This looks fine except for a few nitpicks below:
> }
>
> + dev_pagemap_enable_ops();
> pgmap->type = MEMORY_DEVICE_FS_DAX;
> pgmap->page_free = generic_dax_pagefree;
> pgmap->data = owner;
> @@ -215,6 +216,7 @@ void fs_dax_release(struct dax_device *dax_dev, void
>
The HMM sub-system extended dev_pagemap to arrange a callback when a
dev_pagemap managed page is freed. Since a dev_pagemap page is free /
idle when its reference count is 1 it requires an additional branch to
check the page-type at put_page() time. Given put_page() is a hot-path
we do not want to
