Using latest xfsprogs 2.8.10 ( needed to fix bug http://oss.sgi.com/projects/xfs/faq.html#dir2 )
results in unusable fsck for a xfs fs:
fsck 1.39 (29-May-2006)
If you wish to check the consistency of an XFS filesystem or
repair a damaged filesystem, see xfs_check(8) and xfs_repair(8).
If it is a xfs FS checkfs should use xfs_check instead - for now the check done is useless.
file a bug in upstream bugzilla as their utilities break the standard fsck behavior
*** Bug 338373 has been marked as a duplicate of this bug. ***
For future reference, here is the upstream bugzilla entry, with their subsequent comments:
set your fstab to use an entry of "0" for the fstab pass