Re: [v2 PATCH] mm: dax: add comment for PFN_SPECIAL

[Dan Williams <dan.j.williams@intel.com>]

On Thu, Sep 27, 2018 at 3:17 PM <yang.shi@linux.alibaba.com> wrote:
>
> The comment for PFN_SPECIAL is missed in pfn_t.h. Add comment to get
> consistent with other pfn flags.
>
> Suggested-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
> ---
> v2: rephrase the comment per Dan

Looks good for the -mm tree.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>

>
>  include/linux/pfn_t.h | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
> index 21713dc..d6cc4b5 100644
> --- a/include/linux/pfn_t.h
> +++ b/include/linux/pfn_t.h
> @@ -9,6 +9,8 @@
>   * PFN_SG_LAST - pfn references a page and is the last scatterlist entry
>   * PFN_DEV - pfn is not covered by system memmap by default
>   * PFN_MAP - pfn has a dynamic page mapping established by a device driver
> + * PFN_SPECIAL - for CONFIG_FS_DAX_LIMITED builds to allow XIP, but not
> + *              get_user_pages
>   */
>  #define PFN_FLAGS_MASK (((u64) ~PAGE_MASK) << (BITS_PER_LONG_LONG - PAGE_SHIFT))
>  #define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1))
> --
> 1.8.3.1
>