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

From: Bart Van Assche
Date: Tue Jun 04 2024 - 07:45:09 EST


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.