[PATCH] fix class symlinks in sysfs

The class symlinks in sysfs don't properly handle changing device names.

To demonstrate, rename your network device from eth0 to eth1. Your
pci (or usb, or whatever) device will still have a 'net:eth0' link,
except now it points to /sys/class/net/eth1.

The attached patch makes sure the class symlink name changes when
the class device name changes. It isn't 100% correct, it should be
using sysfs_rename_link. Unfortunately, sysfs_rename_link doesn't exist.

Signed-off-by: Bill Nottingham <notting@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/base/class.c b/drivers/base/class.c
index 3b112e3542f8..ce23dc8c18c5 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -669,6 +669,7 @@ void class_device_destroy(struct class *cls, dev_t devt)
 int class_device_rename(struct class_device *class_dev, char *new_name)
 {
         int error = 0;
+        char *old_class_name = NULL, *new_class_name = NULL;
 
         class_dev = class_device_get(class_dev);
         if (!class_dev)
@@ -677,12 +678,24 @@ int class_device_rename(struct class_device *class_dev, char *new_name)
         pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
                  new_name);
 
+        if (class_dev->dev)
+                old_class_name = make_class_name(class_dev);
+
         strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
 
         error = kobject_rename(&class_dev->kobj, new_name);
 
+        if (class_dev->dev) {
+                new_class_name = make_class_name(class_dev);
+                sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
+                                  new_class_name);
+                sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
+        }
         class_device_put(class_dev);
 
+        kfree(old_class_name);
+        kfree(new_class_name);
+
         return error;
 }