lockdep: Simplify lockdep seqfile code

Use seq_list_start_head() and seq_list_next().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <4A88ED41.5000000@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index 9a7996e..05fb5fd 100644 (file)
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -25,38 +25,12 @@
 
 static void *l_next(struct seq_file *m, void *v, loff_t *pos)
 {
-       struct lock_class *class;
-
-       (*pos)++;
-
-       if (v == SEQ_START_TOKEN)
-               class = m->private;
-       else {
-               class = v;
-
-               if (class->lock_entry.next != &all_lock_classes)
-                       class = list_entry(class->lock_entry.next,
-                                          struct lock_class, lock_entry);
-               else
-                       class = NULL;
-       }
-
-       return class;
+       return seq_list_next(v, &all_lock_classes, pos);
 }
 
 static void *l_start(struct seq_file *m, loff_t *pos)
 {
-       struct lock_class *class;
-       loff_t i = 0;
-
-       if (*pos == 0)
-               return SEQ_START_TOKEN;
-
-       list_for_each_entry(class, &all_lock_classes, lock_entry) {
-               if (++i == *pos)
-               return class;
-       }
-       return NULL;
+       return seq_list_start_head(&all_lock_classes, *pos);
 }
 
 static void l_stop(struct seq_file *m, void *v)
@@ -82,11 +56,11 @@ static void print_name(struct seq_file *m, struct lock_class *class)
 
 static int l_show(struct seq_file *m, void *v)
 {
-       struct lock_class *class = v;
+       struct lock_class *class = list_entry(v, struct lock_class, lock_entry);
        struct lock_list *entry;
        char usage[LOCK_USAGE_CHARS];
 
-       if (v == SEQ_START_TOKEN) {
+       if (v == &all_lock_classes) {
                seq_printf(m, "all lock classes:\n");
                return 0;
        }
@@ -128,17 +102,7 @@ static const struct seq_operations lockdep_ops = {
 
 static int lockdep_open(struct inode *inode, struct file *file)
 {
-       int res = seq_open(file, &lockdep_ops);
-       if (!res) {
-               struct seq_file *m = file->private_data;
-
-               if (!list_empty(&all_lock_classes))
-                       m->private = list_entry(all_lock_classes.next,
-                                       struct lock_class, lock_entry);
-               else
-                       m->private = NULL;
-       }
-       return res;
+       return seq_open(file, &lockdep_ops);
 }
 
 static const struct file_operations proc_lockdep_operations = {