To: Jamie Lokier <jamie@shareable.org>
Cc: JANAK DESAI <janak@us.ibm.com>, viro@ftp.linux.org.uk, chrisw@osdl.org,
       dwmw2@infradead.org, serue@us.ibm.com, mingo@elte.hu,
       linuxram@us.ibm.com, jmorris@namei.org, sds@tycho.nsa.gov,
       akpm@osdl.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH -mm 1/9] unshare system call: system call handler
 function
References: <1134513959.11972.167.camel@hobbs.atlanta.ibm.com>
	<m1k6e687e2.fsf@ebiederm.dsl.xmission.com>
	<43A1D435.5060602@us.ibm.com>
	<m1d5jy83nr.fsf@ebiederm.dsl.xmission.com>
	<43A24362.6000602@us.ibm.com>
	<20051216105048.GA32305@mail.shareable.org>
From: ebiederm@xmission.com (Eric W. Biederman)
Date: Fri, 16 Dec 2005 05:46:23 -0700
In-Reply-To: <20051216105048.GA32305@mail.shareable.org> (Jamie Lokier's
 message of "Fri, 16 Dec 2005 10:50:48 +0000")
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Jamie Lokier <jamie@shareable.org> writes:

> Like clone(), unshare() will have to change from year to year, as new
> flags are added.  It would be good if the default behaviour of 0 bits
> to unshare() also did the right thing, so that programs compiled in
> 2006 still function as expected in 2010.  Hmm, this
> forward-compatibility does not look pretty.

Why all it requires is that whenever someone updates clone they update
unshare.  Given the tiniest bit of refactoring we should be
able to share all of the interesting code paths.

Which should also improve maintenance considerably.

Eric
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