On Wed, Apr 24, 2019 at 07:18:03PM +0200, Andreas Gruenbacher wrote: > Add a page_prepare calback that's called before a page is written to. This > will be used by gfs2 to start a transaction in page_prepare and end it in > page_done. Other filesystems that implement data journaling will require the > same kind of mechanism. This looks basically fine to me. But I think it would be nicer to add a iomap_page_ops structure so that we don't have to add more pointers directly to the iomap. We can make that struct pointer const also to avoid runtime overwriting attacks.