workqueue: set delayed_work->timer function on initialization

delayed_work->timer.function is currently initialized during queue_delayed_work_on(). Export delayed_work_timer_fn() and set delayed_work timer function during delayed_work initialization together with other fields. This ensures the timer function is always valid on an initialized delayed_work. This is to help mod_delayed_work() implementation. To detect delayed_work users which diddle with the internal timer, trigger WARN if timer function doesn't match on queue.

Tejun Heo committed 14 years ago

Commit d8e794d1 parent 8930cab2 files · +15 −5Browse files

Showing the changes to kernel/workqueue.c (1 of 2 files). Show all

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kernel/workqueue.c+4−3

@@ -1112,7 +1112,7 @@ bool queue_work(struct workqueue_struct wq, struct work_struct work) · 1111 unmodified lines
1112	1112	}
1113	1113	EXPORT_SYMBOL_GPL(queue_work);
1114	1114
1115		−static void delayed_work_timer_fn(unsigned long __data)
	1115	+void delayed_work_timer_fn(unsigned long __data)
1116	1116	{
1117	1117	struct delayed_work dwork = (struct delayed_work )__data;
1118	1118	struct cpu_workqueue_struct *cwq = get_work_cwq(&dwork->work);
@@ -1121,6 +1121,7 @@ static void delayed_work_timer_fn(unsigned long __data) · 2 unmodified lines
1121	1121	__queue_work(smp_processor_id(), cwq->wq, &dwork->work);
1122	1122	local_irq_enable();
1123	1123	}
	1124	+EXPORT_SYMBOL_GPL(delayed_work_timer_fn);
1124	1125
1125	1126	/**
1126	1127	* queue_delayed_work_on - queue work on specific CPU after delay
@@ -1145,6 +1146,8 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq, · 18 unmodified lines
1145	1146	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
1146	1147	unsigned int lcpu;
1147	1148
	1149	+ WARN_ON_ONCE(timer->function != delayed_work_timer_fn \|\|
	1150	+ timer->data != (unsigned long)dwork);
1148	1151	BUG_ON(timer_pending(timer));
1149	1152	BUG_ON(!list_empty(&work->entry));
1150	1153
@@ -1168,8 +1171,6 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq, · 17 unmodified lines
1168	1171	set_work_cwq(work, get_cwq(lcpu, wq), 0);
1169	1172
1170	1173	timer->expires = jiffies + delay;
1171		− timer->data = (unsigned long)dwork;
1172		− timer->function = delayed_work_timer_fn;
1173	1174
1174	1175	if (unlikely(cpu >= 0))
1175	1176	add_timer_on(timer, cpu);