From f348d70a324e15afc701a494f32ec468abb7d1eb Mon Sep 17 00:00:00 2001 From: Davide Libenzi Date: Sat, 25 Mar 2006 03:07:39 -0800 Subject: [PATCH] POLLRDHUP/EPOLLRDHUP handling for half-closed devices notifications Implement the half-closed devices notifiation, by adding a new POLLRDHUP (and its alias EPOLLRDHUP) bit to the existing poll/select sets. Since the existing POLLHUP handling, that does not report correctly half-closed devices, was feared to be changed, this implementation leaves the current POLLHUP reporting unchanged and simply add a new bit that is set in the few places where it makes sense. The same thing was discussed and conceptually agreed quite some time ago: http://lkml.org/lkml/2003/7/12/116 Since this new event bit is added to the existing Linux poll infrastruture, even the existing poll/select system calls will be able to use it. As far as the existing POLLHUP handling, the patch leaves it as is. The pollrdhup-2.6.16.rc5-0.10.diff defines the POLLRDHUP for all the existing archs and sets the bit in the six relevant files. The other attached diff is the simple change required to sys/epoll.h to add the EPOLLRDHUP definition. There is "a stupid program" to test POLLRDHUP delivery here: http://www.xmailserver.org/pollrdhup-test.c It tests poll(2), but since the delivery is same epoll(2) will work equally. Signed-off-by: Davide Libenzi Cc: "David S. Miller" Cc: Michael Kerrisk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- net/ipv4/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 4b0272c92d66..19ea5c0b094b 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -365,7 +365,7 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) mask |= POLLHUP; if (sk->sk_shutdown & RCV_SHUTDOWN) - mask |= POLLIN | POLLRDNORM; + mask |= POLLIN | POLLRDNORM | POLLRDHUP; /* Connected? */ if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) { -- cgit v1.2.2