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 --- fs/eventpoll.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 1c2b16fda13..a0f682cdd03 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -599,7 +599,7 @@ sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event) switch (op) { case EPOLL_CTL_ADD: if (!epi) { - epds.events |= POLLERR | POLLHUP; + epds.events |= POLLERR | POLLHUP | POLLRDHUP; error = ep_insert(ep, &epds, tfile, fd); } else @@ -613,7 +613,7 @@ sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event) break; case EPOLL_CTL_MOD: if (epi) { - epds.events |= POLLERR | POLLHUP; + epds.events |= POLLERR | POLLHUP | POLLRDHUP; error = ep_modify(ep, epi, &epds); } else error = -ENOENT; -- cgit v1.2.3-18-g5258