Pull nfsd updates from Bruce Fields:
 "This consists mostly of nfsd container work:

  Scott Mayhew revived an old api that communicates with a userspace
  daemon to manage some on-disk state that's used to track clients
  across server reboots. We've been using a usermode_helper upcall for
  that, but it's tough to run those with the right namespaces, so a
  daemon is much friendlier to container use cases.

  Trond fixed nfsd's handling of user credentials in user namespaces. He
  also contributed patches that allow containers to support different
  sets of NFS protocol versions.

  The only remaining container bug I'm aware of is that the NFS reply
  cache is shared between all containers. If anyone's aware of other
  gaps in our container support, let me know.

  The rest of this is miscellaneous bugfixes"

* tag 'nfsd-5.2' of git://linux-nfs.org/~bfields/linux: (23 commits)
  nfsd: update callback done processing
  locks: move checks from locks_free_lock() to locks_release_private()
  nfsd: fh_drop_write in nfsd_unlink
  nfsd: allow fh_want_write to be called twice
  nfsd: knfsd must use the container user namespace
  SUNRPC: rsi_parse() should use the current user namespace
  SUNRPC: Fix the server AUTH_UNIX userspace mappings
  lockd: Pass the user cred from knfsd when starting the lockd server
  SUNRPC: Temporary sockets should inherit the cred from their parent
  SUNRPC: Cache the process user cred in the RPC server listener
  nfsd: Allow containers to set supported nfs versions
  nfsd: Add custom rpcbind callbacks for knfsd
  SUNRPC: Allow further customisation of RPC program registration
  SUNRPC: Clean up generic dispatcher code
  SUNRPC: Add a callback to initialise server requests
  SUNRPC/nfs: Fix return value for nfs4_callback_compound()
  nfsd: handle legacy client tracking records sent by nfsdcld
  nfsd: re-order client tracking method selection
  nfsd: keep a tally of RECLAIM_COMPLETE operations when using nfsdcld
  nfsd: un-deprecate nfsdcld
  ...