diff options
| author | David Vrabel <david.vrabel@citrix.com> | 2013-02-14 03:18:58 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-02-28 06:59:06 -0800 |
| commit | 29b3bb0be43fea0a49e5235894e1dcbc0ac299dc (patch) | |
| tree | cee0a17f0637f7d2d7eb308d08163ccaf5cb12b0 | |
| parent | 320c1509197bce83d2ebb45d4cc5f9b4d91c05dc (diff) | |
xen-netback: cancel the credit timer when taking the vif down
[ Upstream commit 3e55f8b306cf305832a4ac78aa82e1b40e818ece ]
If the credit timer is left armed after calling
xen_netbk_remove_xenvif(), then it may fire and attempt to schedule
the vif which will then oops as vif->netbk == NULL.
This may happen both in the fatal error path and during normal
disconnection from the front end.
The sequencing during shutdown is critical to ensure that: a)
vif->netbk doesn't become unexpectedly NULL; and b) the net device/vif
is not freed.
1. Mark as unschedulable (netif_carrier_off()).
2. Synchronously cancel the timer.
3. Remove the vif from the schedule list.
4. Remove it from it netback thread group.
5. Wait for vif->refcnt to become 0.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reported-by: Christopher S. Aker <caker@theshore.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/xen-netback/interface.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index b8c5193bd42..221f4265f7d 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -132,6 +132,7 @@ static void xenvif_up(struct xenvif *vif) static void xenvif_down(struct xenvif *vif) { disable_irq(vif->irq); + del_timer_sync(&vif->credit_timeout); xen_netbk_deschedule_xenvif(vif); xen_netbk_remove_xenvif(vif); } @@ -363,8 +364,6 @@ void xenvif_disconnect(struct xenvif *vif) atomic_dec(&vif->refcnt); wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0); - del_timer_sync(&vif->credit_timeout); - if (vif->irq) unbind_from_irqhandler(vif->irq, vif); |