Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - fix handling of backchannel binding in BIND_CONN_TO_SESSION

  Bugfixes:
   - Fix a credential use-after-free issue in pnfs_roc()
   - Fix potential posix_acl refcnt leak in nfs3_set_acl
   - defer slow parts of rpc_free_client() to a workqueue
   - Fix an Oopsable race in __nfs_list_for_each_server()
   - Fix trace point use-after-free race
   - Regression: the RDMA client no longer responds to server disconnect
     requests
   - Fix return values of xdr_stream_encode_item_{present, absent}
   - _pnfs_return_layout() must always wait for layoutreturn completion

  Cleanups:
   - Remove unreachable error conditions"

* tag 'nfs-for-5.7-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: Fix a race in __nfs_list_for_each_server()
  NFSv4.1: fix handling of backchannel binding in BIND_CONN_TO_SESSION
  SUNRPC: defer slow parts of rpc_free_client() to a workqueue.
  NFSv4: Remove unreachable error condition due to rpc_run_task()
  SUNRPC: Remove unreachable error condition
  xprtrdma: Fix use of xdr_stream_encode_item_{present, absent}
  xprtrdma: Fix trace point use-after-free race
  xprtrdma: Restore wake-up-all to rpcrdma_cm_event_handler()
  nfs: Fix potential posix_acl refcnt leak in nfs3_set_acl
  NFS/pnfs: Fix a credential use-after-free issue in pnfs_roc()
  NFS/pnfs: Ensure that _pnfs_return_layout() waits for layoutreturn completion