nfsv4 server patches and status

[J. Bruce Fields]

By the way, I sent email last December summarizing what I think are the
biggest things we'd need to fix before removing the "experimental"
marking from the nfsv4 server code:

	http://linux-nfs.org/pipermail/nfsv4/2006-December/005497.html

I figure I should be sending out an update on that every now and then.
So, the problems listed before were:

	- security on exports: I'm reasonably confident that the work is
	  done, and that everything can be merged in for 2.6.23.

	- reboot recovery: there's been more work here on a prototype.
	  I haven't had a chance to review it lately.  If it's in good
	  shape there's a small chance it could be ready for merging
	  this time around, and hence would get into 2.6.23.  If not
	  then I hope we'll finally have it done for 2.6.24.
 
So that leaves the most annoying one:

	- export paths consistent with nfsv2/v3:  No really promising
	  progress, though (thanks mainly to Bryce Harrington), we do
	  now have some prototype code at:

	  git://linux-nfs.org/~bfields/nfs-tuils.git pseudo-export

	  which attempts to solve the whole problem in userspace by
	  automatically loopback-mounting a file to serve as the NFSv4
	  root, bind-mounting under it everything listed in the exports,
	  and faking up corresponding exports in mountd.  The code
	  more or less works, but I'm not sure it's the right approach.

This is a really important problem, and not one I've had a lot of time
to work on lately, so we could definitely still use help here.

--b.