tracing: Fix error handling to ensure instances can always be removed

Remove debugfs directories for tracing instances during creation if an error
occurs causing the trace_array for that instance to not be added to
ftrace_trace_arrays. If the directory continues to exist after the error, it
cannot be removed because the respective trace_array is not in
ftrace_trace_arrays.

Link: http://lkml.kernel.org/r/1373502874-1706-2-git-send-email-azl@google.com
Cc: stable@vger.kernel.org # 3.10
Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Cc: David Sharp <dhsharp@google.com>
Cc: Alexander Z Lam <lambchop468@gmail.com>
Signed-off-by: Alexander Z Lam <azl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 25b91af..7c3da7b 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5973,8 +5973,10 @@ static int new_instance_create(const char *name)
                goto out_free_tr;
 
        ret = event_trace_add_tracer(tr->dir, tr);
-       if (ret)
+       if (ret) {
+               debugfs_remove_recursive(tr->dir);
                goto out_free_tr;
+       }
 
        init_tracer_debugfs(tr, tr->dir);