[PATCH 3/3] tracing/filters: don't remove old filters when failed to write subsys->filter

[Li Zefan <lizf@cn.fujitsu.com>]

If writing subsys->filter returns EINVAL or ENOSPC, the original
filters in subsys/ and subsys/events/ will be removed. This is
definitely wrong.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---

This bug is not revealed in mainline, since subsys/filter is disabled,
and it's re-enabled in -tip by a002587bf18c3b316bcf48542fccbc4ae2fc972e:

"tracing/filters: add run-time field descriptions to TRACE_EVENT_FORMAT event"

---
 kernel/trace/trace_events.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 789e14e..4511cdb 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -591,7 +591,6 @@ subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 
 	err = filter_add_subsystem_pred(system, pred);
 	if (err < 0) {
-		filter_free_subsystem_preds(system);
 		filter_free_pred(pred);
 		return err;
 	}
-- 
1.5.4.rc3