Comments
Patch
@@ -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);
This is a note to let you know that I have just added a patch titled xen-netback: cancel the credit timer when taking the vif down to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From bb9419be8427f5015615518699baed20a94a6839 Mon Sep 17 00:00:00 2001 From: David Vrabel <david.vrabel@citrix.com> Date: Thu, 14 Feb 2013 03:18:58 +0000 Subject: [PATCH] xen-netback: cancel the credit timer when taking the vif down commit 3e55f8b306cf305832a4ac78aa82e1b40e818ece upstream. 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: Luis Henriques <luis.henriques@canonical.com> --- drivers/net/xen-netback/interface.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) -- 1.8.1.2