kobject: check for duplicate names in kobject_rename

This should catch any duplicate names before we try to tell sysfs to
rename the object.  This happens a lot with older versions of udev and
the network rename scripts.

Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 13 insertions, 0 deletions

diff --git a/lib/kobject.c b/lib/kobject.c
index 03d40360ff1..a7e3bf4d3c7 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -308,6 +308,19 @@ int kobject_rename(struct kobject * kobj, const char *new_name)
         if (!kobj->parent)
                 return -EINVAL;
 
+        /* see if this name is already in use */
+        if (kobj->kset) {
+                struct kobject *temp_kobj;
+                temp_kobj = kset_find_obj(kobj->kset, new_name);
+                if (temp_kobj) {
+                        printk(KERN_WARNING "kobject '%s' can not be renamed "
+                               "to '%s' as '%s' is already in existance.\n",
+                               kobject_name(kobj), new_name, new_name);
+                        kobject_put(temp_kobj);
+                        return -EINVAL;
+                }
+        }
+
         devpath = kobject_get_path(kobj, GFP_KERNEL);
         if (!devpath) {
                 error = -ENOMEM;