block/rsxx: use generic io stats accounting functions to simplify io stat accounting

Use generic io stats accounting help functions (generic_{start,end}_io_acct)
to simplify io stat accounting.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/block/rsxx/dev.c

@@ -112,37 +112,16 @@ static const struct block_device_operations rsxx_fops = {
 
 static void disk_stats_start(struct rsxx_cardinfo *card, struct bio *bio)
 {
-	struct hd_struct *part0 = &card->gendisk->part0;
-	int rw = bio_data_dir(bio);
-	int cpu;
-
-	cpu = part_stat_lock();
-
-	part_round_stats(cpu, part0);
-	part_inc_in_flight(part0, rw);
-
-	part_stat_unlock();
+	generic_start_io_acct(bio_data_dir(bio), bio_sectors(bio),
+			     &card->gendisk->part0);
 }
 
 static void disk_stats_complete(struct rsxx_cardinfo *card,
 				struct bio *bio,
 				unsigned long start_time)
 {
-	struct hd_struct *part0 = &card->gendisk->part0;
-	unsigned long duration = jiffies - start_time;
-	int rw = bio_data_dir(bio);
-	int cpu;
-
-	cpu = part_stat_lock();
-
-	part_stat_add(cpu, part0, sectors[rw], bio_sectors(bio));
-	part_stat_inc(cpu, part0, ios[rw]);
-	part_stat_add(cpu, part0, ticks[rw], duration);
-
-	part_round_stats(cpu, part0);
-	part_dec_in_flight(part0, rw);
-
-	part_stat_unlock();
+	generic_end_io_acct(bio_data_dir(bio), &card->gendisk->part0,
+			   start_time);
 }
 
 static void bio_dma_done_cb(struct rsxx_cardinfo *card,