From: Cong Wang <cong.wang@bytedance.com>
Date: Sun, 4 Jul 2021 12:02:46 -0700
Subject: af_unix: Add a dummy ->close() for sockmap
Patch-mainline: v5.15-rc1
Git-commit: c7272e15f0f18d6e0f423b53207eac7a27ed5a49
References: jsc#PED-1377

Unlike af_inet, unix_proto is very different, it does not even
have a ->close(). We have to add a dummy implementation to
satisfy sockmap. Normally it is just a nop, it is introduced only
for sockmap to replace it.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210704190252.11866-6-xiyou.wangcong@gmail.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
 net/unix/af_unix.c |    9 +++++++++
 1 file changed, 9 insertions(+)

--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -781,10 +781,18 @@ static const struct proto_ops unix_seqpa
 	.show_fdinfo =	unix_show_fdinfo,
 };
 
+static void unix_close(struct sock *sk, long timeout)
+{
+	/* Nothing to do here, unix socket does not need a ->close().
+	 * This is merely for sockmap.
+	 */
+}
+
 static struct proto unix_proto = {
 	.name			= "UNIX",
 	.owner			= THIS_MODULE,
 	.obj_size		= sizeof(struct unix_sock),
+	.close			= unix_close,
 };
 
 static struct sock *unix_create1(struct net *net, struct socket *sock, int kern)
@@ -868,6 +876,7 @@ static int unix_release(struct socket *s
 	if (!sk)
 		return 0;
 
+	sk->sk_prot->close(sk, 0);
 	unix_release_sock(sk, 0);
 	sock->sk = NULL;