linux-kernel - Re: Removing Mandatory Locks

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Message-ID: <765d446cc4190575ab400a3a8038db658196b4bf.camel@kernel.org>
Date:   Fri, 20 Aug 2021 09:03:16 -0400
From:   Jeff Layton <jlayton@...nel.org>
To:     Willy Tarreau <w@....eu>
Cc:     Amir Goldstein <amir73il@...il.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        "Eric W. Biederman" <ebiederm@...ssion.com>,
        Matthew Wilcox <willy@...radead.org>,
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        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
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        Florian Weimer <fweimer@...hat.com>,
        Michael Kerrisk <mtk.manpages@...il.com>
Subject: Re: Removing Mandatory Locks

On Fri, 2021-08-20 at 14:38 +0200, Willy Tarreau wrote:
> On Fri, Aug 20, 2021 at 08:27:12AM -0400, Jeff Layton wrote:
> > I'm fine with any of these approaches if the consensus is that it's too
> > risky to just remove it. OTOH, I've yet to ever hear of any application
> > that uses this feature, even in a historical sense.
> 
> Honestly, I agree. Some have fun of me because I'm often using old
> stuff, but I don't even remember having used an application that
> made use of mandatory locking. I remember having enabled it myself in
> my kernels long ago after discovering its existence in the man pages,
> just to test it. It doesn't rule out the possibility that it exists
> somewhere though, but I think that the immediate removal combined
> with the big fat warning in previous branches should be largely
> enough to avoid the last minute surprise.
> 

Good point. It wouldn't hurt to push such a warning into stable kernels
at the same time. There always is a lag when we do something like this
before some downstream user notices.
-- 
Jeff Layton <jlayton@...nel.org>