[RFC] workqueue: dexpose worker

[Hillf Danton <hdanton@sina.com>]

It does not make much sense to expose worker, workqueue's internal
object, to outsiders, and whatever field inside worker as well.
Nor does worker pool rather than workqueue and work.

Signed-off-by: Hillf Danton <hdanton@sina.com>
---

--- a/kernel/workqueue_internal.h
+++ b/kernel/workqueue_internal.h
@@ -69,6 +69,13 @@ static inline struct worker *current_wq_
 	return NULL;
 }
 
+static inline bool current_is_executing(work_func_t func)
+{
+	struct worker *worker = current_wq_worker();
+
+	return worker && worker->current_func == func;
+}
+
 /*
  * Scheduler hooks for concurrency managed workqueue.  Only to be used from
  * sched/ and workqueue.c.
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -327,8 +327,6 @@ EXPORT_SYMBOL_GPL(async_synchronize_cook
  */
 bool current_is_async(void)
 {
-	struct worker *worker = current_wq_worker();
-
-	return worker && worker->current_func == async_run_entry_fn;
+	return current_is_executing(async_run_entry_fn);
 }
 EXPORT_SYMBOL_GPL(current_is_async);