linux.git/include/linux/sunrpc/svc.h, branch v7.1

Merge tag 'nfsd-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

2026-04-20T17:44:02+00:00

Pull nfsd updates from Chuck Lever:

 - filehandle signing to defend against filehandle-guessing attacks
   (Benjamin Coddington)

   The server now appends a SipHash-2-4 MAC to each filehandle when
   the new "sign_fh" export option is enabled. NFSD then verifies
   filehandles received from clients against the expected MAC;
   mismatches return NFS error STALE

 - convert the entire NLMv4 server-side XDR layer from hand-written C to
   xdrgen-generated code, spanning roughly thirty patches (Chuck Lever)

   XDR functions are generally boilerplate code and are easy to get
   wrong. The goals of this conversion are improved memory safety, lower
   maintenance burden, and groundwork for eventual Rust code generation
   for these functions.

 - improve pNFS block/SCSI layout robustness with two related changes
   (Dai Ngo)

   SCSI persistent reservation fencing is now tracked per client and
   per device via an xarray, to avoid both redundant preempt operations
   on devices already fenced and a potential NFSD deadlock when all nfsd
   threads are waiting for a layout return.

 - scalability and infrastructure improvements

   Sincere thanks to all contributors, reviewers, testers, and bug
   reporters who participated in the v7.1 NFSD development cycle.

* tag 'nfsd-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (83 commits)
  NFSD: Docs: clean up pnfs server timeout docs
  nfsd: fix comment typo in nfsxdr
  nfsd: fix comment typo in nfs3xdr
  NFSD: convert callback RPC program to per-net namespace
  NFSD: use per-operation statidx for callback procedures
  svcrdma: Use contiguous pages for RDMA Read sink buffers
  SUNRPC: Add svc_rqst_page_release() helper
  SUNRPC: xdr.h: fix all kernel-doc warnings
  svcrdma: Factor out WR chain linking into helper
  svcrdma: Add Write chunk WRs to the RPC's Send WR chain
  svcrdma: Clean up use of rdma->sc_pd->device
  svcrdma: Clean up use of rdma->sc_pd->device in Receive paths
  svcrdma: Add fair queuing for Send Queue access
  SUNRPC: Optimize rq_respages allocation in svc_alloc_arg
  SUNRPC: Track consumed rq_pages entries
  svcrdma: preserve rq_next_page in svc_rdma_save_io_pages
  SUNRPC: Handle NULL entries in svc_rqst_release_pages
  SUNRPC: Allocate a separate Reply page array
  SUNRPC: Tighten bounds checking in svc_rqst_replace_page
  NFSD: Sign filehandles
  ...

folio_batch: rename pagevec.h to folio_batch.h

2026-04-05T20:53:07+00:00

struct pagevec was removed in commit 1e0877d58b1e ("mm: remove struct
pagevec").  Rename include/linux/pagevec.h to reflect reality and update
includes tree-wide.  Add the new filename to MAINTAINERS explicitly, as it
no longer matches the "include/linux/page[-_]*" pattern in MEMORY
MANAGEMENT - CORE.

Link: https://lkml.kernel.org/r/20260225-pagevec_cleanup-v2-3-716868cc2d11@columbia.edu
Signed-off-by: Tal Zussman 
Acked-by: David Hildenbrand (Arm) 
Reviewed-by: Jan Kara 
Acked-by: Zi Yan 
Reviewed-by: Lorenzo Stoakes (Oracle) 
Cc: Chris Li 
Cc: Christian Brauner 
Cc: Matthew Wilcox (Oracle) 
Signed-off-by: Andrew Morton

SUNRPC: Add svc_rqst_page_release() helper

2026-04-03T13:26:17+00:00

svc_rqst_replace_page() releases displaced pages through a
per-rqst folio batch, but exposes the add-or-flush sequence
directly. svc_tcp_restore_pages() releases displaced pages
individually with put_page().

Introduce svc_rqst_page_release() to encapsulate the
batched release mechanism. Convert svc_rqst_replace_page()
and svc_tcp_restore_pages() to use it. The latter now
benefits from the same batched release that
svc_rqst_replace_page() already uses.

Reviewed-by: Christoph Hellwig 
Signed-off-by: Chuck Lever

SUNRPC: Optimize rq_respages allocation in svc_alloc_arg

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

svc_alloc_arg() invokes alloc_pages_bulk() with the full rq_maxpages
count (~259 for 1MB messages) for the rq_respages array, causing a
full-array scan despite most slots holding valid pages.

svc_rqst_release_pages() NULLs only the range

  [rq_respages, rq_next_page)

after each RPC, so only that range contains NULL entries. Limit the
rq_respages fill in svc_alloc_arg() to that range instead of
scanning the full array.

svc_init_buffer() initializes rq_next_page to span the entire
rq_respages array, so the first svc_alloc_arg() call fills all
slots.

Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever

SUNRPC: Track consumed rq_pages entries

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

The rq_pages array holds pages allocated for incoming RPC requests.
Two transport receive paths NULL entries in rq_pages to prevent
svc_rqst_release_pages() from freeing pages that the transport has
taken ownership of:

- svc_tcp_save_pages() moves partial request data pages to
  svsk->sk_pages during multi-fragment TCP reassembly.

- svc_rdma_clear_rqst_pages() moves request data pages to
  head->rc_pages because they are targets of active RDMA Read WRs.

A new rq_pages_nfree field in struct svc_rqst records how many
entries were NULLed. svc_alloc_arg() uses it to refill only those
entries rather than scanning the full rq_pages array. In steady
state, the transport NULLs a handful of entries per RPC, so the
allocator visits only those entries instead of the full ~259 slots
(for 1MB messages).

Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever

SUNRPC: Allocate a separate Reply page array

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

struct svc_rqst uses a single dynamically-allocated page array
(rq_pages) for both the incoming RPC Call message and the outgoing
RPC Reply message. rq_respages is a sliding pointer into rq_pages
that each transport receive path must compute based on how many
pages the Call consumed. This boundary tracking is a source of
confusion and bugs, and prevents an RPC transaction from having
both a large Call and a large Reply simultaneously.

Allocate rq_respages as its own page array, eliminating the boundary
arithmetic. This decouples Call and Reply buffer lifetimes,
following the precedent set by rq_bvec (a separate dynamically-
allocated array for I/O vectors).

Each svc_rqst now pins twice as many pages as before. For a server
running 16 threads with a 1MB maximum payload, the additional cost
is roughly 16MB of pinned memory. The new dynamic svc thread count
facility keeps this overhead minimal on an idle server. A subsequent
patch in this series limits per-request repopulation to only the
pages released during the previous RPC, avoiding a full-array scan
on each call to svc_alloc_arg().

Note: We've considered several alternatives to maintaining a full
second array. Each alternative reintroduces either boundary logic
complexity or I/O-path allocation pressure.

rq_next_page is initialized in svc_alloc_arg() and svc_process()
during Reply construction, and in svc_rdma_recvfrom() as a
precaution on error paths. Transport receive paths no longer compute
it from the Call size.

Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever

nfsd/sunrpc: move rq_cachetype into struct nfsd_thread_local_info

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

The svc_rqst->rq_cachetype field is only accessed by nfsd. Move it
into the nfsd_thread_local_info instead.

Signed-off-by: Jeff Layton 
Reviewed-by: Benjamin Coddington 
Signed-off-by: Chuck Lever

nfsd/sunrpc: add svc_rqst->rq_private pointer and remove rq_lease_breaker

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

rq_lease_breaker has always been a NFSv4 specific layering violation in
svc_rqst. The reason it's there though is that we need a place that is
thread-local, and accessible from the svc_rqst pointer.

Add a new rq_private pointer to struct svc_rqst. This is intended for
use by the threads that are handling the service. sunrpc code doesn't
touch it.

In nfsd, define a new struct nfsd_thread_local_info. nfsd declares one
of these on the stack and puts a pointer to it in rq_private.

Add a new ntli_lease_breaker field to the new struct and convert all of
the places that access rq_lease_breaker to use the new field instead.

Signed-off-by: Jeff Layton 
Reviewed-by: Benjamin Coddington 
Signed-off-by: Chuck Lever

sunrpc: allow svc_recv() to return -ETIMEDOUT and -EBUSY

2026-01-28T15:15:42+00:00

To dynamically adjust the thread count, nfsd requires some information
about how busy things are.

Change svc_recv() to take a timeout value, and then allow the wait for
work to time out if it's set. If a timeout is not defined, then the
schedule will be set to MAX_SCHEDULE_TIMEOUT. If the task waits for the
full timeout, then have it return -ETIMEDOUT to the caller.

If it wakes up, finds that there is more work and that no threads are
available, then attempt to set SP_TASK_STARTING. If wasn't already set,
have the task return -EBUSY to cue to the caller that the service could
use more threads.

Signed-off-by: Jeff Layton 
Signed-off-by: Chuck Lever

sunrpc: split new thread creation into a separate function

2026-01-28T15:15:42+00:00

Break out the part of svc_start_kthreads() that creates a thread into
svc_new_thread(), as a new exported helper function.

Signed-off-by: Jeff Layton 
Signed-off-by: Chuck Lever