On 12-06-01 11:07 AM, Theodore Ts'o wrote:

Ext4 updates for 3.5

The major new feature added in this update is Darrick J. Wong's
metadata checksum feature, which adds crc32 checksums to ext4's
metadata fields.  There is also the usual set of cleanups and bug
fixes.

That sounds vaguely like an on-disk change that may have issues
with systems that regularly switch between older and newer kernel versions.

Could you elaborate on it a bit more, thanks!