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Subject: Re: Removing Mandatory Locks
From:   Jeff Layton <jlayton@kernel.org>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     "Eric W. Biederman" <ebiederm@xmission.com>,
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Date:   Thu, 19 Aug 2021 16:18:38 -0400
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On Thu, 2021-08-19 at 12:15 -0700, Linus Torvalds wrote:
> On Thu, Aug 19, 2021 at 11:39 AM Jeff Layton <jlayton@kernel.org> wrote:
> > 
> > I'm all for ripping it out too. It's an insane interface anyway.
> > 
> > I've not heard a single complaint about this being turned off in
> > fedora/rhel or any other distro that has this disabled.
> 
> I'd love to remove it, we could absolutely test it. The fact that
> several major distros have it disabled makes me think it's fine.
> 
> But as always, it would be good to check Android.
> 
> The desktop distros tend to have the same tools and programs, so if
> Fedora and RHEL haven't needed it for years, then it's likely stale in
> Debian too (despite being enabled).
> 
> But Android tends to be very different. Does anybody know?
> 

Now that I think about it a little more, I actually did get one
complaint a few years ago:

Someone had upgraded from an earlier distro that supported the -o mand
mount option to a later one that had disabled it, and they had an (old)
fstab entry that specified it. They didn't actually use mandatory
locking and weren't sure why the option was set, so they removed it and
moved on.

I would feel a lot better about it if we had gotten Debian to turn it
off several years ago too, but I agree it's unlikely anyone uses this
and the risk of removing it is low.

I've spun up a patch to just rip it out. I'll do a bit of testing with
it tomorrow and then send it out.

Cheers,
-- 
Jeff Layton <jlayton@kernel.org>