664  * when they finish. There is defined a safe point for freezing when one work
673 	struct kthread_work *work;  in kthread_worker_fn()  local
696 	work = NULL;  in kthread_worker_fn()
699 		work = list_first_entry(&worker->work_list,  in kthread_worker_fn()
701 		list_del_init(&work->node);  in kthread_worker_fn()
703 	worker->current_work = work;  in kthread_worker_fn()
706 	if (work) {  in kthread_worker_fn()
708 		work->func(work);  in kthread_worker_fn()
809  * Returns true when the work could not be queued at the moment.
814 				   struct kthread_work *work)  in queuing_blocked()  argument
818 	return !list_empty(&work->node) || work->canceling;  in queuing_blocked()
822 					     struct kthread_work *work)  in kthread_insert_work_sanity_check()  argument
825 	WARN_ON_ONCE(!list_empty(&work->node));  in kthread_insert_work_sanity_check()
826 	/* Do not use a work with >1 worker, see kthread_queue_work() */  in kthread_insert_work_sanity_check()
827 	WARN_ON_ONCE(work->worker && work->worker != worker);  in kthread_insert_work_sanity_check()
830 /* insert @work before @pos in @worker */
832 				struct kthread_work *work,  in kthread_insert_work()  argument
835 	kthread_insert_work_sanity_check(worker, work);  in kthread_insert_work()
837 	list_add_tail(&work->node, pos);  in kthread_insert_work()
838 	work->worker = worker;  in kthread_insert_work()
846  * @work: kthread_work to queue
848  * Queue @work to work processor @task for async execution.  @task
850  * if @work was successfully queued, %false if it was already pending.
852  * Reinitialize the work if it needs to be used by another worker.
856 			struct kthread_work *work)  in kthread_queue_work()  argument
862 	if (!queuing_blocked(worker, work)) {  in kthread_queue_work()
863 		kthread_insert_work(worker, work, &worker->work_list);  in kthread_queue_work()
873  *	delayed work when the timer expires.
882 	struct kthread_work *work = &dwork->work;  in kthread_delayed_work_timer_fn()  local
883 	struct kthread_worker *worker = work->worker;  in kthread_delayed_work_timer_fn()
887 	 * This might happen when a pending work is reinitialized.  in kthread_delayed_work_timer_fn()
894 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in kthread_delayed_work_timer_fn()
895 	WARN_ON_ONCE(work->worker != worker);  in kthread_delayed_work_timer_fn()
897 	/* Move the work from worker->delayed_work_list. */  in kthread_delayed_work_timer_fn()
898 	WARN_ON_ONCE(list_empty(&work->node));  in kthread_delayed_work_timer_fn()
899 	list_del_init(&work->node);  in kthread_delayed_work_timer_fn()
900 	if (!work->canceling)  in kthread_delayed_work_timer_fn()
901 		kthread_insert_work(worker, work, &worker->work_list);  in kthread_delayed_work_timer_fn()
912 	struct kthread_work *work = &dwork->work;  in __kthread_queue_delayed_work()  local
917 	 * If @delay is 0, queue @dwork->work immediately.  This is for  in __kthread_queue_delayed_work()
923 		kthread_insert_work(worker, work, &worker->work_list);  in __kthread_queue_delayed_work()
928 	kthread_insert_work_sanity_check(worker, work);  in __kthread_queue_delayed_work()
930 	list_add(&work->node, &worker->delayed_work_list);  in __kthread_queue_delayed_work()
931 	work->worker = worker;  in __kthread_queue_delayed_work()
937  * kthread_queue_delayed_work - queue the associated kthread work
943  * If the work has not been pending it starts a timer that will queue
944  * the work after the given @delay. If @delay is zero, it queues the
945  * work immediately.
947  * Return: %false if the @work has already been pending. It means that
948  * either the timer was running or the work was queued. It returns %true
955 	struct kthread_work *work = &dwork->work;  in kthread_queue_delayed_work()  local
961 	if (!queuing_blocked(worker, work)) {  in kthread_queue_delayed_work()
972 	struct kthread_work	work;  member
976 static void kthread_flush_work_fn(struct kthread_work *work)  in kthread_flush_work_fn()  argument
979 		container_of(work, struct kthread_flush_work, work);  in kthread_flush_work_fn()
985  * @work: work to flush
987  * If @work is queued or executing, wait for it to finish execution.
989 void kthread_flush_work(struct kthread_work *work)  in kthread_flush_work()  argument
992 		KTHREAD_WORK_INIT(fwork.work, kthread_flush_work_fn),  in kthread_flush_work()
998 	worker = work->worker;  in kthread_flush_work()
1003 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in kthread_flush_work()
1004 	WARN_ON_ONCE(work->worker != worker);  in kthread_flush_work()
1006 	if (!list_empty(&work->node))  in kthread_flush_work()
1007 		kthread_insert_work(worker, &fwork.work, work->node.next);  in kthread_flush_work()
1008 	else if (worker->current_work == work)  in kthread_flush_work()
1009 		kthread_insert_work(worker, &fwork.work,  in kthread_flush_work()
1022  * This function removes the work from the worker queue. Also it makes sure
1023  * that it won't get queued later via the delayed work's timer.
1025  * The work might still be in use when this function finishes. See the
1028  * Return: %true if @work was pending and successfully canceled,
1029  *	%false if @work was not pending
1031 static bool __kthread_cancel_work(struct kthread_work *work, bool is_dwork,  in __kthread_cancel_work()  argument
1037 			container_of(work, struct kthread_delayed_work, work);  in __kthread_cancel_work()
1038 		struct kthread_worker *worker = work->worker;  in __kthread_cancel_work()
1046 		work->canceling++;  in __kthread_cancel_work()
1050 		work->canceling--;  in __kthread_cancel_work()
1054 	 * Try to remove the work from a worker list. It might either  in __kthread_cancel_work()
1057 	if (!list_empty(&work->node)) {  in __kthread_cancel_work()
1058 		list_del_init(&work->node);  in __kthread_cancel_work()
1066  * kthread_mod_delayed_work - modify delay of or queue a kthread delayed work
1068  * @dwork: kthread delayed work to queue
1073  * @work is guaranteed to be queued immediately.
1078  * A special case is when the work is being canceled in parallel.
1092 	struct kthread_work *work = &dwork->work;  in kthread_mod_delayed_work()  local
1099 	if (!work->worker)  in kthread_mod_delayed_work()
1102 	/* Work must not be used with >1 worker, see kthread_queue_work() */  in kthread_mod_delayed_work()
1103 	WARN_ON_ONCE(work->worker != worker);  in kthread_mod_delayed_work()
1105 	/* Do not fight with another command that is canceling this work. */  in kthread_mod_delayed_work()
1106 	if (work->canceling)  in kthread_mod_delayed_work()
1109 	ret = __kthread_cancel_work(work, true, &flags);  in kthread_mod_delayed_work()
1118 static bool __kthread_cancel_work_sync(struct kthread_work *work, bool is_dwork)  in __kthread_cancel_work_sync()  argument
1120 	struct kthread_worker *worker = work->worker;  in __kthread_cancel_work_sync()
1128 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in __kthread_cancel_work_sync()
1129 	WARN_ON_ONCE(work->worker != worker);  in __kthread_cancel_work_sync()
1131 	ret = __kthread_cancel_work(work, is_dwork, &flags);  in __kthread_cancel_work_sync()
1133 	if (worker->current_work != work)  in __kthread_cancel_work_sync()
1137 	 * The work is in progress and we need to wait with the lock released.  in __kthread_cancel_work_sync()
1140 	work->canceling++;  in __kthread_cancel_work_sync()
1142 	kthread_flush_work(work);  in __kthread_cancel_work_sync()
1144 	work->canceling--;  in __kthread_cancel_work_sync()
1153  * kthread_cancel_work_sync - cancel a kthread work and wait for it to finish
1154  * @work: the kthread work to cancel
1156  * Cancel @work and wait for its execution to finish.  This function
1157  * can be used even if the work re-queues itself. On return from this
1158  * function, @work is guaranteed to be not pending or executing on any CPU.
1160  * kthread_cancel_work_sync(&delayed_work->work) must not be used for
1163  * The caller must ensure that the worker on which @work was last
1166  * Return: %true if @work was pending, %false otherwise.
1168 bool kthread_cancel_work_sync(struct kthread_work *work)  in kthread_cancel_work_sync()  argument
1170 	return __kthread_cancel_work_sync(work, false);  in kthread_cancel_work_sync()
1175  * kthread_cancel_delayed_work_sync - cancel a kthread delayed work and
1177  * @dwork: the kthread delayed work to cancel
1185 	return __kthread_cancel_work_sync(&dwork->work, true);  in kthread_cancel_delayed_work_sync()
1199 		KTHREAD_WORK_INIT(fwork.work, kthread_flush_work_fn),  in kthread_flush_worker()
1203 	kthread_queue_work(worker, &fwork.work);  in kthread_flush_worker()