From 017a499be5746df215a664775b14e80c087bc941 Mon Sep 17 00:00:00 2001 From: Ross Lagerwall Date: Wed, 8 Feb 2017 10:57:37 +0000 Subject: xen-netfront: Improve error handling during initialization [ Upstream commit e2e004acc7cbe3c531e752a270a74e95cde3ea48 ] This fixes a crash when running out of grant refs when creating many queues across many netdevs. * If creating queues fails (i.e. there are no grant refs available), call xenbus_dev_fatal() to ensure that the xenbus device is set to the closed state. * If no queues are created, don't call xennet_disconnect_backend as netdev->real_num_tx_queues will not have been set correctly. * If setup_netfront() fails, ensure that all the queues created are cleaned up, not just those that have been set up. * If any queues were set up and an error occurs, call xennet_destroy_queues() to clean up the napi context. * If any fatal error occurs, unregister and destroy the netdev to avoid leaving around a half setup network device. Signed-off-by: Ross Lagerwall Reviewed-by: Boris Ostrovsky Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/xen-netfront.c | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index cd442e46afb4..265e2095f8d9 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1854,27 +1854,19 @@ static int talk_to_netback(struct xenbus_device *dev, xennet_destroy_queues(info); err = xennet_create_queues(info, &num_queues); - if (err < 0) - goto destroy_ring; + if (err < 0) { + xenbus_dev_fatal(dev, err, "creating queues"); + kfree(info->queues); + info->queues = NULL; + goto out; + } /* Create shared ring, alloc event channel -- for each queue */ for (i = 0; i < num_queues; ++i) { queue = &info->queues[i]; err = setup_netfront(dev, queue, feature_split_evtchn); - if (err) { - /* setup_netfront() will tidy up the current - * queue on error, but we need to clean up - * those already allocated. - */ - if (i > 0) { - rtnl_lock(); - netif_set_real_num_tx_queues(info->netdev, i); - rtnl_unlock(); - goto destroy_ring; - } else { - goto out; - } - } + if (err) + goto destroy_ring; } again: @@ -1964,9 +1956,10 @@ abort_transaction_no_dev_fatal: xenbus_transaction_end(xbt, 1); destroy_ring: xennet_disconnect_backend(info); - kfree(info->queues); - info->queues = NULL; + xennet_destroy_queues(info); out: + unregister_netdev(info->netdev); + xennet_free_netdev(info->netdev); return err; } -- cgit v1.2.3