workqueue: implement current_is_async()
This function queries whether %current is an async worker executing an
async item. This will be used to implement warning on synchronous
request_module() from async workers.
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/include/linux/async.h b/include/linux/async.h
index 7a24fe9..345169c 100644
--- a/include/linux/async.h
+++ b/include/linux/async.h
@@ -52,4 +52,5 @@
extern void async_synchronize_cookie(async_cookie_t cookie);
extern void async_synchronize_cookie_domain(async_cookie_t cookie,
struct async_domain *domain);
+extern bool current_is_async(void);
#endif