Failure of xfstest 229

[Christoph Hellwig]

On Fri, May 20, 2011 at 09:35:03AM -0700, Chandra Seetharaman wrote:
> 
> Can it run successfully by fluke sometimes ? I did have a successful run
> on the 20G filesystem yesterday once, but not able to reproduce it again

It doesn't fail on thinly provisioned storage which zeroes out any
blocks it gives to the OS.  Similarly it might not fail if all blocks
that it would normally leak are zeroed underneath for some reason,
but it's rather unlikely that this happens by accident.