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Diffstat (limited to 'kernel/kthread.c')
-rw-r--r--kernel/kthread.c19
1 files changed, 12 insertions, 7 deletions
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 6b0a30a944b3..5b37a8567168 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -1162,14 +1162,14 @@ static bool __kthread_cancel_work(struct kthread_work *work)
* modify @dwork's timer so that it expires after @delay. If @delay is zero,
* @work is guaranteed to be queued immediately.
*
- * Return: %true if @dwork was pending and its timer was modified,
- * %false otherwise.
+ * Return: %false if @dwork was idle and queued, %true otherwise.
*
* A special case is when the work is being canceled in parallel.
* It might be caused either by the real kthread_cancel_delayed_work_sync()
* or yet another kthread_mod_delayed_work() call. We let the other command
- * win and return %false here. The caller is supposed to synchronize these
- * operations a reasonable way.
+ * win and return %true here. The return value can be used for reference
+ * counting and the number of queued works stays the same. Anyway, the caller
+ * is supposed to synchronize these operations a reasonable way.
*
* This function is safe to call from any context including IRQ handler.
* See __kthread_cancel_work() and kthread_delayed_work_timer_fn()
@@ -1181,13 +1181,15 @@ bool kthread_mod_delayed_work(struct kthread_worker *worker,
{
struct kthread_work *work = &dwork->work;
unsigned long flags;
- int ret = false;
+ int ret;
raw_spin_lock_irqsave(&worker->lock, flags);
/* Do not bother with canceling when never queued. */
- if (!work->worker)
+ if (!work->worker) {
+ ret = false;
goto fast_queue;
+ }
/* Work must not be used with >1 worker, see kthread_queue_work() */
WARN_ON_ONCE(work->worker != worker);
@@ -1205,8 +1207,11 @@ bool kthread_mod_delayed_work(struct kthread_worker *worker,
* be used for reference counting.
*/
kthread_cancel_delayed_work_timer(work, &flags);
- if (work->canceling)
+ if (work->canceling) {
+ /* The number of works in the queue does not change. */
+ ret = true;
goto out;
+ }
ret = __kthread_cancel_work(work);
fast_queue: