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@xxxxxxxxxx> cc: Willem de Bruijn <willemdebruijn.kernel@xxxxxxxxx> cc: David Ahern <dsahern@xxxxxxxxxx> cc: "David S. Miller" <davem@xxxxxxxxxxxxx> cc: Eric Dumazet <edumazet@xxxxxxxxxx> cc: Jakub Kicinski <kuba@xxxxxxxxxx> cc: Paolo Abeni <pabeni@xxxxxxxxxx> cc: Jens Axboe <axboe@xxxxxxxxx> cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> cc: netdev@xxxxxxxxxxxxxxx --- Notes: ver #6) - udp_sendpage() shouldn't lock the socket around udp_sendpage(). - udp_sendpage() should only set MSG_MORE if MSG_SENDPAGE_NOTLAST is set. net/ipv4/udp.c | 51 ++++++-------------------------------------------- 1 file changed, 6 insertions(+), 45 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index aa32afd871ee..2879dc6d66ea 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -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); + msg.msg_flags |= MSG_MORE; - 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: - 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