/c/1158 actually returns > something useful. That's why the latter is superior to the former. > > In summary, > > Not useful: (and will be probably nacked) > > Change-Id: I3268f9036512c4378cde1da37e0612b43ed4d384 > Message-Id: I3268f9036512c4378cde1da37e0612b43ed4d384 > > Useful: > > Link: https://linux-review.googlesource.com/c/1158 > Link: https://lkml.kernel.org/r/20190826204407.17759-1-daniel.lezcano@linaro.org > > Not as useful: (people will prefer the Link example above) > > Message-Id: 20190826204407.17759-1-daniel.lezcano@linaro.org Hi, A somewhat related point re UUID/Change-ID. For syzbot (or any other bug tracking system) we want to associate bugs with fixes. It turned out there is no good identity of a change that we could use. Commit hash is an obvious first thing to consider, but (1) it changes in linux-next, (2) sometimes the change is not committed yet when we do the association, (3) it is different when backported to LTS (so not possible to say if a fix is in that stable tree or not). We decided to use commit subject, which works to some degree, but also has problems: (1) not necessary unique, (2) sometimes people change subject during backporting (e.g. prepend some prefix), (3) has all the same problems of email clients messing with text (e.g. I can't issue #syz fix command for loo long commit subjects with my email client). Some real UUID/Change-ID would solve all of these problems by giving us capability to refer to changes rather than a commit in a particular tree only.