1BLK_RQ_CHECK_LIMITS(9)           Block Devices          BLK_RQ_CHECK_LIMITS(9)
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NAME

6       blk_rq_check_limits - Helper function to check a request for the queue
7       limit
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SYNOPSIS

10       int blk_rq_check_limits(struct request_queue * q, struct request * rq);
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ARGUMENTS

13       q
14           the queue
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16       rq
17           the request being checked
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DESCRIPTION

20       rq may have been made based on weaker limitations of upper-level queues
21       in request stacking drivers, and it may violate the limitation of q.
22       Since the block layer and the underlying device driver trust rq after
23       it is inserted to q, it should be checked against q before the
24       insertion using this generic function.
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26       This function should also be useful for request stacking drivers in
27       some cases below, so export this fuction. Request stacking drivers like
28       request-based dm may change the queue limits while requests are in the
29       queue (e.g. dm's table swapping). Such request stacking drivers should
30       check those requests agaist the new queue limits again when they
31       dispatch those requests, although such checkings are also done against
32       the old queue limits when submitting requests.
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35Kernel Hackers Manual 2.6.       November 2011          BLK_RQ_CHECK_LIMITS(9)
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