Commit 7ac7c987 authored by David Howells's avatar David Howells Committed by Jakub Kicinski
Browse files

udp: Convert udp_sendpage() to use MSG_SPLICE_PAGES 



Convert udp_sendpage() to use sendmsg() with MSG_SPLICE_PAGES rather than
directly splicing in the pages itself.

This allows ->sendpage() to be replaced by something that can handle
multiple multipage folios in a single transaction.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
cc: David Ahern <dsahern@kernel.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 6d8192bd

net/ipv4/udp.c

+6 −45
Original line number Diff line number Diff line
@@ -1332,54 +1332,15 @@ EXPORT_SYMBOL(udp_sendmsg); 
int udp_sendpage(struct sock *sk, struct page *page, int offset,

		 size_t size, int flags)

{

	struct inet_sock *inet = inet_sk(sk);

	struct udp_sock *up = udp_sk(sk);

	int ret;

	struct bio_vec bvec;

	struct msghdr msg = { .msg_flags = flags | MSG_SPLICE_PAGES };



	if (flags & MSG_SENDPAGE_NOTLAST)

		flags |= MSG_MORE;



	if (!up->pending) {

		struct msghdr msg = {	.msg_flags = flags|MSG_MORE };



		/* Call udp_sendmsg to specify destination address which

		 * sendpage interface can't pass.

		 * This will succeed only when the socket is connected.

		 */

		ret = udp_sendmsg(sk, &msg, 0);

		if (ret < 0)

			return ret;

	}



	lock_sock(sk);



	if (unlikely(!up->pending)) {

		release_sock(sk);

		msg.msg_flags |= MSG_MORE;



		net_dbg_ratelimited("cork failed\n");

		return -EINVAL;

	}



	ret = ip_append_page(sk, &inet->cork.fl.u.ip4,

			     page, offset, size, flags);

	if (ret == -EOPNOTSUPP) {

		release_sock(sk);

		return sock_no_sendpage(sk->sk_socket, page, offset,

					size, flags);

	}

	if (ret < 0) {

		udp_flush_pending_frames(sk);

		goto out;

	}



	up->len += size;

	if (!(READ_ONCE(up->corkflag) || (flags&MSG_MORE)))

		ret = udp_push_pending_frames(sk);

	if (!ret)

		ret = size;

out:

	release_sock(sk);

	return ret;

	bvec_set_page(&bvec, page, size, offset);

	iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, size);

	return udp_sendmsg(sk, &msg, size);

}



#define UDP_SKB_IS_STATELESS 0x80000000