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| author | Paul Durrant <Paul.Durrant@citrix.com> | 2013-12-03 14:06:25 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-12-03 11:49:30 -0500 |
| commit | 67fa36609fe0a0a4b4c99120e5093599556e4c5b (patch) | |
| tree | 4c607aeaa3de8da2b7b3de8d2457195c643281cb | |
| parent | 7ce5a27f2ef8ed4f8f892f46391f933c0e2ac0f1 (diff) | |
| download | op-kernel-dev-67fa36609fe0a0a4b4c99120e5093599556e4c5b.zip op-kernel-dev-67fa36609fe0a0a4b4c99120e5093599556e4c5b.tar.gz | |
xen-netback: clear vif->task on disconnect
xenvif_start_xmit() relies on checking vif->task for NULL to determine
whether the vif is ready to accept packets. The task thread is stopped in
xenvif_disconnect() but task is not set to NULL. Thus, on a re-connect the
check will give a false positive.
Also since commit ea732dff5cfa10789007bf4a5b935388a0bb2a8f (Handle backend
state transitions in a more robust way) it should not be possible for
xenvif_connect() to be called if the vif is already connected so change the
check of vif->tx_irq to a BUG_ON() and also add a BUG_ON(vif->task).
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/xen-netback/interface.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index 2329ccc..870f1fa 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -368,11 +368,11 @@ int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref, unsigned long rx_ring_ref, unsigned int tx_evtchn, unsigned int rx_evtchn) { + struct task_struct *task; int err = -ENOMEM; - /* Already connected through? */ - if (vif->tx_irq) - return 0; + BUG_ON(vif->tx_irq); + BUG_ON(vif->task); err = xenvif_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref); if (err < 0) @@ -411,14 +411,16 @@ int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref, } init_waitqueue_head(&vif->wq); - vif->task = kthread_create(xenvif_kthread, - (void *)vif, "%s", vif->dev->name); - if (IS_ERR(vif->task)) { + task = kthread_create(xenvif_kthread, + (void *)vif, "%s", vif->dev->name); + if (IS_ERR(task)) { pr_warn("Could not allocate kthread for %s\n", vif->dev->name); - err = PTR_ERR(vif->task); + err = PTR_ERR(task); goto err_rx_unbind; } + vif->task = task; + rtnl_lock(); if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN) dev_set_mtu(vif->dev, ETH_DATA_LEN); @@ -461,8 +463,10 @@ void xenvif_disconnect(struct xenvif *vif) if (netif_carrier_ok(vif->dev)) xenvif_carrier_off(vif); - if (vif->task) + if (vif->task) { kthread_stop(vif->task); + vif->task = NULL; + } if (vif->tx_irq) { if (vif->tx_irq == vif->rx_irq) |
