RHEL6: NFS4 server incorrectly returning NFS4ERR_EXPIRED to WRITE due to wraparound of current_fileid leads to infinite protocol loop with NFS4 client

Issue

• NFS4 client hangs to an NFS server that has been up a long time or has handled OPENs for 2^32 or more files
• Linux NFS4 client hangs on a single WRITE with the Linux NFS4 server returning NFS4ERR_EXPIRED to the WRITE repeatedly even after error recovery.
• In the Linux NFS server the current_fileid is a 32-bit counter and if it wraps around, it you can get into an infinite protocol loop of:
  • WRITE / NFS4ERR_EXPIRED
  • RENEW / NFS4_OK
  • OPEN / NFS4_OK (with new stateid, same clientid used in the open that was sent in the RENEW)
  • WRITE / NFS4ERR_EXPIRED (uses new stateid returned in the OPEN reply)