Re: [PATCH V6 08/30] block: introduce chunk_last_segment()

[Christoph Hellwig]

I think both callers would be just as easy to understand by using
nth_page() instead of these magic helpers.  E.g. for guard_bio_eod:

		unsigned offset = (bv.bv_offset + bv.bv_len);
		struct page *page = nth_page(bv.bv_page, offset);

		zero_user(page, offset & PAGE_MASK, truncated_bytes);