[PATCH RESEND v2 12/30] locking/lockdep: let procfs own the seq_file of /proc/lock_stat

[Christian Brauner]

Declare the seq_operations and let procfs open and free the seq_file.
->proc_open() only takes the snapshot of the statistics now and
->proc_release() frees it.

Signed-off-by: Christian Brauner (Amutable) <brauner@xxxxxxxxxx>
---
 kernel/locking/lockdep_proc.c | 48 +++++++++++++++++++------------------------
 1 file changed, 21 insertions(+), 27 deletions(-)

diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index 1916db9aa46b..9b034b5b94bd 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -638,40 +638,35 @@ static const struct seq_operations lockstat_ops = {
 	.show	= ls_show,
 };
 
+/* procfs opens the seq_file */
 static int lock_stat_open(struct inode *inode, struct file *file)
 {
-	int res;
-	struct lock_class *class;
 	struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
+	struct lock_stat_data *iter;
+	struct seq_file *m = file->private_data;
+	struct lock_class *class;
+	unsigned long idx;
 
 	if (!data)
 		return -ENOMEM;
 
-	res = seq_open(file, &lockstat_ops);
-	if (!res) {
-		struct lock_stat_data *iter = data->stats;
-		struct seq_file *m = file->private_data;
-		unsigned long idx;
-
-		iterate_lock_classes(idx, class) {
-			if (!test_bit(idx, lock_classes_in_use))
-				continue;
-			iter->class = class;
-			lock_stats(class, &iter->stats);
-			iter++;
-		}
-
-		data->iter_end = iter;
+	iter = data->stats;
+	iterate_lock_classes(idx, class) {
+		if (!test_bit(idx, lock_classes_in_use))
+			continue;
+		iter->class = class;
+		lock_stats(class, &iter->stats);
+		iter++;
+	}
 
-		sort(data->stats, data->iter_end - data->stats,
-				sizeof(struct lock_stat_data),
-				lock_stat_cmp, NULL);
+	data->iter_end = iter;
 
-		m->private = data;
-	} else
-		vfree(data);
+	sort(data->stats, data->iter_end - data->stats,
+			sizeof(struct lock_stat_data),
+			lock_stat_cmp, NULL);
 
-	return res;
+	m->private = data;
+	return 0;
 }
 
 static ssize_t lock_stat_write(struct file *file, const char __user *buf,
@@ -702,14 +697,13 @@ static int lock_stat_release(struct inode *inode, struct file *file)
 	struct seq_file *seq = file->private_data;
 
 	vfree(seq->private);
-	return seq_release(inode, file);
+	return 0;
 }
 
 static const struct proc_ops lock_stat_proc_ops = {
+	.proc_seq_ops	= &lockstat_ops,
 	.proc_open	= lock_stat_open,
 	.proc_write	= lock_stat_write,
-	.proc_read	= seq_read,
-	.proc_lseek	= seq_lseek,
 	.proc_release	= lock_stat_release,
 };
 #endif /* CONFIG_LOCK_STAT */

-- 
2.53.0