blk_queue_max_hw_sectors — set max sectors for a request for this queue


void blk_queue_max_hw_sectors (struct request_queue * q,
 unsigned int max_hw_sectors);


struct request_queue * q

the request queue for the device

unsigned int max_hw_sectors

max hardware sectors in the usual 512b unit


Enables a low level driver to set a hard upper limit, max_hw_sectors, on the size of requests. max_hw_sectors is set by the device driver based upon the capabilities of the I/O controller.

max_dev_sectors is a hard limit imposed by the storage device for READ/WRITE requests. It is set by the disk driver.

max_sectors is a soft limit imposed by the block layer for filesystem type requests. This value can be overridden on a per-device basis in /sys/block/<device>/queue/max_sectors_kb. The soft limit can not exceed max_hw_sectors.