On Tue, Jun 11 2019 at 9:10am -0400,
Pankaj Gupta <pagupta@xxxxxxxxxx> wrote:
> Hi Mike,
>
> Thanks for the review Please find my reply inline.
>
> >
> > dm_table_supports_dax() is called multiple times (from
> > dm_table_set_restrictions and dm_table_determine_type). It is strange
> > to have a getter have a side-effect of being a setter too. Overloading
> > like this could get you in trouble in the future.
> >
> > Are you certain this is what you want?
>
> I agree with you.
>
> >
> > Or would it be better to refactor dm_table_supports_dax() to take an
> > iterate_devices_fn arg and have callers pass the appropriate function?
> > Then have dm_table_set_restrictions() caller do:
> >
> > if (dm_table_supports_dax(t, device_synchronous, NULL))
> > set_dax_synchronous(t->md->dax_dev);
> >
> > (NULL arg implies dm_table_supports_dax() refactoring would take a int
> > *data pointer rather than int type).
> >
> > Mike
> >
>
> I am sending below patch as per your suggestion. Does it look
> near to what you have in mind?
Yes, it does.. just one nit I noticed inlined below.
> diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
> index 350cf0451456..8d89acc8b8c2 100644
> --- a/drivers/md/dm-table.c
> +++ b/drivers/md/dm-table.c
...
> @@ -1910,8 +1919,13 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
> }
> blk_queue_write_cache(q, wc, fua);
>
> - if (dm_table_supports_dax(t, PAGE_SIZE))
> + if (dm_table_supports_dax(t, device_supports_dax, &page_size)) {
> +
No need for an empty newline here ^
> blk_queue_flag_set(QUEUE_FLAG_DAX, q);
> + if (dm_table_supports_dax(t, device_synchronous, NULL))
> + set_dax_synchronous(t->md->dax_dev);
> + }
> else
> blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
>
Thanks,
Mike
