---
 fs/ext3/super.c           |    8 ++++
 kernel/trace/Makefile     |    1 
 kernel/trace/trace_null.c |   76 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 84 insertions(+), 1 deletion(-)

Index: linux-tip.git/fs/ext3/super.c
===================================================================
--- linux-tip.git.orig/fs/ext3/super.c	2008-10-24 10:08:43.000000000 -0400
+++ linux-tip.git/fs/ext3/super.c	2008-10-27 19:01:22.000000000 -0400
@@ -502,6 +502,9 @@ static void destroy_inodecache(void)
 	kmem_cache_destroy(ext3_inode_cachep);
 }
 
+extern void ftrace_null(void);
+extern void ftrace_nonnull(void);
+
 static void ext3_clear_inode(struct inode *inode)
 {
 	struct ext3_block_alloc_info *rsv = EXT3_I(inode)->i_block_alloc_info;
@@ -519,8 +522,11 @@ static void ext3_clear_inode(struct inod
 #endif
 	ext3_discard_reservation(inode);
 	EXT3_I(inode)->i_block_alloc_info = NULL;
-	if (unlikely(rsv))
+	if (unlikely(rsv)) {
+		ftrace_nonnull();
 		kfree(rsv);
+	} else
+		ftrace_null();
 }
 
 static inline void ext3_show_quota_options(struct seq_file *seq, struct super_block *sb)
Index: linux-tip.git/kernel/trace/Makefile
===================================================================
--- linux-tip.git.orig/kernel/trace/Makefile	2008-10-27 19:00:03.000000000 -0400
+++ linux-tip.git/kernel/trace/Makefile	2008-10-27 19:08:25.000000000 -0400
@@ -13,6 +13,7 @@ endif
 obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o
 obj-$(CONFIG_RING_BUFFER) += ring_buffer.o
 
+obj-$(CONFIG_TRACING) += trace_null.o
 obj-$(CONFIG_TRACING) += trace.o
 obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
 obj-$(CONFIG_SYSPROF_TRACER) += trace_sysprof.o
Index: linux-tip.git/kernel/trace/trace_null.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-tip.git/kernel/trace/trace_null.c	2008-10-27 19:23:15.000000000 -0400
@@ -0,0 +1,76 @@
+/*
+ * Function profiler
+ *
+ * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
+ */
+#include <linux/kallsyms.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/ftrace.h>
+#include <linux/hash.h>
+#include <linux/fs.h>
+#include <asm/local.h>
+#include "trace.h"
+
+
+static atomic_t ftrace_null_count;
+static atomic_t ftrace_nonnull_count;
+
+void ftrace_null(void)
+{
+	atomic_inc(&ftrace_null_count);
+}
+EXPORT_SYMBOL(ftrace_null);
+
+void ftrace_nonnull(void)
+{
+	atomic_inc(&ftrace_nonnull_count);
+}
+EXPORT_SYMBOL(ftrace_nonnull);
+
+static ssize_t
+tracing_read_long(struct file *filp, char __user *ubuf,
+		  size_t cnt, loff_t *ppos)
+{
+	atomic_t *p = filp->private_data;
+	char buf[64];
+	int r;
+
+	r = sprintf(buf, "%d\n", atomic_read(p));
+
+	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static struct file_operations tracing_read_long_fops = {
+	.open		= tracing_open_generic,
+	.read		= tracing_read_long,
+};
+
+
+static __init int ftrace_null_init(void)
+{
+	struct dentry *d_tracer;
+	struct dentry *entry;
+
+	d_tracer = tracing_init_dentry();
+
+	entry = debugfs_create_file("ftrace_null", 0444, d_tracer,
+				    &ftrace_null_count,
+				    &tracing_read_long_fops);
+	if (!entry)
+		pr_warning("Could not create debugfs 'ftrace_null' entry\n");
+
+	entry = debugfs_create_file("ftrace_nonnull", 0444, d_tracer,
+				    &ftrace_nonnull_count,
+				    &tracing_read_long_fops);
+	if (!entry)
+		pr_warning("Could not create debugfs 'ftrace_nonnull' entry\n");
+
+
+	return 0;
+}
+
+device_initcall(ftrace_null_init);