Callers should use either blk_run_queue/__blk_run_queue, or
blk_start_queueing() to invoke request handling instead of calling
->request_fn() directly as that does not take the queue stopped
flag into account.
Also add appropriate comments on the above functions to detail
their usage.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
static void blk_invoke_request_fn(struct request_queue *q)
{
static void blk_invoke_request_fn(struct request_queue *q)
{
+ if (unlikely(blk_queue_stopped(q)))
+ return;
+
/*
* one level of recursion is ok and is much faster than kicking
* the unplug handling
/*
* one level of recursion is ok and is much faster than kicking
* the unplug handling
EXPORT_SYMBOL(blk_sync_queue);
/**
EXPORT_SYMBOL(blk_sync_queue);
/**
- * blk_run_queue - run a single device queue
+ * __blk_run_queue - run a single device queue
+ *
+ * Description:
+ * See @blk_run_queue. This variant must be called with the queue lock
+ * held and interrupts disabled.
+ *
*/
void __blk_run_queue(struct request_queue *q)
{
*/
void __blk_run_queue(struct request_queue *q)
{
/**
* blk_run_queue - run a single device queue
* @q: The queue to run
/**
* blk_run_queue - run a single device queue
* @q: The queue to run
+ *
+ * Description:
+ * Invoke request handling on this queue, if it has pending work to do.
+ * May be used to restart queueing when a request has completed. Also
+ * See @blk_start_queueing.
+ *
*/
void blk_run_queue(struct request_queue *q)
{
*/
void blk_run_queue(struct request_queue *q)
{
*
* This is basically a helper to remove the need to know whether a queue
* is plugged or not if someone just wants to initiate dispatch of requests
*
* This is basically a helper to remove the need to know whether a queue
* is plugged or not if someone just wants to initiate dispatch of requests
+ * for this queue. Should be used to start queueing on a device outside
+ * of ->request_fn() context. Also see @blk_run_queue.
*
* The queue lock must be held with interrupts disabled.
*/
*
* The queue lock must be held with interrupts disabled.
*/
* processing.
*/
blk_remove_plug(q);
* processing.
*/
blk_remove_plug(q);
break;
case ELEVATOR_INSERT_SORT:
break;
case ELEVATOR_INSERT_SORT:
blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
blk_ordered_req_seq(first_rq) > QUEUE_ORDSEQ_DRAIN) {
blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
blk_ordered_req_seq(first_rq) > QUEUE_ORDSEQ_DRAIN) {
blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
elv_drain_elevator(q);
while (q->rq.elvpriv) {
elv_drain_elevator(q);
while (q->rq.elvpriv) {
- blk_remove_plug(q);
- q->request_fn(q);
spin_unlock_irq(q->queue_lock);
msleep(10);
spin_lock_irq(q->queue_lock);
spin_unlock_irq(q->queue_lock);
msleep(10);
spin_lock_irq(q->queue_lock);