From: Oleg Nesterov Date: Sat, 5 Sep 2009 18:17:06 +0000 (-0700) Subject: workqueues: introduce __cancel_delayed_work() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4e49627b9bc29a14b393c480e8c979e3bc922ef7;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git workqueues: introduce __cancel_delayed_work() cancel_delayed_work() has to use del_timer_sync() to guarantee the timer function is not running after return. But most users doesn't actually need this, and del_timer_sync() has problems: it is not useable from interrupt, and it depends on every lock which could be taken from irq. Introduce __cancel_delayed_work() which calls del_timer() instead. The immediate reason for this patch is http://bugzilla.kernel.org/show_bug.cgi?id=13757 but hopefully this helper makes sense anyway. As for 13757 bug, actually we need requeue_delayed_work(), but its semantics are not yet clear. Merge this patch early to resolves cross-tree interdependencies between input and infiniband. Signed-off-by: Oleg Nesterov Cc: Dmitry Torokhov Cc: Roland Dreier Cc: Stefan Richter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 13e1adf55c4c..6273fa97b527 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -240,6 +240,21 @@ static inline int cancel_delayed_work(struct delayed_work *work) return ret; } +/* + * Like above, but uses del_timer() instead of del_timer_sync(). This means, + * if it returns 0 the timer function may be running and the queueing is in + * progress. + */ +static inline int __cancel_delayed_work(struct delayed_work *work) +{ + int ret; + + ret = del_timer(&work->timer); + if (ret) + work_clear_pending(&work->work); + return ret; +} + extern int cancel_delayed_work_sync(struct delayed_work *work); /* Obsolete. use cancel_delayed_work_sync() */