Pull nfsd fixes from Bruce Fields:
 "Two main issues:

   - We found that turning on pNFS by default (when it's configured at
     build time) was too aggressive, so we want to switch the default
     before the 4.0 release.

   - Recent client changes to increase open parallelism uncovered a
     serious bug lurking in the server's open code.

  Also fix a krb5/selinux regression.

  The rest is mainly smaller pNFS fixes"

* 'for-4.0' of git://linux-nfs.org/~bfields/linux:
  sunrpc: make debugfs file creation failure non-fatal
  nfsd: require an explicit option to enable pNFS
  NFSD: Fix bad update of layout in nfsd4_return_file_layout
  NFSD: Take care the return value from nfsd4_encode_stateid
  NFSD: Printk blocklayout length and offset as format 0x%llx
  nfsd: return correct lockowner when there is a race on hash insert
  nfsd: return correct openowner when there is a race to put one in the hash
  NFSD: Put exports after nfsd4_layout_verify fail
  NFSD: Error out when register_shrinker() fail
  NFSD: Take care the return value from nfsd4_decode_stateid
  NFSD: Check layout type when returning client layouts
  NFSD: restore trace event lost in mismerge