commit af668b3c276d0f958a3aa46ef8ec47e2d5d333b3
author Michael S. Tsirkin <mst@redhat.com> Mon Jan 28 00:38:02 2013 +0000
committer David S. Miller <davem@davemloft.net> Tue Jan 29 15:43:03 2013 -0500
tree 68525f9d6ee11d9c1a9033001a4e106c7cb44071
parent 604dfd6efc9b79bce432f2394791708d8e8f6efc

tun: fix carrier on/off status

Commit c8d68e6be1c3b242f1c598595830890b65cea64a removed carrier off call
from tun_detach since it's now called on queue disable and not only on
tun close.  This confuses userspace which used this flag to detect a
free tun. To fix, put this back but under if (clean).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Jason Wang <jasowang@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Tested-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/tun.c

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index cc09b67..ffdb844 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -439,10 +439,13 @@
 	}
 
 	if (clean) {
-		if (tun && tun->numqueues == 0 && tun->numdisabled == 0 &&
-		    !(tun->flags & TUN_PERSIST))
-			if (tun->dev->reg_state == NETREG_REGISTERED)
+		if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
+			netif_carrier_off(tun->dev);
+
+			if (!(tun->flags & TUN_PERSIST) &&
+			    tun->dev->reg_state == NETREG_REGISTERED)
 				unregister_netdevice(tun->dev);
+		}
 
 		BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
 				 &tfile->socket.flags));
@@ -1658,10 +1661,10 @@
 		    device_create_file(&tun->dev->dev, &dev_attr_owner) ||
 		    device_create_file(&tun->dev->dev, &dev_attr_group))
 			pr_err("Failed to create tun sysfs files\n");
-
-		netif_carrier_on(tun->dev);
 	}
 
+	netif_carrier_on(tun->dev);
+
 	tun_debug(KERN_INFO, tun, "tun_set_iff\n");
 
 	if (ifr->ifr_flags & IFF_NO_PI)