kernel.git/Documentation/filesystems/nfs, branch linux-rolling-stable

NFSD: nfsd-io-modes: Separate lists

2025-12-03T14:05:14Z

Sphinx reports htmldocs indentation warnings: Documentation/filesystems/nfs/nfsd-io-modes.rst:58: ERROR: Unexpected indentation. [docutils] Documentation/filesystems/nfs/nfsd-io-modes.rst:59: WARNING: Block quote ends without a blank line; unexpected unindent. [docutils] These caused the lists to be shown as long running paragraphs merged with their previous paragraphs. Fix these by separating the lists with a blank line. Fixes: fa8d4e6784d1b6 ("NFSD: add Documentation/filesystems/nfs/nfsd-io-modes.rst") Reported-by: Stephen Rothwell Closes: https://lore.kernel.org/linux-next/20251202152506.7a2d2d41@canb.auug.org.au/ Signed-off-by: Bagas Sanjaya Reviewed-by: Jeff Layton Reviewed-by: Randy Dunlap Tested-by: Randy Dunlap Signed-off-by: Chuck Lever

NFSD: nfsd-io-modes: Wrap shell snippets in literal code blocks

2025-12-03T14:05:14Z

Sphinx reports htmldocs indentation warnings: Documentation/filesystems/nfs/nfsd-io-modes.rst:29: ERROR: Unexpected indentation. [docutils] Documentation/filesystems/nfs/nfsd-io-modes.rst:34: ERROR: Unexpected indentation. [docutils] Fix these by wrapping shell snippets in literal code blocks. Fixes: fa8d4e6784d1b6 ("NFSD: add Documentation/filesystems/nfs/nfsd-io-modes.rst") Reported-by: Stephen Rothwell Closes: https://lore.kernel.org/linux-next/20251202152506.7a2d2d41@canb.auug.org.au/ Signed-off-by: Bagas Sanjaya Reviewed-by: Jeff Layton Reviewed-by: Randy Dunlap Tested-by: Randy Dunlap Signed-off-by: Chuck Lever

NFSD: Add toctree entry for NFSD IO modes docs

2025-12-03T14:05:14Z

Commit fa8d4e6784d1b6 ("NFSD: add Documentation/filesystems/nfs/nfsd-io-modes.rst") adds documentation for NFSD I/O modes, but it forgets to add toctree entry for it. Hence, Sphinx reports: Documentation/filesystems/nfs/nfsd-io-modes.rst: WARNING: document isn't included in any toctree [toc.not_included] Add the entry. Fixes: fa8d4e6784d1b6 ("NFSD: add Documentation/filesystems/nfs/nfsd-io-modes.rst") Reported-by: Stephen Rothwell Closes: https://lore.kernel.org/linux-next/20251202152506.7a2d2d41@canb.auug.org.au/ Signed-off-by: Bagas Sanjaya Reviewed-by: Jeff Layton Reviewed-by: Randy Dunlap Tested-by: Randy Dunlap Signed-off-by: Chuck Lever

NFSD: add Documentation/filesystems/nfs/nfsd-io-modes.rst

2025-12-01T14:57:10Z

This document details the NFSD IO modes that are configurable using NFSD's experimental debugfs interfaces: /sys/kernel/debug/nfsd/io_cache_read /sys/kernel/debug/nfsd/io_cache_write This document will evolve as NFSD's interfaces do (e.g. if/when NFSD's debugfs interfaces are replaced with per-export controls). Future updates will provide more specific guidance and howto information to help others use and evaluate NFSD's IO modes: BUFFERED, DONTCACHE and DIRECT. Signed-off-by: Mike Snitzer Signed-off-by: Chuck Lever

NFS: nfsd-maintainer-entry-profile: Inline function name prefixes

2025-11-17T13:46:06Z

Sphinx reports htmldocs warnings: Documentation/filesystems/nfs/nfsd-maintainer-entry-profile.rst:185: ERROR: Unknown target name: "nfsd". [docutils] Documentation/filesystems/nfs/nfsd-maintainer-entry-profile.rst:188: ERROR: Unknown target name: "nfsdn". [docutils] Documentation/filesystems/nfs/nfsd-maintainer-entry-profile.rst:192: ERROR: Unknown target name: "nfsd4m". [docutils] These are due to Sphinx confusing function name prefixes for external link syntax. Fix the warnings by inlining the prefixes. Fixes: 3a1ce35030e1e0 ("NFSD: Add a subsystem policy document") Reported-by: Stephen Rothwell Closes: https://lore.kernel.org/linux-next/20251117174218.29365f30@canb.auug.org.au/ Signed-off-by: Bagas Sanjaya Signed-off-by: Chuck Lever

NFSD: Add a subsystem policy document

2025-11-16T23:20:11Z

Steer contributors to NFSD's patchworks instance, list our patch submission preferences, and more. The new document is based on the existing netdev and xfs subsystem policy documents. This is an attempt to add transparency to the process of accepting contributions to NFSD and getting them merged upstream. Suggested-by: "Darrick J. Wong" Cc: Luis Chamberlain Cc: Martin K. Petersen Reviewed-by: NeilBrown [ cel: Hand-edits to address review comments ] Signed-off-by: Chuck Lever

nfsd: disallow file locking and delegations for NFSv4 reexport

2025-03-10T13:11:08Z

We do not and cannot support file locking with NFS reexport over NFSv4.x for the same reason we don't do it for NFSv3: NFS reexport server reboot cannot allow clients to recover locks because the source NFS server has not rebooted, and so it is not in grace. Since the source NFS server is not in grace, it cannot offer any guarantees that the file won't have been changed between the locks getting lost and any attempt to recover/reclaim them. The same applies to delegations and any associated locks, so disallow them too. Clients are no longer allowed to get file locks or delegations from a reexport server, any attempts will fail with operation not supported. Update the "Reboot recovery" section accordingly in Documentation/filesystems/nfs/reexport.rst Signed-off-by: Mike Snitzer Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

nfs: probe for LOCALIO when v3 client reconnects to server

2025-01-14T22:05:10Z

Re-enabling NFSv3 LOCALIO is made more complex (than NFSv4) because v3 is stateless. As such, the hueristic used to identify a LOCALIO probe point is more adhoc by nature: if/when NFSv3 client IO begins to complete again in terms of normal RPC-based NFSv3 server IO, attempt nfs_local_probe_async(). Care is taken to throttle the frequency of nfs_local_probe_async(), otherwise there could be a flood of repeat calls to nfs_local_probe_async(). The throttle is admin controlled using a new module parameter for nfsv3, e.g.: echo 512 > /sys/module/nfsv3/parameters/nfs3_localio_probe_throttle Probe for NFSv3 LOCALIO every N IO requests (512 in this case). Must be power-of-2, defaults to 0 (probing disabled). On systems that expect to use LOCALIO with NFSv3 the admin should configure the 'nfs3_localio_probe_throttle' module parameter. This commit backfills module parameter documentation in localio.rst Signed-off-by: Mike Snitzer Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker

nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_

2025-01-14T22:05:07Z

Also update Documentation/filesystems/nfs/localio.rst accordingly and reduce the technical documentation debt that was previously captured in that document. Signed-off-by: Mike Snitzer Reviewed-by: Jeff Layton Acked-by: Chuck Lever Signed-off-by: Anna Schumaker

nfs/localio: add direct IO enablement with sync and async IO support

2025-01-14T22:04:02Z

This commit simply adds the required O_DIRECT plumbing. It doesn't address the fact that NFS doesn't ensure all writes are page aligned (nor device logical block size aligned as required by O_DIRECT). Because NFS will read-modify-write for IO that isn't aligned, LOCALIO will not use O_DIRECT semantics by default if/when an application requests the use of O_DIRECT. Allow the use of O_DIRECT semantics by: 1: Adding a flag to the nfs_pgio_header struct to allow the NFS O_DIRECT layer to signal that O_DIRECT was used by the application 2: Adding a 'localio_O_DIRECT_semantics' NFS module parameter that when enabled will cause LOCALIO to use O_DIRECT semantics (this may cause IO to fail if applications do not properly align their IO). This commit is derived from code developed by Weston Andros Adamson. Signed-off-by: Mike Snitzer Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker