Re: [PATCHv7 2/6] io_uring: add support for kernel registered bvecs

[Jens Axboe <axboe@kernel.dk>]

On 2/27/25 8:54 AM, Pavel Begunkov wrote:
> On 2/26/25 18:20, Keith Busch wrote:
>> From: Keith Busch <kbusch@kernel.org>
>>
>> Provide an interface for the kernel to leverage the existing
>> pre-registered buffers that io_uring provides. User space can reference
>> these later to achieve zero-copy IO.
>>
>> User space must register an empty fixed buffer table with io_uring in
>> order for the kernel to make use of it.
> 
> Can you also fail rw.c:loop_rw_iter()? Something like:
> 
> loop_rw_iter() {
>     if ((req->flags & REQ_F_BUF_NODE) &&
>         req->buf_node->buf->release)
>         return -EFAULT;
> }

Good point...


-- 
Jens Axboe