@@ -418,9 +418,6 @@ void xenvif_disconnect(struct xenvif *vif)
if (netif_carrier_ok(vif->dev))
xenvif_carrier_off(vif);
- atomic_dec(&vif->refcnt);
- wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0);
-
if (vif->tx_irq) {
if (vif->tx_irq == vif->rx_irq)
unbind_from_irqhandler(vif->tx_irq, vif);
@@ -428,6 +425,7 @@ void xenvif_disconnect(struct xenvif *vif)
unbind_from_irqhandler(vif->tx_irq, vif);
unbind_from_irqhandler(vif->rx_irq, vif);
}
+ vif->tx_irq = 0;
}
xen_netbk_unmap_frontend_rings(vif);
@@ -435,6 +433,9 @@ void xenvif_disconnect(struct xenvif *vif)
void xenvif_free(struct xenvif *vif)
{
+ atomic_dec(&vif->refcnt);
+ wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0);
+
unregister_netdev(vif->dev);
free_netdev(vif->dev);
This is a note to let you know that I have just added a patch titled xen-netback: fix refcnt unbalance for 3.11 and earlier versions to the linux-3.11.y-queue branch of the 3.11.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-3.11.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 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 801e85607eeefc7bef6fcdf016662a0faab54f76 Mon Sep 17 00:00:00 2001 From: Wei Liu <wei.liu2@citrix.com> Date: Thu, 28 Nov 2013 12:48:09 +0000 Subject: xen-netback: fix refcnt unbalance for 3.11 and earlier versions With the introduction of "xen-netback: Don't destroy the netdev until the vif is shut down" (upstream commit id 279f438e36), vif disconnect and free are separated. However in the backported verion reference counting code was not correctly modified, and the reset of vif->tx_irq was lost. If frontend goes through vif life cycle more than once the reference counting is skewed. This patch adds back the missing tx_irq reset line. It also moves several lines of the reference counting code to vif_free, so the moved code corresponds to the counterpart in vif_alloc, thus the reference counting is balanced. 3.12 and onward versions are not affected by this bug, because reference counting code was removed due to the introduction of 1:1 model. This pacth should be backported to all stable verions which are lower than 3.12 and have 279f438e36. Reported-and-tested-by: Tomasz Wroblewski <tomasz.wroblewski@citrix.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/net/xen-netback/interface.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) -- 1.8.3.2