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, 2 insertions, 2 deletions

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 921ef5d1f0b..42f1c11e754 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -646,7 +646,7 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 				rq->cmd_len, rq->cmd);
 	} else  {
 		what |= BLK_TC_ACT(BLK_TC_FS);
-		__blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
+		__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_sectors(rq) << 9,
 				rw, what, rq->errors, 0, NULL);
 	}
 }
@@ -857,7 +857,7 @@ void blk_add_driver_data(struct request_queue *q,
 		__blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA,
 				rq->errors, len, data);
 	else
-		__blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
+		__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_sectors(rq) << 9,
 				0, BLK_TA_DRV_DATA, rq->errors, len, data);
 }
 EXPORT_SYMBOL_GPL(blk_add_driver_data);