I'm hoping to write some tools to help in processing the file system UFS on a disk given access to the raw data. I've learned a bunch about UFS already and know that most Unix/Linux file systems have some commonality. I will read in the FS structures and then hopefully be able to traverse things like a file system driver would. The difficulty now lies in documentation on how UFS does its thing. I've read lots of higher level stuff but I would like to see something like this which is for ext2 - http://homepage.smc.edu/morgan_david/cs40/analyze-ext2.htm .
That page is great in that it shows the full definition of the superblock, inode, directory entry etc. I've also learned how inodes work in other research. I've made a FreeBSD installation and am analyzing it to compare and it is similar. However I know there are differences. Also I'm not sure how some things are done such as finding the inode for a file. That link for ext2 says to do this-
- visiting the inode for the root directory (inode 2) to get the location of the data for the root directory
- visiting the data for the root directory to find the directory entry for alpha1
- visiting the entry for alpha1 to get the location of the inode for alpha1
- visiting the inode for alpha1 to get the location of the data for alpha1
- visiting the data of alpha1 (the alphabet)
I can't figure out step 3. Ok I see the inode number in the directory entry for a file. How does that give you the inode location? How do I find the inode?
Better references would be fantastic. I haven't found any books out there that might help but I'm definitely willing to buy a book.
Thanks for any help!
