[for-6.13 PATCH v2 00/15] nfs/nfsd: fixes and improvements for LOCALIO

Mike Snitzer
2024-11-14T03:59:53Z

Hi,

This v2 is rebased ontop of Chuck's nfsd-next and Trond's nfs-next,
see: https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next

(Neil, ~3 patches from v1 that you Reviewed-by were already staged by
Trond, without your Reviewed-by, because they were in the nfs patch
queue carried over from just after the 6.12 merge window closed).

Changes since v1:
- added Reviewed-by tags and Fixes where provided/suggested
- removed unnecessary use of RCU read-side critical section in
nfs_server_uuid_is_local
- switched to using RCU_INIT_POINTER to set nfs_uuid->net to NULL
- updated Documentation/filesystems/nfs/localio.rst to reflect the
percpu_ref change from nfsd_serv to nfsd_net. Also discuss O_DIRECT
relative to LOCALIO and document the nfs module param (Chuck, I do
think we need it, otherwise O_DIRECT regressions are possible).
- removed redundant code and simplify LOCALIO enablement, the
nfs_client struct is still used in nfs_common/nfslocalio.c but it is
very limited (clp->cl_uuid and the established tracepoints).
- eliminated repeat INIT_WORK in nfs_local_probe_async
- kept the NFS v3 LOCALIO reconnect approach but eliminated the use of
a mutex and also increased the throttling from every 256 to 512
IOs. Updated patch header to expalin that more work is needed.

I think the final NFSv3 reconnect patch works well for now, but I am
completely on board with making it work well for the scenarios that
were discussed. I just didn't have time to perfect the approach. So
I'll defer to Trond, Anna and others on whether or not its best to
just drop patch 15 for now -- so continue to let LOCALIO get disabled,
if the server is restarted, and require manual LOCALIO recovery (via
remount).

Thanks,
Mike

Mike Snitzer (15):
nfs_common: must not hold RCU while calling nfsd_file_put_local
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 | 78 +++----
fs/nfs/client.c | 4 +-
fs/nfs/direct.c | 1 +
fs/nfs/flexfilelayout/flexfilelayout.c | 29 ++-
fs/nfs/flexfilelayout/flexfilelayout.h | 1 +
fs/nfs/inode.c | 3 +
fs/nfs/internal.h | 14 +-
fs/nfs/localio.c | 250 ++++++++++++++++-----
fs/nfs/nfs3proc.c | 32 ++-
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 | 258 +++++++++++++++++-----
fs/nfsd/filecache.c | 32 ++-
fs/nfsd/filecache.h | 2 +-
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 | 2 +-
include/linux/nfs_xdr.h | 1 +
include/linux/nfslocalio.h | 64 ++++--
27 files changed, 688 insertions(+), 282 deletions(-)
create mode 100644 fs/nfs_common/localio_trace.c
create mode 100644 fs/nfs_common/localio_trace.h

--
2.44.0