Re: [PATCH 5/7] fsdax: Dedup file range to use a compare function

From: Christoph Hellwig
Date: Wed Feb 10 2021 - 08:21:02 EST


On Tue, Feb 09, 2021 at 05:46:13PM +0800, Ruan Shiyang wrote:
>
>
> On 2021/2/9 下午5:34, Christoph Hellwig wrote:
>> On Tue, Feb 09, 2021 at 05:15:13PM +0800, Ruan Shiyang wrote:
>>> The dax dedupe comparison need the iomap_ops pointer as argument, so my
>>> understanding is that we don't modify the argument list of
>>> generic_remap_file_range_prep(), but move its code into
>>> __generic_remap_file_range_prep() whose argument list can be modified to
>>> accepts the iomap_ops pointer. Then it looks like this:
>>
>> I'd say just add the iomap_ops pointer to
>> generic_remap_file_range_prep and do away with the extra wrappers. We
>> only have three callers anyway.
>
> OK.

So looking at this again I think your proposal actaully is better,
given that the iomap variant is still DAX specific. Sorry for
the noise.

Also I think dax_file_range_compare should use iomap_apply instead
of open coding it.