+	/*
+	 * In practice groups of pages tend to be accessed/reclaimed/refaulted
+	 * together. To not go over bvec for those who didn't set BIO_WORKINGSET
+	 * approximate it by looking at the first page and inducing it to the
+	 * whole bio
+	 */
+	if (unlikely(PageWorkingset(iter->bvec->bv_page)))
+		bio_set_flag(bio, BIO_WORKINGSET);

IIRC the feedback was that we do not need to deal with BIO_WORKINGSET
at all for direct I/O.

+	bio_set_flag(bio, BIO_NO_PAGE_REF);
+
+	iter->count = 0;
+	return 0;
+}

This helper should go into bio.c, next to bio_iov_iter_get_pages.
And please convert the other callers of bio_iov_iter_get_pages to this
scheme as well.