block: implement blk_rq_pos/[cur_]sectors() and convert obvious ones

Implement accessors - blk_rq_pos(), blk_rq_sectors() and
blk_rq_cur_sectors() which return rq->hard_sector, rq->hard_nr_sectors
and rq->hard_cur_sectors respectively and convert direct references of
the said fields to the accessors.

This is in preparation of request data length handling cleanup.

Geert	: suggested adding const to struct request * parameter to accessors
Sergei	: spotted error in patch description

[ Impact: cleanup ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Tested-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Ackec-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 20 insertions, 3 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6a967cad89fa..4e5f85598728 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -832,13 +832,30 @@ static inline void blk_run_address_space(struct address_space *mapping)
 extern void blkdev_dequeue_request(struct request *req);
 
 /*
- * blk_end_request() takes bytes instead of sectors as a complete size.
- * blk_rq_bytes() returns bytes left to complete in the entire request.
- * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
+ * blk_rq_pos()         : the current sector
+ * blk_rq_bytes()       : bytes left in the entire request
+ * blk_rq_cur_bytes()   : bytes left in the current segment
+ * blk_rq_sectors()     : sectors left in the entire request
+ * blk_rq_cur_sectors() : sectors left in the current segment
  */
+static inline sector_t blk_rq_pos(const struct request *rq)
+{
+        return rq->hard_sector;
+}
+
 extern unsigned int blk_rq_bytes(struct request *rq);
 extern unsigned int blk_rq_cur_bytes(struct request *rq);
 
+static inline unsigned int blk_rq_sectors(const struct request *rq)
+{
+        return rq->hard_nr_sectors;
+}
+
+static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
+{
+        return rq->hard_cur_sectors;
+}
+
 /*
  * Request completion related functions.
  *