Re: [PATCH 5/9] iomap: Support arbitrarily many blocks per page

[Christoph Hellwig]

>  static inline struct iomap_page *to_iomap_page(struct page *page)
>  {
> +	VM_BUG_ON_PGFLAGS(PageTail(page), page);
>  	if (page_has_private(page))
>  		return (struct iomap_page *)page_private(page);
>  	return NULL;

Nit: can you add an empty line after the VM_BUG_ON_PGFLAGS assert to
keep the function readable?  Maybe also add a comment on the assert,
as it isn't totally obvious.

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@xxxxxx>