https://bugs.winehq.org/show_bug.cgi?id=45599
--- Comment #3 from Alistair Leslie-Hughes leslie_alistair@hotmail.com --- (In reply to Dmitry Timoshkov from comment #1)
Apparently O_DIRECT adds strict requirement of an aligned buffer passed to write/pwrite and current code simply is not prepared for that. This patch set should be fixed by removing the server part (and completely omitting the O_DIRECT requirements as a result).
I assume you will post another set of patches at some point. I'd be happy to include them in staging if you want to get them tested before up-streaming them.