Re: [PATCH net-next v3 01/18] net: Copy slab data for sendmsg(MSG_SPLICE_PAGES)

David Howells
2023-06-23T09:09:12Z

Jakub Kicinski <kuba@kernel.org> wrote:

> If we can't reach instant agreement --
> can you strategically separate out the minimal set of changes required
> to just kill MSG_SENDPAGE_NOTLAST. IMHO it's worth getting that into
> 6.5.

Paolo Abeni <pabeni@redhat.com> wrote:

> Given all the above, and the late stage of the current devel cycle,
> would you consider slicing down this series to just kill
> MSG_SENDPAGE_NOTLAST, as Jakub suggested?

I could do that.

There is also another alternative. I could just push the sendpage wrappers up
the stack into the higher-level callers. Basically this:

int udp_sendpage(struct sock *sk, struct page *page, int offset,
size_t size, int flags)
{
struct bio_vec bvec;
struct msghdr msg = { .msg_flags = flags | MSG_SPLICE_PAGES };

if (flags & MSG_SENDPAGE_NOTLAST)
msg.msg_flags |= MSG_MORE;

bvec_set_page(&bvec, page, size, offset);
iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, size);
return udp_sendmsg(sk, &msg, size);
}

and kill off sendpage and MSG_SENDPAGE_NOTLAST.

David