submit_bio() flush to disk immediately

Hi, I am trying to write a bio to a disk block directly using submit_bio(), it works without any errors but on read it shows the old data until I reboot the machine. Is there any way I can flush the particular bio/dirty page immediately or force it to flush before the next read ? code : https://github.com/prashants/km/blob/master/writeblock/writeblock.c Regards.