[PATCH] xen-netfront: Improve error handling during initialization
From: Ross Lagerwall <hidden>
Date: 2017-02-01 15:51:16
Also in:
lkml
Subsystem:
networking drivers, the rest, xen hypervisor interface · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Juergen Gross, Stefano Stabellini
Improve error handling during initialization. This fixes a crash when running out of grant refs when creating many queues across many netdevs. * Delay timer creation so that if initializing a queue fails, the timer has not been setup yet. * 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 stop the timer and 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 <redacted> --- drivers/net/xen-netfront.c | 39 ++++++++++++++++++--------------------- 1 file changed, 18 insertions(+), 21 deletions(-)
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 8315fe7..8ca85af 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c@@ -1596,9 +1596,6 @@ static int xennet_init_queue(struct netfront_queue *queue) spin_lock_init(&queue->tx_lock); spin_lock_init(&queue->rx_lock); - setup_timer(&queue->rx_refill_timer, rx_refill_timeout, - (unsigned long)queue); - snprintf(queue->name, sizeof(queue->name), "%s-q%u", queue->info->netdev->name, queue->id);
@@ -1632,6 +1629,9 @@ static int xennet_init_queue(struct netfront_queue *queue) goto exit_free_tx; } + setup_timer(&queue->rx_refill_timer, rx_refill_timeout, + (unsigned long)queue); + return 0; exit_free_tx:
@@ -1822,27 +1822,23 @@ 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"); + if (num_queues > 0) { + goto destroy_ring; + } else { + 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:
@@ -1932,9 +1928,10 @@ static int talk_to_netback(struct xenbus_device *dev, 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; }
--
2.7.4