[OpenAFS] OpenAFS with Mac OS X

[Nickolai Zeldovich]

> We have a good idea of how to do it, based on how the old NeXT code worked:

I've actually been trying to resurrect the NeXT hack, and, as Jim
Rees points out, there's the more difficult question of what to
do in afs_lookup when crossing a mountpoint.  The vcache needs
to contain the Fid of the remote directory, and in order to get
that, we need to perform a VLDB lookup in the remote cell.  If
the cell is dead (as is often the case with stale ones in /afs)
this will hang for a long time.

One solution would be to introduce delayed mountpoint evaluation
of some sort, but that might require finding and changing all the
code that simply takes the vnode/vcache and pokes the Fid directly,
and replace them with something that'll force the mountpoint eval.
I'd appreciate any comments from people more familiar with this
code :-)

-- kolya