I've been wading through this thread a bit, and while I can't follow everything due some pretty bad reply trimming I'm really really confused by this whole discussion. Every single storage system, be that hard drives, SSDs, file systems or what else much preferres sequential write. Any code that turns perfectly sequential writes into reverse sequential writes is a massive performance bug, zoned or not. So totally independent of zone device support in ublk this needs to be fixed ASAP.
