Re: [PATCH v20 02/12] Add infrastructure for copy offload in block and request layer.

[Bart Van Assche]

On 6/3/24 21:40, Christoph Hellwig wrote:
> There is no requirement to process them synchronously, there is just
> a requirement to preserve the order.  Note that my suggestion a few
> arounds ago also included a copy id to match them up.  If we don't
> need that I'm happy to leave it away.  If need it it to make stacking
> drivers' lifes easier that suggestion still stands.

Including an ID in REQ_OP_COPY_DST and REQ_OP_COPY_SRC operations sounds
much better to me than abusing the merge infrastructure for combining
these two operations into a single request. With the ID-based approach
stacking drivers are allowed to process copy bios asynchronously and it
is no longer necessary to activate merging for copy operations if
merging is disabled (QUEUE_FLAG_NOMERGES).

Thanks,

Bart.