From: Ilya Dryomov <idryomov@gmail.com>
Date: Mon, 31 Oct 2011 09:07:42 +0000 (+0200)
Subject: tracing: fix event_subsystem ref counting
X-Git-Tag: firefly_0821_release~7541^2~2143
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=eda31b190f7c7033b86ff6e8de3866a4ca25b7df;p=firefly-linux-kernel-4.4.55.git

tracing: fix event_subsystem ref counting

commit cb59974742aea24adf6637eb0c4b8e7b48bca6fb upstream.

Fix a bug introduced by e9dbfae5, which prevents event_subsystem from
ever being released.

Ref_count was added to keep track of subsystem users, not for counting
events.  Subsystem is created with ref_count = 1, so there is no need to
increment it for every event, we have nr_events for that.  Fix this by
touching ref_count only when we actually have a new user -
subsystem_open().

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Link: http://lkml.kernel.org/r/1320052062-7846-1-git-send-email-idryomov@gmail.com
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 3e2a7c91c548..2d0493682420 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1096,7 +1096,6 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
 	/* First see if we did not already create this dir */
 	list_for_each_entry(system, &event_subsystems, list) {
 		if (strcmp(system->name, name) == 0) {
-			__get_system(system);
 			system->nr_events++;
 			return system->entry;
 		}