blk_end_request(9) [centos man page]

BLK_END_REQUEST(9)						   Block Devices						BLK_END_REQUEST(9)

NAME

       blk_end_request - Helper function for drivers to complete the request.

SYNOPSIS

       bool blk_end_request(struct request * rq, int error, unsigned int nr_bytes);

ARGUMENTS

       rq
	   the request being processed

       error
	   0 for success, < 0 for error

       nr_bytes
	   number of bytes to complete

DESCRIPTION

       Ends I/O on a number of bytes attached to rq. If rq has leftover, sets it up for the next range of segments.

RETURN

       false - we are done with this request true - still buffers pending for this request

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014							BLK_END_REQUEST(9)

BLK_INIT_QUEUE(9)						   Block Devices						 BLK_INIT_QUEUE(9)

NAME

       blk_init_queue - prepare a request queue for use with a block device

SYNOPSIS

       struct request_queue * blk_init_queue(request_fn_proc * rfn, spinlock_t * lock);

ARGUMENTS

       rfn
	   The function to be called to process requests that have been placed on the queue.

       lock
	   Request queue spin lock

DESCRIPTION

       If a block device wishes to use the standard request handling procedures, which sorts requests and coalesces adjacent requests, then it
       must call blk_init_queue. The function rfn will be called when there are requests on the queue that need to be processed. If the device
       supports plugging, then rfn may not be called immediately when requests are available on the queue, but may be called at some time later
       instead. Plugged queues are generally unplugged when a buffer belonging to one of the requests on the queue is needed, or due to memory
       pressure.

       rfn is not required, or even expected, to remove all requests off the queue, but only as many as it can handle at a time. If it does leave
       requests on the queue, it is responsible for arranging that the requests get dealt with eventually.

       The queue spin lock must be held while manipulating the requests on the request queue; this lock will be taken also from interrupt context,
       so irq disabling is needed for it.

       Function returns a pointer to the initialized request queue, or NULL if it didn't succeed.

NOTE

       blk_init_queue must be paired with a blk_cleanup_queue call when the block device is deactivated (such as at module unload).

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014							 BLK_INIT_QUEUE(9)