On Tue, Jun 28, 2022 at 07:56:27PM +0100, Pavel Begunkov wrote:
> Add an bvec specialised and optimised path in zerocopy_sg_from_iter.
> It'll be used later for {get,put}_page() optimisations.
> 
> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
> ---
>  net/core/datagram.c | 47 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 47 insertions(+)
> 

Rather than propagating iter functions, I have been using the attached
patch for a few months now. It leverages your ubuf_info in msghdr to
allow in kernel users to pass in their own iter handler.