[pnfs] NFSv4.1 (DEVELOPER ONLY)

[J. Bruce Fields]

On Mon, Aug 17, 2009 at 12:19:27PM -0400, William A. (Andy) Adamson wrote:
> I think NFSv4.0 should be moved from EXPERIMENTAL before NFSv4.1 gets
> moved from DEVELOPER -> EXPERIMENTAL!
> 
> What is left to do in NFSv4.0 to allow this to happen?

Todo's I know of that should probably be fixed first:

	- on the client side (we probably want to move client and server
	  out of experimental at roughly the same time, if possible?)
	  there's the mount negotiation to finish.  Steve intends his
	  mount configuration stuff to be a first step.
	- server-side exports coordinated with v2/v3: I need to take a
	  day or two to think about Steve's patches.  Will do that soon!
	- server-side reboot recovery code: the other kernel people
	  really hate the current v4 recovery code, and it has indeed
	  been a generator of weird bugs.  I tried to pick this up early
	  this week and write down a basic design, then got distracted.
	  Would like to get this fixed sooner rather than later just
	  because it will likely be a backwards-incompatible change,
	  hence easier to do while there are fewer users.
	- proper delegation enforcement: currently e.g. if you edit a
	  delegated file with a text editor, delegation-holding clients
	  don't get an update (because the server is not correctly
	  breaking leases on rename/unlink).  I have a patch series that
	  needs a few more bug fixes and some review.

Some other todo's I can think of that I'm not might also block
EXPERIMENTAL removal (but I'm not as sure):

	- Turn on 4.0 reply cache.  Theoretical problem, not sure if
	  we've seen it in practice.
	- Make sure deferrals don't replay non-idempotent operations.
	  (Neil is close to fixing this.)  Theoretical problem, not sure
	  if we've seen it in practice.

This is a little off the top of my head; anything I've forgotten?

--b.