BLK_RQ_CHECK_LIMITS(9) Block Devices BLK_RQ_CHECK_LIMITS(9)NAMEblk_rq_check_limits - Helper function to check a request for the queue
int blk_rq_check_limits(struct request_queue * q, struct request * rq);
the request being checked
rq may have been made based on weaker limitations of upper-level queues
in request stacking drivers, and it may violate the limitation of q.
Since the block layer and the underlying device driver trust rq after
it is inserted to q, it should be checked against q before the
insertion using this generic function.
This function should also be useful for request stacking drivers in
some cases below, so export this function. Request stacking drivers
like request-based dm may change the queue limits while requests are in
the queue (e.g. dm's table swapping). Such request stacking drivers
should check those requests agaist the new queue limits again when they
dispatch those requests, although such checkings are also done against
the old queue limits when submitting requests.
COPYRIGHTKernel Hackers Manual 3.8. June 2014 BLK_RQ_CHECK_LIMITS(9)