[RFC PATCH v2 18/48] udp: Convert udp_sendpage() to use MSG_SPLICE_PAGES
From: David Howells <dhowells@redhat.com>
Date: 2023-03-29 14:18:06
Also in:
linux-fsdevel, linux-mm, lkml
Subsystem:
networking [general], the rest, user datagram protocol (udp) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Willem de Bruijn
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: David Howells <dhowells@redhat.com> cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> cc: netdev@vger.kernel.org --- net/ipv4/udp.c | 50 +++++++++----------------------------------------- 1 file changed, 9 insertions(+), 41 deletions(-)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index c605d171eb2d..097feb92e215 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c@@ -1332,52 +1332,20 @@ 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); + struct bio_vec bvec; + struct msghdr msg = { + .msg_flags = flags | MSG_SPLICE_PAGES | MSG_MORE + }; int ret; - if (flags & MSG_SENDPAGE_NOTLAST) - flags |= MSG_MORE; + bvec_set_page(&bvec, page, size, offset); + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, size); - 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; - } + if (flags & MSG_SENDPAGE_NOTLAST) + msg.msg_flags |= MSG_MORE; lock_sock(sk); - - if (unlikely(!up->pending)) { - release_sock(sk); - - 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: + ret = udp_sendmsg(sk, &msg, size); release_sock(sk); return ret; }