diff mbox series

[v2,11/13] sendmsg: clear SEND_SPACE if write caused wmem to grow too large

Message ID 20191118214538.21931-12-fw@strlen.de
State Accepted, archived
Delegated to: Matthieu Baerts
Headers show
Series [v2] mptcp: wmem accounting and nonblocking io support | expand

Commit Message

Florian Westphal Nov. 18, 2019, 9:45 p.m. UTC 
This is needed when we get rid of __tcp_poll and let mptcp_poll only
rely on msk->flags -- we need to avoid EPOLLOUT if the write filled
too much sndbuf space.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 net/mptcp/protocol.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
diff mbox series

Patch

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 8b22cf245580..9f2cbf2b89fb 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -421,6 +421,22 @@  static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
 	return backup;
 }
 
+static void ssk_check_wmem(struct mptcp_sock *msk, struct sock *ssk)
+{
+	struct socket *sock;
+
+	if (likely(sk_stream_is_writeable(ssk)))
+		return;
+
+	sock = READ_ONCE(ssk->sk_socket);
+
+	if (sock) {
+		clear_bit(MPTCP_SEND_SPACE, &msk->flags);
+		smp_mb__after_atomic();
+		set_bit(SOCK_NOSPACE, &sock->flags);
+	}
+}
+
 static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 {
 	int mss_now = 0, size_goal = 0, ret = 0;
@@ -485,6 +501,7 @@  static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 			mptcp_reset_timer(sk);
 	}
 
+	ssk_check_wmem(msk, ssk);
 	release_sock(ssk);
 
 out: