[PATCH net-next 3/5] tcp: add recv_should_stop helper

["Matthieu Baerts (NGI0)" <matttbe@kernel.org>]

From: Geliang Tang <tanggeliang@kylinos.cn>

Factor out a new helper tcp_recv_should_stop() from tcp_recvmsg_locked()
and tcp_splice_read() to check whether to stop receiving. And use this
helper in mptcp_recvmsg() and mptcp_splice_read() to reduce redundant code.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
To: Neal Cardwell <ncardwell@google.com>
To: Kuniyuki Iwashima <kuniyu@google.com>
To: David Ahern <dsahern@kernel.org>
---
 include/net/tcp.h    |  8 ++++++++
 net/ipv4/tcp.c       |  9 ++-------
 net/mptcp/protocol.c | 11 +++--------
 3 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 565943c34b7e..6156d1d068e1 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -3077,4 +3077,12 @@ enum skb_drop_reason tcp_inbound_hash(struct sock *sk,
 		const void *saddr, const void *daddr,
 		int family, int dif, int sdif);
 
+static inline int tcp_recv_should_stop(struct sock *sk)
+{
+	return sk->sk_err ||
+	       sk->sk_state == TCP_CLOSE ||
+	       (sk->sk_shutdown & RCV_SHUTDOWN) ||
+	       signal_pending(current);
+}
+
 #endif	/* _TCP_H */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index bd2c3c4587e1..e57eaffc007a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -888,9 +888,7 @@ ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
 		release_sock(sk);
 		lock_sock(sk);
 
-		if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
-		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
-		    signal_pending(current))
+		if (tcp_recv_should_stop(sk))
 			break;
 	}
 
@@ -2755,10 +2753,7 @@ static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
 
 		if (copied) {
 			if (!timeo ||
-			    sk->sk_err ||
-			    sk->sk_state == TCP_CLOSE ||
-			    (sk->sk_shutdown & RCV_SHUTDOWN) ||
-			    signal_pending(current))
+			    tcp_recv_should_stop(sk))
 				break;
 		} else {
 			if (sock_flag(sk, SOCK_DONE))
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index e21e416cd19a..2f4776a4f06a 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2333,11 +2333,8 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 			break;
 
 		if (copied) {
-			if (sk->sk_err ||
-			    sk->sk_state == TCP_CLOSE ||
-			    (sk->sk_shutdown & RCV_SHUTDOWN) ||
-			    !timeo ||
-			    signal_pending(current))
+			if (tcp_recv_should_stop(sk) ||
+			    !timeo)
 				break;
 		} else {
 			if (sk->sk_err) {
@@ -4520,9 +4517,7 @@ static ssize_t mptcp_splice_read(struct socket *sock, loff_t *ppos,
 		release_sock(sk);
 		lock_sock(sk);
 
-		if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
-		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
-		    signal_pending(current))
+		if (tcp_recv_should_stop(sk))
 			break;
 	}
 

-- 
2.53.0