From 93dc6107a76daed81c07f50215fa6ae77691634f Mon Sep 17 00:00:00 2001
From: Jason Baron <jbaron@redhat.com>
Date: Fri, 16 Mar 2012 16:34:03 -0400
Subject: [PATCH] Don't limit non-nested epoll paths
Commit 28d82dc1c4ed ("epoll: limit paths") that I did to limit the
number of possible wakeup paths in epoll is causing a few applications
to longer work (dovecot for one).
The original patch is really about limiting the amount of epoll nesting
(since epoll fds can be attached to other fds). Thus, we probably can
allow an unlimited number of paths of depth 1. My current patch limits
it at 1000. And enforce the limits on paths that have a greater depth.
This is captured in: https://bugzilla.redhat.com/show_bug.cgi?id=681578
Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/eventpoll.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index ea54cdef04dd..4d9d3a45e356 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -988,6 +988,10 @@ static int path_count[PATH_ARR_SIZE];
static int path_count_inc(int nests)
{
+ /* Allow an arbitrary number of depth 1 paths */
+ if (nests == 0)
+ return 0;
+
if (++path_count[nests] > path_limits[nests])
return -1;
return 0;
--
GitLab