RE: generic/064 test failures on ext4 (4.2-rc*)

[Namjae Jeon <namjae.jeon@samsung.com>]

Hi,

Sorry for late response.
I am on vacation. I will check this issue as soon as getting back.

Thanks!

> Yes, that's what is going on.  If delayed allocation is disabled (as
> it is in some configuration scenarios), ext4's block allocator doesn't
> do as well, and in some cases it will pick a starting block number for
> the file that ends up splitting the initial file across block groups'
> meta data blocks.
> 
> > Really, the number of extents or holes at the intermediate stage
> > doesn't matter. What matters is that after collapsing the holes back
> > out of the file, then number of extents is identical to the original
> > file (i.e. that fcollapse() undoes finsert() exactly).
> 
> Yup.
> 
> > So changing this code to use _within_tolerance to say that 100 >=
> > num_extents >= 105 is ok would probably be better:
> >
> > 	_within_tolerance "Extent count" $nextents 100 0 5%
> >
> > This will output a standard pass/fail message rather than an exact
> > count.  This allows some wiggle room for filesystem configurations
> > that have unexpected non-contiguous baseline allocation behaviour to
> > pass the test.
> 
> Works for me.
> 
> Thanks,
> 
> 					- Ted