From: Geliang Tang <tanggeliang@kylinos.cn>

As a wrapper of __tcp_space_from_win(), this patch adds a MPTCP dedicated
space_from_win helper mptcp_space_from_win() in protocol.h to paired with
mptcp_win_from_space().

Use it instead of __tcp_space_from_win() in both mptcp_rcv_space_adjust()
and mptcp_set_rcvlowat().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/protocol.c | 2 +-
 net/mptcp/protocol.h | 5 +++++
 net/mptcp/sockopt.c  | 2 +-
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 04dda32ccbef..8b0a5b74a3b1 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2040,7 +2040,7 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied)
 		do_div(grow, msk->rcvq_space.space);
 		rcvwin += (grow << 1);
 
-		rcvbuf = min_t(u64, __tcp_space_from_win(scaling_ratio, rcvwin),
+		rcvbuf = min_t(u64, mptcp_space_from_win(sk, rcvwin),
 			       READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[2]));
 
 		if (rcvbuf > sk->sk_rcvbuf) {
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index b5fb26ece2b8..19d60b6d5b45 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -386,6 +386,11 @@ static inline int mptcp_win_from_space(const struct sock *sk, int space)
 	return __tcp_win_from_space(mptcp_sk(sk)->scaling_ratio, space);
 }
 
+static inline int mptcp_space_from_win(const struct sock *sk, int win)
+{
+	return __tcp_space_from_win(mptcp_sk(sk)->scaling_ratio, win);
+}
+
 static inline int __mptcp_space(const struct sock *sk)
 {
 	return mptcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - __mptcp_rmem(sk));
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 7265b6733f5a..00e06c698415 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -1581,7 +1581,7 @@ int mptcp_set_rcvlowat(struct sock *sk, int val)
 	if (sk->sk_userlocks & SOCK_RCVBUF_LOCK)
 		return 0;
 
-	space = __tcp_space_from_win(mptcp_sk(sk)->scaling_ratio, val);
+	space = mptcp_space_from_win(sk, val);
 	if (space <= sk->sk_rcvbuf)
 		return 0;
 
-- 
2.43.0