Commit a0cd1285 authored by Jens Axboe's avatar Jens Axboe
Browse files

block: add end_queued_request() and end_dequeued_request() helpers 



We can use this helper in the elevator core for BLKPREP_KILL, and it'll
also be useful for the empty barrier patch.

Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 992c5dda

block/elevator.c

+1 −8
Original line number Diff line number Diff line
@@ -751,15 +751,8 @@ struct request *elv_next_request(struct request_queue *q) 
			rq = NULL;

			break;

		} else if (ret == BLKPREP_KILL) {

			int nr_bytes = rq->hard_nr_sectors << 9;



			if (!nr_bytes)

				nr_bytes = rq->data_len;



			blkdev_dequeue_request(rq);

			rq->cmd_flags |= REQ_QUIET;

			end_that_request_chunk(rq, 0, nr_bytes);

			end_that_request_last(rq, 0);

			end_queued_request(rq, 0);

		} else {

			printk(KERN_ERR "%s: bad return=%d\n", __FUNCTION__,

								ret);

block/ll_rw_blk.c

+73 −5
Original line number Diff line number Diff line
@@ -3630,15 +3630,83 @@ void end_that_request_last(struct request *req, int uptodate) 


EXPORT_SYMBOL(end_that_request_last);



void end_request(struct request *req, int uptodate)

static inline void __end_request(struct request *rq, int uptodate,

				 unsigned int nr_bytes, int dequeue)

{

	if (!end_that_request_first(req, uptodate, req->hard_cur_sectors)) {

		add_disk_randomness(req->rq_disk);

		blkdev_dequeue_request(req);

		end_that_request_last(req, uptodate);

	if (!end_that_request_chunk(rq, uptodate, nr_bytes)) {

		if (dequeue)

			blkdev_dequeue_request(rq);

		add_disk_randomness(rq->rq_disk);

		end_that_request_last(rq, uptodate);

	}

}



static unsigned int rq_byte_size(struct request *rq)

{

	if (blk_fs_request(rq))

		return rq->hard_nr_sectors << 9;



	return rq->data_len;

}



/**

 * end_queued_request - end all I/O on a queued request

 * @rq:		the request being processed

 * @uptodate:	error value or 0/1 uptodate flag

 *

 * Description:

 *     Ends all I/O on a request, and removes it from the block layer queues.

 *     Not suitable for normal IO completion, unless the driver still has

 *     the request attached to the block layer.

 *

 **/

void end_queued_request(struct request *rq, int uptodate)

{

	__end_request(rq, uptodate, rq_byte_size(rq), 1);

}

EXPORT_SYMBOL(end_queued_request);



/**

 * end_dequeued_request - end all I/O on a dequeued request

 * @rq:		the request being processed

 * @uptodate:	error value or 0/1 uptodate flag

 *

 * Description:

 *     Ends all I/O on a request. The request must already have been

 *     dequeued using blkdev_dequeue_request(), as is normally the case

 *     for most drivers.

 *

 **/

void end_dequeued_request(struct request *rq, int uptodate)

{

	__end_request(rq, uptodate, rq_byte_size(rq), 0);

}

EXPORT_SYMBOL(end_dequeued_request);





/**

 * end_request - end I/O on the current segment of the request

 * @rq:		the request being processed

 * @uptodate:	error value or 0/1 uptodate flag

 *

 * Description:

 *     Ends I/O on the current segment of a request. If that is the only

 *     remaining segment, the request is also completed and freed.

 *

 *     This is a remnant of how older block drivers handled IO completions.

 *     Modern drivers typically end IO on the full request in one go, unless

 *     they have a residual value to account for. For that case this function

 *     isn't really useful, unless the residual just happens to be the

 *     full current segment. In other words, don't use this function in new

 *     code. Either use end_request_completely(), or the

 *     end_that_request_chunk() (along with end_that_request_last()) for

 *     partial completions.

 *

 **/

void end_request(struct request *req, int uptodate)

{

	__end_request(req, uptodate, req->hard_cur_sectors << 9, 1);

}

EXPORT_SYMBOL(end_request);



static void blk_rq_bio_prep(struct request_queue *q, struct request *rq,

include/linux/blkdev.h

+3 −1
Original line number Diff line number Diff line
@@ -729,7 +729,9 @@ static inline void blk_run_address_space(struct address_space *mapping) 
extern int end_that_request_first(struct request *, int, int);

extern int end_that_request_chunk(struct request *, int, int);

extern void end_that_request_last(struct request *, int);

extern void end_request(struct request *req, int uptodate);

extern void end_request(struct request *, int);

extern void end_queued_request(struct request *, int);

extern void end_dequeued_request(struct request *, int);

extern void blk_complete_request(struct request *);



/*