First 128KB of XFS partition is NULL.

[Ajeet Yadav]

Dear All,
I have received a corrupted disk from team testing XFS, when I look
hexdump of partiton. Its 0000 in first 128KB.
Our kernel is 2.6.30.9 however we have backported XFS from 2.6.34,
Arch MIP with VIPT cache.
This arch previously had many issues but after properly implementing
"xfs: fix xfs to work with Virtually Indexed architectures " most
problem resolved.

Can anyone make guess in what case first 128KB may become NULL, I seem
to be impossible because file system does not modify all 128KB at the
begining of partition at once.