NAME¶
blk_rq_check_limits - Helper function to check a request for the queue limit
SYNOPSIS¶
int
blk_rq_check_limits(struct request_queue * q,
struct request * rq);
ARGUMENTS¶
q
the queue
rq
the request being checked
DESCRIPTION¶
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.
COPYRIGHT¶