kernel/git/stable/linux.git/Documentation/sunrpc, branch master

nfsd: add support to CB_NOTIFY for dir attribute changes

2026-08-10T13:54:35+00:00

If the client requested dir attribute change notifications, send those alongside any set of add/remove/rename events. Note that the server will still recall the delegation on a SETATTR, so these are only sent for changes to child dirents. Signed-off-by: Jeff Layton [ cel: folded "nfsd: fix CB_NOTIFY workqueue loop when queue overflows" ] [ cel: folded "nfsd: recall deleg if a requested dir attr change can't be encoded" ] Link: https://patch.msgid.link/20260616-dir-deleg-v7-20-6cbc7eac0ade@kernel.org Signed-off-by: Chuck Lever

nfsd: add notification handlers for dir events

2026-08-10T13:54:35+00:00

Add the necessary parts to accept a fsnotify callback for directory change event and create a CB_NOTIFY request for it. When a dir nfsd_file is created set a handle_event callback to handle the notification. Use that to allocate a nfsd_notify_event object and then hand off a reference to each delegation's CB_NOTIFY. If anything fails along the way, recall any affected delegations. Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260616-dir-deleg-v7-10-6cbc7eac0ade@kernel.org Signed-off-by: Chuck Lever

nfsd: add callback encoding and decoding linkages for CB_NOTIFY

2026-08-10T13:54:35+00:00

Add routines for encoding and decoding CB_NOTIFY messages. These call into the code generated by xdrgen to do the actual encoding and decoding. For now, the encoder is a stub. Later patches will flesh out the payload encoding. Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260616-dir-deleg-v7-7-6cbc7eac0ade@kernel.org Signed-off-by: Chuck Lever

nfs_common: add new NOTIFY4_* flags proposed in RFC8881bis

2026-08-10T13:54:35+00:00

RFC8881bis adds some new flags to GET_DIR_DELEGATION that later patches will consume. In particular, Linux nfsd can't easily provide info about directory cookies and ordering. The new flags allow it to omit that information. There is some risk here -- RFC8881bis is still a working group document, and has been for years. The changes to directory delegations have been stable for the last year or so however, so the hope is that those parts won't change (much). Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260616-dir-deleg-v7-3-6cbc7eac0ade@kernel.org Signed-off-by: Chuck Lever

nfsd: add protocol support for CB_NOTIFY

2026-08-10T13:54:35+00:00

Add the necessary bits to nfs4_1.x and remove the duplicate definitions from nfs4.h and the uapi nfs4 header. Regenerate the xdr files. Note that regenerating these files caused conflicts with the definitions of NFS4_VERIFIER_SIZE and NFS4_FHSIZE in include/uapi/linux/nfs4.h. These constants are defined by the RFC, and are not part of the kernel API. They have been removed. Userspace consumers who require those constants should plan to get them from more authoritative sources. The nfsstat4 enum defined in the .x is fed to the xdrgen-generated wire encoder and decoder, which treat every enumerated value as legal on the wire. Do not carry the NFS4ERR_FIRST_FREE sentinel (which is not a protocol error code) into the .x; keeping it would make 10097 a value that could leak onto the wire. Instead base nfsd's internal error codes (NFSERR_EOF and friends) at an impossible nfsstat4 value, as lockd does for its nlm__int__* status codes. Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260616-dir-deleg-v7-2-6cbc7eac0ade@kernel.org Signed-off-by: Chuck Lever

Documentation: Add the RPC language description of NLM version 3

2026-06-09T20:32:59+00:00

In order to generate source code to encode and decode NLMv3 protocol elements, include a copy of the RPC language description of NLMv3 for xdrgen to process. The language description is derived from the Open Group's XNFS specification: https://pubs.opengroup.org/onlinepubs/9629799/chap10.htm#tagcjh_11_03 The C code committed here was generated from the new nlm3.x file using tools/net/sunrpc/xdrgen/xdrgen. The goals of replacing hand-written XDR functions with ones that are tool-generated are to improve memory safety and make XDR encoding and decoding less brittle to maintain. Parts of the NFSv4 protocol are still being extended actively. Tool-generated XDR code reduces the time it takes to get a working implementation of new protocol elements. The xdrgen utility derives both the type definitions and the encode/decode functions directly from protocol specifications, using names and symbols familiar to anyone who knows those specs. Unlike hand-written code that can inadvertently diverge from the specification, xdrgen guarantees that the generated code matches the specification exactly. We would eventually like xdrgen to generate Rust code as well, making the conversion of the kernel's NFS stacks to use Rust just a little easier for us. Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

Documentation: Add the RPC language description of NLM version 4

2026-03-30T01:25:09+00:00

In order to generate source code to encode and decode NLMv4 protocol elements, include a copy of the RPC language description of NLMv4 for xdrgen to process. The language description is an amalgam of RFC 1813 and the Open Group's XNFS specification: https://pubs.opengroup.org/onlinepubs/9629799/chap10.htm The C code committed here was generated from the new nlm4.x file using tools/net/sunrpc/xdrgen/xdrgen. The goals of replacing hand-written XDR functions with ones that are tool-generated are to improve memory safety and make XDR encoding and decoding less brittle to maintain. The xdrgen utility derives both the type definitions and the encode/decode functions directly from protocol specifications, using names and symbols familiar to anyone who knows those specs. Unlike hand-written code that can inadvertently diverge from the specification, xdrgen guarantees that the generated code matches the specification exactly. We would eventually like xdrgen to generate Rust code as well, making the conversion of the kernel's NFS stacks to use Rust just a little easier for us. Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

Add RPC language definition of NFSv4 POSIX ACL extension

2026-01-29T14:48:33+00:00

The language definition was extracted from the new draft-ietf-nfsv4-posix-acls specification. This ensures good constant and type name alignment between the spec and the Linux kernel source code, and brings in some basic XDR utilities for handling NFSv4 POSIX draft ACLs. Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

nfsd: rename NFS4_SHARE_WANT_* constants to OPEN4_SHARE_ACCESS_WANT_*

2025-01-21T20:30:01+00:00

Add the OPEN4_SHARE_ACCESS_WANT constants from the nfs4.1 and delstid draft into the nfs4_1.x file, and regenerate the headers and source files. Do a mass renaming of NFS4_SHARE_WANT_* to OPEN4_SHARE_ACCESS_WANT_* in the nfsd directory. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

nfsd: switch to autogenerated definitions for open_delegation_type4

2025-01-21T20:30:01+00:00

Rename the enum with the same name in include/linux/nfs4.h, add the proper enum to nfs4_1.x and regenerate the headers and source files. Do a mass rename of all NFS4_OPEN_DELEGATE_* to OPEN_DELEGATE_* in the nfsd directory. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever