PLEASE TEST: IPI deadlock avoidance patch

[Daniel Eriksson]

Lukas Ertl wrote:

> I've identified and fixed (hopefully) a source of possible 
> data corruption on RAID5 plexes three days ago.  You need
> rev. 1.6 of geom_vinum_raid5.c.

I have now tested with 6-CURRENT compiled from sources dated
2004.08.29.21.00.00 (which includes your patch), and I must unfortunately
report that it does not fix the problem. I tested by duplicating a bunch
(9GB+) of binary files with known crc checksums on the same filesystem, and
I ended up with ~10% corrupt files. Running the exact same test under a
kernel compiled without SMP worked without any problems. (Testbed: SMP
machine with 4 SATA discs in a gvinum RAID-5 array)

I have managed to secure some more testing time on the server today, so I
will be trying this with regular vinum later to see if that makes a
difference. I'll report back here on the list.

/Daniel Eriksson