diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 976c466..47f1c95 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -178,6 +178,7 @@
 void sysfs_put(struct sysfs_dirent *sd);
 void sysfs_printk_last_file(void);
 
+/* Called to clear a ns tag when it is no longer valid */
 void sysfs_exit_ns(enum kobj_ns_type type, const void *tag);
 
 int __must_check sysfs_init(void);