[PATCH net-next] l2tp: ppp: remove unused backlog callback

[Qingfang Deng <qingfang.deng@linux.dev>]

PPPoL2TP sessions receive packets through pppol2tp_recv(), which passes
packets directly to PPP or queues them on sk_receive_queue. No receive
path queues packets on the session socket backlog or calls
sk_receive_skb() with that socket, so pppol2tp_backlog_recv() is unused.

Remove the unused callback. L2TP/IP control sockets retain their
separate backlog callbacks. Selftests passed.

Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev>
---
 net/l2tp/l2tp_ppp.c | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 4f311d473a64..15e02864bfd5 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -454,17 +454,6 @@ static struct proto pppol2tp_sk_proto = {
 	.obj_size = sizeof(struct pppox_sock),
 };
 
-static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
-{
-	int rc;
-
-	rc = l2tp_udp_encap_recv(sk, skb);
-	if (rc)
-		kfree_skb(skb);
-
-	return NET_RX_SUCCESS;
-}
-
 /* socket() handler. Initialize a new struct sock.
  */
 static int pppol2tp_create(struct net *net, struct socket *sock, int kern)
@@ -482,7 +471,6 @@ static int pppol2tp_create(struct net *net, struct socket *sock, int kern)
 	sock->state  = SS_UNCONNECTED;
 	sock->ops    = &pppol2tp_ops;
 
-	sk->sk_backlog_rcv = pppol2tp_backlog_recv;
 	sk->sk_protocol	   = PX_PROTO_OL2TP;
 	sk->sk_family	   = PF_PPPOX;
 	sk->sk_state	   = PPPOX_NONE;
-- 
2.43.0