From 8cb80eb1896aea2b7531a6de15954a2df4b821a6 Mon Sep 17 00:00:00 2001 From: Parthasarathy Bhuvaragan Date: Thu, 9 May 2019 07:13:42 +0200 Subject: [PATCH] tipc: fix hanging clients using poll with EPOLLOUT flag [ Upstream commit ff946833b70e0c7f93de9a3f5b329b5ae2287b38 ] commit 517d7c79bdb398 ("tipc: fix hanging poll() for stream sockets") introduced a regression for clients using non-blocking sockets. After the commit, we send EPOLLOUT event to the client even in TIPC_CONNECTING state. This causes the subsequent send() to fail with ENOTCONN, as the socket is still not in TIPC_ESTABLISHED state. In this commit, we: - improve the fix for hanging poll() by replacing sk_data_ready() with sk_state_change() to wake up all clients. - revert the faulty updates introduced by commit 517d7c79bdb398 ("tipc: fix hanging poll() for stream sockets"). Fixes: 517d7c79bdb398 ("tipc: fix hanging poll() for stream sockets") Signed-off-by: Parthasarathy Bhuvaragan Acked-by: Jon Maloy Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/tipc/socket.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 75681845679e..f13fb607c563 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -709,11 +709,11 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock, switch (sk->sk_state) { case TIPC_ESTABLISHED: - case TIPC_CONNECTING: if (!tsk->cong_link_cnt && !tsk_conn_cong(tsk)) mask |= POLLOUT; /* fall thru' */ case TIPC_LISTEN: + case TIPC_CONNECTING: if (!skb_queue_empty(&sk->sk_receive_queue)) mask |= (POLLIN | POLLRDNORM); break; @@ -1588,7 +1588,7 @@ static bool filter_connect(struct tipc_sock *tsk, struct sk_buff *skb) return true; /* If empty 'ACK-' message, wake up sleeping connect() */ - sk->sk_data_ready(sk); + sk->sk_state_change(sk); /* 'ACK-' message is neither accepted nor rejected: */ msg_set_dest_droppable(hdr, 1); -- 2.20.1