From: Robert Milasan <rmilasan@suse.com>
Cc: Werner Fink <werner@suse.de>
Subject: udev always rename network

Date: Thu, 28 Mar 2013 09:24:43 +0000
udev: ensure that the network interfaces are renamed even if they exist (bnc#809843).

Date: Tue,  4 Mar 2014 10:29:21 +0000
Port the patch of Robert to systemd v210 and test it out.

---
 src/udev/udev-event.c |   41 +++++++++++++++++++++++++++++++++++++----
 1 file changed, 37 insertions(+), 4 deletions(-)


Index: systemd-221/src/udev/udev-event.c
===================================================================
--- systemd-221.orig/src/udev/udev-event.c
+++ systemd-221/src/udev/udev-event.c
@@ -796,20 +796,53 @@ out:
 static int rename_netif(struct udev_event *event) {
         struct udev_device *dev = event->dev;
         char name[IFNAMSIZ];
+        char interim[IFNAMSIZ], *ptr = &interim[0];
         const char *oldname;
-        int r;
+        int r, loop;
 
         oldname = udev_device_get_sysname(dev);
 
         strscpy(name, IFNAMSIZ, event->name);
 
         r = rtnl_set_link_name(&event->rtnl, udev_device_get_ifindex(dev), name);
-        if (r < 0)
+        if (r == 0) {
+                log_info("renamed network interface %s to %s\n", oldname, name);
+                return r;
+        } else if (r != -EEXIST) {
                 return log_error_errno(r, "Error changing net interface name '%s' to '%s': %m", oldname, name);
+	}
 
-        log_debug("renamed network interface '%s' to '%s'", oldname, name);
+        /* free our own name, another process may wait for us */
+        strpcpyf(&ptr, IFNAMSIZ, "rename%u", udev_device_get_ifindex(dev));
 
-        return 0;
+        r = rtnl_set_link_name(&event->rtnl, udev_device_get_ifindex(dev), interim);
+        if (r < 0) {
+                log_error("error changing net interface name %s to %s: %s",
+                          oldname, interim, strerror(-r));
+                return r;
+        }
+
+        /* log temporary name */
+        log_info("renamed network interface %s to %s\n", oldname, interim);
+
+        loop = 90 * 20;
+        while (loop--) {
+                const struct timespec duration = { 0, 1000 * 1000 * 1000 / 20 };
+                nanosleep(&duration, NULL);
+
+                r = rtnl_set_link_name(&event->rtnl, udev_device_get_ifindex(dev), name);
+                if (r == 0) {
+                        log_info("renamed network interface %s to %s\n", interim, name);
+                        break;
+                }
+
+                if (r != -EEXIST) {
+                        log_error("error changing net interface name %s to %s: %s",
+                                  interim, name, strerror(-r));
+                        break;
+                }
+        }
+        return r;
 }
 
 void udev_event_execute_rules(struct udev_event *event,