nfsd: add netlink upcall for the svc_export cache

Add netlink-based cache upcall support for the svc_export (nfsd.export)
cache to Documentation/netlink/specs/nfsd.yaml and regenerate the
resulting files.

Implement nfsd_cache_notify() which sends a NFSD_CMD_CACHE_NOTIFY
multicast event to the "exportd" group, carrying the cache type so
userspace knows which cache has pending requests.

Implement nfsd_nl_svc_export_get_reqs_dumpit() which snapshots
pending svc_export cache requests and sends each entry's seqno,
client name, and path over netlink.

Implement nfsd_nl_svc_export_set_reqs_doit() which parses svc_export
cache responses from userspace (client, path, expiry, flags, anon
uid/gid, fslocations, uuid, secinfo, xprtsec, fsid, or negative
flag) and updates the cache via svc_export_lookup() /
svc_export_update().

Wire up the svc_export_notify() callback in svc_export_cache_template
so cache misses trigger NFSD_CMD_CACHE_NOTIFY multicast events with
NFSD_CACHE_TYPE_SVC_EXPORT.

Note that the export-flags and xprtsec-mode enums are organized to match
their counterparts in include/uapi/linux/nfsd/export.h. The intent is
that future export options will only be added to the netlink headers,
which should eliminate the need to keep so much in sync.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
Jeff Layton 2026-03-25 10:40:31 -04:00 • committed by Chuck Lever
commit 912fc994b9
9 changed files with 815 additions and 16 deletions