Programming Assignment

1. This assignment is a pair programming effort.

2. Purpose: Develop a set of tools that can helptorecover a damaged file system. For many reasons, the information in a directory file, in an inode etc. may get damaged and cannot be read. As a result, a user program will not be able to access some parts of the file system. In this exercise, we ask you to develop a set of tools and show that you can use them to recover a file system ifone or more of its directory inode is damaged.

3. Requirements:

1) Your tools and recovery program will work on the xv6 file system.

2) Write a program, called the directoryWalker, that prints out the names of each file and directory in a file system tree, starting at a given point in the tree. The program will also write the inodes associated with each file and directory.

3) Write a program, called the inodeTBWalker, that prints out all the allocated inodes. You obtain this set of inodes from the inode table.

4) Write a program that will compare the output from the two Walkers.

5) Write a program that can erase the information (including the block pointers) in a directory inode so that you can test and demonstrate your results.

6) Write a program that can recover a file system if one or more of its directory inode is damaged and therefore cannot be read. Can you do this just by having the Walkers as specified above? What is the best you can do in terms of the number of damaged directory inodes?

7) Can you recover the file system if other parts of the file system data structure is damaged?Implementation not necessary but will count.