979  * when they finish. There is defined a safe point for freezing when one work
988 	struct kthread_work *work;  in kthread_worker_fn()  local
1011 	work = NULL;  in kthread_worker_fn()
1014 		work = list_first_entry(&worker->work_list,  in kthread_worker_fn()
1016 		list_del_init(&work->node);  in kthread_worker_fn()
1018 	worker->current_work = work;  in kthread_worker_fn()
1021 	if (work) {  in kthread_worker_fn()
1022 		kthread_work_func_t func = work->func;  in kthread_worker_fn()
1024 		trace_sched_kthread_work_execute_start(work);  in kthread_worker_fn()
1025 		work->func(work);  in kthread_worker_fn()
1027 		 * Avoid dereferencing work after this point.  The trace  in kthread_worker_fn()
1030 		trace_sched_kthread_work_execute_end(work, func);  in kthread_worker_fn()
1119  * how to handle pending work items, prevent queuing new ones, and
1151  * Returns true when the work could not be queued at the moment.
1156 				   struct kthread_work *work)  in queuing_blocked()  argument
1160 	return !list_empty(&work->node) || work->canceling;  in queuing_blocked()
1164 					     struct kthread_work *work)  in kthread_insert_work_sanity_check()  argument
1167 	WARN_ON_ONCE(!list_empty(&work->node));  in kthread_insert_work_sanity_check()
1168 	/* Do not use a work with >1 worker, see kthread_queue_work() */  in kthread_insert_work_sanity_check()
1169 	WARN_ON_ONCE(work->worker && work->worker != worker);  in kthread_insert_work_sanity_check()
1172 /* insert @work before @pos in @worker */
1174 				struct kthread_work *work,  in kthread_insert_work()  argument
1177 	kthread_insert_work_sanity_check(worker, work);  in kthread_insert_work()
1179 	trace_sched_kthread_work_queue_work(worker, work);  in kthread_insert_work()
1181 	list_add_tail(&work->node, pos);  in kthread_insert_work()
1182 	work->worker = worker;  in kthread_insert_work()
1190  * @work: kthread_work to queue
1192  * Queue @work to work processor @task for async execution.  @task
1194  * if @work was successfully queued, %false if it was already pending.
1196  * Reinitialize the work if it needs to be used by another worker.
1200 			struct kthread_work *work)  in kthread_queue_work()  argument
1206 	if (!queuing_blocked(worker, work)) {  in kthread_queue_work()
1207 		kthread_insert_work(worker, work, &worker->work_list);  in kthread_queue_work()
1217  *	delayed work when the timer expires.
1227 	struct kthread_work *work = &dwork->work;  in kthread_delayed_work_timer_fn()  local
1228 	struct kthread_worker *worker = work->worker;  in kthread_delayed_work_timer_fn()
1232 	 * This might happen when a pending work is reinitialized.  in kthread_delayed_work_timer_fn()
1239 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in kthread_delayed_work_timer_fn()
1240 	WARN_ON_ONCE(work->worker != worker);  in kthread_delayed_work_timer_fn()
1242 	/* Move the work from worker->delayed_work_list. */  in kthread_delayed_work_timer_fn()
1243 	WARN_ON_ONCE(list_empty(&work->node));  in kthread_delayed_work_timer_fn()
1244 	list_del_init(&work->node);  in kthread_delayed_work_timer_fn()
1245 	if (!work->canceling)  in kthread_delayed_work_timer_fn()
1246 		kthread_insert_work(worker, work, &worker->work_list);  in kthread_delayed_work_timer_fn()
1257 	struct kthread_work *work = &dwork->work;  in __kthread_queue_delayed_work()  local
1262 	 * If @delay is 0, queue @dwork->work immediately.  This is for  in __kthread_queue_delayed_work()
1268 		kthread_insert_work(worker, work, &worker->work_list);  in __kthread_queue_delayed_work()
1273 	kthread_insert_work_sanity_check(worker, work);  in __kthread_queue_delayed_work()
1275 	list_add(&work->node, &worker->delayed_work_list);  in __kthread_queue_delayed_work()
1276 	work->worker = worker;  in __kthread_queue_delayed_work()
1282  * kthread_queue_delayed_work - queue the associated kthread work
1288  * If the work has not been pending it starts a timer that will queue
1289  * the work after the given @delay. If @delay is zero, it queues the
1290  * work immediately.
1292  * Return: %false if the @work has already been pending. It means that
1293  * either the timer was running or the work was queued. It returns %true
1300 	struct kthread_work *work = &dwork->work;  in kthread_queue_delayed_work()  local
1306 	if (!queuing_blocked(worker, work)) {  in kthread_queue_delayed_work()
1317 	struct kthread_work	work;  member
1321 static void kthread_flush_work_fn(struct kthread_work *work)  in kthread_flush_work_fn()  argument
1324 		container_of(work, struct kthread_flush_work, work);  in kthread_flush_work_fn()
1330  * @work: work to flush
1332  * If @work is queued or executing, wait for it to finish execution.
1334 void kthread_flush_work(struct kthread_work *work)  in kthread_flush_work()  argument
1337 		KTHREAD_WORK_INIT(fwork.work, kthread_flush_work_fn),  in kthread_flush_work()
1343 	worker = work->worker;  in kthread_flush_work()
1348 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in kthread_flush_work()
1349 	WARN_ON_ONCE(work->worker != worker);  in kthread_flush_work()
1351 	if (!list_empty(&work->node))  in kthread_flush_work()
1352 		kthread_insert_work(worker, &fwork.work, work->node.next);  in kthread_flush_work()
1353 	else if (worker->current_work == work)  in kthread_flush_work()
1354 		kthread_insert_work(worker, &fwork.work,  in kthread_flush_work()
1368  * not manipulate the work list_head any longer.
1373 static void kthread_cancel_delayed_work_timer(struct kthread_work *work,  in kthread_cancel_delayed_work_timer()  argument
1377 		container_of(work, struct kthread_delayed_work, work);  in kthread_cancel_delayed_work_timer()
1378 	struct kthread_worker *worker = work->worker;  in kthread_cancel_delayed_work_timer()
1386 	work->canceling++;  in kthread_cancel_delayed_work_timer()
1390 	work->canceling--;  in kthread_cancel_delayed_work_timer()
1394  * This function removes the work from the worker queue.
1397  * the timer used by delayed work is not running, e.g. by calling
1400  * The work might still be in use when this function finishes. See the
1403  * Return: %true if @work was pending and successfully canceled,
1404  *	%false if @work was not pending
1406 static bool __kthread_cancel_work(struct kthread_work *work)  in __kthread_cancel_work()  argument
1409 	 * Try to remove the work from a worker list. It might either  in __kthread_cancel_work()
1412 	if (!list_empty(&work->node)) {  in __kthread_cancel_work()
1413 		list_del_init(&work->node);  in __kthread_cancel_work()
1421  * kthread_mod_delayed_work - modify delay of or queue a kthread delayed work
1423  * @dwork: kthread delayed work to queue
1428  * @work is guaranteed to be queued immediately.
1432  * A special case is when the work is being canceled in parallel.
1447 	struct kthread_work *work = &dwork->work;  in kthread_mod_delayed_work()  local
1454 	if (!work->worker) {  in kthread_mod_delayed_work()
1459 	/* Work must not be used with >1 worker, see kthread_queue_work() */  in kthread_mod_delayed_work()
1460 	WARN_ON_ONCE(work->worker != worker);  in kthread_mod_delayed_work()
1463 	 * Temporary cancel the work but do not fight with another command  in kthread_mod_delayed_work()
1464 	 * that is canceling the work as well.  in kthread_mod_delayed_work()
1470 	 * when doing so. But the work can be removed from the queue (list)  in kthread_mod_delayed_work()
1474 	kthread_cancel_delayed_work_timer(work, &flags);  in kthread_mod_delayed_work()
1475 	if (work->canceling) {  in kthread_mod_delayed_work()
1480 	ret = __kthread_cancel_work(work);  in kthread_mod_delayed_work()
1490 static bool __kthread_cancel_work_sync(struct kthread_work *work, bool is_dwork)  in __kthread_cancel_work_sync()  argument
1492 	struct kthread_worker *worker = work->worker;  in __kthread_cancel_work_sync()
1500 	/* Work must not be used with >1 worker, see kthread_queue_work(). */  in __kthread_cancel_work_sync()
1501 	WARN_ON_ONCE(work->worker != worker);  in __kthread_cancel_work_sync()
1504 		kthread_cancel_delayed_work_timer(work, &flags);  in __kthread_cancel_work_sync()
1506 	ret = __kthread_cancel_work(work);  in __kthread_cancel_work_sync()
1508 	if (worker->current_work != work)  in __kthread_cancel_work_sync()
1512 	 * The work is in progress and we need to wait with the lock released.  in __kthread_cancel_work_sync()
1515 	work->canceling++;  in __kthread_cancel_work_sync()
1517 	kthread_flush_work(work);  in __kthread_cancel_work_sync()
1519 	work->canceling--;  in __kthread_cancel_work_sync()
1528  * kthread_cancel_work_sync - cancel a kthread work and wait for it to finish
1529  * @work: the kthread work to cancel
1531  * Cancel @work and wait for its execution to finish.  This function
1532  * can be used even if the work re-queues itself. On return from this
1533  * function, @work is guaranteed to be not pending or executing on any CPU.
1535  * kthread_cancel_work_sync(&delayed_work->work) must not be used for
1538  * The caller must ensure that the worker on which @work was last
1541  * Return: %true if @work was pending, %false otherwise.
1543 bool kthread_cancel_work_sync(struct kthread_work *work)  in kthread_cancel_work_sync()  argument
1545 	return __kthread_cancel_work_sync(work, false);  in kthread_cancel_work_sync()
1550  * kthread_cancel_delayed_work_sync - cancel a kthread delayed work and
1552  * @dwork: the kthread delayed work to cancel
1560 	return __kthread_cancel_work_sync(&dwork->work, true);  in kthread_cancel_delayed_work_sync()
1574 		KTHREAD_WORK_INIT(fwork.work, kthread_flush_work_fn),  in kthread_flush_worker()
1578 	kthread_queue_work(worker, &fwork.work);  in kthread_flush_worker()
1591  * Note that this function is not responsible for handling delayed work, so
1592  * caller should be responsible for queuing or canceling all delayed work items