__blk_drain_queue - drain requests from request_queue
void __blk_drain_queue(struct request_queue * q, bool drain_all);
Drain requests from q. If drain_all is set, all requests are drained. If not, only ELVPRIV requests are drained. The caller is responsible for ensuring that no new requests which need to be drained are queued.
|January 2017||Kernel Hackers Manual 4.8.|