[MPTCP] [PATCH v2 4/4] mptcp: switch mptcp_poll to mptcp socket wait queue

tcp_poll places current task on a wait queue. This can cause us to block forever -- some subflows might never receive any data because they're used as a backup/fallback path. This makes mptcp_poll wait on the mptcp socket wait queue instead. __tcp_poll is used instead to tcp_poll so current task won't wait again after mptcp socket has been woken from the subflow layer. Signed-off-by: Florian Westphal <fw(a)strlen.de&gt; --- net/mptcp/protocol.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index c7755cde9810..c2b29f8d0377 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1238,11 +1238,13 @@ static __poll_t mptcp_poll(struct file *file, struct socket *sock, return ret; } + sock_poll_wait(file, sock, wait); + mptcp_for_each_subflow(msk, subflow) { struct socket *tcp_sock; tcp_sock = mptcp_subflow_tcp_socket(subflow); - ret |= tcp_poll(file, tcp_sock, wait); + ret |= __tcp_poll(tcp_sock->sk); } release_sock(sk); -- 2.21.0