> Fixes: 82cb14175e7d ("xfs: add support for sub-pagesize writeback
> without buffer_heads")
I've never seen line breaks in Fixes tags, is this really a valid format?
> + /*
> + * At least migrate_page_move_mapping() assumes that pages with private
> + * data have their count elevated by 1.
> + */
I'd drop the "At least".
Otherwise this looks fine to me:
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
