xfstests: test ext4 statfs

[Rich Johnston]

On 10/26/2012 01:39 PM, Eric Sandeen wrote:
> On 10/26/12 1:03 PM, Rich Johnston wrote:
>> On 10/25/2012 12:19 PM, Eric Sandeen wrote:
>>> Calculating free blocks in ext[234] is surprisingly hard, since
>>> by default we report "bsd" style df which doesn't count filesystem
>>> "overhead" blocks as used.
>>>
>>> With a lot of code dedicated to sorting out what to report as
>>> free, things tend to go wrong surprisingly often.
>>>
>>> Here's a test to actually try to stop the next regression.  ;)
>>>
>>> NB: For bsddf, the kernel currently does not count journal blocks
>>> as overhead; it probably should.  But the test below looks to have
>>> the result within 1% of perfection, so it still passes even if
>>> the kernel doesn't count the journal against free blocks.
>>>
>>> Signed-off-by: Eric Sandeen <sandeen at redhat.com>
>>>
>>> ---
>>>

>
>
> Yep - it's an ext4 bug.  I sent a patch to fix it.
>
> [PATCH] ext4: fix overhead calculations in ext4_stats, again
>
> You might want to retest w/ that.
>
> -Eric
>
>>> +

Thanks Eric,

Everything passes now.

Reviewed-by: Rich Johnston <rjohnston at sgi.com>