bcache: use bio_{start,end}_io_acct

Switch bcache to use the nicer bio accounting helpers, and call the
routines where we also sample the start time to give coherent accounting
results.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/md/bcache/request.c

@@ -668,9 +668,7 @@ static void backing_request_endio(struct bio *bio)
 static void bio_complete(struct search *s)
 {
 	if (s->orig_bio) {
-		generic_end_io_acct(s->d->disk->queue, bio_op(s->orig_bio),
-				    &s->d->disk->part0, s->start_time);
-
+		bio_end_io_acct(s->orig_bio, s->start_time);
 		trace_bcache_request_end(s->d, s->orig_bio);
 		s->orig_bio->bi_status = s->iop.status;
 		bio_endio(s->orig_bio);
@@ -730,7 +728,7 @@ static inline struct search *search_alloc(struct bio *bio,
 	s->recoverable		= 1;
 	s->write		= op_is_write(bio_op(bio));
 	s->read_dirty_data	= 0;
-	s->start_time		= jiffies;
+	s->start_time		= bio_start_io_acct(bio);
 
 	s->iop.c		= d->c;
 	s->iop.bio		= NULL;
@@ -1082,8 +1080,7 @@ static void detached_dev_end_io(struct bio *bio)
 	bio->bi_end_io = ddip->bi_end_io;
 	bio->bi_private = ddip->bi_private;
 
-	generic_end_io_acct(ddip->d->disk->queue, bio_op(bio),
-			    &ddip->d->disk->part0, ddip->start_time);
+	bio_end_io_acct(bio, ddip->start_time);
 
 	if (bio->bi_status) {
 		struct cached_dev *dc = container_of(ddip->d,
@@ -1108,7 +1105,7 @@ static void detached_dev_do_request(struct bcache_device *d, struct bio *bio)
 	 */
 	ddip = kzalloc(sizeof(struct detached_dev_io_private), GFP_NOIO);
 	ddip->d = d;
-	ddip->start_time = jiffies;
+	ddip->start_time = bio_start_io_acct(bio);
 	ddip->bi_end_io = bio->bi_end_io;
 	ddip->bi_private = bio->bi_private;
 	bio->bi_end_io = detached_dev_end_io;
@@ -1190,11 +1187,6 @@ blk_qc_t cached_dev_make_request(struct request_queue *q, struct bio *bio)
 		}
 	}
 
-	generic_start_io_acct(q,
-			      bio_op(bio),
-			      bio_sectors(bio),
-			      &d->disk->part0);
-
 	bio_set_dev(bio, dc->bdev);
 	bio->bi_iter.bi_sector += dc->sb.data_offset;
 
@@ -1311,8 +1303,6 @@ blk_qc_t flash_dev_make_request(struct request_queue *q, struct bio *bio)
 		return BLK_QC_T_NONE;
 	}
 
-	generic_start_io_acct(q, bio_op(bio), bio_sectors(bio), &d->disk->part0);
-
 	s = search_alloc(bio, d);
 	cl = &s->cl;
 	bio = &s->bio.bio;