[PATCH 3.16 70/99] tracing: Fix tracing_stat return values in error handling paths

[Ben Hutchings]

3.16.84-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>

commit afccc00f75bbbee4e4ae833a96c2d29a7259c693 upstream.

tracing_stat_init() was always returning '0', even on the error paths.  It
now returns -ENODEV if tracing_init_dentry() fails or -ENOMEM if it fails
to created the 'trace_stat' debugfs directory.

Link: http://lkml.kernel.org/r/1410299381-20108-1-git-send-email-luis.henriques@xxxxxxxxxxxxx

Fixes: ed6f1c996bfe4 ("tracing: Check return value of tracing_init_dentry()")
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 kernel/trace/trace_stat.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -277,19 +277,23 @@ static int tracing_stat_init(void)
 
 	d_tracing = tracing_init_dentry();
 	if (!d_tracing)
-		return 0;
+		return -ENODEV;
 
 	stat_dir = debugfs_create_dir("trace_stat", d_tracing);
-	if (!stat_dir)
+	if (!stat_dir) {
 		pr_warning("Could not create debugfs "
 			   "'trace_stat' entry\n");
+		return -ENOMEM;
+	}
 	return 0;
 }
 
 static int init_stat_file(struct stat_session *session)
 {
-	if (!stat_dir && tracing_stat_init())
-		return -ENODEV;
+	int ret;
+
+	if (!stat_dir && (ret = tracing_stat_init()))
+		return ret;
 
 	session->file = debugfs_create_file(session->ts->name, 0644,
 					    stat_dir,