/**
* 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.
*/
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;
WARN_ON(irqs_disabled());
spin_lock_irq(q->queue_lock);
if (unlikely(blk_queue_dead(q))) {
spin_unlock_irq(q->queue_lock);
rq->errors = -ENXIO;
if (rq->end_io)
rq->end_io(rq, rq->errors);
return;
}
rq->rq_disk = bd_disk;
rq->end_io = done;
__elv_add_request(q, rq, where);
__blk_run_queue(q);
/* the queue is stopped so it won't be run */
if (rq->cmd_type == REQ_TYPE_PM_RESUME)
q->request_fn(q);
spin_unlock_irq(q->queue_lock);
}
static ssize_t queue_state_write(void *data, const char __user *buf,
size_t count, loff_t *ppos)
{
struct request_queue *q = data;
char opbuf[16] = { }, *op;
/*
* The "state" attribute is removed after blk_cleanup_queue() has called
* blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
* triggering a use-after-free.
*/
if (blk_queue_dead(q))
return -ENOENT;
if (count >= sizeof(opbuf)) {
pr_err("%s: operation too long\n", __func__);
goto inval;
}
if (copy_from_user(opbuf, buf, count))
return -EFAULT;
op = strstrip(opbuf);
if (strcmp(op, "run") == 0) {
blk_mq_run_hw_queues(q, true);
} else if (strcmp(op, "start") == 0) {
blk_mq_start_stopped_hw_queues(q, true);
} else {
pr_err("%s: unsupported operation '%s'\n", __func__, op);
inval:
pr_err("%s: use either 'run' or 'start'\n", __func__);
return -EINVAL;
}
return count;
}
inline void __blk_run_queue_uncond(struct request_queue *q)
{
if (unlikely(blk_queue_dead(q)))
return;
q->request_fn_active++;
if (!q->notified_urgent &&
q->elevator->type->ops.elevator_is_urgent_fn &&
q->urgent_request_fn &&
q->elevator->type->ops.elevator_is_urgent_fn(q) &&
list_empty(&q->flush_data_in_flight)) {
q->notified_urgent = true;
q->urgent_request_fn(q);
} else
q->request_fn(q);
q->request_fn_active--;
}
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_dead(q)) {
mutex_unlock(&q->sysfs_lock);
return -ENOENT;
}
res = entry->show(q, page);
mutex_unlock(&q->sysfs_lock);
return res;
}
void blk_run_queue_async(struct request_queue *q)
{
if (likely(!blk_queue_stopped(q) && !blk_queue_dead(q)))
mod_delayed_work(kblockd_workqueue, &q->delay_work, 0);
}
void blk_delay_queue(struct request_queue *q, unsigned long msecs)
{
if (likely(!blk_queue_dead(q)))
queue_delayed_work(kblockd_workqueue, &q->delay_work,
msecs_to_jiffies(msecs));
}