Read-only XFS support for FreeBSD 6-CURRENT

Hi,

I have uploaded a snapshot of my XFS filesystem port for FreeBSD to
http://people.freebsd.org/~kan/xfs. This snapshot allows XFS partitions
to be mounted read-only under FreeBSD.  The port is based on XFS sources
available from SGI for Linux, so it is covered by GPL and should be
handled appropriately.

The read-only XFS access was quite stable in my testing and managed to
survive through multiple 'make -j12 buildworld' rounds with src/ stored
on XFS partition, so I think it is a good time for a wider community to
take it for a spin and start reporting bugs/panics that I overlooked.

This is still a work in progress, so do not try to use it unless you are
familiar with kernel debugging procedures and willing to share your
kernel.debug+xfs.ko+vmcore files with me. Patches are of course most
welcome too. There is a lot to be done still and any help counts.

I would like to thank Russell Cattelan and Craig Rodrigues for helping
me with this work.
--
Alexander Kabaev