systemd/1006-udev-always-rename-network.patch

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.

---
 udev-event.c |   40 ++++++++++++++++++++++++++++++++++++----
 1 file changed, 36 insertions(+), 4 deletions(-)

--- systemd-210/src/udev/udev-event.c
+++ systemd-210/src/udev/udev-event.c	2014-03-04 11:19:50.583710411 +0100
@@ -765,10 +765,42 @@ static int rename_netif(struct udev_even
                 return r;
 
         r = rtnl_set_link_name(rtnl, udev_device_get_ifindex(dev), name);
-        if (r < 0)
-                log_error("error changing net interface name %s to %s: %s",
-                          oldname, name, strerror(-r));
-        else
+        if (r < 0) {
+                char interim[IFNAMSIZ], *ptr = &interim[0];
+                int loop = 90;
+
+                /* keep trying if the destination interface name already exists */
+                if (r != -EEXIST) {
+                        log_error("error changing net interface name %s to %s: %s",
+                                  oldname, name, strerror(-r));
+                        return r;
+                }
+
+                /* free our own name, another process may wait for us */
+                strpcpyf(&ptr, IFNAMSIZ, "rename%u", udev_device_get_ifindex(dev));
+
+                r = rtnl_set_link_name(rtnl, udev_device_get_ifindex(dev), interim);
+                if (r < 0) {
+                        log_error("error changing net interface name %s to %s: %s",
+                                  oldname, name, strerror(-r));
+                        return r;
+                }
+
+                /* log temporary name */
+                print_kmsg("renamed network interface %s to %s", oldname, interim);
+                do {
+                        r = rtnl_set_link_name(rtnl, udev_device_get_ifindex(dev), name);
+                        if (r == 0) {
+                                print_kmsg("renamed network interface %s to %s", oldname, name);
+                                return r;
+                        }
+                        if (r != -EEXIST) {
+                                log_error("error changing net interface name %s to %s: %s",
+                                          oldname, name, strerror(-r));
+                                return r;
+                        }
+                } while (loop-- > 0);
+        } else
                 print_kmsg("renamed network interface %s to %s", oldname, name);
 
         return r;