Insert a request into queue for execution
int blk_execute_rq(struct request_queue * q, struct gendisk * bd_disk, struct request * rq, int at_head);
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
Insert a fully prepared request at the back of the I/O scheduler queue for execution and wait for completion.