[PATCH 17/32] closures: closure_wait_event()

Kent Overstreet
2023-05-09T16:59:20Z

From: Kent Overstreet <kent.overstreet@gmail.com>

Like wait_event() - except, because it uses closures and closure
waitlists it doesn't have the restriction on modifying task state inside
the condition check, like wait_event() does.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---
include/linux/closure.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)

diff --git a/include/linux/closure.h b/include/linux/closure.h
index 0ec9e7bc8d..36b4a83f9b 100644
--- a/include/linux/closure.h
+++ b/include/linux/closure.h
@@ -374,4 +374,26 @@ static inline void closure_call(struct closure *cl, closure_fn fn,
continue_at_nobarrier(cl, fn, wq);
}

+#define __closure_wait_event(waitlist, _cond) \
+do { \
+ struct closure cl; \
+ \
+ closure_init_stack(&cl); \
+ \
+ while (1) { \
+ closure_wait(waitlist, &cl); \
+ if (_cond) \
+ break; \
+ closure_sync(&cl); \
+ } \
+ closure_wake_up(waitlist); \
+ closure_sync(&cl); \
+} while (0)
+
+#define closure_wait_event(waitlist, _cond) \
+do { \
+ if (!(_cond)) \
+ __closure_wait_event(waitlist, _cond); \
+} while (0)
+
#endif /* _LINUX_CLOSURE_H */
--
2.40.1