[PATCH v12 00/24] nfs/nfsd: add support for localio

[Mike Snitzer <snitzer@kernel.org>]

These latest changes are available in my git tree here:
https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next

Significant progress was made on the entire series, I implemented all
3 changes NeilBrown suggested here:
https://marc.info/?l=linux-nfs&m=172004547710968&w=2

And Neil kindly provided review of a preliminary v12 that I then used
to refine this final v12 further.  Neil found the series much cleaner
and approachable.

This v12 also switches the NFS client's localio code over to driving
IO in terms of nfsd's nfsd_file (rather than a simple file pointer).
I checked with Jeff Layton and he likes the switch to using nfsd_file
(Jeff did suggest I make sure to keep struct nfsd_file completely
opaque to the client).  Proper use of nfsd_file provides a solid
performance improvement (as detailed in the last patch's commit
header) thanks especially to the nfsd filecache's GC feature (which
localio now makes use of).

Testing:
- Chuck's kdevops NFS testing has been operating against the
  nfs-localio-for-next branch for a while now (not sure if LOCALIO is
  enabled or if Chuck is just verifying the branch works with LOCALIO
  disabled).
- Verified all of Hammerspace's various sanity tests pass (this
  includes numerous pNFS and flexfiles tests).

Please review, I'm hopeful I've addressed any outstanding issues and
that these changes worthy of being merged for v6.12.  If you see
something, say something ;)

Changes since v11:
- The required localio specific changes in fs/nfsd/ are much simpler
  (thanks to the prelim patches that update common code to support the
   the localio case, fs/nfsd/localio.c in particular is now very lean)
- Improved the localio protocol to address NeilBrown's issue #1.
  Replaced GETUUID with UUID_IS_LOCAL RPC, which inverts protocol such
  that client generates a nonce (shortlived single-use UUID) and
  proceeds to verify the server sees it in nfs_common.
  - this eliminated the need to add 'struct nfsd_uuid' to nfsd_net
- Finished the RFC series NeilBrown started to introduce
  nfsd_file_acquire_local(), enables the use of a "fake" svc_rqst to
  be eliminated: https://marc.info/?l=linux-nfs&m=171980269529965&w=2 
  (uses auth_domain as suggested, addresses NeilBrown's issue #2)
- rpcauth_map_clnt_to_svc_cred_local now uses userns of client and
  from_{kuid,kgid}_munged (hopefully addresses NeilBrown's issue #3)
- Updated nfs_local_call_write() to override_creds() with the cred
  used by the client to open the localio file.
- To avoid localio hitting writeback deadlock (same as is done for
  existing loopback NFSD support in nfsd_vfs_write() function): set
  PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO in nfs_local_call_write() and
  restore current->flags before return.
- Factored nfs_stat_to_errno and nfs4_stat_to_errno out to nfs_common
  to eliminate localio code creating yet another copy of them.
  (eliminates existing duplication between fs/nfs/nfs[23]xdr.c)
- Simplified Kconfig so that NFS_LOCALIO depends on NFS_FS and
  NFSD_LOCALIO depends on NFSD.
- Only support localio if UNIX Authentication (AUTH_UNIX) is used.
- Improved workqueue patch to not use wait_for_completion().
- Dropped 2 prelim fs/nfs/ patches that weren't actually needed.
- Updated localio.rst to reflect the various changes listed above,
  also added a new "FAQ" section from Trond (which was informed by an
  in-person discussion about localio that Trond had with Christoph).
- Fixed "nfsd: add nfsd_file_acquire_local()" commit to work with
  NFSv3 (had been testing with NFSv4.2 and the fact that NFSv3
  regressed due to 'nfs_ver' not being properly initialized for
  non-LOCALIO callers was missed.
- Fixed issue Neil reported where "When using localio, if I open,
  read, don't close, then try to stop the server and umount the
  exported filesystem I get EBUSY for the umount."
  - fix by removing refcount on localio file (no longer cache open
    localio file in the client).
- Fixed nfsd tracepoints that were impacted by the possibility they'd
  be passed a NULL rqstp when using localio.
- Rebased on cel/nfsd-next (based on v6.11-rc4) to layer upon Neil's
  various changes that were originally motivated by LOCALIO, reduces
  footprint of this patchset.
- Exported nfsd_file interfaces needed to switch the nfs client's
  localio code over to using it.
- Switched the the nfs client's localio code over to using nfsd_file.

Thanks,
Mike

Mike Snitzer (13):
  nfs_common: factor out nfs_errtbl and nfs_stat_to_errno
  nfs_common: factor out nfs4_errtbl and nfs4_stat_to_errno
  nfs: factor out {encode,decode}_opaque_fixed to nfs_xdr.h
  nfsd: fix nfsfh tracepoints to properly handle NULL rqstp
  SUNRPC: remove call_allocate() BUG_ONs
  nfs_common: add NFS LOCALIO auxiliary protocol enablement
  nfsd: implement server support for NFS_LOCALIO_PROGRAM
  nfs: implement client support for NFS_LOCALIO_PROGRAM
  nfs: add Documentation/filesystems/nfs/localio.rst
  nfsd: use GC for nfsd_file returned by nfsd_file_acquire_local
  nfs_common: expose localio's required nfsd symbols to nfs client
  nfs: push localio nfsd_file_put call out to client
  nfs: switch client to use nfsd_file for localio

NeilBrown (3):
  nfsd: factor out __fh_verify to allow NULL rqstp to be passed
  nfsd: add nfsd_file_acquire_local()
  SUNRPC: replace program list with program array

Trond Myklebust (4):
  nfs: enable localio for non-pNFS IO
  pnfs/flexfiles: enable localio support
  nfs/localio: use dedicated workqueues for filesystem read and write
  nfs: add FAQ section to Documentation/filesystems/nfs/localio.rst

Weston Andros Adamson (4):
  SUNRPC: add rpcauth_map_clnt_to_svc_cred_local
  nfsd: add localio support
  nfs: pass struct file to nfs_init_pgio and nfs_init_commit
  nfs: add localio support

 Documentation/filesystems/nfs/localio.rst | 255 +++++++
 fs/Kconfig                                |   3 +
 fs/nfs/Kconfig                            |  15 +
 fs/nfs/Makefile                           |   1 +
 fs/nfs/client.c                           |  15 +-
 fs/nfs/filelayout/filelayout.c            |   6 +-
 fs/nfs/flexfilelayout/flexfilelayout.c    | 142 +++-
 fs/nfs/flexfilelayout/flexfilelayout.h    |   2 +
 fs/nfs/flexfilelayout/flexfilelayoutdev.c |   6 +
 fs/nfs/inode.c                            |  57 +-
 fs/nfs/internal.h                         |  61 +-
 fs/nfs/localio.c                          | 784 ++++++++++++++++++++++
 fs/nfs/nfs2xdr.c                          |  70 +-
 fs/nfs/nfs3xdr.c                          | 108 +--
 fs/nfs/nfs4xdr.c                          |  84 +--
 fs/nfs/nfstrace.h                         |  61 ++
 fs/nfs/pagelist.c                         |  16 +-
 fs/nfs/pnfs_nfs.c                         |   2 +-
 fs/nfs/write.c                            |  12 +-
 fs/nfs_common/Makefile                    |   5 +
 fs/nfs_common/common.c                    | 134 ++++
 fs/nfs_common/nfslocalio.c                | 194 ++++++
 fs/nfsd/Kconfig                           |  15 +
 fs/nfsd/Makefile                          |   1 +
 fs/nfsd/export.c                          |   8 +-
 fs/nfsd/filecache.c                       |  90 ++-
 fs/nfsd/filecache.h                       |   5 +
 fs/nfsd/localio.c                         | 183 +++++
 fs/nfsd/netns.h                           |   8 +-
 fs/nfsd/nfsctl.c                          |   2 +-
 fs/nfsd/nfsd.h                            |   6 +-
 fs/nfsd/nfsfh.c                           | 114 ++--
 fs/nfsd/nfsfh.h                           |   5 +
 fs/nfsd/nfssvc.c                          | 100 ++-
 fs/nfsd/trace.h                           |  39 +-
 fs/nfsd/vfs.h                             |  10 +
 include/linux/nfs.h                       |   9 +
 include/linux/nfs_common.h                |  17 +
 include/linux/nfs_fs_sb.h                 |  10 +
 include/linux/nfs_xdr.h                   |  20 +-
 include/linux/nfslocalio.h                |  56 ++
 include/linux/sunrpc/auth.h               |   4 +
 include/linux/sunrpc/svc.h                |   7 +-
 net/sunrpc/auth.c                         |  22 +
 net/sunrpc/clnt.c                         |   6 -
 net/sunrpc/svc.c                          |  68 +-
 net/sunrpc/svc_xprt.c                     |   2 +-
 net/sunrpc/svcauth_unix.c                 |   3 +-
 48 files changed, 2428 insertions(+), 415 deletions(-)
 create mode 100644 Documentation/filesystems/nfs/localio.rst
 create mode 100644 fs/nfs/localio.c
 create mode 100644 fs/nfs_common/common.c
 create mode 100644 fs/nfs_common/nfslocalio.c
 create mode 100644 fs/nfsd/localio.c
 create mode 100644 include/linux/nfs_common.h
 create mode 100644 include/linux/nfslocalio.h

-- 
2.44.0