mptcp: consolidate transition to TCP_CLOSE in mptcp_do_fastclose()

The MPTCP code always set the msk state to TCP_CLOSE before
calling performing the fast-close. Move such state transition in
mptcp_do_fastclose() to avoid some code duplication.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Paolo Abeni

net/mptcp/protocol.c

@@ -2655,6 +2655,7 @@ static void mptcp_do_fastclose(struct sock *sk)
 	struct mptcp_subflow_context *subflow, *tmp;
 	struct mptcp_sock *msk = mptcp_sk(sk);
 
+	inet_sk_state_store(sk, TCP_CLOSE);
 	mptcp_for_each_subflow_safe(msk, subflow, tmp)
 		__mptcp_close_ssk(sk, mptcp_subflow_tcp_sock(subflow),
 				  subflow, MPTCP_CF_FASTCLOSE);
@@ -2692,10 +2693,9 @@ static void mptcp_worker(struct work_struct *work)
 	 * even if it is orphaned and in FIN_WAIT2 state
 	 */
 	if (sock_flag(sk, SOCK_DEAD)) {
-		if (mptcp_should_close(sk)) {
-			inet_sk_state_store(sk, TCP_CLOSE);
+		if (mptcp_should_close(sk))
 			mptcp_do_fastclose(sk);
-		}
+
 		if (sk->sk_state == TCP_CLOSE) {
 			__mptcp_destroy_sock(sk);
 			goto unlock;
@@ -2938,7 +2938,6 @@ static void __mptcp_destroy_sock(struct sock *sk)
 void __mptcp_unaccepted_force_close(struct sock *sk)
 {
 	sock_set_flag(sk, SOCK_DEAD);
-	inet_sk_state_store(sk, TCP_CLOSE);
 	mptcp_do_fastclose(sk);
 	__mptcp_destroy_sock(sk);
 }
@@ -2980,7 +2979,6 @@ bool __mptcp_close(struct sock *sk, long timeout)
 		/* If the msk has read data, or the caller explicitly ask it,
 		 * do the MPTCP equivalent of TCP reset, aka MPTCP fastclose
 		 */
-		inet_sk_state_store(sk, TCP_CLOSE);
 		mptcp_do_fastclose(sk);
 		timeout = 0;
 	} else if (mptcp_close_state(sk)) {