diff --git a/fs/char_dev.c b/fs/char_dev.c
index e82aac9..a69a5d8 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -150,7 +150,7 @@
 	struct char_device_struct *cd = NULL, **cp;
 	int i = major_to_index(major);
 
-	up(&chrdevs_lock);
+	down(&chrdevs_lock);
 	for (cp = &chrdevs[i]; *cp; cp = &(*cp)->next)
 		if ((*cp)->major == major &&
 		    (*cp)->baseminor == baseminor &&