mptcp: add mptcp_destroy_common helper

This patch added a new helper named mptcp_destroy_common containing the
shared code between mptcp_destroy() and mptcp_sock_destruct().
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mptcp/protocol.c

@@ -2128,16 +2128,21 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err,
 	return newsk;
 }
 
+void mptcp_destroy_common(struct mptcp_sock *msk)
+{
+	skb_rbtree_purge(&msk->out_of_order_queue);
+	mptcp_token_destroy(msk);
+	mptcp_pm_free_anno_list(msk);
+}
+
 static void mptcp_destroy(struct sock *sk)
 {
 	struct mptcp_sock *msk = mptcp_sk(sk);
 
-	skb_rbtree_purge(&msk->out_of_order_queue);
-	mptcp_token_destroy(msk);
 	if (msk->cached_ext)
 		__skb_ext_put(msk->cached_ext);
 
-	mptcp_pm_free_anno_list(msk);
+	mptcp_destroy_common(msk);
 	sk_sockets_allocated_dec(sk);
 }
 

net/mptcp/protocol.h

@@ -408,6 +408,7 @@ bool mptcp_finish_join(struct sock *sk);
 void mptcp_data_acked(struct sock *sk);
 void mptcp_subflow_eof(struct sock *sk);
 bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq);
+void mptcp_destroy_common(struct mptcp_sock *msk);
 
 void __init mptcp_token_init(void);
 static inline void mptcp_token_init_request(struct request_sock *req)

net/mptcp/subflow.c

@@ -435,9 +435,7 @@ static void mptcp_sock_destruct(struct sock *sk)
 		sock_orphan(sk);
 	}
 
-	skb_rbtree_purge(&mptcp_sk(sk)->out_of_order_queue);
-	mptcp_token_destroy(mptcp_sk(sk));
-	mptcp_pm_free_anno_list(mptcp_sk(sk));
+	mptcp_destroy_common(mptcp_sk(sk));
 	inet_sock_destruct(sk);
 }