Commit graph

68 commits

Author SHA1 Message Date
Ksawlii
9b92164945 Revert "nfsd: Don't call freezable_schedule_timeout() after each successful page allocation in svc_alloc_arg()."
This reverts commit 64d856f842.
2024-11-24 00:23:50 +01:00
Ksawlii
f2f218a130 Revert "sunrpc: don't change ->sv_stats if it doesn't exist"
This reverts commit e4c6a8a3a1.
2024-11-24 00:23:45 +01:00
Ksawlii
181d28ae2b Revert "sunrpc: pass in the sv_stats struct through svc_create_pooled"
This reverts commit bdc4a7b40a.
2024-11-24 00:23:44 +01:00
Ksawlii
4229090b10 Revert "sunrpc: use the struct net as the svc proc private"
This reverts commit 2877cd403d.
2024-11-24 00:23:44 +01:00
Ksawlii
8529212e6d Revert "svcrdma: Catch another Reply chunk overflow case"
This reverts commit 6d3cecf9a4.
2024-11-24 00:23:42 +01:00
Ksawlii
7ce3a6de6c Revert "net, sunrpc: Remap EPERM in case of connection failure in xs_tcp_setup_socket"
This reverts commit feb4fd6546.
2024-11-24 00:23:36 +01:00
Daniel Borkmann
feb4fd6546 net, sunrpc: Remap EPERM in case of connection failure in xs_tcp_setup_socket
commit 626dfed5fa3bfb41e0dffd796032b555b69f9cde upstream.

When using a BPF program on kernel_connect(), the call can return -EPERM. This
causes xs_tcp_setup_socket() to loop forever, filling up the syslog and causing
the kernel to potentially freeze up.

Neil suggested:

  This will propagate -EPERM up into other layers which might not be ready
  to handle it. It might be safer to map EPERM to an error we would be more
  likely to expect from the network system - such as ECONNREFUSED or ENETDOWN.

ECONNREFUSED as error seems reasonable. For programs setting a different error
can be out of reach (see handling in 4fbac77d2d09) in particular on kernels
which do not have f10d05966196 ("bpf: Make BPF_PROG_RUN_ARRAY return -err
instead of allow boolean"), thus given that it is better to simply remap for
consistent behavior. UDP does handle EPERM in xs_udp_send_request().

Fixes: d74bad4e74ee ("bpf: Hooks for sys_connect")
Fixes: 4fbac77d2d09 ("bpf: Hooks for sys_bind")
Co-developed-by: Lex Siegel <usiegl00@gmail.com>
Signed-off-by: Lex Siegel <usiegl00@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trondmy@kernel.org>
Cc: Anna Schumaker <anna@kernel.org>
Link: https://github.com/cilium/cilium/issues/33395
Link: https://lore.kernel.org/bpf/171374175513.12877.8993642908082014881@noble.neil.brown.name
Link: https://patch.msgid.link/9069ec1d59e4b2129fc23433349fd5580ad43921.1720075070.git.daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@witekio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:21:09 +01:00
Chuck Lever
6d3cecf9a4 svcrdma: Catch another Reply chunk overflow case
[ Upstream commit e5decb2eb5f4d1f64ba9196b4bad0e26a441c81c ]

When space in the Reply chunk runs out in the middle of a segment,
we end up passing a zero-length SGL to rdma_rw_ctx_init(), and it
oopses.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Stable-dep-of: ffc17e1479e8 ("platform/x86: dell-smbios: Fix error path in dell_smbios_init()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:21:04 +01:00
Josef Bacik
2877cd403d sunrpc: use the struct net as the svc proc private
[ Upstream commit 418b9687dece5bd763c09b5c27a801a7e3387be9 ]

nfsd is the only thing using this helper, and it doesn't use the private
currently.  When we switch to per-network namespace stats we will need
the struct net * in order to get to the nfsd_net.  Use the net as the
proc private so we can utilize this when we make the switch over.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:21:02 +01:00
Josef Bacik
bdc4a7b40a sunrpc: pass in the sv_stats struct through svc_create_pooled
[ Upstream commit f094323867668d50124886ad884b665de7319537 ]

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>
[ cel: adjusted to apply to v5.10.y ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:21:02 +01:00
Josef Bacik
e4c6a8a3a1 sunrpc: don't change ->sv_stats if it doesn't exist
[ Upstream commit ab42f4d9a26f1723dcfd6c93fcf768032b2bb5e7 ]

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>
[ cel: adjusted to apply to v5.10.y ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:21:02 +01:00
Kuniyuki Iwashima
64d856f842 nfsd: Don't call freezable_schedule_timeout() after each successful page allocation in svc_alloc_arg().
When commit 390390240145 ("nfsd: don't allow nfsd threads to be
signalled.") is backported to 5.10, it was adjusted considering commit
3feac2b55293 ("sunrpc: exclude from freezer when waiting for requests:").

However, 3feac2b55293 is based on commit f6e70aab9dfe ("SUNRPC: refresh
rq_pages using a bulk page allocator"), which converted page-by-page
allocation to a batch allocation, so schedule_timeout() is placed
un-nested.

As a result, the backported commit 7229200f6866 ("nfsd: don't allow nfsd
threads to be signalled.") placed freezable_schedule_timeout() in the wrong
place.

Now, freezable_schedule_timeout() is called after every successful page
allocation, and we see 30%+ performance regression on 5.10.220 in our
test suite.

Let's move it to the correct place so that freezable_schedule_timeout()
is called only when page allocation fails.

Fixes: 7229200f6866 ("nfsd: don't allow nfsd threads to be signalled.")
Reported-by: Hughdan Liu <hughliu@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:20:50 +01:00
Benjamin Coddington
61018c458c SUNRPC: Fix a race to wake a sync task
[ Upstream commit ed0172af5d6fc07d1b40ca82f5ca3979300369f7 ]

We've observed NFS clients with sync tasks sleeping in __rpc_execute
waiting on RPC_TASK_QUEUED that have not responded to a wake-up from
rpc_make_runnable().  I suspect this problem usually goes unnoticed,
because on a busy client the task will eventually be re-awoken by another
task completion or xprt event.  However, if the state manager is draining
the slot table, a sync task missing a wake-up can result in a hung client.

We've been able to prove that the waker in rpc_make_runnable() successfully
calls wake_up_bit() (ie- there's no race to tk_runstate), but the
wake_up_bit() call fails to wake the waiter.  I suspect the waker is
missing the load of the bit's wait_queue_head, so waitqueue_active() is
false.  There are some very helpful comments about this problem above
wake_up_bit(), prepare_to_wait(), and waitqueue_active().

Fix this by inserting smp_mb__after_atomic() before the wake_up_bit(),
which pairs with prepare_to_wait() calling set_current_state().

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:20:24 +01:00
NeilBrown
63510ce638 SUNRPC: avoid soft lockup when transmitting UDP to reachable server.
[ Upstream commit 6258cf25d5e3155c3219ab5a79b970eef7996356 ]

Prior to the commit identified below, call_transmit_status() would
handle -EPERM and other errors related to an unreachable server by
falling through to call_status() which added a 3-second delay and
handled the failure as a timeout.

Since that commit, call_transmit_status() falls through to
handle_bind().  For UDP this moves straight on to handle_connect() and
handle_transmit() so we immediately retransmit - and likely get the same
error.

This results in an indefinite loop in __rpc_execute() which triggers a
soft-lockup warning.

For the errors that indicate an unreachable server,
call_transmit_status() should fall back to call_status() as it did
before.  This cannot cause the thundering herd that the previous patch
was avoiding, as the call_status() will insert a delay.

Fixes: ed7dc973bd91 ("SUNRPC: Prevent thundering herd when the socket is not connected")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:20:09 +01:00
Chuck Lever
0c57c1ea68 xprtrdma: Fix rpcrdma_reqs_reset()
[ Upstream commit acd9f2dd23c632568156217aac7a05f5a0313152 ]

Avoid FastReg operations getting MW_BIND_ERR after a reconnect.

rpcrdma_reqs_reset() is called on transport tear-down to get each
rpcrdma_req back into a clean state.

MRs on req->rl_registered are waiting for a FastReg, are already
registered, or are waiting for invalidation. If the transport is
being torn down when reqs_reset() is called, the matching LocalInv
might never be posted. That leaves these MR registered /and/ on
req->rl_free_mrs, where they can be re-used for the next
connection.

Since xprtrdma does not keep specific track of the MR state, it's
not possible to know what state these MRs are in, so the only safe
thing to do is release them immediately.

Fixes: 5de55ce951a1 ("xprtrdma: Release in-flight MRs on disconnect")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:20:09 +01:00
Chuck Lever
09c5519173 xprtrdma: Rename frwr_release_mr()
[ Upstream commit f912af77e2c1ba25bd40534668b10da5b20f686a ]

Clean up: To be consistent with other functions in this source file,
follow the naming convention of putting the object being acted upon
before the action itself.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Stable-dep-of: acd9f2dd23c6 ("xprtrdma: Fix rpcrdma_reqs_reset()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:20:09 +01:00
Gaosheng Cui
28f59fc31b gss_krb5: Fix the error handling path for crypto_sync_skcipher_setkey
[ Upstream commit a3123341dc358952ce2bf8067fbdfb7eaadf71bb ]

If we fail to call crypto_sync_skcipher_setkey, we should free the
memory allocation for cipher, replace err_return with err_free_cipher
to free the memory of cipher.

Fixes: 4891f2d008e4 ("gss_krb5: import functionality to derive keys into the kernel")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:20:08 +01:00
Chuck Lever
580a775fb5 SUNRPC: Fix a NULL pointer deref in trace_svc_stats_latency()
[ Upstream commit 5c11720767f70d34357d00a15ba5a0ad052c40fe ]

Some paths through svc_process() leave rqst->rq_procinfo set to
NULL, which triggers a crash if tracing happens to be enabled.

Fixes: 89ff87494c6e ("SUNRPC: Display RPC procedure names instead of proc numbers")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:31 +01:00
Yunjian Wang
64a9cf7edf SUNRPC: Fix null pointer dereference in svc_rqst_free()
[ Upstream commit b9f83ffaa0c096b4c832a43964fe6bff3acffe10 ]

When alloc_pages_node() returns null in svc_rqst_alloc(), the
null rq_scratch_page pointer will be dereferenced when calling
put_page() in svc_rqst_free(). Fix it by adding a null check.

Addresses-Coverity: ("Dereference after null check")
Fixes: 5191955d6fc6 ("SUNRPC: Prepare for xdr_stream-style decoding on the server-side")
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:31 +01:00
Chen Hanxiao
5c050a0709 SUNRPC: return proper error from gss_wrap_req_priv
[ Upstream commit 33c94d7e3cb84f6d130678d6d59ba475a6c489cf ]

don't return 0 if snd_buf->len really greater than snd_buf->buflen

Signed-off-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
Fixes: 0c77668ddb4e ("SUNRPC: Introduce trace points in rpc_auth_gss.ko")
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:02 +01:00
Chuck Lever
cff4ebbbbf nfsd: don't allow nfsd threads to be signalled.
[ Upstream commit 3903902401451b1cd9d797a8c79769eb26ac7fe5 ]

The original implementation of nfsd used signals to stop threads during
shutdown.
In Linux 2.3.46pre5 nfsd gained the ability to shutdown threads
internally it if was asked to run "0" threads.  After this user-space
transitioned to using "rpc.nfsd 0" to stop nfsd and sending signals to
threads was no longer an important part of the API.

In commit 3ebdbe5203a8 ("SUNRPC: discard svo_setup and rename
svc_set_num_threads_sync()") (v5.17-rc1~75^2~41) we finally removed the
use of signals for stopping threads, using kthread_stop() instead.

This patch makes the "obvious" next step and removes the ability to
signal nfsd threads - or any svc threads.  nfsd stops allowing signals
and we don't check for their delivery any more.

This will allow for some simplification in later patches.

A change worth noting is in nfsd4_ssc_setup_dul().  There was previously
a signal_pending() check which would only succeed when the thread was
being shut down.  It should really have tested kthread_should_stop() as
well.  Now it just does the latter, not the former.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
[ cel: adjusted to apply to v5.10.y ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:28:32 +01:00
Dan Carpenter
b85d90d836 nfsd: fix double fget() bug in __write_ports_addfd()
[ Upstream commit c034203b6a9dae6751ef4371c18cb77983e30c28 ]

The bug here is that you cannot rely on getting the same socket
from multiple calls to fget() because userspace can influence
that.  This is a kind of double fetch bug.

The fix is to delete the svc_alien_sock() function and instead do
the checking inside the svc_addsock() function.

Fixes: 3064639423c4 ("nfsd: check passed socket's net matches NFSd superblock's one")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: NeilBrown <neilb@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:28:32 +01:00
Chuck Lever
5b133c1ad1 Revert "SUNRPC: Use RMW bitops in single-threaded hot paths"
[ Upstream commit 7827c81f0248e3c2f40d438b020f3d222f002171 ]

The premise that "Once an svc thread is scheduled and executing an
RPC, no other processes will touch svc_rqst::rq_flags" is false.
svc_xprt_enqueue() examines the RQ_BUSY flag in scheduled nfsd
threads when determining which thread to wake up next.

Found via KCSAN.

Fixes: 28df0988815f ("SUNRPC: Use RMW bitops in single-threaded hot paths")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:28:29 +01:00
Chuck Lever
f6d3097d21 NFSD: Refactor common code out of dirlist helpers
[ Upstream commit 98124f5bd6c76699d514fbe491dd95265369cc99 ]

The dust has settled a bit and it's become obvious what code is
totally common between nfsd_init_dirlist_pages() and
nfsd3_init_dirlist_pages(). Move that common code to SUNRPC.

The new helper brackets the existing xdr_init_decode_pages() API.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:28:23 +01:00
Chuck Lever
f98b7203d3 SUNRPC: Parametrize how much of argsize should be zeroed
[ Upstream commit 103cc1fafee48adb91fca0e19deb869fd23e46ab ]

Currently, SUNRPC clears the whole of .pc_argsize before processing
each incoming RPC transaction. Add an extra parameter to struct
svc_procedure to enable upper layers to reduce the amount of each
operation's argument structure that is zeroed by SUNRPC.

The size of struct nfsd4_compoundargs, in particular, is a lot to
clear on each incoming RPC Call. A subsequent patch will cut this
down to something closer to what NFSv2 and NFSv3 uses.

This patch should cause no behavior changes.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:28:23 +01:00
Chuck Lever
0de18fdf8d SUNRPC: Optimize xdr_reserve_space()
[ Upstream commit 62ed448cc53b654036f7d7f3c99f299d79ad14c3 ]

Transitioning between encode buffers is quite infrequent. It happens
about 1 time in 400 calls to xdr_reserve_space(), measured on NFSD
with a typical build/test workload.

Force the compiler to remove that code from xdr_reserve_space(),
which is a hot path on both the server and the client. This change
reduces the size of xdr_reserve_space() from 10 cache lines to 2
when compiled with -Os.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:58 +01:00
Chuck Lever
7da9080d87 SUNRPC: Use RMW bitops in single-threaded hot paths
[ Upstream commit 28df0988815f63e2af5e6718193c9f68681ad7ff ]

I noticed CPU pipeline stalls while using perf.

Once an svc thread is scheduled and executing an RPC, no other
processes will touch svc_rqst::rq_flags. Thus bus-locked atomics are
not needed outside the svc thread scheduler.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:58 +01:00
Chuck Lever
2c57725d69 NFSD: Move svc_serv_ops::svo_function into struct svc_serv
[ Upstream commit 37902c6313090235c847af89c5515591261ee338 ]

Hoist svo_function back into svc_serv and remove struct
svc_serv_ops, since the struct is now devoid of fields.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:54 +01:00
Chuck Lever
2b70332cac NFSD: Remove svc_serv_ops::svo_module
[ Upstream commit f49169c97fceb21ad6a0aaf671c50b0f520f15a5 ]

struct svc_serv_ops is about to be removed.

Neil Brown says:
> I suspect svo_module can go as well - I don't think the thread is
> ever the thing that primarily keeps a module active.

A random sample of kthread_create() callers shows sunrpc is the only
one that manages module reference count in this way.

Suggested-by: Neil Brown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:54 +01:00
Chuck Lever
e3a0f44371 SUNRPC: Remove svc_shutdown_net()
[ Upstream commit c7d7ec8f043e53ad16e30f5ebb8b9df415ec0f2b ]

Clean up: svc_shutdown_net() now does nothing but call
svc_close_net(). Replace all external call sites.

svc_close_net() is renamed to be the inverse of svc_xprt_create().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:54 +01:00
Chuck Lever
758fcc041e SUNRPC: Rename svc_close_xprt()
[ Upstream commit 4355d767a21b9445958fc11bce9a9701f76529d3 ]

Clean up: Use the "svc_xprt_<task>" function naming convention as
is used for other external APIs.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:54 +01:00
Chuck Lever
bee0c024d6 SUNRPC: Rename svc_create_xprt()
[ Upstream commit 352ad31448fecc78a2e9b78da64eea5d63b8d0ce ]

Clean up: Use the "svc_xprt_<task>" function naming convention as
is used for other external APIs.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:54 +01:00
Chuck Lever
9b54c62e38 SUNRPC: Remove svo_shutdown method
[ Upstream commit 87cdd8641c8a1ec6afd2468265e20840a57fd888 ]

Clean up. Neil observed that "any code that calls svc_shutdown_net()
knows what the shutdown function should be, and so can call it
directly."

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:54 +01:00
Chuck Lever
4a3e4e558d SUNRPC: Merge svc_do_enqueue_xprt() into svc_enqueue_xprt()
[ Upstream commit c0219c499799c1e92bd570c15a47e6257a27bb15 ]

Neil says:
"These functions were separated in commit 0971374e2818 ("SUNRPC:
Reduce contention in svc_xprt_enqueue()") so that the XPT_BUSY check
happened before taking any spinlocks.

We have since moved or removed the spinlocks so the extra test is
fairly pointless."

I've made this a separate patch in case the XPT_BUSY change has
unexpected consequences and needs to be reverted.

Suggested-by: Neil Brown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:54 +01:00
Chuck Lever
de06412bad SUNRPC: Remove the .svo_enqueue_xprt method
[ Upstream commit a9ff2e99e9fa501ec965da03c18a5422b37a2f44 ]

We have never been able to track down and address the underlying
cause of the performance issues with workqueue-based service
support. svo_enqueue_xprt is called multiple times per RPC, so
it adds instruction path length, but always ends up at the same
function: svc_xprt_do_enqueue(). We do not anticipate needing
this flexibility for dynamic nfsd thread management support.

As a micro-optimization, remove .svo_enqueue_xprt because
Spectre/Meltdown makes virtual function calls more costly.

This change essentially reverts commit b9e13cdfac70 ("nfsd/sunrpc:
turn enqueueing a svc_xprt into a svc_serv operation").

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:53 +01:00
NeilBrown
1d1b43f1b8 lockd: use svc_set_num_threads() for thread start and stop
[ Upstream commit 6b044fbaab02292fedb17565dbb3f2528083b169 ]

svc_set_num_threads() does everything that lockd_start_svc() does, except
set sv_maxconn.  It also (when passed 0) finds the threads and
stops them with kthread_stop().

So move the setting for sv_maxconn, and use svc_set_num_thread()

We now don't need nlmsvc_task.

Now that we use svc_set_num_threads() it makes sense to set svo_module.
This request that the thread exists with module_put_and_exit().
Also fix the documentation for svo_module to make this explicit.

svc_prepare_thread is now only used where it is defined, so it can be
made static.

Signed-off-by: NeilBrown <neilb@suse.de>
[ cel: address merge conflict with fd2468fa1301 ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:51 +01:00
NeilBrown
0d86a30cbb SUNRPC: always treat sv_nrpools==1 as "not pooled"
[ Upstream commit 93aa619eb0b42eec2f3a9b4d9db41f5095390aec ]

Currently 'pooled' services hold a reference on the pool_map, and
'unpooled' services do not.
svc_destroy() uses the presence of ->svo_function (via
svc_serv_is_pooled()) to determine if the reference should be dropped.
There is no direct correlation between being pooled and the use of
svo_function, though in practice, lockd is the only non-pooled service,
and the only one not to use svo_function.

This is untidy and would cause problems if we changed lockd to use
svc_set_num_threads(), which requires the use of ->svo_function.

So change the test for "is the service pooled" to "is sv_nrpools > 1".

This means that when svc_pool_map_get() returns 1, it must NOT take a
reference to the pool.

We discard svc_serv_is_pooled(), and test sv_nrpools directly.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:51 +01:00
NeilBrown
188b003050 SUNRPC: move the pool_map definitions (back) into svc.c
[ Upstream commit cf0e124e0a489944d08fcc3c694d2b234d2cc658 ]

These definitions are not used outside of svc.c, and there is no
evidence that they ever have been.  So move them into svc.c
and make the declarations 'static'.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:51 +01:00
NeilBrown
ab30e7bffb SUNRPC: discard svo_setup and rename svc_set_num_threads_sync()
[ Upstream commit 3ebdbe5203a874614819700d3f470724cb803709 ]

The ->svo_setup callback serves no purpose.  It is always called from
within the same module that chooses which callback is needed.  So
discard it and call the relevant function directly.

Now that svc_set_num_threads() is no longer used remove it and rename
svc_set_num_threads_sync() to remove the "_sync" suffix.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:50 +01:00
NeilBrown
f1f6cafeb9 SUNRPC: use sv_lock to protect updates to sv_nrthreads.
[ Upstream commit 2a36395fac3b72771f87c3ee4387e3a96d85a7cc ]

Using sv_lock means we don't need to hold the service mutex over these
updates.

In particular,  svc_exit_thread() no longer requires synchronisation, so
threads can exit asynchronously.

Note that we could use an atomic_t, but as there are many more read
sites than writes, that would add unnecessary noise to the code.
Some reads are already racy, and there is no need for them to not be.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:50 +01:00
NeilBrown
58232d691d SUNRPC: stop using ->sv_nrthreads as a refcount
[ Upstream commit ec52361df99b490f6af412b046df9799b92c1050 ]

The use of sv_nrthreads as a general refcount results in clumsy code, as
is seen by various comments needed to explain the situation.

This patch introduces a 'struct kref' and uses that for reference
counting, leaving sv_nrthreads to be a pure count of threads.  The kref
is managed particularly in svc_get() and svc_put(), and also nfsd_put();

svc_destroy() now takes a pointer to the embedded kref, rather than to
the serv.

nfsd allows the svc_serv to exist with ->sv_nrhtreads being zero.  This
happens when a transport is created before the first thread is started.
To support this, a 'keep_active' flag is introduced which holds a ref on
the svc_serv.  This is set when any listening socket is successfully
added (unless there are running threads), and cleared when the number of
threads is set.  So when the last thread exits, the nfs_serv will be
destroyed.
The use of 'keep_active' replaces previous code which checked if there
were any permanent sockets.

We no longer clear ->rq_server when nfsd() exits.  This was done
to prevent svc_exit_thread() from calling svc_destroy().
Instead we take an extra reference to the svc_serv to prevent
svc_destroy() from being called.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:50 +01:00
NeilBrown
a1ed765f29 SUNRPC/NFSD: clean up get/put functions.
[ Upstream commit 8c62d12740a1450d2e8456d5747f440e10db281a ]

svc_destroy() is poorly named - it doesn't necessarily destroy the svc,
it might just reduce the ref count.
nfsd_destroy() is poorly named for the same reason.

This patch:
 - removes the refcount functionality from svc_destroy(), moving it to
   a new svc_put().  Almost all previous callers of svc_destroy() now
   call svc_put().
 - renames nfsd_destroy() to nfsd_put() and improves the code, using
   the new svc_destroy() rather than svc_put()
 - removes a few comments that explain the important for balanced
   get/put calls.  This should be obvious.

The only non-trivial part of this is that svc_destroy() would call
svc_sock_update() on a non-final decrement.  It can no longer do that,
and svc_put() isn't really a good place of it.  This call is now made
from svc_exit_thread() which seems like a good place.  This makes the
call *before* sv_nrthreads is decremented rather than after.  This
is not particularly important as the call just sets a flag which
causes sv_nrthreads set be checked later.  A subsequent patch will
improve the ordering.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:50 +01:00
Chuck Lever
252ec73572 NFSD: Have legacy NFSD WRITE decoders use xdr_stream_subsegment()
[ Upstream commit dae9a6cab8009e526570e7477ce858dcdfeb256e ]

Refactor.

Now that the NFSv2 and NFSv3 XDR decoders have been converted to
use xdr_streams, the WRITE decoder functions can use
xdr_stream_subsegment() to extract the WRITE payload into its own
xdr_buf, just as the NFSv4 WRITE XDR decoder currently does.

That makes it possible to pass the first kvec, pages array + length,
page_base, and total payload length via a single function parameter.

The payload's page_base is not yet assigned or used, but will be in
subsequent patches.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
[ cel: adjusted to apply to v5.10.y ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:48 +01:00
Chuck Lever
af8db3370b SUNRPC: Trace calls to .rpc_call_done
[ Upstream commit b40887e10dcacc5e8ae3c1a99dcba20877c4831b ]

Introduce a single tracepoint that can replace simple dprintk call
sites in upper layer "rpc_call_done" callbacks. Example:

   kworker/u24:2-1254  [001]   771.026677: rpc_stats_latency:    task:00000001@00000002 xid=0x16a6f3c0 rpcbindv2 GETPORT backlog=446 rtt=101 execute=555
   kworker/u24:2-1254  [001]   771.026677: rpc_task_call_done:   task:00000001@00000002 flags=ASYNC|DYNAMIC|SOFT|SOFTCONN|SENT runstate=RUNNING|ACTIVE status=0 action=rpcb_getport_done
   kworker/u24:2-1254  [001]   771.026678: rpcb_setport:         task:00000001@00000002 status=0 port=20048

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:47 +01:00
Chuck Lever
83656eacdb SUNRPC: Eliminate the RQ_AUTHERR flag
[ Upstream commit 9082e1d914f8b27114352b1940bbcc7522f682e7 ]

Now that there is an alternate method for returning an auth_stat
value, replace the RQ_AUTHERR flag with use of that new method.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:45 +01:00
Chuck Lever
9705fedbeb SUNRPC: Set rq_auth_stat in the pg_authenticate() callout
[ Upstream commit 5c2465dfd457f3015eebcc3ace50570e1d896aeb ]

In a few moments, rq_auth_stat will need to be explicitly set to
rpc_auth_ok before execution gets to the dispatcher.

svc_authenticate() already sets it, but it often gets reset to
rpc_autherr_badcred right after that call, even when authentication
is successful. Let's ensure that the pg_authenticate callout and
svc_set_client() set it properly in every case.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:45 +01:00
Chuck Lever
c51740a8d7 SUNRPC: Add svc_rqst::rq_auth_stat
[ Upstream commit 438623a06bacd69c40c4af633bb09a3bbb9dfc78 ]

I'd like to take commit 4532608d71c8 ("SUNRPC: Clean up generic
dispatcher code") even further by using only private local SVC
dispatchers for all kernel RPC services. This change would enable
the removal of the logic that switches between
svc_generic_dispatch() and a service's private dispatcher, and
simplify the invocation of the service's pc_release method
so that humans can visually verify that it is always invoked
properly.

All that will come later.

First, let's provide a better way to return authentication errors
from SVC dispatcher functions. Instead of overloading the dispatch
method's *statp argument, add a field to struct svc_rqst that can
hold an error value.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:45 +01:00
Chuck Lever
02094bf7cf SUNRPC: Add svc_rqst_replace_page() API
[ Upstream commit 2f0f88f42f2eab0421ed37d7494de9124fdf0d34 ]

Replacing a page in rq_pages[] requires a get_page(), which is a
bus-locked operation, and a put_page(), which can be even more
costly.

To reduce the cost of replacing a page in rq_pages[], batch the
put_page() operations by collecting "freed" pages in a pagevec,
and then release those pages when the pagevec is full. This
pagevec is also emptied when each RPC completes.

[ cel: adjusted to apply without f6e70aab9dfe ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:44 +01:00
Chuck Lever
aa29daf2f0 SUNRPC: Export svc_xprt_received()
[ Upstream commit 7dcfbd86adc45f6d6b37278efd22530cf80ab474 ]

Prepare svc_xprt_received() to be called from transport code instead
of from generic RPC server code.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:36 +01:00
Chuck Lever
ff3549728d NFSD: Replace the internals of the READ_BUF() macro
[ Upstream commit c1346a1216ab5cb04a265380ac9035d91b16b6d5 ]

Convert the READ_BUF macro in nfs4xdr.c from open code to instead
use the new xdr_stream-style decoders already in use by the encode
side (and by the in-kernel NFS client implementation). Once this
conversion is done, each individual NFSv4 argument decoder can be
independently cleaned up to replace these macros with C code.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:21 +01:00