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From:   Rodrigo Campos <rodrigo@kinvolk.io>
Date:   Wed, 18 Aug 2021 11:34:26 +0200
Message-ID: <CACaBj2ZgrA2JeeGenXxEf5ha6OYaFrj2=iuVXnQxC=kZLZpjng@mail.gmail.com>
Subject: Re: Removing Mandatory Locks
To:     "Eric W. Biederman" <ebiederm@xmission.com>
Cc:     Matthew Wilcox <willy@infradead.org>,
        Andy Lutomirski <luto@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        David Laight <David.Laight@aculab.com>,
        David Hildenbrand <david@redhat.com>,
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        Andrew Morton <akpm@linux-foundation.org>,
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On Tue, Aug 17, 2021 at 6:49 PM Eric W. Biederman <ebiederm@xmission.com> wrote:
>
> Matthew Wilcox <willy@infradead.org> writes:
>
> > On Fri, Aug 13, 2021 at 05:49:19PM -0700, Andy Lutomirski wrote:
> >> [0] we have mandatory locks, too. Sigh.
> >
> > I'd love to remove that.  Perhaps we could try persuading more of the
> > distros to disable the CONFIG option first.
>
> Yes.  The support is disabled in RHEL8.

If it helps, it seems to be enabled on the just released debian stable:
    $ grep CONFIG_MANDATORY_FILE_LOCKING /boot/config-5.10.0-8-amd64
    CONFIG_MANDATORY_FILE_LOCKING=y

Also the new 5.13 kernel in experimental has it too:
    $ grep CONFIG_MANDATORY_FILE_LOCKING /boot/config-5.13.0-trunk-amd64
    CONFIG_MANDATORY_FILE_LOCKING=y