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: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe 2007-09-21 10:41:07 +02:00
parent 992c5ddaf1
commit a0cd128542
3 changed files with 77 additions and 14 deletions

View file

@ -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);

View file

@ -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,

View file

@ -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 *);
/*