/**
* blk_execute_rq_nowait - insert a request into queue for execution
* @q: queue to insert the request in
* @bd_disk: matching gendisk
* @rq: request to insert
* @at_head: insert request at head or tail of queue
* @done: I/O completion handler
*
* Description:
* Insert a fully prepared request at the back of the I/O scheduler queue
* for execution. Don't wait for completion.
*
* Note:
* This function will invoke @done directly if the queue is dead.
*/
void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
struct request *rq, int at_head,
rq_end_io_fn *done)
{
int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
bool is_pm_resume;
WARN_ON(irqs_disabled());
rq->rq_disk = bd_disk;
rq->end_io = done;
/*
* need to check this before __blk_run_queue(), because rq can
* be freed before that returns.
*/
is_pm_resume = rq->cmd_type == REQ_TYPE_PM_RESUME;
spin_lock_irq(q->queue_lock);
if (unlikely(blk_queue_dying(q))) {
rq->errors = -ENXIO;
if (rq->end_io)
rq->end_io(rq, rq->errors);
spin_unlock_irq(q->queue_lock);
return;
}
__elv_add_request(q, rq, where);
__blk_run_queue(q);
/* the queue is stopped so it won't be run */
if (is_pm_resume)
__blk_run_queue_uncond(q);
spin_unlock_irq(q->queue_lock);
}
static ssize_t
queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
{
struct queue_sysfs_entry *entry = to_queue(attr);
struct request_queue *q =
container_of(kobj, struct request_queue, kobj);
ssize_t res;
if (!entry->show)
return -EIO;
mutex_lock(&q->sysfs_lock);
if (blk_queue_dying(q)) {
mutex_unlock(&q->sysfs_lock);
return -ENOENT;
}
res = entry->show(q, page);
mutex_unlock(&q->sysfs_lock);
return res;
}
static int ide_pm_execute_rq(struct request *rq)
{
struct request_queue *q = rq->q;
DECLARE_COMPLETION_ONSTACK(wait);
rq->end_io_data = &wait;
rq->end_io = ide_end_sync_rq;
spin_lock_irq(q->queue_lock);
if (unlikely(blk_queue_dying(q))) {
rq->rq_flags |= RQF_QUIET;
scsi_req(rq)->result = -ENXIO;
__blk_end_request_all(rq, BLK_STS_OK);
spin_unlock_irq(q->queue_lock);
return -ENXIO;
}
__elv_add_request(q, rq, ELEVATOR_INSERT_FRONT);
__blk_run_queue_uncond(q);
spin_unlock_irq(q->queue_lock);
wait_for_completion_io(&wait);
return scsi_req(rq)->result ? -EIO : 0;
}