Hi,

I have updated and reworked bio traversal patch.

Main idea is now reversed - instead of introducing rq->hard_bio as
pointer for bio to be completed and using rq->bio as pointer for bio
to be submitted, rq->cbio is introduced for submissions and rq->bio
is used for completions.

This minimizes changes to block layer and assures that all existing
block users are not affected by this patch.

Please check it and forward to Linus, or tell what changes you
need to find this code acceptable.

--
Bartlomiej