Commit Graph

354 Commits

Author SHA1 Message Date
Chuck Lever
4e2866b2ba SUNRPC: Add svc_rqst_page_release() helper
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 <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-04-03 09:26:17 -04:00
Chuck Lever
d7f3efd9ff SUNRPC: Optimize rq_respages allocation in svc_alloc_arg
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 <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-03-29 21:25:09 -04:00
Chuck Lever
7ed7504287 SUNRPC: Track consumed rq_pages entries
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 <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-03-29 21:25:09 -04:00
Chuck Lever
22cc2ba5c2 SUNRPC: Handle NULL entries in svc_rqst_release_pages
svc_rqst_release_pages() releases response pages between rq_respages
and rq_next_page. It currently passes the entire range to
release_pages(), which does not expect NULL entries.

A subsequent patch preserves the rq_next_page pointer in
svc_rdma_save_io_pages() so that it accurately records how many
response pages were consumed. After that change, the range

  [rq_respages, rq_next_page)

can contain NULL entries where pages have already been transferred
to a send context.

Iterate through the range entry by entry, skipping NULLs, to handle
this case correctly.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-03-29 21:25:09 -04:00
Chuck Lever
ee66b9e3e1 SUNRPC: Allocate a separate Reply page array
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 <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-03-29 21:25:09 -04:00
Chuck Lever
46ca8dd244 SUNRPC: Tighten bounds checking in svc_rqst_replace_page
svc_rqst_replace_page() builds the Reply buffer by advancing
rq_next_page through the response page range. The bounds
check validates rq_next_page against the full rq_pages array,
but the valid range for rq_next_page is

  [rq_respages, rq_page_end].

Use those bounds instead.

This is correct today because rq_respages and rq_page_end
both point into rq_pages, and it prepares for a subsequent
change that separates the Reply page array from rq_pages.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-03-29 21:25:09 -04:00
Linus Torvalds
bf4afc53b7 Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Kees Cook
69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Jeff Layton
7f221b340d sunrpc: split new thread creation into a separate function
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 <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-01-28 10:15:42 -05:00
Jeff Layton
7ffc7ade2c sunrpc: introduce the concept of a minimum number of threads per pool
Add a new pool->sp_nrthrmin field to track the minimum number of threads
in a pool. Add min_threads parameters to both svc_set_num_threads() and
svc_set_pool_threads(). If min_threads is non-zero and less than the
max, svc_set_num_threads() will ensure that the number of running
threads is between the min and the max.

If the min is 0 or greater than the max, then it is ignored, and the
maximum number of threads will be started, and never spun down.

For now, the min_threads is always 0, but a later patch will pass the
proper value through from nfsd.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-01-28 10:15:42 -05:00
Jeff Layton
6cd60f4274 sunrpc: track the max number of requested threads in a pool
The kernel currently tracks the number of threads running in a pool in
the "sp_nrthreads" field. In the future, where threads are dynamically
spun up and down, it'll be necessary to keep track of the maximum number
of requested threads separately from the actual number running.

Add a pool->sp_nrthrmax parameter to track this. When userland changes
the number of threads in a pool, update that value accordingly.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-01-28 10:15:42 -05:00
Jeff Layton
2c01f0cf32 sunrpc: remove special handling of NULL pool from svc_start/stop_kthreads()
Now that svc_set_num_threads() handles distributing the threads among
the available pools, remove the special handling of a NULL pool pointer
from svc_start_kthreads() and svc_stop_kthreads().

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-01-28 10:15:42 -05:00
Jeff Layton
e344f87262 sunrpc: split svc_set_num_threads() into two functions
svc_set_num_threads() will set the number of running threads for a given
pool. If the pool argument is set to NULL however, it will distribute
the threads among all of the pools evenly.

These divergent codepaths complicate the move to dynamic threading.
Simplify the API by splitting these two cases into different helpers:

Add a new svc_set_pool_threads() function that sets the number of
threads in a single, given pool. Modify svc_set_num_threads() to
distribute the threads evenly between all of the pools and then call
svc_set_pool_threads() for each.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-01-28 10:15:42 -05:00
Linus Torvalds
81538c8e42 NFSD 6.18 Release Notes
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.
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Merge tag 'nfsd-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

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()
  ...
2025-10-06 13:22:21 -07:00
Anna Schumaker
d57e43b72b SUNRPC: Update svcxdr_init_decode() to call xdr_set_scratch_folio()
The only snag here is that __folio_alloc_node() doesn't handle
NUMA_NO_NODE, so I also need to update svc_pool_map_get_node() to return
numa_mem_id() instead. I arrived at this approach by  looking at what
other users of __folio_alloc_node() do for this case.

Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2025-09-23 13:29:50 -04:00
Chuck Lever
62c0c0e749 SUNRPC: Move the svc_rpcb_cleanup() call sites
Clean up: because svc_rpcb_cleanup() and svc_xprt_destroy_all()
are always invoked in pairs, we can deduplicate code by moving
the svc_rpcb_cleanup() call sites into svc_xprt_destroy_all().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2025-09-23 13:28:19 -04:00
Chuck Lever
d73d06dac6 SUNRPC: Move the svc_rpcb_cleanup() call sites
Clean up: because svc_rpcb_cleanup() and svc_xprt_destroy_all()
are always invoked in pairs, we can deduplicate code by moving
the svc_rpcb_cleanup() call sites into svc_xprt_destroy_all().

Tested-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-09-21 19:24:50 -04:00
Jeff Layton
d9adbb6e10 sunrpc: delay pc_release callback until after the reply is sent
The server-side sunrpc code currently calls pc_release before sending
the reply. Change svc_process and svc_process_bc to call pc_release
after sending the reply instead.

Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-09-21 19:24:50 -04:00
Jeff Layton
c8af9d3d4b sunrpc: reset rq_accept_statp when starting a new RPC
rq_accept_statp should point to the location of the accept_status in the
reply. This field is not reset between RPCs so if svc_authenticate or
pg_authenticate return SVC_DENIED without setting the pointer, it could
result in the status being written to the wrong place.

This pointer starts its lifetime as NULL. Reset it on every iteration
so we get consistent behavior if this happens.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-07-14 12:46:48 -04:00
Jeff Layton
6f0e26243b sunrpc: remove SVC_SYSERR
Nothing returns this error code.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-07-14 12:46:48 -04:00
Jeff Layton
d49afc90a3 sunrpc: fix handling of unknown auth status codes
In the case of an unknown error code from svc_authenticate or
pg_authenticate, return AUTH_ERROR with a status of AUTH_FAILED. Also
add the other auth_stat value from RFC 5531, and document all the status
codes.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-07-14 12:46:47 -04:00
Jeff Layton
f26c930530 sunrpc: new tracepoints around svc thread wakeups
Convert the svc_wake_up tracepoint into svc_pool_thread_event class.
Have it also record the pool id, and add new tracepoints for when the
thread is already running and for when there are no idle threads.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-07-14 12:46:38 -04:00
Jeff Layton
94d10a4dba sunrpc: handle SVC_GARBAGE during svc auth processing as auth error
tianshuo han reported a remotely-triggerable crash if the client sends a
kernel RPC server a specially crafted packet. If decoding the RPC reply
fails in such a way that SVC_GARBAGE is returned without setting the
rq_accept_statp pointer, then that pointer can be dereferenced and a
value stored there.

If it's the first time the thread has processed an RPC, then that
pointer will be set to NULL and the kernel will crash. In other cases,
it could create a memory scribble.

The server sunrpc code treats a SVC_GARBAGE return from svc_authenticate
or pg_authenticate as if it should send a GARBAGE_ARGS reply. RFC 5531
says that if authentication fails that the RPC should be rejected
instead with a status of AUTH_ERR.

Handle a SVC_GARBAGE return as an AUTH_ERROR, with a reason of
AUTH_BADCRED instead of returning GARBAGE_ARGS in that case. This
sidesteps the whole problem of touching the rpc_accept_statp pointer in
this situation and avoids the crash.

Cc: stable@kernel.org
Fixes: 29cd2927fb ("SUNRPC: Fix encoding of accepted but unsuccessful RPC replies")
Reported-by: tianshuo han <hantianshuo233@gmail.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-06-19 09:35:45 -04:00
Benjamin Coddington
8b3ac9faba SUNRPC: Cleanup/fix initial rq_pages allocation
While investigating some reports of memory-constrained NUMA machines
failing to mount v3 and v4.0 nfs mounts, we found that svc_init_buffer()
was not attempting to retry allocations from the bulk page allocator.
Typically, this results in a single page allocation being returned and
the mount attempt fails with -ENOMEM.  A retry would have allowed the mount
to succeed.

Additionally, it seems that the bulk allocation in svc_init_buffer() is
redundant because svc_alloc_arg() will perform the required allocation and
does the correct thing to retry the allocations.

The call to allocate memory in svc_alloc_arg() drops the preferred node
argument, but I expect we'll still allocate on the preferred node because
the allocation call happens within the svc thread context, which chooses
the node with memory closest to the current thread's execution.

This patch cleans out the bulk allocation in svc_init_buffer() to allow
svc_alloc_arg() to handle the allocation/retry logic for rq_pages.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Fixes: ed603bcf4f ("sunrpc: Replace the rq_pages array with dynamically-allocated memory")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-06-12 20:37:33 -04:00
Chuck Lever
b406c6b781 SUNRPC: Remove svc_fill_write_vector()
Clean up: This API is no longer used.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-05-15 16:16:25 -04:00
Chuck Lever
f2e597353d NFSD: De-duplicate the svc_fill_write_vector() call sites
All three call sites do the same thing.

I'm struggling with this a bit, however. struct xdr_buf is an XDR
layer object and unmarshaling a WRITE payload is clearly a task
intended to be done by the proc and xdr functions, not by VFS. This
feels vaguely like a layering violation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-05-15 16:16:23 -04:00
Chuck Lever
59cf734654 sunrpc: Replace the rq_bvec array with dynamically-allocated memory
As a step towards making NFSD's maximum rsize and wsize variable at
run-time, replace the fixed-size rq_bvec[] array in struct svc_rqst
with a chunk of dynamically-allocated memory.

The rq_bvec[] array contains enough bio_vecs to handle each page in
a maximum size RPC message.

On a system with 8-byte pointers and 4KB pages, pahole reports that
the rq_bvec[] array is 4144 bytes. This patch replaces that array
with a single 8-byte pointer field.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-05-15 16:16:23 -04:00
Chuck Lever
ed603bcf4f sunrpc: Replace the rq_pages array with dynamically-allocated memory
As a step towards making NFSD's maximum rsize and wsize variable at
run-time, replace the fixed-size rq_vec[] array in struct svc_rqst
with a chunk of dynamically-allocated memory.

On a system with 8-byte pointers and 4KB pages, pahole reports that
the rq_pages[] array is 2080 bytes. This patch replaces that with
a single 8-byte pointer field.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-05-15 16:16:22 -04:00
Chuck Lever
1a58791292 sunrpc: Remove backchannel check in svc_init_buffer()
The server's backchannel uses struct svc_rqst, but does not use the
pages in svc_rqst::rq_pages. It's rq_arg::pages and rq_res::pages
comes from the RPC client's page allocator. Currently,
svc_init_buffer() skips allocating pages in rq_pages for that
reason.

Except that, svc_rqst::rq_pages is filled anyway when a backchannel
svc_rqst is passed to svc_recv() -> and then to svc_alloc_arg().

This isn't really a problem at the moment, except that these pages
are allocated but then never used, as far as I can tell.

The problem is that later in this series, in addition to populating
the entries of rq_pages[], svc_init_buffer() will also allocate the
memory underlying the rq_pages[] array itself. If that allocation is
skipped, then svc_alloc_args() chases a NULL pointer for ingress
backchannel requests.

This approach avoids introducing extra conditional logic in
svc_alloc_args(), which is a hot path.

Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-05-15 16:16:22 -04:00
Luiz Capitulino
6bf9b5b40a mm: alloc_pages_bulk: rename API
The previous commit removed the page_list argument from
alloc_pages_bulk_noprof() along with the alloc_pages_bulk_list() function.

Now that only the *_array() flavour of the API remains, we can do the
following renaming (along with the _noprof() ones):

  alloc_pages_bulk_array -> alloc_pages_bulk
  alloc_pages_bulk_array_mempolicy -> alloc_pages_bulk_mempolicy
  alloc_pages_bulk_array_node -> alloc_pages_bulk_node

Link: https://lkml.kernel.org/r/275a3bbc0be20fbe9002297d60045e67ab3d4ada.1734991165.git.luizcap@redhat.com
Signed-off-by: Luiz Capitulino <luizcap@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:31 -08:00
NeilBrown
1d498df44e sunrpc: fix prog selection loop in svc_process_common
If the rq_prog is not in the list of programs, then we use the last
program in the list and we don't get the expected rpc_prog_unavail error
as the subsequent tests on 'progp' being NULL are ineffective.

We should only assign progp when we find the right program, and we
should initialize it to NULL

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 86ab08beb3 ("SUNRPC: replace program list with program array")
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-30 15:37:07 -04:00
NeilBrown
86ab08beb3 SUNRPC: replace program list with program array
A service created with svc_create_pooled() can be given a linked list of
programs and all of these will be served.

Using a linked list makes it cumbersome when there are several programs
that can be optionally selected with CONFIG settings.

After this patch is applied, API consumers must use only
svc_create_pooled() when creating an RPC service that listens for more
than one RPC program.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:30 -04:00
NeilBrown
3391fc92db sunrpc: allow svc threads to fail initialisation cleanly
If an svc thread needs to perform some initialisation that might fail,
it has no good way to handle the failure.

Before the thread can exit it must call svc_exit_thread(), but that
requires the service mutex to be held.  The thread cannot simply take
the mutex as that could deadlock if there is a concurrent attempt to
shut down all threads (which is unlikely, but not impossible).

nfsd currently call svc_exit_thread() unprotected in the unlikely event
that unshare_fs_struct() fails.

We can clean this up by introducing svc_thread_init_status() by which an
svc thread can report whether initialisation has succeeded.  If it has,
it continues normally into the action loop.  If it has not,
svc_thread_init_status() immediately aborts the thread.
svc_start_kthread() waits for either of these to happen, and calls
svc_exit_thread() (under the mutex) if the thread aborted.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:03 -04:00
NeilBrown
59f3b13816 sunrpc: merge svc_rqst_alloc() into svc_prepare_thread()
The only caller of svc_rqst_alloc() is svc_prepare_thread().  So merge
the one into the other and simplify.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:03 -04:00
NeilBrown
9dcbc4e070 sunrpc: don't take ->sv_lock when updating ->sv_nrthreads.
As documented in svc_xprt.c, sv_nrthreads is protected by the service
mutex, and it does not need ->sv_lock.
(->sv_lock is needed only for sv_permsocks, sv_tempsocks, and
sv_tmpcnt).

So remove the unnecessary locking.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:03 -04:00
NeilBrown
60749cbe3d sunrpc: change sp_nrthreads from atomic_t to unsigned int.
sp_nrthreads is only ever accessed under the service mutex
  nlmsvc_mutex nfs_callback_mutex nfsd_mutex
so these is no need for it to be an atomic_t.

The fact that all code using it is single-threaded means that we can
simplify svc_pool_victim and remove the temporary elevation of
sp_nrthreads.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:03 -04:00
NeilBrown
16ef80eedc sunrpc: document locking rules for svc_exit_thread()
The locking required for svc_exit_thread() is not obvious, so document
it in a kdoc comment.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:03 -04:00
NeilBrown
f2b27e1d72 SUNRPC: make various functions static, or not exported.
Various functions are only used within the sunrpc module, and several
are only use in the one file.  So clean up:

These are marked static, and any EXPORT is removed.
  svc_rcpb_setup()
  svc_rqst_alloc()
  svc_rqst_free()  - also moved before first use
  svc_rpcbind_set_version()
  svc_drop() - also moved to svc.c

These are now not EXPORTed, but are not static.
  svc_authenticate()
  svc_sock_update_bufs()

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-01 10:04:56 -04:00
Arnd Bergmann
7852809734 sunrpc: avoid -Wformat-security warning
Using a non-constant string as an sprintf-style is potentially dangerous:

net/sunrpc/svc.c: In function 'param_get_pool_mode':
net/sunrpc/svc.c:164:32: error: format not a string literal and no format arguments [-Werror=format-security]

Use a literal "%s" format instead.

Fixes: 5f71f3c325 ("sunrpc: refactor pool_mode setting code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-07-19 10:05:23 -04:00
Jeff Layton
5f71f3c325 sunrpc: refactor pool_mode setting code
Allow the pool_mode setting code to be called from internal callers
so we can call it from a new netlink op. Add a new svc_pool_map_get
function to return the current setting. Change the existing module
parameter handling to use the new interfaces under the hood.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-07-08 14:10:05 -04:00
Jeff Layton
8e0c8d2395 sunrpc: fix up the special handling of sv_nrpools == 1
Only pooled services take a reference to the svc_pool_map. The sunrpc
code has always used the sv_nrpools value to detect whether the service
is pooled.

The problem there is that nfsd is a pooled service, but when it's
running in "global" pool_mode, it doesn't take a reference to the pool
map because it has a sv_nrpools value of 1. This means that we have
two separate codepaths for starting the server, depending on whether
it's pooled or not.

Fix this by adding a new flag to the svc_serv, that indicates whether
the serv is pooled. With this we can have the nfsd service
unconditionally take a reference, regardless of pool_mode.

Note that this is a behavior change for
/sys/module/sunrpc/parameters/pool_mode. Usually this file does not
allow you to change the pool-mode while there are nfsd threads running,
but if the pool-mode is "global" it's allowed. My assumption is that
this is a bug, since it probably should never have worked this way.

This patch changes the behavior such that you get back EBUSY even
when nfsd is running in global mode. I think this is more reasonable
behavior, and given that most people set this today using the module
parameter, it's doubtful anyone will notice.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-07-08 14:10:04 -04:00
Chuck Lever
6ddc9deacc SUNRPC: Fix backchannel reply, again
I still see "RPC: Could not send backchannel reply error: -110"
quite often, along with slow-running tests. Debugging shows that the
backchannel is still stumbling when it has to queue a callback reply
on a busy transport.

Note that every one of these timeouts causes a connection loss by
virtue of the xprt_conditional_disconnect() call in that arm of
call_cb_transmit_status().

I found that setting to_maxval is necessary to get the RPC timeout
logic to behave whenever to_exponential is not set.

Fixes: 57331a59ac ("NFSv4.1: Use the nfs_client's rpc timeouts for backchannel")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-06-21 17:26:02 -04:00
Aleksandr Aprelkov
a576f36971 sunrpc: removed redundant procp check
since vs_proc pointer is dereferenced before getting it's address there's
no need to check for NULL.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 8e5b67731d ("SUNRPC: Add a callback to initialise server requests")
Signed-off-by: Aleksandr Aprelkov <aaprelkov@usergate.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-05-06 09:07:18 -04:00
Chuck Lever
bc4a27e915 SUNRPC: Remove EXPORT_SYMBOL_GPL for svc_process_bc()
svc_process_bc(), previously known as bc_svc_process(), was
added in commit 4d6bbb6233 ("nfs41: Backchannel bc_svc_process()")
but there has never been a call site outside of the sunrpc.ko
module.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:15 -05:00
Josef Bacik
f094323867 sunrpc: pass in the sv_stats struct through svc_create_pooled
Since only one service actually reports the rpc stats there's not much
of a reason to have a pointer to it in the svc_program struct.  Adjust
the svc_create_pooled function to take the sv_stats as an argument and
pass the struct through there as desired instead of getting it from the
svc_program->pg_stats.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:08 -05:00
Josef Bacik
ab42f4d9a2 sunrpc: don't change ->sv_stats if it doesn't exist
We check for the existence of ->sv_stats elsewhere except in the core
processing code.  It appears that only nfsd actual exports these values
anywhere, everybody else just has a write only copy of sv_stats in their
svc_program.  Add a check for ->sv_stats before every adjustment to
allow us to eliminate the stats struct from all the users who don't
report the stats.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:07 -05:00
Samasth Norway Ananda
ccbca118ef NFSv4.1: Assign the right value for initval and retries for rpc timeout
Make sure the rpc timeout was assigned with the correct value for
initial timeout and max number of retries.

Fixes: 57331a59ac ("NFSv4.1: Use the nfs_client's rpc timeouts for backchannel")
Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@oracle.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-29 13:39:48 -05:00
Linus Torvalds
587217f970 NFS Client Updates for Linux 6.8
New Features:
   * Always ask for type with READDIR
   * Remove nfs_writepage()
 
 Bugfixes:
   * Fix a suspicious RCU usage warning
   * Fix a blocklayoutdriver reference leak
   * Fix the block driver's calculation of layoutget size
   * Fix handling NFS4ERR_RETURNCONFLICT
   * Fix _xprt_switch_find_current_entry()
   * Fix v4.1 backchannel request timeouts
   * Don't add zero-length pnfs block devices
   * Use the parent cred in nfs_access_login_time()
 
 Cleanups:
   * A few improvements when dealing with referring calls from the server
   * Clean up various unused variables, struct fields, and function calls
   * Various tracepoint improvements
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Merge tag 'nfs-for-6.8-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull nfs client updates from Anna Schumaker:
 "New Features:
   - Always ask for type with READDIR
   - Remove nfs_writepage()

  Bugfixes:
   - Fix a suspicious RCU usage warning
   - Fix a blocklayoutdriver reference leak
   - Fix the block driver's calculation of layoutget size
   - Fix handling NFS4ERR_RETURNCONFLICT
   - Fix _xprt_switch_find_current_entry()
   - Fix v4.1 backchannel request timeouts
   - Don't add zero-length pnfs block devices
   - Use the parent cred in nfs_access_login_time()

  Cleanups:
   - A few improvements when dealing with referring calls from the
     server
   - Clean up various unused variables, struct fields, and function
     calls
   - Various tracepoint improvements"

* tag 'nfs-for-6.8-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (21 commits)
  NFSv4.1: Use the nfs_client's rpc timeouts for backchannel
  SUNRPC: Fixup v4.1 backchannel request timeouts
  rpc_pipefs: Replace one label in bl_resolve_deviceid()
  nfs: Remove writepage
  NFS: drop unused nfs_direct_req bytes_left
  pNFS: Fix the pnfs block driver's calculation of layoutget size
  nfs: print fileid in lookup tracepoints
  nfs: rename the nfs_async_rename_done tracepoint
  nfs: add new tracepoint at nfs4 revalidate entry point
  SUNRPC: fix _xprt_switch_find_current_entry logic
  NFSv4.1/pnfs: Ensure we handle the error NFS4ERR_RETURNCONFLICT
  NFSv4.1: if referring calls are complete, trust the stateid argument
  NFSv4: Track the number of referring calls in struct cb_process_state
  NFS: Use parent's objective cred in nfs_access_login_time()
  NFSv4: Always ask for type with READDIR
  pnfs/blocklayout: Don't add zero-length pnfs_block_dev
  blocklayoutdriver: Fix reference leak of pnfs_device_node
  SUNRPC: Fix a suspicious RCU usage warning
  SUNRPC: Create a helper function for accessing the rpc_clnt's xprt_switch
  SUNRPC: Remove unused function rpc_clnt_xprt_switch_put()
  ...
2024-01-10 16:13:57 -08:00
NeilBrown
1e3577a452 SUNRPC: discard sv_refcnt, and svc_get/svc_put
sv_refcnt is no longer useful.
lockd and nfs-cb only ever have the svc active when there are a non-zero
number of threads, so sv_refcnt mirrors sv_nrthreads.

nfsd also keeps the svc active between when a socket is added and when
the first thread is started, but we don't really need a refcount for
that.  We can simply not destroy the svc while there are any permanent
sockets attached.

So remove sv_refcnt and the get/put functions.
Instead of a final call to svc_put(), call svc_destroy() instead.
This is changed to also store NULL in the passed-in pointer to make it
easier to avoid use-after-free situations.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07 17:54:33 -05:00
Chuck Lever
3587b5c753 SUNRPC: Remove RQ_SPLICE_OK
This flag is no longer used.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07 17:54:26 -05:00