void generic_unplug_device (void * data);
Linux uses plugging to build bigger requests queues before letting the device have at them. If a queue is plugged, the I/O scheduler is still adding and merging requests on the queue. Once the queue gets unplugged (either by manually calling this function, or by calling blk_run_queues), the request_fn defined for the queue is invoked and transfers started.
This documentation was generated with kernel version 2.6.0.