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

  Stable bugfixes:
   - nfs: don't create zero-length requests

   - several LAYOUTGET bugfixes

  Features:
   - several performance related features

   - more aggressive caching when we can rely on close-to-open
     cache consistency

   - remove serialisation of O_DIRECT reads and writes

   - optimise several code paths to not flush to disk unnecessarily.

     However allow for the idiosyncracies of pNFS for those layout
     types that need to issue a LAYOUTCOMMIT before the metadata can
     be updated on the server.

   - SUNRPC updates to the client data receive path

   - pNFS/SCSI support RH/Fedora dm-mpath device nodes

   - pNFS files/flexfiles can now use unprivileged ports when
     the generic NFS mount options allow it.

  Bugfixes:
   - Don't use RDMA direct data placement together with data
     integrity or privacy security flavours

   - Remove the RDMA ALLPHYSICAL memory registration mode as
     it has potential security holes.

   - Several layout recall fixes to improve NFSv4.1 protocol
     compliance.

   - Fix an Oops in the pNFS files and flexfiles connection
     setup to the DS

   - Allow retry of operations that used a returned delegation
      stateid

   - Don't mark the inode as revalidated if a LAYOUTCOMMIT is
     outstanding

   - Fix writeback races in nfs4_copy_range() and
     nfs42_proc_deallocate()"

* tag 'nfs-for-4.8-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (104 commits)
  pNFS: Actively set attributes as invalid if LAYOUTCOMMIT is outstanding
  NFSv4: Clean up lookup of SECINFO_NO_NAME
  NFSv4.2: Fix warning "variable ‘stateids’ set but not used"
  NFSv4: Fix warning "no previous prototype for ‘nfs4_listxattr’"
  SUNRPC: Fix a compiler warning in fs/nfs/clnt.c
  pNFS: Remove redundant smp_mb() from pnfs_init_lseg()
  pNFS: Cleanup - do layout segment initialisation in one place
  pNFS: Remove redundant stateid invalidation
  pNFS: Remove redundant pnfs_mark_layout_returned_if_empty()
  pNFS: Clear the layout metadata if the server changed the layout stateid
  pNFS: Cleanup - don't open code pnfs_mark_layout_stateid_invalid()
  NFS: pnfs_mark_matching_lsegs_return() should match the layout sequence id
  pNFS: Do not set plh_return_seq for non-callback related layoutreturns
  pNFS: Ensure layoutreturn acts as a completion for layout callbacks
  pNFS: Fix CB_LAYOUTRECALL stateid verification
  pNFS: Always update the layout barrier seqid on LAYOUTGET
  pNFS: Always update the layout stateid if NFS_LAYOUT_INVALID_STID is set
  pNFS: Clear the layout return tracking on layout reinitialisation
  pNFS: LAYOUTRETURN should only update the stateid if the layout is valid
  nfs: don't create zero-length requests
  ...