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, 1 insertions, 1 deletions

diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index c8d087655eff..c167de5b9eff 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -163,7 +163,7 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
          * For an empty barrier, there's no actual BAR request, which
          * in turn makes POSTFLUSH unnecessary.  Mask them off.
          */
-        if (!rq->hard_nr_sectors) {
+        if (!blk_rq_sectors(rq)) {
                 q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
                                 QUEUE_ORDERED_DO_POSTFLUSH);
                 /*