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author | Davide Libenzi <davidel@xmailserver.org> | 2006-03-25 03:07:39 -0800 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-25 08:22:56 -0800 |
commit | f348d70a324e15afc701a494f32ec468abb7d1eb (patch) | |
tree | a4cb43429f7f08a6621c581bd99e4a03198e8c67 /fs/eventpoll.c | |
parent | 501f2499b897ca4be68b1acc7a4bc8cf66f5fd24 (diff) | |
download | lwn-f348d70a324e15afc701a494f32ec468abb7d1eb.tar.gz lwn-f348d70a324e15afc701a494f32ec468abb7d1eb.zip |
[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 <davidel@xmailserver.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/eventpoll.c')
-rw-r--r-- | fs/eventpoll.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 1c2b16fda13a..a0f682cdd03e 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; |