That was wrong assumption that all drivers disable irqs before waking up a wait queue. Even assert line is removed the whole logic stays correct: epoll always locks rwlock with irqs disabled and by itself does not call from interrupts, thus it is up to driver how to call wake_up_locked(), because if driver does not handle any interrupts (like fuse in the the report) of course it is safe on its side to take a simple spin_lock.
Signed-off-by: Roman Penyaev <[email protected]> Reported-by: [email protected] Cc: Davidlohr Bueso <[email protected]> Cc: Jason Baron <[email protected]> Cc: Al Viro <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: [email protected] Cc: [email protected] --- fs/eventpoll.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index f307c8679027..f5f88250cdf2 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1217,12 +1217,6 @@ static int ep_poll_callback(wait_queue_entry_t *wait, unsigned mode, int sync, v __poll_t pollflags = key_to_poll(key); int ewake = 0; - /* - * Called by irq context or interrupts are disabled by the wake_up_*poll - * callers. - */ - lockdep_assert_irqs_disabled(); - read_lock(&ep->lock); ep_set_busy_poll_napi_id(epi); -- 2.19.1
