After commit 
d38afeec26ed ("tcp/udp: Call inet6_destroy_sock()
in IPv6 sk->sk_destruct()."), we call inet6_destroy_sock() in
sk->sk_destruct() by setting inet6_sock_destruct() to it to make
sure we do not leak inet6-specific resources.
Now we can remove unnecessary inet6_destroy_sock() calls in
sk->sk_prot->destroy().
DCCP and SCTP have their own sk->sk_destruct() function, so we
change them separately in the following patches.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
 #include <linux/bpf-cgroup.h>
 #include <net/ping.h>
 
-static void ping_v6_destroy(struct sock *sk)
-{
-       inet6_destroy_sock(sk);
-}
-
 /* Compatibility glue so we can support IPv6 when it's compiled as a module */
 static int dummy_ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
                                 int *addr_len)
        .owner =        THIS_MODULE,
        .init =         ping_init_sock,
        .close =        ping_close,
-       .destroy =      ping_v6_destroy,
        .pre_connect =  ping_v6_pre_connect,
        .connect =      ip6_datagram_connect_v6_only,
        .disconnect =   __udp_disconnect,
 
        lock_sock(sk);
        ip6_flush_pending_frames(sk);
        release_sock(sk);
-
-       inet6_destroy_sock(sk);
 }
 
 static int rawv6_init_sk(struct sock *sk)
 
        return 0;
 }
 
-static void tcp_v6_destroy_sock(struct sock *sk)
-{
-       tcp_v4_destroy_sock(sk);
-       inet6_destroy_sock(sk);
-}
-
 #ifdef CONFIG_PROC_FS
 /* Proc filesystem TCPv6 sock list dumping. */
 static void get_openreq6(struct seq_file *seq,
        .accept                 = inet_csk_accept,
        .ioctl                  = tcp_ioctl,
        .init                   = tcp_v6_init_sock,
-       .destroy                = tcp_v6_destroy_sock,
+       .destroy                = tcp_v4_destroy_sock,
        .shutdown               = tcp_shutdown,
        .setsockopt             = tcp_setsockopt,
        .getsockopt             = tcp_getsockopt,
 
                        udp_encap_disable();
                }
        }
-
-       inet6_destroy_sock(sk);
 }
 
 /*
 
 
        if (tunnel)
                l2tp_tunnel_delete(tunnel);
-
-       inet6_destroy_sock(sk);
 }
 
 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 
 
 static struct proto mptcp_v6_prot;
 
-static void mptcp_v6_destroy(struct sock *sk)
-{
-       mptcp_destroy(sk);
-       inet6_destroy_sock(sk);
-}
-
 static struct inet_protosw mptcp_v6_protosw = {
        .type           = SOCK_STREAM,
        .protocol       = IPPROTO_MPTCP,
        mptcp_v6_prot = mptcp_prot;
        strcpy(mptcp_v6_prot.name, "MPTCPv6");
        mptcp_v6_prot.slab = NULL;
-       mptcp_v6_prot.destroy = mptcp_v6_destroy;
        mptcp_v6_prot.obj_size = sizeof(struct mptcp6_sock);
 
        err = proto_register(&mptcp_v6_prot, 1);