Re: [MAINTAINERS/KERNEL SUMMIT] Trust and maintenance of file systems

Thorsten Leemhuis
2023-09-07T11:18:35Z

On 07.09.23 12:29, Christian Brauner wrote:
>> So why can't that work similarly for unmaintained file systems? We could
>> even establish the rule that Linus should only apply patches to some
>> parts of the kernel if the test suite for unmaintained file systems
>> succeeded without regressions. And only accept new file system code if a
>
> Reading this mail scared me.

Sorry about that, I can fully understand that. It's just that some
statements in this thread sounded a whole lot like "filesystems want to
opt-out of the no regression rule" to me. That's why I at some point
thought I had to speak up.

> The list of reiserfs bugs alone is crazy.

Well, we regularly remove drivers or even support for whole archs
without getting into conflict with the "no regressions" rule, so I'd say
that should be possible for file systems as well.

And I think for reiserfs we are on track with that.

But what about hfsplus? From hch's initial mail of this thread it sounds
like that is something users would miss. So removing it without a very
strong need[1] seems wrong to me. That's why I got involved in this
discussion.

[1] e.g. data loss or damage (as mentioned in my earlier mail) or
substantial security problems (forgot to mentioned them in my earlier mail)

> I think it's also worth clarifying something:
> Right now, everyone who does fs wide changes does their absolute best to
> account for every filesytem that's in the tree. And for people not
> familiar or even refusing to care about any other filesystems the
> maintainers and reviewers will remind them about consequences for other
> filesystems as far as they have that knowledge. And that's already a
> major task.
>
> For every single fs/ wide change we try to make absolutely sure that if
> it regresses anything - even the deadest-of-dead filesystems - it will
> be fixed as soon as we get a report. [...]

I know. Big thx to everyone doing the work here!

> But it is very scary to think that we might be put even more under the
> yoke of dead filesystems.

That is not my intent. I just want to ensure the "no regressions" rule
is not forgotten in this discussion.

>> test suite that is easy to integrate in CI systems exists (e.g.
>> something smaller and faster than what the ext4 and xfs developers run
>> regularly, but smaller and faster should likely be good enough here).
>
> The big question of course is who is going to do that?
> [...]
> That'll be a fulltime job for quite a while I would expect.

Yeah, I know. :-/

Ciao, Thorsten