xfs_diff.sh modifies xfs partition and saves allocation groups and logs for
making diff of FS metadata states before and after modifications.
xfs_diff.sh reads partition map from config file, which creates automatically
via xfs-debug utilite. 
Limitations:
- only root can perform,
- mount point of device /dev/sXYZ is /mnt/sXYZ

usage: xfs_diff [DEV]
       xfs_diff clean

populate_with_files.sh serves for creating a lot of files and corresponding
inodes. It helps to test files with huge inode number and physical offset. 
Run it manually if you want to take a test with populated FS.
