[dm-devel] [PATCH] dm, dax: Make sure dm_dax_flush() is called if device supports it

[Dan Williams]

On Tue, Jul 25, 2017 at 12:43 PM, Vivek Goyal <vgoyal at redhat.com> wrote:
> Right now, dm_dax_flush() is not being called and I think it is not being
> called becuase DAXDEV_WRITE_CACHE is not set on dm dax device.
>
> If underlying dax device supports write cache, set DAXDEV_WRITE_CACHE on
> dm dax device. This will get dm_dax_flush() being called.
>
> Signed-off-by: Vivek Goyal <vgoyal at redhat.com>
> ---
>  drivers/dax/super.c   |  5 +++++
>  drivers/md/dm-table.c | 33 +++++++++++++++++++++++++++++++++
>  include/linux/dax.h   |  1 +
>  3 files changed, 39 insertions(+)
>
> diff --git a/drivers/dax/super.c b/drivers/dax/super.c
> index ce9e563e6e1d..5c5e7b9f6831 100644
> --- a/drivers/dax/super.c
> +++ b/drivers/dax/super.c
> @@ -278,6 +278,11 @@ void dax_write_cache(struct dax_device *dax_dev, bool wc)
>  }
>  EXPORT_SYMBOL_GPL(dax_write_cache);
>
> +bool dax_write_cache_enabled(struct dax_device *dax_dev)
> +{
> +       return test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags);
> +}

We need :

    EXPORT_SYMBOL_GPL(dax_write_cache_enabled)

...but other than that, looks good to me.

Acked-by: Dan Williams <dan.j.williams at intel.com>