diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 1240b9d94b03935030ac9d59f5dda71e35b22fe4..33d31d768706b354319b540e2aa7fdbaf4d3b45d 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2326,35 +2326,17 @@ void flush_workqueue(struct workqueue_struct *wq) } EXPORT_SYMBOL_GPL(flush_workqueue); -/** - * flush_work - wait for a work to finish executing the last queueing instance - * @work: the work to flush - * - * Wait until @work has finished execution. This function considers - * only the last queueing instance of @work. If @work has been - * enqueued across different CPUs on a non-reentrant workqueue or on - * multiple workqueues, @work might still be executing on return on - * some of the CPUs from earlier queueing. - * - * If @work was queued only on a non-reentrant, ordered or unbound - * workqueue, @work is guaranteed to be idle on return if it hasn't - * been requeued since flush started. - * - * RETURNS: - * %true if flush_work() waited for the work to finish execution, - * %false if it was already idle. - */ -bool flush_work(struct work_struct *work) +static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr, + bool wait_executing) { struct worker *worker = NULL; struct global_cwq *gcwq; struct cpu_workqueue_struct *cwq; - struct wq_barrier barr; might_sleep(); gcwq = get_work_gcwq(work); if (!gcwq) - return 0; + return false; spin_lock_irq(&gcwq->lock); if (!list_empty(&work->entry)) { @@ -2367,26 +2349,54 @@ bool flush_work(struct work_struct *work) cwq = get_work_cwq(work); if (unlikely(!cwq || gcwq != cwq->gcwq)) goto already_gone; - } else { + } else if (wait_executing) { worker = find_worker_executing_work(gcwq, work); if (!worker) goto already_gone; cwq = worker->current_cwq; - } + } else + goto already_gone; - insert_wq_barrier(cwq, &barr, work, worker); + insert_wq_barrier(cwq, barr, work, worker); spin_unlock_irq(&gcwq->lock); lock_map_acquire(&cwq->wq->lockdep_map); lock_map_release(&cwq->wq->lockdep_map); - - wait_for_completion(&barr.done); - destroy_work_on_stack(&barr.work); return true; already_gone: spin_unlock_irq(&gcwq->lock); return false; } + +/** + * flush_work - wait for a work to finish executing the last queueing instance + * @work: the work to flush + * + * Wait until @work has finished execution. This function considers + * only the last queueing instance of @work. If @work has been + * enqueued across different CPUs on a non-reentrant workqueue or on + * multiple workqueues, @work might still be executing on return on + * some of the CPUs from earlier queueing. + * + * If @work was queued only on a non-reentrant, ordered or unbound + * workqueue, @work is guaranteed to be idle on return if it hasn't + * been requeued since flush started. + * + * RETURNS: + * %true if flush_work() waited for the work to finish execution, + * %false if it was already idle. + */ +bool flush_work(struct work_struct *work) +{ + struct wq_barrier barr; + + if (start_flush_work(work, &barr, true)) { + wait_for_completion(&barr.done); + destroy_work_on_stack(&barr.work); + return true; + } else + return false; +} EXPORT_SYMBOL_GPL(flush_work); static bool wait_on_cpu_work(struct global_cwq *gcwq, struct work_struct *work)