Re: [for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[Mike Snitzer <snitzer@kernel.org>]

On Fri, Nov 22, 2024 at 09:31:23PM -0500, Mike Snitzer wrote:
> On Fri, Nov 22, 2024 at 12:26:39PM -0500, Jeff Layton wrote:
> > On Fri, 2024-11-15 at 20:40 -0500, Mike Snitzer wrote:
> > > Hi,
> > > 
> > > All available here:
> > > https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next
> > > 
> > > Changes since v2:
> > > - switched from rcu_assign_pointer to RCU_INIT_POINTER when setting to
> > >   NULL.
> > > - removed some unnecessary #if IS_ENABLED(CONFIG_NFS_LOCALIO)
> > > - revised the NFS v3 probe patch to use a new nfsv3.ko modparam
> > >   'nfs3_localio_probe_throttle' to control if NFSv3 will probe for
> > >   LOCALIO. Avoids use of NFS_CS_LOCAL_IO and will probe every
> > >   'nfs3_localio_probe_throttle' IO requests (defaults to 0, disabled).
> > > - added "Module Parameters" section to localio.rst
> > > 
> > > All review appreciated, thanks.
> > > Mike
> > > 
> > > Mike Snitzer (14):
> > >   nfs/localio: add direct IO enablement with sync and async IO support
> > >   nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations
> > >   nfs_common: rename functions that invalidate LOCALIO nfs_clients
> > >   nfs_common: move localio_lock to new lock member of nfs_uuid_t
> > >   nfs: cache all open LOCALIO nfsd_file(s) in client
> > >   nfsd: update percpu_ref to manage references on nfsd_net
> > >   nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
> > >   nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
> > >   nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
> > >   nfs_common: track all open nfsd_files per LOCALIO nfs_client
> > >   nfs_common: add nfs_localio trace events
> > >   nfs/localio: remove redundant code and simplify LOCALIO enablement
> > >   nfs: probe for LOCALIO when v4 client reconnects to server
> > >   nfs: probe for LOCALIO when v3 client reconnects to server
> > > 
> > >  Documentation/filesystems/nfs/localio.rst |  98 +++++----
> > >  fs/nfs/client.c                           |   6 +-
> > >  fs/nfs/direct.c                           |   1 +
> > >  fs/nfs/flexfilelayout/flexfilelayout.c    |  25 +--
> > >  fs/nfs/flexfilelayout/flexfilelayout.h    |   1 +
> > >  fs/nfs/inode.c                            |   3 +
> > >  fs/nfs/internal.h                         |   9 +-
> > >  fs/nfs/localio.c                          | 232 +++++++++++++++-----
> > >  fs/nfs/nfs3proc.c                         |  46 +++-
> > >  fs/nfs/nfs4state.c                        |   1 +
> > >  fs/nfs/nfstrace.h                         |  32 ---
> > >  fs/nfs/pagelist.c                         |   5 +-
> > >  fs/nfs/write.c                            |   3 +-
> > >  fs/nfs_common/Makefile                    |   3 +-
> > >  fs/nfs_common/localio_trace.c             |  10 +
> > >  fs/nfs_common/localio_trace.h             |  56 +++++
> > >  fs/nfs_common/nfslocalio.c                | 250 +++++++++++++++++-----
> > >  fs/nfsd/filecache.c                       |  20 +-
> > >  fs/nfsd/localio.c                         |   9 +-
> > >  fs/nfsd/netns.h                           |  12 +-
> > >  fs/nfsd/nfsctl.c                          |   6 +-
> > >  fs/nfsd/nfssvc.c                          |  40 ++--
> > >  include/linux/nfs_fs.h                    |  22 +-
> > >  include/linux/nfs_fs_sb.h                 |   3 +-
> > >  include/linux/nfs_xdr.h                   |   1 +
> > >  include/linux/nfslocalio.h                |  48 +++--
> > >  26 files changed, 674 insertions(+), 268 deletions(-)
> > >  create mode 100644 fs/nfs_common/localio_trace.c
> > >  create mode 100644 fs/nfs_common/localio_trace.h
> > > 
> > 
> > I went through the set and it looks mostly sane to me. The one concern
> > I have is that you have the client set up to start caching nfsd files
> > before there is a mechanism to call it and ask them to return them. You
> > might see some weird behavior there on a bisect, but it looks like it
> > all gets resolved in the end.
> 
> Yeah, couldn't see a better way to atomically pivot to the new disable
> functionality without it needing to be a large muddled patch.
> 
> Shouldn't be bad even if someone did bisect, its only the server being
> restarted during LOCALIO that could see issues (unlikely thing for
> someone to be testing for specifically with a bisect).
> 
> > How do you intend for this to go in? Since most of this is client side,
> > will this be going in via Trond/Anna's tree?
> 
> Yes, likely easiest to have it go through Trond/Anna's tree.  Trond
> did have it in his testing tree, maybe your Reviewed-by helps it all
> land.
> 
> > You can add:
> > 
> > Reviewed-by: Jeff Layton <jlayton@kernel.org>
> 
> Thanks,
> Mike
> 

Hi all,

These LOCALIO changes didn't land for 6.13 merge, please advise on if
we might get these changes staged for 6.14 now-ish.

Trond and/or Anna, do you feel comfortable picking this series up
(nfsd cachnges too) or would you like to see any changes before that
is possible?

Thanks,
Mike