usage:
1. insert module
sudo insmod yramfs.ko
2. mount file system
sudo mount -t yramfs none /mnt/yramfs
3. unmount
sudo unmout /mnt/yramfs
4. remove moudule
sudo rmmod yramfs
The steps of registerring a file system with the kernel as a kernel module:
1. During module initialization, kernel register the file system with a
handler be called to fill the super block structure while mounting, also a
handler to do the cleanup during unmounting the file system.
2. the super block operations are set at the time of mounting. The operation
tables for inodes and files are set when the inode is opend.
3. The root most inode is allocated at the time of mounting during the super
block initialization
4. The first step before opening an inode is lookup. The inode of a file is
looked up by calling the lookup handler of the parent inode.
Referenced documents on internet:
http://www.win.tue.nl/~aeb/linux/lk/lk-8.html
http://tldp.org/LDP/tlk/fs/filesystem.html
http://thecoffeedesk.com/geocities/rkfs.html
Referenced source code on internet:
http://pages.cpsc.ucalgary.ca/~crwth/programming/VFS/inodes.php