sysfs: remove error messages for -EEXIST case

It is possible that the entry in sysfs already exists, one case of this is
when a network device is renamed to bonding_masters. Anyway, in this case
the proper error path is for device_rename to return an error code, not to
generate bogus backtrace and errors.

Also, to avoid possible races, the create link should be done before the
remove link. This makes a device rename atomic operation like other renames.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/base/core.c

@@ -1218,13 +1218,11 @@ int device_rename(struct device *dev, char *new_name)
 	}
 #else
 	if (dev->class) {
-		sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
 		error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
 					  dev->bus_id);
-		if (error) {
-			dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
-				__func__, error);
-		}
+		if (error)
+			goto out;
+		sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
 	}
 #endif
 

fs/sysfs/dir.c

@@ -419,12 +419,8 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
  */
 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
 {
-	if (sysfs_find_dirent(acxt->parent_sd, sd->s_name)) {
-		printk(KERN_WARNING "sysfs: duplicate filename '%s' "
-		       "can not be created\n", sd->s_name);
-		WARN_ON(1);
+	if (sysfs_find_dirent(acxt->parent_sd, sd->s_name))
 		return -EEXIST;
-	}
 
 	sd->s_parent = sysfs_get(acxt->parent_sd);