-void blk_finish_queue_drain(request_queue_t *q)
-{
- struct request_list *rl = &q->rq;
- struct request *rq;
- int requeued = 0;
-
- spin_lock_irq(q->queue_lock);
- clear_bit(QUEUE_FLAG_DRAIN, &q->queue_flags);
-
- while (!list_empty(&q->drain_list)) {
- rq = list_entry_rq(q->drain_list.next);
-
- list_del_init(&rq->queuelist);
- elv_requeue_request(q, rq);
- requeued++;
- }
-
- if (requeued)
- q->request_fn(q);
-
- spin_unlock_irq(q->queue_lock);
-
- wake_up(&rl->wait[0]);
- wake_up(&rl->wait[1]);
- wake_up(&rl->drain);
-}
-
-static int wait_drain(request_queue_t *q, struct request_list *rl, int dispatch)
-{
- int wait = rl->count[READ] + rl->count[WRITE];
-
- if (dispatch)
- wait += !list_empty(&q->queue_head);
-
- return wait;
-}
-
-/*
- * We rely on the fact that only requests allocated through blk_alloc_request()
- * have io scheduler private data structures associated with them. Any other
- * type of request (allocated on stack or through kmalloc()) should not go
- * to the io scheduler core, but be attached to the queue head instead.
- */
-void blk_wait_queue_drained(request_queue_t *q, int wait_dispatch)
-{
- struct request_list *rl = &q->rq;
- DEFINE_WAIT(wait);
-
- spin_lock_irq(q->queue_lock);
- set_bit(QUEUE_FLAG_DRAIN, &q->queue_flags);
-
- while (wait_drain(q, rl, wait_dispatch)) {
- prepare_to_wait(&rl->drain, &wait, TASK_UNINTERRUPTIBLE);
-
- if (wait_drain(q, rl, wait_dispatch)) {
- __generic_unplug_device(q);
- spin_unlock_irq(q->queue_lock);
- io_schedule();
- spin_lock_irq(q->queue_lock);
- }
-
- finish_wait(&rl->drain, &wait);
- }
-
- spin_unlock_irq(q->queue_lock);
-}
-
-/*
- * block waiting for the io scheduler being started again.
- */
-static inline void block_wait_queue_running(request_queue_t *q)
-{
- DEFINE_WAIT(wait);
-
- while (unlikely(test_bit(QUEUE_FLAG_DRAIN, &q->queue_flags))) {
- struct request_list *rl = &q->rq;
-
- prepare_to_wait_exclusive(&rl->drain, &wait,
- TASK_UNINTERRUPTIBLE);
-
- /*
- * re-check the condition. avoids using prepare_to_wait()
- * in the fast path (queue is running)
- */
- if (test_bit(QUEUE_FLAG_DRAIN, &q->queue_flags))
- io_schedule();
-
- finish_wait(&rl->drain, &wait);
- }
-}
-