Revert "mptcp: add data lock for sk timers"

This reverts commit 4293248.

Additional locks are not needed, all the touched sections
are already under mptcp socket lock protection.

Fixes: 4293248 ("mptcp: add data lock for sk timers")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/mptcp/protocol.c

@@ -1613,10 +1613,8 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags)
 
 out:
 	/* ensure the rtx timer is running */
-	mptcp_data_lock(sk);
 	if (!mptcp_timer_pending(sk))
 		mptcp_reset_timer(sk);
-	mptcp_data_unlock(sk);
 	if (copied)
 		__mptcp_check_send_data_fin(sk);
 }
@@ -2529,10 +2527,8 @@ static void __mptcp_retrans(struct sock *sk)
 reset_timer:
 	mptcp_check_and_set_pending(sk);
 
-	mptcp_data_lock(sk);
 	if (!mptcp_timer_pending(sk))
 		mptcp_reset_timer(sk);
-	mptcp_data_unlock(sk);
 }
 
 static void mptcp_mp_fail_no_response(struct mptcp_sock *msk)
@@ -2711,10 +2707,8 @@ void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how)
 		} else {
 			pr_debug("Sending DATA_FIN on subflow %p", ssk);
 			tcp_send_ack(ssk);
-			mptcp_data_lock(sk);
 			if (!mptcp_timer_pending(sk))
 				mptcp_reset_timer(sk);
-			mptcp_data_unlock(sk);
 		}
 		break;
 	}
@@ -2815,10 +2809,8 @@ static void __mptcp_destroy_sock(struct sock *sk)
 	/* join list will be eventually flushed (with rst) at sock lock release time*/
 	list_splice_init(&msk->conn_list, &conn_list);
 
-	mptcp_data_lock(sk);
 	mptcp_stop_timer(sk);
 	sk_stop_timer(sk, &sk->sk_timer);
-	mptcp_data_unlock(sk);
 	msk->pm.status = 0;
 
 	/* clears msk->subflow, allowing the following loop to close
@@ -2880,9 +2872,7 @@ static void mptcp_close(struct sock *sk, long timeout)
 		__mptcp_destroy_sock(sk);
 		do_cancel_work = true;
 	} else {
-		mptcp_data_lock(sk);
 		sk_reset_timer(sk, &sk->sk_timer, jiffies + TCP_TIMEWAIT_LEN);
-		mptcp_data_unlock(sk);
 	}
 	release_sock(sk);
 	if (do_cancel_work)
@@ -2927,10 +2917,8 @@ static int mptcp_disconnect(struct sock *sk, int flags)
 		__mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_FASTCLOSE);
 	}
 
-	mptcp_data_lock(sk);
 	mptcp_stop_timer(sk);
 	sk_stop_timer(sk, &sk->sk_timer);
-	mptcp_data_unlock(sk);
 
 	if (mptcp_sk(sk)->token)
 		mptcp_event(MPTCP_EVENT_CLOSED, mptcp_sk(sk), NULL, GFP_KERNEL);