From: Gang Yan <[email protected]>
Add __mptcp_subflow_set_rcvbuf() helper to write the subflow sk_rcvbuf,
but also to call the recently added tcp_set_rcvbuf() helper to update
window_clamp. This is needed because the window clap is updated when
scaling_ratio changes, in tcp_measure_rcv_mss(). Until scaling_ratio
changes, the subflow is stuck with the old window clamp which may be
based on a small initial buffer.
Use this new helper in both mptcp_sol_socket_sync_intval() (setsockopt
path) and sync_socket_options() (new subflow creation path).
Note that this patch depends on commit b025461303d8 ("tcp: update
window_clamp when SO_RCVBUF is set"): it fixes the issue on TCP side,
but the same fix is needed on MPTCP side as well.
Fixes: a2cbb1603943 ("tcp: Update window clamping condition")
Cc: [email protected]
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/619
Signed-off-by: Gang Yan <[email protected]>
Reviewed-by: Matthieu Baerts (NGI0) <[email protected]>
Signed-off-by: Matthieu Baerts (NGI0) <[email protected]>
---
v2: remove 'inline' keyword (NIPA) + update Fixes tag (Jakub)
---
net/mptcp/sockopt.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 1cf608e7357b..87b5796d0135 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -67,6 +67,12 @@ static int mptcp_get_int_option(struct mptcp_sock *msk,
sockptr_t optval,
return 0;
}
+static void __mptcp_subflow_set_rcvbuf(struct sock *ssk, int val)
+{
+ WRITE_ONCE(ssk->sk_rcvbuf, val);
+ tcp_set_rcvbuf(ssk, val);
+}
+
static void mptcp_sol_socket_sync_intval(struct mptcp_sock *msk, int optname,
int val)
{
struct mptcp_subflow_context *subflow;
@@ -100,7 +106,7 @@ static void mptcp_sol_socket_sync_intval(struct mptcp_sock
*msk, int optname, in
case SO_RCVBUF:
case SO_RCVBUFFORCE:
ssk->sk_userlocks |= SOCK_RCVBUF_LOCK;
- WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf);
+ __mptcp_subflow_set_rcvbuf(ssk, sk->sk_rcvbuf);
break;
case SO_MARK:
if (READ_ONCE(ssk->sk_mark) != sk->sk_mark) {
@@ -1560,7 +1566,7 @@ static void sync_socket_options(struct mptcp_sock *msk,
struct sock *ssk)
mptcp_subflow_ctx(ssk)->cached_sndbuf = sk->sk_sndbuf;
}
if (sk->sk_userlocks & SOCK_RCVBUF_LOCK)
- WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf);
+ __mptcp_subflow_set_rcvbuf(ssk, sk->sk_rcvbuf);
}
if (sock_flag(sk, SOCK_LINGER)) {
--
2.53.0
