This is a completely rewritten filesystem checker for GFS.  Performance

characteristics are significantly improved.  The design follows the 5-pass

fsck design found in "Fsck - The UNIX File System Check Program"

by McKusick & Kowalkski (1994)

  - http://citeseer.ist.psu.edu/mckusick94fsck.html

Line item list of supported features:

1. Detects and replaces missing/bad root inode

2. Detects and relinks unlinked inodes to l+f

   o If a file is zero length, it is not relinked to l+f - unless it

     has an extended attribute attached to it.

3. Detects duplicate blocks and removes inodes containing them

4. Detects bad blocks (block number out of range) and removes inodes

   containing them - Currently EAs that have blocks are removed but

   the inode containing them is left.

5. Detects bad metadata headers and clears the structure

6. Fixes bad resource group bitmaps

7. Fixes incorrect resource group counts

8. Creates l+f directory if missing

9. Detects and removes duplicate '.' and '..' entries

10. Creates '.' if missing

11. Beginning of support for internationalization

12. Checks extended attributes