Re: [PATCH 2/2] libnvdimm, dax: fix alignment validation

[Johannes Thumshirn]

On Wed, May 18, 2016 at 04:44:07PM -0700, Dan Williams wrote:
> Testing the dax-device autodetect support revealed a probe failure with
> the following result:
> 
>     dax0.1: bad offset: 0x8200000 dax disabled
> 
> The original pfn-device implementation inferred the alignment from
> ilog2(offset), now that the alignment is explicit the is_power_of_2()
> needs replacing with a real sanity check against the recorded alignment.
> Otherwise the alignment check is useless in the implicit case and only
> the minimum size of the offset matters.
> 
> This self-consistency check is further validated by the probe path that
> will re-check that the offset is large enough to contain all the
> metadata required to enable the device.
> 
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>

Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>

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