On Sun, 26 Jan 2020 13:07:38 +0100, Lukas Straub said:

> I am planing to write a new device-mapper target and I'm wondering if there
> is a ordering guarantee for the operation inside a single bio? For example if I
> issue a write bio to sector 0 of length 4, is it guaranteed that sector 0 is
> written first and sector 3 is written last?

I'll bite.  What are you doing where the order of writing out a single bio matters?