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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>
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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>
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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>
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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>
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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>
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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()
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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>
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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>
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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>
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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>
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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>
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Nothing returns this error code.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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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>
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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>
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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: 29cd2927fb91 ("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>
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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: ed603bcf4fea ("sunrpc: Replace the rq_pages array with dynamically-allocated memory")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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Clean up: This API is no longer used.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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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>
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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>
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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>
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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>
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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>
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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: 86ab08beb3f0 ("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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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: 5f71f3c32553 ("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>
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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>
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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>
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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: 57331a59ac0d ("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>
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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: 8e5b67731d08 ("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>
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svc_process_bc(), previously known as bc_svc_process(), was
added in commit 4d6bbb6233c9 ("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>
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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>
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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>
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Make sure the rpc timeout was assigned with the correct value for
initial timeout and max number of retries.
Fixes: 57331a59ac0d ("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>
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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()
...
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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>
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This flag is no longer used.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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