blk_queue_end_tag(9) [suse man page]

BLK_QUEUE_END_TAG(9)						   Block Devices					      BLK_QUEUE_END_TAG(9)

NAME

       blk_queue_end_tag - end tag operations for a request

SYNOPSIS

       void blk_queue_end_tag(struct request_queue * q, struct request * rq);

ARGUMENTS

       q
	   the request queue for the device

       rq
	   the request that has completed

DESCRIPTION

       Typically called when end_that_request_first returns 0, meaning all transfers have been done for a request. It's important to call this
       function before end_that_request_last, as that will put the request back on the free list thus corrupting the internal tag list.

NOTES

       queue lock must be held.

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010						      BLK_QUEUE_END_TAG(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 2.6.					     July 2010							 BLK_INIT_QUEUE(9)