Pull nfsd updates from Chuck Lever:
 "Mike Snitzer has prototyped a mechanism for disabling I/O caching in
  NFSD. This is introduced in v6.18 as an experimental feature. This
  enables scaling NFSD in /both/ directions:

   - NFS service can be supported on systems with small memory
     footprints, such as low-cost cloud instances

   - Large NFS workloads will be less likely to force the eviction of
     server-local activity, helping it avoid thrashing

  Jeff Layton contributed a number of fixes to the new attribute
  delegation implementation (based on a pending Internet RFC) that we
  hope will make attribute delegation reliable enough to enable by
  default, as it is on the Linux NFS client.

  The remaining patches in this pull request are clean-ups and minor
  optimizations. Many thanks to the contributors, reviewers, testers,
  and bug reporters who participated during the v6.18 NFSD development
  cycle"

* tag 'nfsd-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (42 commits)
  nfsd: discard nfserr_dropit
  SUNRPC: Make RPCSEC_GSS_KRB5 select CRYPTO instead of depending on it
  NFSD: Add io_cache_{read,write} controls to debugfs
  NFSD: Do the grace period check in ->proc_layoutget
  nfsd: delete unnecessary NULL check in __fh_verify()
  NFSD: Allow layoutcommit during grace period
  NFSD: Disallow layoutget during grace period
  sunrpc: fix "occurence"->"occurrence"
  nfsd: Don't force CRYPTO_LIB_SHA256 to be built-in
  nfsd: nfserr_jukebox in nlm_fopen should lead to a retry
  NFSD: Reduce DRC bucket size
  NFSD: Delay adding new entries to LRU
  SUNRPC: Move the svc_rpcb_cleanup() call sites
  NFS: Remove rpcbind cleanup for NFSv4.0 callback
  nfsd: unregister with rpcbind when deleting a transport
  NFSD: Drop redundant conversion to bool
  sunrpc: eliminate return pointer in svc_tcp_sendmsg()
  sunrpc: fix pr_notice in svc_tcp_sendto() to show correct length
  nfsd: decouple the xprtsec policy check from check_nfsd_access()
  NFSD: Fix destination buffer size in nfsd4_ssc_setup_dul()
  ...

Since the opaque is fixed in size, the caller already knows how many
bytes were decoded, on success. Thus, xdr_stream_decode_opaque_fixed()
doesn't need to return that value. And, xdr_stream_decode_u32 and _u64
both return zero on success.

This patch simplifies the caller's error checking to avoid potential
integer promotion issues.

Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Add a netlink family for PSP and allow drivers to register support.

The "PSP device" is its own object. This allows us to perform more
flexible reference counting / lifetime control than if PSP information
was part of net_device. In the future we should also be able
to "delegate" PSP access to software devices, such as *vlan, veth
or netkit more easily.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250917000954.859376-3-daniel.zahka@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The ethtool FEC histogram series run into a build issue with
type: uint + multi-attr: True. Auto scalars use 64b types,
we need to convert them explicitly when rendering the types.

No current spec needs this, and the ethtool FEC histogram
doesn't need this either any more, so not posting as a fix.

Link: https://lore.kernel.org/8f52c5b8-bd8a-44b8-812c-4f30d50f63ff@redhat.com
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The attribute WGALLOWEDIP_A_IPADDR can contain either an IPv4
or an IPv6 address depending on WGALLOWEDIP_A_FAMILY, however
in practice it is enough to look at the attribute length.

This patch implements an ipv4-or-v6 display hint, that can
deal with this kind of attribute.

It only implements this display hint for genetlink-legacy, it
can be added to other protocol variants if needed, but we don't
want to encourage it's use.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250915144301.725949-12-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This patch adds support for decoding hex input, so
that binary attributes can be read through --json.

Example (using future wireguard.yaml):
 $ sudo ./tools/net/ynl/pyynl/cli.py --family wireguard \
   --do set-device --json '{"ifindex":3,
     "private-key":"2a ae 6c 35 c9 4f cf <... to 32 bytes>"}'

In order to somewhat mirror what is done in _formatted_string(),
then for non-binary attributes attempt to convert it to an int.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250915144301.725949-11-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This patch adds support for encoding indexed-array
attributes with sub-type nest in pyynl.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250915144301.725949-10-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This patch moves nest packing into a helper function,
that can also be used for packing indexed arrays.

No behavioural changes intended.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250915144301.725949-9-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Since TypeArrayNest can now be used with many other sub-types
than nest, then rename it to TypeIndexedArray, to reduce
confusion.

This patch continues the rename, that was started in commit
aa6485d813ad ("ynl: rename array-nest to indexed-array"),
when the YNL type was renamed.

In order to get rid of all references to the old naming,
within ynl, then renaming some variables in _multi_parse().

This is a trivial patch with no behavioural changes intended.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20250915144301.725949-8-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In nested arrays don't require that the intermediate attribute
type should be a valid attribute type, it might just be zero
or an incrementing index, it is often not even used.

See include/net/netlink.h about NLA_NESTED_ARRAY:
> The difference to NLA_NESTED is the structure:
> NLA_NESTED has the nested attributes directly inside
> while an array has the nested attributes at another
> level down and the attribute types directly in the
> nesting don't matter.

Example based on include/uapi/linux/wireguard.h:
 > WGDEVICE_A_PEERS: NLA_NESTED
 >   0: NLA_NESTED
 >     WGPEER_A_PUBLIC_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
 >     [..]
 >   0: NLA_NESTED
 >     ...
 >   ...

Previous the check required that the nested type was valid
in the parent attribute set, which in this case resolves to
WGDEVICE_A_UNSPEC, which is YNL_PT_REJECT, and it took the
early exit and returned YNL_PARSE_CB_ERROR.

This patch renames the old nl_attr_validate() to
__nl_attr_validate(), and creates a new inline function
nl_attr_validate() to mimic the old one.

The new __nl_attr_validate() takes the attribute type as an
argument, so we can use it to validate attributes of a
nested attribute, in the context of the parents attribute
type, which in the above case is generated as:
[WGDEVICE_A_PEERS] = {
  .name = "peers",
  .type = YNL_PT_NEST,
  .nest = &wireguard_wgpeer_nest,
},

__nl_attr_validate() only checks if the attribute length
is plausible for a given attribute type, so the .nest in
the above example is not used.

As the new inline function needs to be defined after
ynl_attr_type(), then the definitions are moved down,
so we avoid a forward declaration of ynl_attr_type().

Some other examples are NL80211_BAND_ATTR_FREQS (nest) and
NL80211_ATTR_SUPPORTED_COMMANDS (u32) both in nl80211-user.c
$ make -C tools/net/ynl/generated nl80211-user.c

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20250915144301.725949-7-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>