blk_queue_max_phys_segments -- set max phys segments for a request for this queue
void blk_queue_max_phys_segments (request_queue_t * q, unsigned short max_segments);
the request queue for the device
max number of segments
Enables a low level driver to set an upper limit on the number of
physical data segments in a request. This would be the largest sized
scatter list the driver could handle.