Re: [Nbd] [RESEND][PATCH 0/5] nbd improvements

On Thu, Sep 15, 2016 at 12:49:35PM +0200, Wouter Verhelst wrote:

A while back, we spent quite some time defining the semantics of the
various commands in the face of the NBD_CMD_FLUSH and NBD_CMD_FLAG_FUA
write barriers. At the time, we decided that it would be unreasonable
to expect servers to make these write barriers effective across
different connections.

Do you have a nbd protocol specification?  treating a flush or fua
as any sort of barrier is incredibly stupid.  Is it really documented
that way, and if yes, why?