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authorMax Krasnyansky <maxk@qualcomm.com>2008-07-10 16:59:11 -0700
committerDavid S. Miller <davem@davemloft.net>2008-07-10 16:59:11 -0700
commite35259a95331ae4a9146cc03ab49aad641cab957 (patch)
tree703ee0018e29c07215e2bb3f3bc0b9040d2ce6fe
parentccf9b3b83d0e56fbf20c00a08b15031ce13204a7 (diff)
tun: Persistent devices can get stuck in xoff state
The scenario goes like this. App stops reading from tun/tap. TX queue gets full and driver does netif_stop_queue(). App closes fd and TX queue gets flushed as part of the cleanup. Next time the app opens tun/tap and starts reading from it but the xoff state is not cleared. We're stuck. Normally xoff state is cleared when netdev is brought up. But in the case of persistent devices this happens only during initial setup. The fix is trivial. If device is already up when an app opens it we clear xoff state and that gets things moving again. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/tun.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 7ab94c825b5..b9018bfa0a9 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -602,6 +602,12 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
tun->attached = 1;
get_net(dev_net(tun->dev));
+ /* Make sure persistent devices do not get stuck in
+ * xoff state.
+ */
+ if (netif_running(tun->dev))
+ netif_wake_queue(tun->dev);
+
strcpy(ifr->ifr_name, tun->dev->name);
return 0;