--- zzzz-none-000/linux-3.10.107/kernel/trace/trace_stat.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/kernel/trace/trace_stat.c	2021-02-04 17:41:59.000000000 +0000
@@ -12,7 +12,7 @@
 #include <linux/list.h>
 #include <linux/slab.h>
 #include <linux/rbtree.h>
-#include <linux/debugfs.h>
+#include <linux/tracefs.h>
 #include "trace_stat.h"
 #include "trace.h"
 
@@ -43,46 +43,15 @@
 /* The root directory for all stat files */
 static struct dentry		*stat_dir;
 
-/*
- * Iterate through the rbtree using a post order traversal path
- * to release the next node.
- * It won't necessary release one at each iteration
- * but it will at least advance closer to the next one
- * to be released.
- */
-static struct rb_node *release_next(struct tracer_stat *ts,
-				    struct rb_node *node)
+static void __reset_stat_session(struct stat_session *session)
 {
-	struct stat_node *snode;
-	struct rb_node *parent = rb_parent(node);
+	struct stat_node *snode, *n;
 
-	if (node->rb_left)
-		return node->rb_left;
-	else if (node->rb_right)
-		return node->rb_right;
-	else {
-		if (!parent)
-			;
-		else if (parent->rb_left == node)
-			parent->rb_left = NULL;
-		else
-			parent->rb_right = NULL;
-
-		snode = container_of(node, struct stat_node, node);
-		if (ts->stat_release)
-			ts->stat_release(snode->stat);
+	rbtree_postorder_for_each_entry_safe(snode, n, &session->stat_root, node) {
+		if (session->ts->stat_release)
+			session->ts->stat_release(snode->stat);
 		kfree(snode);
-
-		return parent;
 	}
-}
-
-static void __reset_stat_session(struct stat_session *session)
-{
-	struct rb_node *node = session->stat_root.rb_node;
-
-	while (node)
-		node = release_next(session->ts, node);
 
 	session->stat_root = RB_ROOT;
 }
@@ -96,7 +65,7 @@
 
 static void destroy_session(struct stat_session *session)
 {
-	debugfs_remove(session->file);
+	tracefs_remove(session->file);
 	__reset_stat_session(session);
 	mutex_destroy(&session->stat_mutex);
 	kfree(session);
@@ -307,12 +276,12 @@
 	struct dentry *d_tracing;
 
 	d_tracing = tracing_init_dentry();
-	if (!d_tracing)
+	if (IS_ERR(d_tracing))
 		return 0;
 
-	stat_dir = debugfs_create_dir("trace_stat", d_tracing);
+	stat_dir = tracefs_create_dir("trace_stat", d_tracing);
 	if (!stat_dir)
-		pr_warning("Could not create debugfs "
+		pr_warning("Could not create tracefs "
 			   "'trace_stat' entry\n");
 	return 0;
 }
@@ -322,7 +291,7 @@
 	if (!stat_dir && tracing_stat_init())
 		return -ENODEV;
 
-	session->file = debugfs_create_file(session->ts->name, 0644,
+	session->file = tracefs_create_file(session->ts->name, 0644,
 					    stat_dir,
 					    session, &tracing_stat_fops);
 	if (!session->file)