Re: [PATCHv2] tun: fix carrier on/off status

From: Jason Wang
Date: Mon Jan 28 2013 - 06:15:58 EST


On 01/28/2013 06:38 PM, Michael S. Tsirkin wrote:
> 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@xxxxxxxxxx>
>
> ---
>
> Changes from v1:
> Don't set carrier off unless all queues are closed.
>
> Note: didn't test in MQ mode - Jason, care checking this does the
> right thing there?

Tested-by: Jason Wang <jasowang@xxxxxxxxxx>
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
>
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index af372d0..06b2723 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -434,10 +434,13 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
> }
>
> 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));
> @@ -1644,10 +1647,10 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
> 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)
> --
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