trace_stack: Simplify seqfile code

Li Zefan · Ingo Molnar · commit 2fc5f0cff4cf · 2009-08-17T11:25:09.000+02:00
Extract duplicate code in t_start() and t_next().

Signed-off-by: Li Zefan &lt;lizf@cn.fujitsu.com&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
LKML-Reference: &lt;4A891A91.4030602@cn.fujitsu.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
@@ -186,43 +186,33 @@ static const struct file_operations stack_max_size_fops = {
 };
 
 static void *
-t_next(struct seq_file *m, void *v, loff_t *pos)
+__next(struct seq_file *m, loff_t *pos)
 {
-	long i;
+	long n = *pos - 1;
 
-	(*pos)++;
-
-	if (v == SEQ_START_TOKEN)
-		i = 0;
-	else {
-		i = *(long *)v;
-		i++;
-	}
-
-	if (i >= max_stack_trace.nr_entries ||
-	    stack_dump_trace[i] == ULONG_MAX)
+	if (n >= max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX)
 		return NULL;
 
-	m->private = (void *)i;
-
+	m->private = (void *)n;
 	return &m->private;
 }
 
-static void *t_start(struct seq_file *m, loff_t *pos)
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	void *t = SEQ_START_TOKEN;
-	loff_t l = 0;
+	(*pos)++;
+	return __next(m, pos);
+}
 
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
 	local_irq_disable();
 	__raw_spin_lock(&max_stack_lock);
 
 	if (*pos == 0)
 		return SEQ_START_TOKEN;
 
-	for (; t && l < *pos; t = t_next(m, t, &l))
-		;
-
-	return t;
+	return __next(m, pos);
 }
 
 static void t_stop(struct seq_file *m, void *p)
