blk_end_request: add bidi completion interface (take 4)

This patch adds a variant of the interface, blk_end_bidi_request(),
which completes a bidi request.

Bidi request must be completed as a whole, both rq and rq->next_rq
at once.  So the interface has 2 arguments for completion size.

As for ->end_io, only rq->end_io is called (rq->next_rq->end_io is not
called).  So if special completion handling is needed, the handler
must be set to rq->end_io.
And the handler must take care of freeing next_rq too, since
the interface doesn't care of it if rq->end_io is not NULL.

Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 63fe7542b3fa..029b7097f9e5 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -728,6 +728,8 @@ static inline void blk_run_address_space(struct address_space *mapping)
  */
 extern int blk_end_request(struct request *rq, int error, int nr_bytes);
 extern int __blk_end_request(struct request *rq, int error, int nr_bytes);
+extern int blk_end_bidi_request(struct request *rq, int error, int nr_bytes,
+				int bidi_bytes);
 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);