Upcoming ABI Breakage in RELENG_7
Vlad GALU
dudu at dudu.ro
Wed Jul 30 10:04:44 UTC 2008
On 7/30/08, David Southwell <david at vizion2000.net> wrote:
> 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.
>
ABI breakage occurs when internal data structures change (for
instance, when members of the structure are removed or added). Kernel
modules which expect those structures to look in a certain way will
need to be recompiled. Also, depending on what data structures suffer
the changes, ioctl() operations may fail, requiring a rebuild of the
userland programs which issue the ioctl()s. And I'm sure that there
are many other examples that I can't think of right now :)
--
~/.signature: no such file or directory
More information about the freebsd-stable
mailing list