A simple filesystem to understand things.

This is a Work In Progress. Do not use this yet.

The source files are licensed under Creative Commons Zero License.
More information at:	http://creativecommons.org/publicdomain/zero/1.0/
Full license text at:	http://creativecommons.org/publicdomain/zero/1.0/legalcode

To compile:
------------
install linux kernel sources and run make from the checkedout directory.

To test:
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psankar@linux-9dni:~/src/simplefs> make

psankar@linux-9dni:~/src/simplefs> dd bs=4096 count=100 if=/dev/zero of=image
100+0 records in
100+0 records out
409600 bytes (410 kB) copied, 0.00106026 s, 386 MB/s

psankar@linux-9dni:~/src/simplefs> ./mkfs-simplefs image
Super block written succesfully
root directory inode written succesfully
welcomefile inode written succesfully
inode store padding bytes (after the two inodes) written sucessfully
root directory datablocks (name+inode_no pair for welcomefile) written succesfully
padding after the rootdirectory children written succesfully
welcomefilebody has been written succesfully

psankar@linux-9dni:~/src/simplefs>

Now as root:

linux-9dni:/home/psankar/src/simplefs # insmod simplefs.ko ; mount -o loop -t simplefs image /home/psankar/src/simplefs/mount/ ; dmesg
[51422.091945] Sucessfully registered simplefs
[51422.094713] The magic number obtained in disk is: [268640275]
[51422.094719] simplefs filesystem of version [1] formatted with a block size of [4096] detected in the device.
[51422.094744] simplefs is succesfully mounted on [/dev/loop5]

linux-9dni:/home/psankar/src/simplefs # cat mount/vanakkam
Love is God. God is Love. Anbe Murugan.

linux-9dni:/home/psankar/src/simplefs # cp mount/vanakkam .

linux-9dni:/home/psankar/src/simplefs # cat vanakkam
Love is God. God is Love. Anbe Murugan.

linux-9dni:/home/psankar/src/simplefs # umount mount; rmmod simplefs.ko ; dmesg
[51422.091945] Sucessfully registered simplefs
[51422.094713] The magic number obtained in disk is: [268640275]
[51422.094719] simplefs filesystem of version [1] formatted with a block size of [4096] detected in the device.
[51422.094744] simplefs is succesfully mounted on [/dev/loop5]
[51469.971919] simplefs superblock is destroyed. Unmount succesful.
[51469.977426] Sucessfully unregistered simplefs

linux-9dni:/home/psankar/src/simplefs #