centos man page for blk_stop_queue

BLK_STOP_QUEUE(9)						   Block Devices						 BLK_STOP_QUEUE(9)

NAME
       blk_stop_queue - stop a queue

SYNOPSIS
       void blk_stop_queue(struct request_queue * q);

ARGUMENTS
       q
	   The struct request_queue in question

DESCRIPTION
       The Linux block layer assumes that a block driver will consume all entries on the request queue when the request_fn strategy is called.
       Often this will not happen, because of hardware limitations (queue depth settings). If a device driver gets a 'queue full' response, or if
       it simply chooses not to queue more I/O at one point, it can call this function to prevent the request_fn from being called until the
       driver has signalled it's ready to go again. This happens by calling blk_start_queue to restart queue operations. Queue lock must be held.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							 BLK_STOP_QUEUE(9)