The e2fsck program does a number of checks on a filesystem, including inode bitmap integrity and directory connectivity.  This presented a number of problems: e2fsck run on a partition with a undelete directory would report errors since it found the reserved inode 6 in use and because it found the undelete directory unconnected to the root filesystem hierarchy.

We then had to change e2fsck so it would treat inode 6 as a valid inode and so it would not complain when finding it unconnected to root.  That was what we proceded to do.  A copy of the new e2fsck is included in the undelete implementation distribution.