On 8/11/23 03:52, Nitesh Shetty wrote:

We achieve copy offload by sending 2 bio's with source and destination
info and merge them to form a request. This request is sent to driver.
So this design works only for request based storage drivers.

[ ... ]

Overall series supports:
========================
	1. Driver
		- NVMe Copy command (single NS, TP 4065), including support
		in nvme-target (for block and file back end).

	2. Block layer
		- Block-generic copy (REQ_OP_COPY_DST/SRC), operation with
                   interface accommodating two block-devs
                 - Merging copy requests in request layer
		- Emulation, for in-kernel user when offload is natively
                 absent
		- dm-linear support (for cases not requiring split)

	3. User-interface
		- copy_file_range

Is this sufficient? The combination of dm-crypt, dm-linear and the NVMe 
driver is very common. What is the plan for supporting dm-crypt? 
Shouldn't bio splitting be supported for dm-linear?

Thanks,

Bart.