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From: David Southwell <david@vizion2000.net>
Organization: Voice and Vision
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Date: Wed, 30 Jul 2008 02:47:34 -0700
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Cc: Ken Smith <kensmith@cse.buffalo.edu>,
	freebsd-current <freebsd-current@freebsd.org>
Subject: Re: Upcoming ABI Breakage in RELENG_7
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On Tuesday 29 July 2008 08:45:45 Ken Smith wrote:
> Normally the FreeBSD Project tries very hard to avoid ABI breakage in
> "Stable Branches".  However occasionally the fix for a bug can not be
> implemented without ABI breakage, and it is decided that the fix
> warrants the impact of the ABI breakage.  We have one of those
> situations coming along for RELENG_7 (what will become FreeBSD 7.1).
> The ABI breakage should only impact kernel modules that are not part of
> the baseline system (those will be patched by the MFC) which deal with
> advisory locks.  As such the impact should not cause many people
> problems.
>
> The work that will be MFCed fixes issues with filesystem advisory locks,
> and moves the advisory locks list from filesystem-private data
> structures into the vnode structure.
>
> The MFC will be done by Kostantin Belousov some time this coming Friday
> (August 1st, 2008) if you have concerns and want to watch for it.
>
> Thanks.
Sometimes information gets posted to this list on the assumption that everyone 
understand what the writer means.

This is one of those occasions!!

For those of us who are not as well informed and experienced  as others could 
someone please explain what is meant by an  ABI breakage, its implications 
and how to deal with them.

Thanks

David