Increment/complete a bio by some number of bytes
void bio_advance(struct bio * bio, unsigned bytes);
bio
bio to advance
bytes
number of bytes to complete
This updates bi_sector, bi_size and bi_idx; if the number of bytes to complete doesn't align with a bvec boundary, then bv_len and bv_offset will be updated on the last bvec as well.
bio will then represent the remaining, uncompleted portion of the io.