Commit Graph

324 Commits

Author SHA1 Message Date
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
Benjamin Coddington
57331a59ac NFSv4.1: Use the nfs_client's rpc timeouts for backchannel
For backchannel requests that lookup the appropriate nfs_client, use the
state-management rpc_clnt's rpc_timeout parameters for the backchannel's
response.  When the nfs_client cannot be found, fall back to using the
xprt's default timeout parameters.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-01-04 17:01:01 -05:00
Chuck Lever
789ce196a3 SUNRPC: Remove BUG_ON call sites
There is no need to take down the whole system for these assertions.

I'd rather not attempt a heroic save here, as some bug has occurred
that has left the transport data structures in an unknown state.
Just warn and then leak the left-over resources.

Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:10 -04:00
NeilBrown
15d39883ee SUNRPC: change the back-channel queue to lwq
This removes the need to store and update back-links in the list.
It also remove the need for the _bh version of spin_lock().

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:08 -04:00
NeilBrown
580a25756a SUNRPC: discard sp_lock
sp_lock is now only used to protect sp_all_threads.  This isn't needed
as sp_all_threads is only manipulated through svc_set_num_threads(),
which is already serialized.  Read-acccess only requires rcu_read_lock().
So no more locking is needed.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:08 -04:00
NeilBrown
2e8fc923fe SUNRPC: change sp_nrthreads to atomic_t
Using an atomic_t avoids the need to take a spinlock (which can soon be
removed).

Choosing a thread to kill needs to be careful as we cannot set the "die
now" bit atomically with the test on the count.  Instead we temporarily
increase the count.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:07 -04:00
NeilBrown
9a0e6accc0 SUNRPC: use lwq for sp_sockets - renamed to sp_xprts
lwq avoids using back pointers in lists, and uses less locking.
This introduces a new spinlock, but the other one will be removed in a
future patch.

For svc_clean_up_xprts(), we now dequeue the entire queue, walk it to
remove and process the xprts that need cleaning up, then re-enqueue the
remaining queue.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:07 -04:00
NeilBrown
5b80147e0c SUNRPC: only have one thread waking up at a time
Currently if several items of work become available in quick succession,
that number of threads (if available) will be woken.  By the time some
of them wake up another thread that was already cache-warm might have
come along and completed the work.  Anecdotal evidence suggests as many
as 15% of wakes find nothing to do once they get to the point of
looking.

This patch changes svc_pool_wake_idle_thread() to wake the first thread
on the queue but NOT remove it.  Subsequent calls will wake the same
thread.  Once that thread starts it will dequeue itself and after
dequeueing some work to do, it will wake the next thread if there is more
work ready.  This results in a more orderly increase in the number of
busy threads.

As a bonus, this allows us to reduce locking around the idle queue.
svc_pool_wake_idle_thread() no longer needs to take a lock (beyond
rcu_read_lock()) as it doesn't manipulate the queue, it just looks at
the first item.

The thread itself can avoid locking by using the new
llist_del_first_this() interface.  This will safely remove the thread
itself if it is the head.  If it isn't the head, it will do nothing.
If multiple threads call this concurrently only one will succeed.  The
others will do nothing, so no corruption can result.

If a thread wakes up and finds that it cannot dequeue itself that means
either
- that it wasn't woken because it was the head of the queue.  Maybe the
  freezer woke it.  In that case it can go back to sleep (after trying
  to freeze of course).
- some other thread found there was nothing to do very recently, and
  placed itself on the head of the queue in front of this thread.
  It must check again after placing itself there, so it can be deemed to
  be responsible for any pending work, and this thread can go back to
  sleep until woken.

No code ever tests for busy threads any more.  Only each thread itself
cares if it is busy.  So svc_thread_busy() is no longer needed.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:07 -04:00
NeilBrown
9bd4161c59 SUNRPC: change service idle list to be an llist
With an llist we don't need to take a lock to add a thread to the list,
though we still need a lock to remove it.  That will go in the next
patch.

Unlike double-linked lists, a thread cannot reliably remove itself from
the list.  Only the first thread can be removed, and that can change
asynchronously.  So some care is needed.

We already check if there is pending work to do, so we are unlikely to
add ourselves to the idle list and then want to remove ourselves again.

If we DO find something needs to be done after adding ourselves to the
list, we simply wake up the first thread on the list.  If that was us,
we successfully removed ourselves and can continue.  If it was some
other thread, they will do the work that needs to be done.  We can
safely sleep until woken.

We also remove the test on freezing() from rqst_should_sleep().  Instead
we set TASK_FREEZABLE before scheduling.  This makes is safe to
schedule() when a freeze is pending.  As we now loop waiting to be
removed from the idle queue, this is a cleaner way to handle freezing.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:05 -04:00
NeilBrown
2b65a22684 SUNRPC: discard SP_CONGESTED
We can tell if a pool is congested by checking if the idle list is
empty.  We don't need a separate flag.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:05 -04:00
NeilBrown
5ff817b235 SUNRPC: add list of idle threads
Rather than searching a list of threads to find an idle one, having a
list of idle threads allows an idle thread to be found immediately.

This adds some spin_lock calls which is not ideal, but as the hold-time
is tiny it is still faster than searching a list.  A future patch will
remove them using llist.h.  This involves some subtlety and so is left
to a separate patch.

This removes the need for the RQ_BUSY flag.  The rqst is "busy"
precisely when it is not on the "idle" list.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:04 -04:00
NeilBrown
fa341560ca SUNRPC: change how svc threads are asked to exit.
svc threads are currently stopped using kthread_stop().  This requires
identifying a specific thread.  However we don't care which thread
stops, just as long as one does.

So instead, set a flag in the svc_pool to say that a thread needs to
die, and have each thread check this flag instead of calling
kthread_should_stop().  The first thread to find and clear this flag
then moves towards exiting.

This removes an explicit dependency on sp_all_threads which will make a
future patch simpler.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:04 -04:00
NeilBrown
063ab935a4 SUNRPC: integrate back-channel processing with svc_recv()
Using svc_recv() for (NFSv4.1) back-channel handling means we have just
one mechanism for waking threads.

Also change kthread_freezable_should_stop() in nfs4_callback_svc() to
kthread_should_stop() as used elsewhere.
kthread_freezable_should_stop() effectively adds a try_to_freeze() call,
and svc_recv() already contains that at an appropriate place.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:03 -04:00
Chuck Lever
6ed8cdf967 SUNRPC: Clean up bc_svc_process()
The test robot complained that, in some build configurations, the
@error variable in bc_svc_process's only caller is set but never
used. This happens because dprintk() is the only consumer of that
value.

 - Remove the dprintk() call sites in favor of the svc_process
   tracepoint
 - The @error variable and the return value of bc_svc_process() are
   now unused, so get rid of them.
 - The @serv parameter is set to rqstp->rq_serv by the only caller,
   and bc_svc_process() then uses it only to set rqstp->rq_serv. It
   can be removed.
 - Rename bc_svc_process() according to the convention that
   globally-visible RPC server functions have names that begin with
   "svc_"; and because it is globally-visible, give it a proper
   kdoc comment.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308121314.HA8Rq2XG-lkp@intel.com/
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:03 -04:00
Linus Torvalds
99d99825fc NFS CLient Updates for Linux 6.6
New Features:
   * Enable the NFS v4.2 READ_PLUS operation by default
 
 Stable Fixes:
   * NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info
   * NFS: Fix a potential data corruption
 
 Bugfixes:
   * Fix various READ_PLUS issues including:
     * smatch warnings
     * xdr size calculations
     * scratch buffer handling
     * 32bit / highmem xdr page handling
   * Fix checkpatch errors in file.c
   * Fix redundant readdir request after an EOF
   * Fix handling of COPY ERR_OFFLOAD_NO_REQ
   * Fix assignment of xprtdata.cred
 
 Cleanups:
   * Remove unused xprtrdma function declarations
   * Clean up an integer overflow check to avoid a warning
   * Clean up #includes in dns_resolve.c
   * Clean up nfs4_get_device_info so we don't pass a NULL pointer to __free_page()
   * Clean up sunrpc TCP socket timeout configuration
   * Guard against READDIR loops when entry names are too long
   * Use EXCHID4_FLAG_USE_PNFS_DS for DS servers
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Merge tag 'nfs-for-6.6-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client updates from Anna Schumaker:
 "New Features:
   - Enable the NFS v4.2 READ_PLUS operation by default

  Stable Fixes:
   - NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info
   - NFS: Fix a potential data corruption

  Bugfixes:
   - Fix various READ_PLUS issues including:
      - smatch warnings
      - xdr size calculations
      - scratch buffer handling
      - 32bit / highmem xdr page handling
   - Fix checkpatch errors in file.c
   - Fix redundant readdir request after an EOF
   - Fix handling of COPY ERR_OFFLOAD_NO_REQ
   - Fix assignment of xprtdata.cred

  Cleanups:
   - Remove unused xprtrdma function declarations
   - Clean up an integer overflow check to avoid a warning
   - Clean up #includes in dns_resolve.c
   - Clean up nfs4_get_device_info so we don't pass a NULL pointer
     to __free_page()
   - Clean up sunrpc TCP socket timeout configuration
   - Guard against READDIR loops when entry names are too long
   - Use EXCHID4_FLAG_USE_PNFS_DS for DS servers"

* tag 'nfs-for-6.6-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (22 commits)
  pNFS: Fix assignment of xprtdata.cred
  NFSv4.2: fix handling of COPY ERR_OFFLOAD_NO_REQ
  NFS: Guard against READDIR loop when entry names exceed MAXNAMELEN
  NFSv4.1: use EXCHGID4_FLAG_USE_PNFS_DS for DS server
  NFS/pNFS: Set the connect timeout for the pNFS flexfiles driver
  SUNRPC: Don't override connect timeouts in rpc_clnt_add_xprt()
  SUNRPC: Allow specification of TCP client connect timeout at setup
  SUNRPC: Refactor and simplify connect timeout
  SUNRPC: Set the TCP_SYNCNT to match the socket timeout
  NFS: Fix a potential data corruption
  nfs: fix redundant readdir request after get eof
  nfs/blocklayout: Use the passed in gfp flags
  filemap: Fix errors in file.c
  NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info
  NFS: Move common includes outside ifdef
  SUNRPC: clean up integer overflow check
  xprtrdma: Remove unused function declaration rpcrdma_bc_post_recv()
  NFS: Enable the READ_PLUS operation by default
  SUNRPC: kmap() the xdr pages during decode
  NFSv4.2: Rework scratch handling for READ_PLUS (again)
  ...
2023-08-31 15:36:41 -07:00
NeilBrown
2a4557452a SUNRPC: Remove return value of svc_pool_wake_idle_thread()
The returned value is not used (any more), so don't return it.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
d2f0ef1cbf SUNRPC: Clean up svc_set_num_threads
Document the API contract and remove stale or obvious comments.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
f208e9508a SUNRPC: Count ingress RPC messages per svc_pool
svc_xprt_enqueue() can be costly, since it involves selecting and
waking up a process.

More than one enqueue is done per incoming RPC. For example,
svc_data_ready() enqueues, and so does svc_xprt_receive(). Also, if
an RPC message requires more than one call to ->recvfrom() to
receive it fully, each one of those calls does an enqueue.

To get a sense of the average number of transport enqueue operations
needed to process an incoming RPC message, re-use the "packets" pool
stat. Track the number of complete RPC messages processed by each
thread pool.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
850bac3ae4 SUNRPC: Deduplicate thread wake-up code
Refactor: Extract the loop that finds an idle service thread from
svc_xprt_enqueue() and svc_wake_up(). Both functions do just about
the same thing.

Note that svc_wake_up() currently does not hold the RCU read lock
while waking the target thread. It indeed should hold the lock, just
as svc_xprt_enqueue() does, to ensure the rqstp does not vanish
during the wake-up. This patch adds the RCU lock for svc_wake_up().

Note that shrinking the pool thread count is rare, and calls to
svc_wake_up() are also quite infrequent. In practice, this race is
very unlikely to be hit, so we are not marking the lock fix for
stable backport at this time.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
78c542f916 SUNRPC: Add enum svc_auth_status
In addition to the benefits of using an enum rather than a set of
macros, we now have a named type that can improve static type
checking of function return values.

As part of this change, I removed a stale comment from svcauth.h;
the return values from current implementations of the
auth_ops::release method are all zero/negative errno, not the SVC_OK
enum values as the old comment suggested.

Suggested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
NeilBrown
c743b4259c SUNRPC: remove timeout arg from svc_recv()
Most svc threads have no interest in a timeout.
nfsd sets it to 1 hour, but this is a wart of no significance.

lockd uses the timeout so that it can call nlmsvc_retry_blocked().
It also sometimes calls svc_wake_up() to ensure this is called.

So change lockd to be consistent and always use svc_wake_up() to trigger
nlmsvc_retry_blocked() - using a timer instead of a timeout to
svc_recv().

And change svc_recv() to not take a timeout arg.

This makes the sp_threads_timedout counter always zero.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
NeilBrown
f78116d3bf SUNRPC: call svc_process() from svc_recv().
All callers of svc_recv() go on to call svc_process() on success.
Simplify callers by having svc_recv() do that for them.

This loses one call to validate_process_creds() in nfsd.  That was
debugging code added 14 years ago.  I don't think we need to keep it.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Anna Schumaker
61182c796d SUNRPC: kmap() the xdr pages during decode
If the pages are in HIGHMEM then we need to make sure they're mapped
before trying to read data off of them, otherwise we could end up with a
NULL pointer dereference.

The downside to this is that we need an extra cleanup step at the end of
decode to kunmap() the last page. I introduced an xdr_finish_decode()
function to do this. Right now this function only calls the
unmap_current_page() function, but other generic cleanup steps could be
added in the future if we come across anything else.

Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-08-23 15:58:47 -04:00
Linus Torvalds
6e17c6de3d - Yosry Ahmed brought back some cgroup v1 stats in OOM logs.
- Yosry has also eliminated cgroup's atomic rstat flushing.
 
 - Nhat Pham adds the new cachestat() syscall.  It provides userspace
   with the ability to query pagecache status - a similar concept to
   mincore() but more powerful and with improved usability.
 
 - Mel Gorman provides more optimizations for compaction, reducing the
   prevalence of page rescanning.
 
 - Lorenzo Stoakes has done some maintanance work on the get_user_pages()
   interface.
 
 - Liam Howlett continues with cleanups and maintenance work to the maple
   tree code.  Peng Zhang also does some work on maple tree.
 
 - Johannes Weiner has done some cleanup work on the compaction code.
 
 - David Hildenbrand has contributed additional selftests for
   get_user_pages().
 
 - Thomas Gleixner has contributed some maintenance and optimization work
   for the vmalloc code.
 
 - Baolin Wang has provided some compaction cleanups,
 
 - SeongJae Park continues maintenance work on the DAMON code.
 
 - Huang Ying has done some maintenance on the swap code's usage of
   device refcounting.
 
 - Christoph Hellwig has some cleanups for the filemap/directio code.
 
 - Ryan Roberts provides two patch series which yield some
   rationalization of the kernel's access to pte entries - use the provided
   APIs rather than open-coding accesses.
 
 - Lorenzo Stoakes has some fixes to the interaction between pagecache
   and directio access to file mappings.
 
 - John Hubbard has a series of fixes to the MM selftesting code.
 
 - ZhangPeng continues the folio conversion campaign.
 
 - Hugh Dickins has been working on the pagetable handling code, mainly
   with a view to reducing the load on the mmap_lock.
 
 - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from
   128 to 8.
 
 - Domenico Cerasuolo has improved the zswap reclaim mechanism by
   reorganizing the LRU management.
 
 - Matthew Wilcox provides some fixups to make gfs2 work better with the
   buffer_head code.
 
 - Vishal Moola also has done some folio conversion work.
 
 - Matthew Wilcox has removed the remnants of the pagevec code - their
   functionality is migrated over to struct folio_batch.
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Merge tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:

 - Yosry Ahmed brought back some cgroup v1 stats in OOM logs

 - Yosry has also eliminated cgroup's atomic rstat flushing

 - Nhat Pham adds the new cachestat() syscall. It provides userspace
   with the ability to query pagecache status - a similar concept to
   mincore() but more powerful and with improved usability

 - Mel Gorman provides more optimizations for compaction, reducing the
   prevalence of page rescanning

 - Lorenzo Stoakes has done some maintanance work on the
   get_user_pages() interface

 - Liam Howlett continues with cleanups and maintenance work to the
   maple tree code. Peng Zhang also does some work on maple tree

 - Johannes Weiner has done some cleanup work on the compaction code

 - David Hildenbrand has contributed additional selftests for
   get_user_pages()

 - Thomas Gleixner has contributed some maintenance and optimization
   work for the vmalloc code

 - Baolin Wang has provided some compaction cleanups,

 - SeongJae Park continues maintenance work on the DAMON code

 - Huang Ying has done some maintenance on the swap code's usage of
   device refcounting

 - Christoph Hellwig has some cleanups for the filemap/directio code

 - Ryan Roberts provides two patch series which yield some
   rationalization of the kernel's access to pte entries - use the
   provided APIs rather than open-coding accesses

 - Lorenzo Stoakes has some fixes to the interaction between pagecache
   and directio access to file mappings

 - John Hubbard has a series of fixes to the MM selftesting code

 - ZhangPeng continues the folio conversion campaign

 - Hugh Dickins has been working on the pagetable handling code, mainly
   with a view to reducing the load on the mmap_lock

 - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment
   from 128 to 8

 - Domenico Cerasuolo has improved the zswap reclaim mechanism by
   reorganizing the LRU management

 - Matthew Wilcox provides some fixups to make gfs2 work better with the
   buffer_head code

 - Vishal Moola also has done some folio conversion work

 - Matthew Wilcox has removed the remnants of the pagevec code - their
   functionality is migrated over to struct folio_batch

* tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits)
  mm/hugetlb: remove hugetlb_set_page_subpool()
  mm: nommu: correct the range of mmap_sem_read_lock in task_mem()
  hugetlb: revert use of page_cache_next_miss()
  Revert "page cache: fix page_cache_next/prev_miss off by one"
  mm/vmscan: fix root proactive reclaim unthrottling unbalanced node
  mm: memcg: rename and document global_reclaim()
  mm: kill [add|del]_page_to_lru_list()
  mm: compaction: convert to use a folio in isolate_migratepages_block()
  mm: zswap: fix double invalidate with exclusive loads
  mm: remove unnecessary pagevec includes
  mm: remove references to pagevec
  mm: rename invalidate_mapping_pagevec to mapping_try_invalidate
  mm: remove struct pagevec
  net: convert sunrpc from pagevec to folio_batch
  i915: convert i915_gpu_error to use a folio_batch
  pagevec: rename fbatch_count()
  mm: remove check_move_unevictable_pages()
  drm: convert drm_gem_put_pages() to use a folio_batch
  i915: convert shmem_sg_free_table() to use a folio_batch
  scatterlist: add sg_set_folio()
  ...
2023-06-28 10:28:11 -07:00
Matthew Wilcox (Oracle)
76fa884290 net: convert sunrpc from pagevec to folio_batch
Remove the last usage of pagevecs.  There is a slight change here; we now
free the folio_batch as soon as it fills up instead of freeing the
folio_batch when we try to add a page to a full batch.  This should have
no effect in practice.

Link: https://lkml.kernel.org/r/20230621164557.3510324-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-23 16:59:30 -07:00
Chuck Lever
00a87e5d1d SUNRPC: Address RCU warning in net/sunrpc/svc.c
$ make C=1 W=1 net/sunrpc/svc.o
make[1]: Entering directory 'linux/obj/manet.1015granger.net'
  GEN     Makefile
  CALL    linux/server-development/scripts/checksyscalls.sh
  DESCEND objtool
  INSTALL libsubcmd_headers
  DESCEND bpf/resolve_btfids
  INSTALL libsubcmd_headers
  CC [M]  net/sunrpc/svc.o
  CHECK   linux/server-development/net/sunrpc/svc.c
linux/server-development/net/sunrpc/svc.c:1225:9: warning: incorrect type in argument 1 (different address spaces)
linux/server-development/net/sunrpc/svc.c:1225:9:    expected struct spinlock [usertype] *lock
linux/server-development/net/sunrpc/svc.c:1225:9:    got struct spinlock [noderef] __rcu *
linux/server-development/net/sunrpc/svc.c:1227:40: warning: incorrect type in argument 1 (different address spaces)
linux/server-development/net/sunrpc/svc.c:1227:40:    expected struct spinlock [usertype] *lock
linux/server-development/net/sunrpc/svc.c:1227:40:    got struct spinlock [noderef] __rcu *
make[1]: Leaving directory 'linux/obj/manet.1015granger.net'

Warning introduced by commit 913292c97d ("sched.h: Annotate
sighand_struct with __rcu").

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-06-17 13:18:07 -04:00
Azeem Shaikh
a9156d7e7d SUNRPC: Use sysfs_emit in place of strlcpy/sprintf
Part of an effort to remove strlcpy() tree-wide [1].

Direct replacement is safe here since the getter in kernel_params_ops
handles -errno return [2].

[1] https://github.com/KSPP/linux/issues/89
[2] https://elixir.bootlin.com/linux/v6.4-rc6/source/include/linux/moduleparam.h#L52

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-06-17 13:18:07 -04:00
Chuck Lever
88e4d41a26 SUNRPC: Use __alloc_bulk_pages() in svc_init_buffer()
Clean up: Use the bulk page allocator when filling a server thread's
buffer page array.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-06-05 09:01:44 -04:00
Chuck Lever
07a2730593 SUNRPC: Fix trace_svc_register() call site
The trace event recorded incorrect values for the registered family,
protocol, and port because the arguments are in the wrong order.

Fixes: b4af59328c ("SUNRPC: Trace server-side rpcbind registration events")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-05-14 15:58:14 -04:00
Chuck Lever
29cd2927fb SUNRPC: Fix encoding of accepted but unsuccessful RPC replies
Jiri Slaby says:
> I bisected to this ... as it breaks nfs3-only servers in 6.3.
> I.e. /etc/nfs.conf containing:
> [nfsd]
> vers4=no
>
> The client sees:
>  mount("10.0.2.15:/tmp", "/mnt", "nfs", 0, "vers=4.2,addr=10.0.2.15,clientad"...) = -1 EIO (Input/output error)
>  write(2, "mount.nfs: mount system call fai"..., 45
>  mount.nfs: mount system call failed for /mnt
>
> And the kernel says:
>  nfs4_discover_server_trunking unhandled error -5. Exiting with error EIO

Reported-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://bugzilla.suse.com/show_bug.cgi?id=1210995
Fixes: 4bcf0343e8 ("SUNRPC: Set rq_accept_statp inside ->accept methods")
Tested-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-05-03 09:35:51 -04:00
Chuck Lever
6a0cdf56bf SUNRPC: Be even lazier about releasing pages
A single RPC transaction that touches only a couple of pages means
rq_pvec will not be even close to full in svc_xpt_release(). This is
a common case.

Instead, just leave the pages in rq_pvec until it is completely
full. This improves the efficiency of the batch release mechanism
on workloads that involve small RPC messages.

The rq_pvec is also fully emptied just before thread exit.

Reviewed-by: Calum Mackay <calum.mackay@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-04-27 18:49:23 -04:00