UBIFS - strange behaviour after enabling chk_index

[Richard Weinberger]

Marcin,

On 15.09.2016 08:33, Krzeminski, Marcin (Nokia - PL/Wroclaw) wrote:
>> Is this the SPI-NOR device you talked about on IRC?
> Yes.

The one where you're facing issues after a power cut?

>> Maybe the check is broken, maybe it uncovers a hard to hit issue on your
>> flash. Both could be.
>>
>> Do you emulate exactly the same device in qemu?
> Yes, this part of HW is virtualized in Qemu, in fact the same SW build runs on Qemu and HW.
> Since it reproduce on both it allows to think that this is SW related (at least for now),
> but sure does not mean that this is UBI/UBIFS.
> 
> Back to problem, it seem that this could be a debug facility issue, since file system and data
> are not corrupted. If data on flash are correct (I have done many test and all passed,
> so currently I assume that drier is working properly), it could be that data in debug structure
> in this case are somehow outdated/bad (d->old_zroot).
> In test script, if I copy the same file twice (instead of three times) the problem does not
> reproduce. 
> I will try to debug this more, maybe you have any inside where to look?

I think chk_index exposes the power cut issue you told me on IRC.
For whatever reason the index corrupts on your flash. And chk_index
catches this very early.

Maybe there is an issue in the SPI-NOR code or UBI itself has trouble
with your flash (layout).

Thanks,
//richard