linux-stable.git/fs/lockd, branch v5.17.2

Merge tag 'nfsd-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

2022-02-02T18:14:31+00:00

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

lockd: fix failure to cleanup client locks

2022-01-27T15:45:25+00:00

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 7f024fcd5c97 ("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: 7f024fcd5c97 ("Keep read and write fds with each nlm_file")
Signed-off-by: J. Bruce Fields 
[ cel: fixed checkpatch.pl nit ]
Signed-off-by: Chuck Lever

lockd: fix server crash on reboot of client holding lock

2022-01-18T22:07:48+00:00

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 
Fixes: 7f024fcd5c97 ("Keep read and write fds with each nlm_file")
Signed-off-by: J. Bruce Fields 
Signed-off-by: Chuck Lever

Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2022-01-17T03:49:30+00:00

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//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
  ...

nfs: block notification on fs with its own ->lock

2022-01-08T19:42:01+00:00

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 f657f8eef3ff ("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 f657f8eef3ff ("nfs: don't atempt
blocking locks on nfs reexports") [sic] and commit b840be2f00c0 ("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 
Signed-off-by: J. Bruce Fields 
[ cel: Description rewritten to address checkpatch nits ]
[ cel: Fixed warning when SUNRPC debugging is disabled ]
[ cel: Fixed NULL check ]
Signed-off-by: Chuck Lever 
Reviewed-by: Vasily Averin

lockd: use svc_set_num_threads() for thread start and stop

2021-12-13T18:42:58+00:00

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 
Signed-off-by: Chuck Lever

lockd: rename lockd_create_svc() to lockd_get()

2021-12-13T18:42:56+00:00

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 
Signed-off-by: Chuck Lever

lockd: introduce lockd_put()

2021-12-13T18:42:56+00:00

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 
Signed-off-by: Chuck Lever

lockd: move svc_exit_thread() into the thread

2021-12-13T18:42:55+00:00

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 
Signed-off-by: Chuck Lever

lockd: move lockd_start_svc() call into lockd_create_svc()

2021-12-13T18:42:55+00:00

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 
Signed-off-by: Chuck Lever