> + /* > + * It is safe to truncate the last bvec in the following way > + * even though multipage bvec is supported, but we need to > + * fix the parameters passed to zero_user(). > + */ > + struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];
A 'we need to fix XXX' comment isn't very useful. Just fix it in the series (which I suspect you're going to do anyway). Also a bio_last_vec helper might be nice for something like this and documents properly converted places much better than these comments.
