716  * when they finish. There is defined a safe point for freezing when one work
725 	struct kthread_work *work;  in kthread_worker_fn()  local
748 	work = NULL;  in kthread_worker_fn()
751 		work = list_first_entry(&worker->work_list,  in kthread_worker_fn()
753 		list_del_init(&work->node);  in kthread_worker_fn()
755 	worker->current_work = work;  in kthread_worker_fn()
758 	if (work) {  in kthread_worker_fn()
759 		kthread_work_func_t func = work->func;  in kthread_worker_fn()
761 		trace_sched_kthread_work_execute_start(work);  in kthread_worker_fn()
762 		work->func(work);  in kthread_worker_fn()
764 		 * Avoid dereferencing work after this point.  The trace  in kthread_worker_fn()
767 		trace_sched_kthread_work_execute_end(work, func);  in kthread_worker_fn()
853  * how to handle pending work items, prevent queuing new ones, and
886  * Returns true when the work could not be queued at the moment.
891 				   struct kthread_work *work)  in queuing_blocked()  argument
895 	return !list_empty(&work->node) || work->canceling;  in queuing_blocked()
899 					     struct kthread_work *work)  in kthread_insert_work_sanity_check()  argument
902 	WARN_ON_ONCE(!list_empty(&work->node));  in kthread_insert_work_sanity_check()
903 	/* Do not use a work with >1 worker, see kthread_queue_work() */  in kthread_insert_work_sanity_check()
904 	WARN_ON_ONCE(work->worker && work->worker != worker);  in kthread_insert_work_sanity_check()
907 /* insert @work before @pos in @worker */
909 				struct kthread_work *work,  in kthread_insert_work()  argument
912 	kthread_insert_work_sanity_check(worker, work);  in kthread_insert_work()
914 	trace_sched_kthread_work_queue_work(worker, work);  in kthread_insert_work()
916 	list_add_tail(&work->node, pos);  in kthread_insert_work()
917 	work->worker = worker;  in kthread_insert_work()
925  * @work: kthread_work to queue
927  * Queue @work to work processor @task for async execution.  @task
929  * if @work was successfully queued, %false if it was already pending.
931  * Reinitialize the work if it needs to be used by another worker.
935 			struct kthread_work *work)  in kthread_queue_work()  argument
941 	if (!queuing_blocked(worker, work)) {  in kthread_queue_work()
942 		kthread_insert_work(worker, work, &worker->work_list);  in kthread_queue_work()
952  *	delayed work when the timer expires.
961 	struct kthread_work *work = &dwork->work;  in kthread_delayed_work_timer_fn()  local
962 	struct kthread_worker *worker = work->worker;  in kthread_delayed_work_timer_fn()
966 	 * This might happen when a pending work is reinitialized.  in kthread_delayed_work_timer_fn()
973 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in kthread_delayed_work_timer_fn()
974 	WARN_ON_ONCE(work->worker != worker);  in kthread_delayed_work_timer_fn()
976 	/* Move the work from worker->delayed_work_list. */  in kthread_delayed_work_timer_fn()
977 	WARN_ON_ONCE(list_empty(&work->node));  in kthread_delayed_work_timer_fn()
978 	list_del_init(&work->node);  in kthread_delayed_work_timer_fn()
979 	if (!work->canceling)  in kthread_delayed_work_timer_fn()
980 		kthread_insert_work(worker, work, &worker->work_list);  in kthread_delayed_work_timer_fn()
991 	struct kthread_work *work = &dwork->work;  in __kthread_queue_delayed_work()  local
997 	 * If @delay is 0, queue @dwork->work immediately.  This is for  in __kthread_queue_delayed_work()
1003 		kthread_insert_work(worker, work, &worker->work_list);  in __kthread_queue_delayed_work()
1008 	kthread_insert_work_sanity_check(worker, work);  in __kthread_queue_delayed_work()
1010 	list_add(&work->node, &worker->delayed_work_list);  in __kthread_queue_delayed_work()
1011 	work->worker = worker;  in __kthread_queue_delayed_work()
1017  * kthread_queue_delayed_work - queue the associated kthread work
1023  * If the work has not been pending it starts a timer that will queue
1024  * the work after the given @delay. If @delay is zero, it queues the
1025  * work immediately.
1027  * Return: %false if the @work has already been pending. It means that
1028  * either the timer was running or the work was queued. It returns %true
1035 	struct kthread_work *work = &dwork->work;  in kthread_queue_delayed_work()  local
1041 	if (!queuing_blocked(worker, work)) {  in kthread_queue_delayed_work()
1052 	struct kthread_work	work;  member
1056 static void kthread_flush_work_fn(struct kthread_work *work)  in kthread_flush_work_fn()  argument
1059 		container_of(work, struct kthread_flush_work, work);  in kthread_flush_work_fn()
1065  * @work: work to flush
1067  * If @work is queued or executing, wait for it to finish execution.
1069 void kthread_flush_work(struct kthread_work *work)  in kthread_flush_work()  argument
1072 		KTHREAD_WORK_INIT(fwork.work, kthread_flush_work_fn),  in kthread_flush_work()
1078 	worker = work->worker;  in kthread_flush_work()
1083 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in kthread_flush_work()
1084 	WARN_ON_ONCE(work->worker != worker);  in kthread_flush_work()
1086 	if (!list_empty(&work->node))  in kthread_flush_work()
1087 		kthread_insert_work(worker, &fwork.work, work->node.next);  in kthread_flush_work()
1088 	else if (worker->current_work == work)  in kthread_flush_work()
1089 		kthread_insert_work(worker, &fwork.work,  in kthread_flush_work()
1103  * not manipulate the work list_head any longer.
1108 static void kthread_cancel_delayed_work_timer(struct kthread_work *work,  in kthread_cancel_delayed_work_timer()  argument
1112 		container_of(work, struct kthread_delayed_work, work);  in kthread_cancel_delayed_work_timer()
1113 	struct kthread_worker *worker = work->worker;  in kthread_cancel_delayed_work_timer()
1121 	work->canceling++;  in kthread_cancel_delayed_work_timer()
1125 	work->canceling--;  in kthread_cancel_delayed_work_timer()
1129  * This function removes the work from the worker queue.
1132  * the timer used by delayed work is not running, e.g. by calling
1135  * The work might still be in use when this function finishes. See the
1138  * Return: %true if @work was pending and successfully canceled,
1139  *	%false if @work was not pending
1141 static bool __kthread_cancel_work(struct kthread_work *work)  in __kthread_cancel_work()  argument
1144 	 * Try to remove the work from a worker list. It might either  in __kthread_cancel_work()
1147 	if (!list_empty(&work->node)) {  in __kthread_cancel_work()
1148 		list_del_init(&work->node);  in __kthread_cancel_work()
1156  * kthread_mod_delayed_work - modify delay of or queue a kthread delayed work
1158  * @dwork: kthread delayed work to queue
1163  * @work is guaranteed to be queued immediately.
1167  * A special case is when the work is being canceled in parallel.
1182 	struct kthread_work *work = &dwork->work;  in kthread_mod_delayed_work()  local
1189 	if (!work->worker) {  in kthread_mod_delayed_work()
1194 	/* Work must not be used with >1 worker, see kthread_queue_work() */  in kthread_mod_delayed_work()
1195 	WARN_ON_ONCE(work->worker != worker);  in kthread_mod_delayed_work()
1198 	 * Temporary cancel the work but do not fight with another command  in kthread_mod_delayed_work()
1199 	 * that is canceling the work as well.  in kthread_mod_delayed_work()
1205 	 * when doing so. But the work can be removed from the queue (list)  in kthread_mod_delayed_work()
1209 	kthread_cancel_delayed_work_timer(work, &flags);  in kthread_mod_delayed_work()
1210 	if (work->canceling) {  in kthread_mod_delayed_work()
1215 	ret = __kthread_cancel_work(work);  in kthread_mod_delayed_work()
1225 static bool __kthread_cancel_work_sync(struct kthread_work *work, bool is_dwork)  in __kthread_cancel_work_sync()  argument
1227 	struct kthread_worker *worker = work->worker;  in __kthread_cancel_work_sync()
1235 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in __kthread_cancel_work_sync()
1236 	WARN_ON_ONCE(work->worker != worker);  in __kthread_cancel_work_sync()
1239 		kthread_cancel_delayed_work_timer(work, &flags);  in __kthread_cancel_work_sync()
1241 	ret = __kthread_cancel_work(work);  in __kthread_cancel_work_sync()
1243 	if (worker->current_work != work)  in __kthread_cancel_work_sync()
1247 	 * The work is in progress and we need to wait with the lock released.  in __kthread_cancel_work_sync()
1250 	work->canceling++;  in __kthread_cancel_work_sync()
1252 	kthread_flush_work(work);  in __kthread_cancel_work_sync()
1254 	work->canceling--;  in __kthread_cancel_work_sync()
1263  * kthread_cancel_work_sync - cancel a kthread work and wait for it to finish
1264  * @work: the kthread work to cancel
1266  * Cancel @work and wait for its execution to finish.  This function
1267  * can be used even if the work re-queues itself. On return from this
1268  * function, @work is guaranteed to be not pending or executing on any CPU.
1270  * kthread_cancel_work_sync(&delayed_work->work) must not be used for
1273  * The caller must ensure that the worker on which @work was last
1276  * Return: %true if @work was pending, %false otherwise.
1278 bool kthread_cancel_work_sync(struct kthread_work *work)  in kthread_cancel_work_sync()  argument
1280 	return __kthread_cancel_work_sync(work, false);  in kthread_cancel_work_sync()
1285  * kthread_cancel_delayed_work_sync - cancel a kthread delayed work and
1287  * @dwork: the kthread delayed work to cancel
1295 	return __kthread_cancel_work_sync(&dwork->work, true);  in kthread_cancel_delayed_work_sync()
1309 		KTHREAD_WORK_INIT(fwork.work, kthread_flush_work_fn),  in kthread_flush_worker()
1313 	kthread_queue_work(worker, &fwork.work);  in kthread_flush_worker()