Fix various abuse of bio fields in umem.c
umem.c:
advances bi_idx and bi_sector to track where it is up to.
But it is only ever doing this on one bio, so the updated
fields can easily be kept elsewhere (current_*).
updates bi_size, but never uses the updated values, so
this isn't needed.
reuses bi_phys_segments to count how many iovecs have been
completely. As the completion happens sequentiually, we
can store this information outside the bio too.
Signed-off-by: Neil Brown <neilb@suse.de>
diff .prev/drivers/block/umem.c ./drivers/block/umem.c
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>