I make block device driver module and insert module on Ubuntu. And then I want to mount that module as file system using 'mkfs'command. But, mkfs command didn't work more with following message:
writing superblocks and filesystem accounting information
mkfs doesn't mount block devices. It creates filsystems on them. (I hope that there was nothing interesting on you device; mkfs has deleted the data on block device). To mount a block devices (or better to say to mount the filesystem that is on the blockdevice) you must use mount:
# mount /dev/sda1 /mnt
(presuming /dev/sda1 is the device you try to mount).
Don't forget to unmount the device when you need it no more:
# umount /mnt
