Pull nfsd updates from Chuck Lever:

 - Update NFSv2 and NFSv3 XDR decoding functions

 - Further improve support for re-exporting NFS mounts

 - Convert NFSD stats to per-CPU counters

 - Add batch Receive posting to the server's RPC/RDMA transport

* tag 'nfsd-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (65 commits)
  nfsd: skip some unnecessary stats in the v4 case
  nfs: use change attribute for NFS re-exports
  NFSv4_2: SSC helper should use its own config.
  nfsd: cstate->session->se_client -> cstate->clp
  nfsd: simplify nfsd4_check_open_reclaim
  nfsd: remove unused set_client argument
  nfsd: find_cpntf_state cleanup
  nfsd: refactor set_client
  nfsd: rename lookup_clientid->set_client
  nfsd: simplify nfsd_renew
  nfsd: simplify process_lock
  nfsd4: simplify process_lookup1
  SUNRPC: Correct a comment
  svcrdma: DMA-sync the receive buffer in svc_rdma_recvfrom()
  svcrdma: Reduce Receive doorbell rate
  svcrdma: Deprecate stat variables that are no longer used
  svcrdma: Restore read and write stats
  svcrdma: Convert rdma_stat_sq_starve to a per-CPU counter
  svcrdma: Convert rdma_stat_recv to a per-CPU counter
  svcrdma: Refactor svc_rdma_init() and svc_rdma_clean_up()
  ...

Remove duplicated helper functions to parse opaque XDR objects
and place inside new file net/sunrpc/auth_gss/auth_gss_internal.h.
In the new file carry the license and copyright from the source file
net/sunrpc/auth_gss/auth_gss.c.  Finally, update the comment inside
include/linux/sunrpc/xdr.h since lockd is not the only user of
struct xdr_netobj.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Clean up: The unit of XDR alignment is defined by RFC 4506,
not as part of the RPC message header. Thus it belongs in
include/linux/sunrpc/xdr.h.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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

  Features:

   - NFSv3: Add emulation of lookupp() to improve open_by_filehandle()
     support

   - A series of patches to improve readdir performance, particularly
     with large directories

   - Basic support for using NFS/RDMA with the pNFS files and flexfiles
     drivers

   - Micro-optimisations for RDMA

   - RDMA tracing improvements

  Bugfixes:

   - Fix a long standing bug with xs_read_xdr_buf() when receiving
     partial pages (Dan Aloni)

   - Various fixes for getxattr and listxattr, when used over non-TCP
     transports

   - Fixes for containerised NFS from Sargun Dhillon

   - switch nfsiod to be an UNBOUND workqueue (Neil Brown)

   - READDIR should not ask for security label information if there is
     no LSM policy (Olga Kornievskaia)

   - Avoid using interval-based rebinding with TCP in lockd (Calum
     Mackay)

   - A series of RPC and NFS layer fixes to support the NFSv4.2
     READ_PLUS code

   - A couple of fixes for pnfs/flexfiles read failover

  Cleanups:

   - Various cleanups for the SUNRPC xdr code in conjunction with the
     READ_PLUS fixes"

* tag 'nfs-for-5.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (90 commits)
  NFS/pNFS: Fix a typo in ff_layout_resend_pnfs_read()
  pNFS/flexfiles: Avoid spurious layout returns in ff_layout_choose_ds_for_read
  NFSv4/pnfs: Add tracing for the deviceid cache
  fs/lockd: convert comma to semicolon
  NFSv4.2: fix error return on memory allocation failure
  NFSv4.2/pnfs: Don't use READ_PLUS with pNFS yet
  NFSv4.2: Deal with potential READ_PLUS data extent buffer overflow
  NFSv4.2: Don't error when exiting early on a READ_PLUS buffer overflow
  NFSv4.2: Handle hole lengths that exceed the READ_PLUS read buffer
  NFSv4.2: decode_read_plus_hole() needs to check the extent offset
  NFSv4.2: decode_read_plus_data() must skip padding after data segment
  NFSv4.2: Ensure we always reset the result->count in decode_read_plus()
  SUNRPC: When expanding the buffer, we may need grow the sparse pages
  SUNRPC: Cleanup - constify a number of xdr_buf helpers
  SUNRPC: Clean up open coded setting of the xdr_stream 'nwords' field
  SUNRPC: _copy_to/from_pages() now check for zero length
  SUNRPC: Cleanup xdr_shrink_bufhead()
  SUNRPC: Fix xdr_expand_hole()
  SUNRPC: Fixes for xdr_align_data()
  SUNRPC: _shift_data_left/right_pages should check the shift length
  ...

There are a number of xdr helpers for struct xdr_buf that do not change
the structure itself. Mark those as taking const pointers for
documentation purposes.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

We do want to try to grow the buffer if possible, but if that attempt
fails, we still want to move the data and truncate the XDR message.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

The main use case right now for xdr_align_data() is to shift the page
data to the left, and in practice shrink the total XDR data buffer.
This patch ensures that we fix up the accounting for the buffer length
as we shift that data around.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Refactor for clarity.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Convert the READ_BUF macro in nfs4xdr.c from open code to instead
use the new xdr_stream-style decoders already in use by the encode
side (and by the in-kernel NFS client implementation). Once this
conversion is done, each individual NFSv4 argument decoder can be
independently cleaned up to replace these macros with C code.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>