Upcoming ABI Breakage in RELENG_7

Matt datahead4 at gmail.com
Tue Aug 5 19:18:21 UTC 2008

On Tue, Jul 29, 2008 at 10:45 AM, Ken Smith <kensmith at cse.buffalo.edu> 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.

Just updated to 7-STABLE last night and found that Truecrypt (which
uses a combination of fuse and mdconfig to mount its encrypted
volumes) is now completely unable to mount its encrypted volumes.
I've rebuilt fusefs-kmod and fusefs-libs as well as Truecrypt to no

As Truecrypt is implementing an encrypted file system, I am assuming
at this point that the kernel ABI breakage may be what is causing this
new problem.  Are the any calls in particular that I should be looking
for in the Truecrypt code to see where it might be choking on the new
kernel ABI?  I've briefly reviewed some of the changes in r181119 but
lack the experience to discern anything useful from them.  I'd like to
file an issue with the Truecrypt devs if I can get an idea of where
the breakage might be.


> Thanks.
> --
>                                                Ken Smith
> - From there to here, from here to      |       kensmith at cse.buffalo.edu
>  there, funny things are everywhere.   |
>                      - Theodore Geisel |

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