710  * when they finish. There is defined a safe point for freezing when one work
719 	struct kthread_work *work;  in kthread_worker_fn()  local
742 	work = NULL;  in kthread_worker_fn()
745 		work = list_first_entry(&worker->work_list,  in kthread_worker_fn()
747 		list_del_init(&work->node);  in kthread_worker_fn()
749 	worker->current_work = work;  in kthread_worker_fn()
752 	if (work) {  in kthread_worker_fn()
754 		work->func(work);  in kthread_worker_fn()
855  * Returns true when the work could not be queued at the moment.
860 				   struct kthread_work *work)  in queuing_blocked()  argument
864 	return !list_empty(&work->node) || work->canceling;  in queuing_blocked()
868 					     struct kthread_work *work)  in kthread_insert_work_sanity_check()  argument
871 	WARN_ON_ONCE(!list_empty(&work->node));  in kthread_insert_work_sanity_check()
872 	/* Do not use a work with >1 worker, see kthread_queue_work() */  in kthread_insert_work_sanity_check()
873 	WARN_ON_ONCE(work->worker && work->worker != worker);  in kthread_insert_work_sanity_check()
876 /* insert @work before @pos in @worker */
878 				struct kthread_work *work,  in kthread_insert_work()  argument
881 	kthread_insert_work_sanity_check(worker, work);  in kthread_insert_work()
883 	list_add_tail(&work->node, pos);  in kthread_insert_work()
884 	work->worker = worker;  in kthread_insert_work()
892  * @work: kthread_work to queue
894  * Queue @work to work processor @task for async execution.  @task
896  * if @work was successfully queued, %false if it was already pending.
898  * Reinitialize the work if it needs to be used by another worker.
902 			struct kthread_work *work)  in kthread_queue_work()  argument
908 	if (!queuing_blocked(worker, work)) {  in kthread_queue_work()
909 		kthread_insert_work(worker, work, &worker->work_list);  in kthread_queue_work()
919  *	delayed work when the timer expires.
928 	struct kthread_work *work = &dwork->work;  in kthread_delayed_work_timer_fn()  local
929 	struct kthread_worker *worker = work->worker;  in kthread_delayed_work_timer_fn()
933 	 * This might happen when a pending work is reinitialized.  in kthread_delayed_work_timer_fn()
940 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in kthread_delayed_work_timer_fn()
941 	WARN_ON_ONCE(work->worker != worker);  in kthread_delayed_work_timer_fn()
943 	/* Move the work from worker->delayed_work_list. */  in kthread_delayed_work_timer_fn()
944 	WARN_ON_ONCE(list_empty(&work->node));  in kthread_delayed_work_timer_fn()
945 	list_del_init(&work->node);  in kthread_delayed_work_timer_fn()
946 	if (!work->canceling)  in kthread_delayed_work_timer_fn()
947 		kthread_insert_work(worker, work, &worker->work_list);  in kthread_delayed_work_timer_fn()
958 	struct kthread_work *work = &dwork->work;  in __kthread_queue_delayed_work()  local
964 	 * If @delay is 0, queue @dwork->work immediately.  This is for  in __kthread_queue_delayed_work()
970 		kthread_insert_work(worker, work, &worker->work_list);  in __kthread_queue_delayed_work()
975 	kthread_insert_work_sanity_check(worker, work);  in __kthread_queue_delayed_work()
977 	list_add(&work->node, &worker->delayed_work_list);  in __kthread_queue_delayed_work()
978 	work->worker = worker;  in __kthread_queue_delayed_work()
984  * kthread_queue_delayed_work - queue the associated kthread work
990  * If the work has not been pending it starts a timer that will queue
991  * the work after the given @delay. If @delay is zero, it queues the
992  * work immediately.
994  * Return: %false if the @work has already been pending. It means that
995  * either the timer was running or the work was queued. It returns %true
1002 	struct kthread_work *work = &dwork->work;  in kthread_queue_delayed_work()  local
1008 	if (!queuing_blocked(worker, work)) {  in kthread_queue_delayed_work()
1019 	struct kthread_work	work;  member
1023 static void kthread_flush_work_fn(struct kthread_work *work)  in kthread_flush_work_fn()  argument
1026 		container_of(work, struct kthread_flush_work, work);  in kthread_flush_work_fn()
1032  * @work: work to flush
1034  * If @work is queued or executing, wait for it to finish execution.
1036 void kthread_flush_work(struct kthread_work *work)  in kthread_flush_work()  argument
1039 		KTHREAD_WORK_INIT(fwork.work, kthread_flush_work_fn),  in kthread_flush_work()
1045 	worker = work->worker;  in kthread_flush_work()
1050 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in kthread_flush_work()
1051 	WARN_ON_ONCE(work->worker != worker);  in kthread_flush_work()
1053 	if (!list_empty(&work->node))  in kthread_flush_work()
1054 		kthread_insert_work(worker, &fwork.work, work->node.next);  in kthread_flush_work()
1055 	else if (worker->current_work == work)  in kthread_flush_work()
1056 		kthread_insert_work(worker, &fwork.work,  in kthread_flush_work()
1070  * not manipulate the work list_head any longer.
1075 static void kthread_cancel_delayed_work_timer(struct kthread_work *work,  in kthread_cancel_delayed_work_timer()  argument
1079 		container_of(work, struct kthread_delayed_work, work);  in kthread_cancel_delayed_work_timer()
1080 	struct kthread_worker *worker = work->worker;  in kthread_cancel_delayed_work_timer()
1088 	work->canceling++;  in kthread_cancel_delayed_work_timer()
1092 	work->canceling--;  in kthread_cancel_delayed_work_timer()
1096  * This function removes the work from the worker queue.
1099  * the timer used by delayed work is not running, e.g. by calling
1102  * The work might still be in use when this function finishes. See the
1105  * Return: %true if @work was pending and successfully canceled,
1106  *	%false if @work was not pending
1108 static bool __kthread_cancel_work(struct kthread_work *work)  in __kthread_cancel_work()  argument
1111 	 * Try to remove the work from a worker list. It might either  in __kthread_cancel_work()
1114 	if (!list_empty(&work->node)) {  in __kthread_cancel_work()
1115 		list_del_init(&work->node);  in __kthread_cancel_work()
1123  * kthread_mod_delayed_work - modify delay of or queue a kthread delayed work
1125  * @dwork: kthread delayed work to queue
1130  * @work is guaranteed to be queued immediately.
1134  * A special case is when the work is being canceled in parallel.
1149 	struct kthread_work *work = &dwork->work;  in kthread_mod_delayed_work()  local
1156 	if (!work->worker) {  in kthread_mod_delayed_work()
1161 	/* Work must not be used with >1 worker, see kthread_queue_work() */  in kthread_mod_delayed_work()
1162 	WARN_ON_ONCE(work->worker != worker);  in kthread_mod_delayed_work()
1165 	 * Temporary cancel the work but do not fight with another command  in kthread_mod_delayed_work()
1166 	 * that is canceling the work as well.  in kthread_mod_delayed_work()
1172 	 * when doing so. But the work can be removed from the queue (list)  in kthread_mod_delayed_work()
1176 	kthread_cancel_delayed_work_timer(work, &flags);  in kthread_mod_delayed_work()
1177 	if (work->canceling) {  in kthread_mod_delayed_work()
1182 	ret = __kthread_cancel_work(work);  in kthread_mod_delayed_work()
1192 static bool __kthread_cancel_work_sync(struct kthread_work *work, bool is_dwork)  in __kthread_cancel_work_sync()  argument
1194 	struct kthread_worker *worker = work->worker;  in __kthread_cancel_work_sync()
1202 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in __kthread_cancel_work_sync()
1203 	WARN_ON_ONCE(work->worker != worker);  in __kthread_cancel_work_sync()
1206 		kthread_cancel_delayed_work_timer(work, &flags);  in __kthread_cancel_work_sync()
1208 	ret = __kthread_cancel_work(work);  in __kthread_cancel_work_sync()
1210 	if (worker->current_work != work)  in __kthread_cancel_work_sync()
1214 	 * The work is in progress and we need to wait with the lock released.  in __kthread_cancel_work_sync()
1217 	work->canceling++;  in __kthread_cancel_work_sync()
1219 	kthread_flush_work(work);  in __kthread_cancel_work_sync()
1221 	work->canceling--;  in __kthread_cancel_work_sync()
1230  * kthread_cancel_work_sync - cancel a kthread work and wait for it to finish
1231  * @work: the kthread work to cancel
1233  * Cancel @work and wait for its execution to finish.  This function
1234  * can be used even if the work re-queues itself. On return from this
1235  * function, @work is guaranteed to be not pending or executing on any CPU.
1237  * kthread_cancel_work_sync(&delayed_work->work) must not be used for
1240  * The caller must ensure that the worker on which @work was last
1243  * Return: %true if @work was pending, %false otherwise.
1245 bool kthread_cancel_work_sync(struct kthread_work *work)  in kthread_cancel_work_sync()  argument
1247 	return __kthread_cancel_work_sync(work, false);  in kthread_cancel_work_sync()
1252  * kthread_cancel_delayed_work_sync - cancel a kthread delayed work and
1254  * @dwork: the kthread delayed work to cancel
1262 	return __kthread_cancel_work_sync(&dwork->work, true);  in kthread_cancel_delayed_work_sync()
1276 		KTHREAD_WORK_INIT(fwork.work, kthread_flush_work_fn),  in kthread_flush_worker()
1280 	kthread_queue_work(worker, &fwork.work);  in kthread_flush_worker()