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| author |   J. Bruce Fields <bfields@redhat.com> | 2020-05-06 12:09:34 -0400 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2020-05-08 21:23:10 -0400 |
| commit | 52782c92ac85c4e393eb4a903a62e6c24afa633f (patch) | |
| tree | ff14ce08344fd48a5d6228527bbd949c012a13d4 | |
| parent | sunrpc: Remove unused function ip_map_update (diff) | |
| download | linux-dev-52782c92ac85c4e393eb4a903a62e6c24afa633f.tar.xz linux-dev-52782c92ac85c4e393eb4a903a62e6c24afa633f.zip | |
kthread: save thread function
It's handy to keep the kthread_fn just as a unique cookie to identify
classes of kthreads. E.g. if you can verify that a given task is
running your thread_fn, then you may know what sort of type kthread_data
points to.
We'll use this in nfsd to pass some information into the vfs. Note it
will need kthread_data() exported too.
Original-patch-by: Tejun Heo <tj@kernel.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| -rw-r--r-- | include/linux/kthread.h | 1 | ||||
| -rw-r--r-- | kernel/kthread.c | 17 |
2 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 8bbcaad7ef0f..c2a274b79c42 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -57,6 +57,7 @@ bool kthread_should_stop(void); bool kthread_should_park(void); bool __kthread_should_park(struct task_struct *k); bool kthread_freezable_should_stop(bool *was_frozen); +void *kthread_func(struct task_struct *k); void *kthread_data(struct task_struct *k); void *kthread_probe_data(struct task_struct *k); int kthread_park(struct task_struct *k); diff --git a/kernel/kthread.c b/kernel/kthread.c index bfbfa481be3a..b84fc7eec035 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -46,6 +46,7 @@ struct kthread_create_info struct kthread { unsigned long flags; unsigned int cpu; + int (*threadfn)(void *); void *data; struct completion parked; struct completion exited; @@ -153,6 +154,20 @@ bool kthread_freezable_should_stop(bool *was_frozen) EXPORT_SYMBOL_GPL(kthread_freezable_should_stop); /** + * kthread_func - return the function specified on kthread creation + * @task: kthread task in question + * + * Returns NULL if the task is not a kthread. + */ +void *kthread_func(struct task_struct *task) +{ + if (task->flags & PF_KTHREAD) + return to_kthread(task)->threadfn; + return NULL; +} +EXPORT_SYMBOL_GPL(kthread_func); + +/** * kthread_data - return data value specified on kthread creation * @task: kthread task in question * @@ -164,6 +179,7 @@ void *kthread_data(struct task_struct *task) { return to_kthread(task)->data; } +EXPORT_SYMBOL_GPL(kthread_data); /** * kthread_probe_data - speculative version of kthread_data() @@ -244,6 +260,7 @@ static int kthread(void *_create) do_exit(-ENOMEM); } + self->threadfn = threadfn; self->data = data; init_completion(&self->exited); init_completion(&self->parked); |