[PATCH 0/5] nfs4.1: Initial SP4_MACH_CRED implementation

[Weston Andros Adamson <dros@netapp.com>]

These patches are the initial client-side SP4_MACH_CRED implementation.

Patch 1 is a repost with a few cleanups

Patch 2 adds the sp4 handler that replaces the cred on an rpc message (and
picks the right rpc_clnt).  Note that for now, we always use the machine cred
if supported - we could only use it if the user cred expires, but this is
simple and spec compliant.

Patch 3-5 implement SP4_MACH_CRED "features":
  - cleanup - CLOSE and LOCKU use machine cred
  - secinfo - SECINFO and SECINFO_NO_NAME use machine cred
  - stateid - TEST_STATEID and FREE_STATEID use machine cred

There are three more features that I've been working on, but need to be tested
before I post:
  - commit - COMMIT uses machine cred
  - write - WRITE uses machine cred, forces stable writes unless commit feature
            is also enabled
  - recovery - OPEN and LOCK can use machine cred - only in recovery.

The commit and write cases should be easy to test against a hacked nfsd, but
I need to think more about how to test the recovery stuff...

-dros