From: Ingo Molnar <redacted>
Date: Mon, 29 Oct 2007 22:17:46 +0100

hm, this seems to have popped up in the last few days, never had it 
before:

  sysfs: duplicate filename 'eth0' can not be created
  WARNING: at fs/sysfs/dir.c:424 sysfs_add_one()

I checked in a change from Stephen Hemminger last week which
should keep this case from emitting warning messages.

commit c8d90dca3211966ba5189e0f3d4bccd558d9ae08
Author: Stephen Hemminger [off-list ref]
Date:   Fri Oct 26 03:53:42 2007 -0700

    [NET] dev_change_name: ignore changes to same name
    
    Prevent error/backtrace from dev_rename() when changing
    name of network device to the same name. This is a common
    situation with udev and other scripts that bind addr to device.
    
    Signed-off-by: Stephen Hemminger [off-list ref]
    Signed-off-by: David S. Miller [off-list ref]

diff --git a/net/core/dev.c b/net/core/dev.c
index f1647d7..ddfef3b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c

@@ -883,6 +883,9 @@ int dev_change_name(struct net_device *dev, char *newname)
 	if (!dev_valid_name(newname))
 		return -EINVAL;
 
+	if (strncmp(newname, dev->name, IFNAMSIZ) == 0)
+		return 0;
+
 	memcpy(oldname, dev->name, IFNAMSIZ);
 
 	if (strchr(newname, '%')) {