[SPDK] NVMe command ordering

[Jonas Pfefferle <pepperjo at japf.ch>]

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Hi @all,

Can anyone clarify this for me:
NVMe spec 6.3 Command Ordering Requirements
"For all commands which are not part of a fused operation (refer to section 
4.10), or for which the write size is greater than AWUN, each command is 
processed as an independent entity without reference to other commands 
submitted to the same I/O Submission Queue or to commands submitted to other 
I/O Submission Queues"

So writes <= AWUN size are atomic but there is no ordering between the 
commands, e.g. write command A issued before write command B to the same LBA 
can be executed in order AB or BA, the only thing guaranteed is that they 
are executed atomically? And there is no way to enforce ordering except on 
the host side?

Regards,
Jonas