[BLOCK] aoe: update for combined io statistics

			unsigned long duration = jiffies - buf->start_time;

			unsigned long n_sect = buf->bio->bi_size >> 9;

			struct gendisk *disk = d->gd;

			const int rw = bio_data_dir(buf->bio);

			if (bio_data_dir(buf->bio) == WRITE) {

				disk_stat_inc(disk, writes);

				disk_stat_add(disk, write_ticks, duration);

				disk_stat_add(disk, write_sectors, n_sect);

			} else {

				disk_stat_inc(disk, reads);

				disk_stat_add(disk, read_ticks, duration);

				disk_stat_add(disk, read_sectors, n_sect);

			}

			disk_stat_inc(disk, ios[rw]);

			disk_stat_add(disk, ticks[rw], duration);

			disk_stat_add(disk, sectors[rw], n_sect);

			disk_stat_add(disk, io_ticks, duration);

			n = (buf->flags & BUFFL_FAIL) ? -EIO : 0;

			bio_endio(buf->bio, buf->bio->bi_size, n);