Re: [PATCH 4/4] io_uring/uring_cmd: implement ->sqe_copy() to avoid unnecessary copies

[Jens Axboe <axboe@kernel.dk>]

On 6/6/25 3:05 PM, Jens Axboe wrote:
>> Is it necessary to pass the sqe? Wouldn't it always be ioucmd->sqe?
>> Presumably any other opcode that implements ->sqe_copy() would also
>> have the sqe pointer stashed somewhere. Seems like it would simplify
>> the core io_uring code a bit not to have to thread the sqe through
>> several function calls.
> 
> It's not necessary, but I would rather get rid of needing to store an
> SQE since that is a bit iffy than get rid of passing the SQE. When it
> comes from the core, you _know_ it's going to be valid. I feel like you
> need a fairly intimate understanding of io_uring issue flow to make any
> judgement on this, if you were adding an opcode and defining this type
> of handler.

Actually did go that route anyway, because we still need to stash it.
And if we do go that route, then we can keep all the checking in the
core and leave the handler just a basic copy with a void return. Which
is pretty nice.

Anyway, checkout v3 and see what you thing.

-- 
Jens Axboe