BLK_SYNC_QUEUE(9) Block Devices BLK_SYNC_QUEUE(9)
NAME blk_sync_queue - cancel any pending callbacks on a queue
SYNOPSIS void blk_sync_queue(struct request_queue * q);
ARGUMENTS q the queue
DESCRIPTION The block layer may perform asynchronous callback activity on a queue, such as calling the unplug function after a timeout. A block device may call blk_sync_queue to ensure that any such activity is cancelled, thus allowing it to release resources that the callbacks might use. The caller must already have made sure that its ->make_request_fn will not re-add plugging prior to calling this function.
This function does not cancel any asynchronous activity arising out of elevator or throttling code. That would require elevaotor_exit and blk_throtl_exit to be called with queue lock initialized.
COPYRIGHT Kernel Hackers Manual 2.6. November 2013 BLK_SYNC_QUEUE(9)