Commit Graph

625 Commits

Author SHA1 Message Date
Chuck Lever
65ba3d2425 SUNRPC: Use per-CPU counters to tally server RPC counts
- Improves counting accuracy
 - Reduces cross-CPU memory traffic

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-02-20 09:20:32 -05:00
Chuck Lever
cee4db1945 SUNRPC: Refactor RPC server dispatch method
Currently, svcauth_gss_accept() pre-reserves response buffer space
for the RPC payload length and GSS sequence number before returning
to the dispatcher, which then adds the header's accept_stat field.

The problem is the accept_stat field is supposed to go before the
length and seq_num fields. So svcauth_gss_release() has to relocate
the accept_stat value (see svcauth_gss_prepare_to_wrap()).

To enable these fields to be added to the response buffer in the
correct (final) order, the pointer to the accept_stat has to be made
available to svcauth_gss_accept() so that it can set it before
reserving space for the length and seq_num fields.

As a first step, move the pointer to the location of the accept_stat
field into struct svc_rqst.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-02-20 09:20:31 -05:00
Chuck Lever
8dd41d70f3 SUNRPC: Push svcxdr_init_encode() into svc_process_common()
Now that all vs_dispatch functions invoke svcxdr_init_encode(), it
is common code and can be pushed down into the generic RPC server.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-02-20 09:20:27 -05:00
Chuck Lever
dba5eaa46b SUNRPC: Push svcxdr_init_decode() into svc_process_common()
Now that all vs_dispatch functions invoke svcxdr_init_decode(), it
is common code and can be pushed down into the generic RPC server.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-02-20 09:20:09 -05:00
Linus Torvalds
764822972d NFSD 6.2 Release Notes
This release introduces support for the CB_RECALL_ANY operation.
 NFSD can send this operation to request that clients return any
 delegations they choose. The server uses this operation to handle
 low memory scenarios or indicate to a client when that client has
 reached the maximum number of delegations the server supports.
 
 The NFSv4.2 READ_PLUS operation has been simplified temporarily
 whilst support for sparse files in local filesystems and the VFS is
 improved.
 
 Two major data structure fixes appear in this release:
 
 * The nfs4_file hash table is replaced with a resizable hash table
   to reduce the latency of NFSv4 OPEN operations.
 
 * Reference counting in the NFSD filecache has been hardened against
   races.
 
 In furtherance of removing support for NFSv2 in a subsequent kernel
 release, a new Kconfig option enables server-side support for NFSv2
 to be left out of a kernel build.
 
 MAINTAINERS has been updated to indicate that changes to fs/exportfs
 should go through the NFSD tree.
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Merge tag 'nfsd-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd updates from Chuck Lever:
 "This release introduces support for the CB_RECALL_ANY operation. NFSD
  can send this operation to request that clients return any delegations
  they choose. The server uses this operation to handle low memory
  scenarios or indicate to a client when that client has reached the
  maximum number of delegations the server supports.

  The NFSv4.2 READ_PLUS operation has been simplified temporarily whilst
  support for sparse files in local filesystems and the VFS is improved.

  Two major data structure fixes appear in this release:

   - The nfs4_file hash table is replaced with a resizable hash table to
     reduce the latency of NFSv4 OPEN operations.

   - Reference counting in the NFSD filecache has been hardened against
     races.

  In furtherance of removing support for NFSv2 in a subsequent kernel
  release, a new Kconfig option enables server-side support for NFSv2 to
  be left out of a kernel build.

  MAINTAINERS has been updated to indicate that changes to fs/exportfs
  should go through the NFSD tree"

* tag 'nfsd-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (49 commits)
  NFSD: Avoid clashing function prototypes
  SUNRPC: Fix crasher in unwrap_integ_data()
  SUNRPC: Make the svc_authenticate tracepoint conditional
  NFSD: Use only RQ_DROPME to signal the need to drop a reply
  SUNRPC: Clean up xdr_write_pages()
  SUNRPC: Don't leak netobj memory when gss_read_proxy_verf() fails
  NFSD: add CB_RECALL_ANY tracepoints
  NFSD: add delegation reaper to react to low memory condition
  NFSD: add support for sending CB_RECALL_ANY
  NFSD: refactoring courtesy_client_reaper to a generic low memory shrinker
  trace: Relocate event helper files
  NFSD: pass range end to vfs_fsync_range() instead of count
  lockd: fix file selection in nlmsvc_cancel_blocked
  lockd: ensure we use the correct file descriptor when unlocking
  lockd: set missing fl_flags field when retrieving args
  NFSD: Use struct_size() helper in alloc_session()
  nfsd: return error if nfs4_setacl fails
  lockd: set other missing fields when unlocking files
  NFSD: Add an nfsd_file_fsync tracepoint
  sunrpc: svc: Remove an unused static function svc_ungetu32()
  ...
2022-12-12 20:54:39 -08:00
Jeff Layton
9f27783b4d lockd: fix file selection in nlmsvc_cancel_blocked
We currently do a lock_to_openmode call based on the arguments from the
NLM_UNLOCK call, but that will always set the fl_type of the lock to
F_UNLCK, and the O_RDONLY descriptor is always chosen.

Fix it to use the file_lock from the block instead.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:11 -05:00
Jeff Layton
69efce009f lockd: ensure we use the correct file descriptor when unlocking
Shared locks are set on O_RDONLY descriptors and exclusive locks are set
on O_WRONLY ones. nlmsvc_unlock however calls vfs_lock_file twice, once
for each descriptor, but it doesn't reset fl_file. Ensure that it does.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:11 -05:00
Jeff Layton
75c7940d2a lockd: set missing fl_flags field when retrieving args
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:11 -05:00
Trond Myklebust
18ebd35b61 lockd: set other missing fields when unlocking files
vfs_lock_file() expects the struct file_lock to be fully initialised by
the caller. Re-exported NFSv3 has been seen to Oops if the fl_file field
is NULL.

Fixes: aec158242b ("lockd: set fl_owner when unlocking files")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216582
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:11 -05:00
Jeff Layton
98b41ffe0a lockd: use locks_inode_context helper
lockd currently doesn't access i_flctx safely. This requires a
smp_load_acquire, as the pointer is set via cmpxchg (a release
operation).

Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
2022-11-30 05:08:10 -05:00
Chuck Lever
103cc1fafe SUNRPC: Parametrize how much of argsize should be zeroed
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>
2022-09-26 14:02:42 -04:00
Wolfram Sang
97f8e62572 lockd: move from strlcpy with unused retval to strscpy
Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-09-26 14:02:20 -04:00
Jeff Layton
6930bcbfb6 lockd: detect and reject lock arguments that overflow
lockd doesn't currently vet the start and length in nlm4 requests like
it should, and can end up generating lock requests with arguments that
overflow when passed to the filesystem.

The NLM4 protocol uses unsigned 64-bit arguments for both start and
length, whereas struct file_lock tracks the start and end as loff_t
values. By the time we get around to calling nlm4svc_retrieve_args,
we've lost the information that would allow us to determine if there was
an overflow.

Start tracking the actual start and len for NLM4 requests in the
nlm_lock. In nlm4svc_retrieve_args, vet these values to ensure they
won't cause an overflow, and return NLM4_FBIG if they do.

Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=392
Reported-by: Jan Kasiak <j.kasiak@gmail.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@vger.kernel.org> # 5.14+
2022-08-04 10:28:48 -04:00
Benjamin Coddington
184cefbe62 NLM: Defend against file_lock changes after vfs_test_lock()
Instead of trusting that struct file_lock returns completely unchanged
after vfs_test_lock() when there's no conflicting lock, stash away our
nlm_lockowner reference so we can properly release it for all cases.

This defends against another file_lock implementation overwriting fl_owner
when the return type is F_UNLCK.

Reported-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
Tested-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29 20:08:56 -04:00
Jeff Layton
1197eb5906 lockd: fix nlm_close_files
This loop condition tries a bit too hard to be clever. Just test for
the two indices we care about explicitly.

Cc: J. Bruce Fields <bfields@fieldses.org>
Fixes: 7f024fcd5c ("Keep read and write fds with each nlm_file")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-11 15:49:56 -04:00
Jeff Layton
aec158242b lockd: set fl_owner when unlocking files
Unlocking a POSIX lock on an inode with vfs_lock_file only works if
the owner matches. Ensure we set it in the request.

Cc: J. Bruce Fields <bfields@fieldses.org>
Fixes: 7f024fcd5c ("Keep read and write fds with each nlm_file")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-11 15:49:56 -04:00
Chuck Lever
37902c6313 NFSD: Move svc_serv_ops::svo_function into struct svc_serv
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>
2022-02-28 10:26:40 -05:00
Chuck Lever
f49169c97f NFSD: Remove svc_serv_ops::svo_module
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>
2022-02-28 10:26:40 -05:00
Chuck Lever
c7d7ec8f04 SUNRPC: Remove svc_shutdown_net()
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>
2022-02-28 10:26:40 -05:00
Chuck Lever
352ad31448 SUNRPC: Rename svc_create_xprt()
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>
2022-02-28 10:26:39 -05:00
Chuck Lever
87cdd8641c SUNRPC: Remove svo_shutdown method
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>
2022-02-28 10:26:39 -05:00
Chuck Lever
a9ff2e99e9 SUNRPC: Remove the .svo_enqueue_xprt method
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 b9e13cdfac ("nfsd/sunrpc:
turn enqueueing a svc_xprt into a svc_serv operation").

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-02-28 10:26:39 -05:00
Linus Torvalds
88808fbbea Notable bug fixes:
- Ensure SM_NOTIFY doesn't crash the NFS server host
 - Ensure NLM locks are cleaned up after client reboot
 - Fix a leak of internal NFSv4 lease information
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Merge tag 'nfsd-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fixes from Chuck Lever:
 "Notable bug fixes:

   - Ensure SM_NOTIFY doesn't crash the NFS server host

   - Ensure NLM locks are cleaned up after client reboot

   - Fix a leak of internal NFSv4 lease information"

* tag 'nfsd-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  nfsd: nfsd4_setclientid_confirm mistakenly expires confirmed client.
  lockd: fix failure to cleanup client locks
  lockd: fix server crash on reboot of client holding lock
2022-02-02 10:14:31 -08:00
J. Bruce Fields
d19a7af73b lockd: fix failure to cleanup client locks
In my testing, we're sometimes hitting the request->fl_flags & FL_EXISTS
case in posix_lock_inode, presumably just by random luck since we're not
actually initializing fl_flags here.

This probably didn't matter before commit 7f024fcd5c ("Keep read and
write fds with each nlm_file") since we wouldn't previously unlock
unless we knew there were locks.

But now it causes lockd to give up on removing more locks.

We could just initialize fl_flags, but really it seems dubious to be
calling vfs_lock_file with random values in some of the fields.

Fixes: 7f024fcd5c ("Keep read and write fds with each nlm_file")
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
[ cel: fixed checkpatch.pl nit ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-27 10:45:25 -05:00
J. Bruce Fields
6e7f90d163 lockd: fix server crash on reboot of client holding lock
I thought I was iterating over the array when actually the iteration is
over the values contained in the array?

Ugh, keep it simple.

Symptoms were a null deference in vfs_lock_file() when an NFSv3 client
that previously held a lock came back up and sent a notify.

Reported-by: Jonathan Woithe <jwoithe@just42.net>
Fixes: 7f024fcd5c ("Keep read and write fds with each nlm_file")
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-18 17:07:48 -05:00
Linus Torvalds
35ce8ae9ae Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull signal/exit/ptrace updates from Eric Biederman:
 "This set of changes deletes some dead code, makes a lot of cleanups
  which hopefully make the code easier to follow, and fixes bugs found
  along the way.

  The end-game which I have not yet reached yet is for fatal signals
  that generate coredumps to be short-circuit deliverable from
  complete_signal, for force_siginfo_to_task not to require changing
  userspace configured signal delivery state, and for the ptrace stops
  to always happen in locations where we can guarantee on all
  architectures that the all of the registers are saved and available on
  the stack.

  Removal of profile_task_ext, profile_munmap, and profile_handoff_task
  are the big successes for dead code removal this round.

  A bunch of small bug fixes are included, as most of the issues
  reported were small enough that they would not affect bisection so I
  simply added the fixes and did not fold the fixes into the changes
  they were fixing.

  There was a bug that broke coredumps piped to systemd-coredump. I
  dropped the change that caused that bug and replaced it entirely with
  something much more restrained. Unfortunately that required some
  rebasing.

  Some successes after this set of changes: There are few enough calls
  to do_exit to audit in a reasonable amount of time. The lifetime of
  struct kthread now matches the lifetime of struct task, and the
  pointer to struct kthread is no longer stored in set_child_tid. The
  flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is
  removed. Issues where task->exit_code was examined with
  signal->group_exit_code should been examined were fixed.

  There are several loosely related changes included because I am
  cleaning up and if I don't include them they will probably get lost.

  The original postings of these changes can be found at:
     https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.org
     https://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.org
     https://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org

  I trimmed back the last set of changes to only the obviously correct
  once. Simply because there was less time for review than I had hoped"

* 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits)
  ptrace/m68k: Stop open coding ptrace_report_syscall
  ptrace: Remove unused regs argument from ptrace_report_syscall
  ptrace: Remove second setting of PT_SEIZED in ptrace_attach
  taskstats: Cleanup the use of task->exit_code
  exit: Use the correct exit_code in /proc/<pid>/stat
  exit: Fix the exit_code for wait_task_zombie
  exit: Coredumps reach do_group_exit
  exit: Remove profile_handoff_task
  exit: Remove profile_task_exit & profile_munmap
  signal: clean up kernel-doc comments
  signal: Remove the helper signal_group_exit
  signal: Rename group_exit_task group_exec_task
  coredump: Stop setting signal->group_exit_task
  signal: Remove SIGNAL_GROUP_COREDUMP
  signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process
  signal: Make coredump handling explicit in complete_signal
  signal: Have prepare_signal detect coredumps using signal->core_state
  signal: Have the oom killer detect coredumps using signal->core_state
  exit: Move force_uaccess back into do_exit
  exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit
  ...
2022-01-17 05:49:30 +02:00
J. Bruce Fields
40595cdc93 nfs: block notification on fs with its own ->lock
NFSv4.1 supports an optional lock notification feature which notifies
the client when a lock comes available.  (Normally NFSv4 clients just
poll for locks if necessary.)  To make that work, we need to request a
blocking lock from the filesystem.

We turned that off for NFS in commit f657f8eef3 ("nfs: don't atempt
blocking locks on nfs reexports") [sic] because it actually blocks the
nfsd thread while waiting for the lock.

Thanks to Vasily Averin for pointing out that NFS isn't the only
filesystem with that problem.

Any filesystem that leaves ->lock NULL will use posix_lock_file(), which
does the right thing.  Simplest is just to assume that any filesystem
that defines its own ->lock is not safe to request a blocking lock from.

So, this patch mostly reverts commit f657f8eef3 ("nfs: don't atempt
blocking locks on nfs reexports") [sic] and commit b840be2f00 ("lockd:
don't attempt blocking locks on nfs reexports"), and instead uses a
check of ->lock (Vasily's suggestion) to decide whether to support
blocking lock notifications on a given filesystem.  Also add a little
documentation.

Perhaps someday we could add back an export flag later to allow
filesystems with "good" ->lock methods to support blocking lock
notifications.

Reported-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
[ cel: Description rewritten to address checkpatch nits ]
[ cel: Fixed warning when SUNRPC debugging is disabled ]
[ cel: Fixed NULL check ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Vasily Averin <vvs@virtuozzo.com>
2022-01-08 14:42:01 -05:00
NeilBrown
6b044fbaab lockd: use svc_set_num_threads() for thread start and stop
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>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13 13:42:58 -05:00
NeilBrown
ecd3ad68d2 lockd: rename lockd_create_svc() to lockd_get()
lockd_create_svc() already does an svc_get() if the service already
exists, so it is more like a "get" than a "create".

So:
 - Move the increment of nlmsvc_users into the function as well
 - rename to lockd_get().

It is now the inverse of lockd_put().

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13 13:42:56 -05:00
NeilBrown
865b674069 lockd: introduce lockd_put()
There is some cleanup that is duplicated in lockd_down() and the failure
path of lockd_up().
Factor these out into a new lockd_put() and call it from both places.

lockd_put() does *not* take the mutex - that must be held by the caller.
It decrements nlmsvc_users and if that reaches zero, it cleans up.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13 13:42:56 -05:00
NeilBrown
6a4e2527a6 lockd: move svc_exit_thread() into the thread
The normal place to call svc_exit_thread() is from the thread itself
just before it exists.
Do this for lockd.

This means that nlmsvc_rqst is not used out side of lockd_start_svc(),
so it can be made local to that function, and renamed to 'rqst'.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13 13:42:55 -05:00
NeilBrown
b73a297204 lockd: move lockd_start_svc() call into lockd_create_svc()
lockd_start_svc() only needs to be called once, just after the svc is
created.  If the start fails, the svc is discarded too.

It thus makes sense to call lockd_start_svc() from lockd_create_svc().
This allows us to remove the test against nlmsvc_rqst at the start of
lockd_start_svc() - it must always be NULL.

lockd_up() only held an extra reference on the svc until a thread was
created - then it dropped it.  The thread - and thus the extra reference
- will remain until kthread_stop() is called.
Now that the thread is created in lockd_create_svc(), the extra
reference can be dropped there.  So the 'serv' variable is no longer
needed in lockd_up().

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13 13:42:55 -05:00
NeilBrown
5a8a7ff574 lockd: simplify management of network status notifiers
Now that the network status notifiers use nlmsvc_serv rather then
nlmsvc_rqst the management can be simplified.

Notifier unregistration synchronises with any pending notifications so
providing we unregister before nlm_serv is freed no further interlock
is required.

So we move the unregister call to just before the thread is killed
(which destroys the service) and just before the service is destroyed in
the failure-path of lockd_up().

Then nlm_ntf_refcnt and nlm_ntf_wq can be removed.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13 13:42:55 -05:00
NeilBrown
2840fe864c lockd: introduce nlmsvc_serv
lockd has two globals - nlmsvc_task and nlmsvc_rqst - but mostly it
wants the 'struct svc_serv', and when it doesn't want it exactly it can
get to what it wants from the serv.

This patch is a first step to removing nlmsvc_task and nlmsvc_rqst.  It
introduces nlmsvc_serv to store the 'struct svc_serv*'.  This is set as
soon as the serv is created, and cleared only when it is destroyed.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13 13:42:54 -05:00
NeilBrown
ec52361df9 SUNRPC: stop using ->sv_nrthreads as a refcount
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>
2021-12-13 13:42:51 -05:00
NeilBrown
8c62d12740 SUNRPC/NFSD: clean up get/put functions.
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>
2021-12-13 13:42:50 -05:00
NeilBrown
df5e49c880 SUNRPC: change svc_get() to return the svc.
It is common for 'get' functions to return the object that was 'got',
and there are a couple of places where users of svc_get() would be a
little simpler if svc_get() did that.

Make it so.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13 13:42:50 -05:00
Linus Torvalds
38764c7340 A slow cycle for nfsd: mainly cleanup, including Neil's patch dropping
support for a filehandle format deprecated 20 years ago, and further
 xdr-related cleanup from Chuck.
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Merge tag 'nfsd-5.16' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "A slow cycle for nfsd: mainly cleanup, including Neil's patch dropping
  support for a filehandle format deprecated 20 years ago, and further
  xdr-related cleanup from Chuck"

* tag 'nfsd-5.16' of git://linux-nfs.org/~bfields/linux: (26 commits)
  nfsd4: remove obselete comment
  nfsd: document server-to-server-copy parameters
  NFSD:fix boolreturn.cocci warning
  nfsd: update create verifier comment
  SUNRPC: Change return value type of .pc_encode
  SUNRPC: Replace the "__be32 *p" parameter to .pc_encode
  NFSD: Save location of NFSv4 COMPOUND status
  SUNRPC: Change return value type of .pc_decode
  SUNRPC: Replace the "__be32 *p" parameter to .pc_decode
  SUNRPC: De-duplicate .pc_release() call sites
  SUNRPC: Simplify the SVC dispatch code path
  SUNRPC: Capture value of xdr_buf::page_base
  SUNRPC: Add trace event when alloc_pages_bulk() makes no progress
  svcrdma: Split svcrmda_wc_{read,write} tracepoints
  svcrdma: Split the svcrdma_wc_send() tracepoint
  svcrdma: Split the svcrdma_wc_receive() tracepoint
  NFSD: Have legacy NFSD WRITE decoders use xdr_stream_subsegment()
  SUNRPC: xdr_stream_subsegment() must handle non-zero page_bases
  NFSD: Initialize pointer ni with NULL and not plain integer 0
  NFSD: simplify struct nfsfh
  ...
2021-11-10 16:45:54 -08:00
Chuck Lever
b40887e10d SUNRPC: Trace calls to .rpc_call_done
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>
2021-10-20 18:09:54 -04:00
Chuck Lever
130e2054d4 SUNRPC: Change return value type of .pc_encode
Returning an undecorated integer is an age-old trope, but it's
not clear (even to previous experts in this code) that the only
valid return values are 1 and 0. These functions do not return
a negative errno, rpc_stat value, or a positive length.

Document there are only two valid return values by having
.pc_encode return only true or false.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13 11:34:49 -04:00
Chuck Lever
fda4944114 SUNRPC: Replace the "__be32 *p" parameter to .pc_encode
The passed-in value of the "__be32 *p" parameter is now unused in
every server-side XDR encoder, and can be removed.

Note also that there is a line in each encoder that sets up a local
pointer to a struct xdr_stream. Passing that pointer from the
dispatcher instead saves one line per encoder function.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13 11:34:49 -04:00
Chuck Lever
c44b31c263 SUNRPC: Change return value type of .pc_decode
Returning an undecorated integer is an age-old trope, but it's
not clear (even to previous experts in this code) that the only
valid return values are 1 and 0. These functions do not return
a negative errno, rpc_stat value, or a positive length.

Document there are only two valid return values by having
.pc_decode return only true or false.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13 10:29:41 -04:00
Chuck Lever
16c663642c SUNRPC: Replace the "__be32 *p" parameter to .pc_decode
The passed-in value of the "__be32 *p" parameter is now unused in
every server-side XDR decoder, and can be removed.

Note also that there is a line in each decoder that sets up a local
pointer to a struct xdr_stream. Passing that pointer from the
dispatcher instead saves one line per decoder function.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13 10:29:41 -04:00
Linus Torvalds
cf1d2c3e7e Critical bug fixes:
- Fix crash in NLM TEST procedure
 - NFSv4.1+ backchannel not restored after PATH_DOWN
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Merge tag 'nfsd-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fixes from Chuck Lever:
 "Critical bug fixes:

   - Fix crash in NLM TEST procedure

   - NFSv4.1+ backchannel not restored after PATH_DOWN"

* tag 'nfsd-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  nfsd: back channel stuck in SEQ4_STATUS_CB_PATH_DOWN
  NLM: Fix svcxdr_encode_owner()
2021-09-22 09:21:02 -07:00
Chuck Lever
89c485c7a3 NLM: Fix svcxdr_encode_owner()
Dai Ngo reports that, since the XDR overhaul, the NLM server crashes
when the TEST procedure wants to return NLM_DENIED. There is a bug
in svcxdr_encode_owner() that none of our standard test cases found.

Replace the open-coded function with a call to an appropriate
pre-fabricated XDR helper.

Reported-by: Dai Ngo <Dai.Ngo@oracle.com>
Fixes: a6a63ca565 ("lockd: Common NLM XDR helpers")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-09-17 10:35:10 -04:00
Linus Torvalds
0961f0c00e NFS Client Updates for Linux 5.15
- New Features:
   - Better client responsiveness when server isn't replying
   - Use refcount_t in sunrpc rpc_client refcount tracking
   - Add srcaddr and dst_port to the sunrpc sysfs info files
   - Add basic support for connection sharing between servers with multiple NICs`
 
 - Bugfixes and Cleanups:
   - Sunrpc tracepoint cleanups
   - Disconnect after ib_post_send() errors to avoid deadlocks
   - Fix for tearing down rpcrdma_reps
   - Fix a potential pNFS layoutget livelock loop
   - pNFS layout barrier fixes
   - Fix a potential memory corruption in rpc_wake_up_queued_task_set_status()
   - Fix reconnection locking
   - Fix return value of get_srcport()
   - Remove rpcrdma_post_sends()
   - Remove pNFS dead code
   - Remove copy size restriction for inter-server copies
   - Overhaul the NFS callback service
   - Clean up sunrpc TCP socket shutdowns
   - Always provide aligned buffers to RPC read layers
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Merge tag 'nfs-for-5.15-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client updates from Anna Schumaker:
 "New Features:
   - Better client responsiveness when server isn't replying
   - Use refcount_t in sunrpc rpc_client refcount tracking
   - Add srcaddr and dst_port to the sunrpc sysfs info files
   - Add basic support for connection sharing between servers with multiple NICs`

  Bugfixes and Cleanups:
   - Sunrpc tracepoint cleanups
   - Disconnect after ib_post_send() errors to avoid deadlocks
   - Fix for tearing down rpcrdma_reps
   - Fix a potential pNFS layoutget livelock loop
   - pNFS layout barrier fixes
   - Fix a potential memory corruption in rpc_wake_up_queued_task_set_status()
   - Fix reconnection locking
   - Fix return value of get_srcport()
   - Remove rpcrdma_post_sends()
   - Remove pNFS dead code
   - Remove copy size restriction for inter-server copies
   - Overhaul the NFS callback service
   - Clean up sunrpc TCP socket shutdowns
   - Always provide aligned buffers to RPC read layers"

* tag 'nfs-for-5.15-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (39 commits)
  NFS: Always provide aligned buffers to the RPC read layers
  NFSv4.1 add network transport when session trunking is detected
  SUNRPC enforce creation of no more than max_connect xprts
  NFSv4 introduce max_connect mount options
  SUNRPC add xps_nunique_destaddr_xprts to xprt_switch_info in sysfs
  SUNRPC keep track of number of transports to unique addresses
  NFSv3: Delete duplicate judgement in nfs3_async_handle_jukebox
  SUNRPC: Tweak TCP socket shutdown in the RPC client
  SUNRPC: Simplify socket shutdown when not reusing TCP ports
  NFSv4.2: remove restriction of copy size for inter-server copy.
  NFS: Clean up the synopsis of callback process_op()
  NFS: Extract the xdr_init_encode/decode() calls from decode_compound
  NFS: Remove unused callback void decoder
  NFS: Add a private local dispatcher for NFSv4 callback operations
  SUNRPC: Eliminate the RQ_AUTHERR flag
  SUNRPC: Set rq_auth_stat in the pg_authenticate() callout
  SUNRPC: Add svc_rqst::rq_auth_stat
  SUNRPC: Add dst_port to the sysfs xprt info file
  SUNRPC: Add srcaddr as a file in sysfs
  sunrpc: Fix return value of get_srcport()
  ...
2021-09-04 10:25:26 -07:00
J. Bruce Fields
b840be2f00 lockd: don't attempt blocking locks on nfs reexports
As in the v4 case, it doesn't work well to block waiting for a lock on
an nfs filesystem.

As in the v4 case, that means we're depending on the client to poll.
It's probably incorrect to depend on that, but I *think* clients do poll
in practice.  In any case, it's an improvement over hanging the lockd
thread indefinitely as we currently are.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-26 15:32:18 -04:00
J. Bruce Fields
7f024fcd5c Keep read and write fds with each nlm_file
We shouldn't really be using a read-only file descriptor to take a write
lock.

Most filesystems will put up with it.  But NFS, for example, won't.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-23 18:05:31 -04:00
J. Bruce Fields
b661601a9f lockd: update nlm_lookup_file reexport comment
Update comment to reflect that we *do* allow reexport, whether it's a
good idea or not....

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-23 12:56:17 -04:00
J. Bruce Fields
a81041b7d8 nlm: minor refactoring
Make this lookup slightly more concise, and prepare for changing how we
look this up in a following patch.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-23 12:56:17 -04:00