From patchwork Wed Feb 1 15:50:22 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ross Lagerwall X-Patchwork-Id: 722594 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vD70f2FTRz9t2D for ; Thu, 2 Feb 2017 02:51:46 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752508AbdBAPvQ (ORCPT ); Wed, 1 Feb 2017 10:51:16 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:49402 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750926AbdBAPvO (ORCPT ); Wed, 1 Feb 2017 10:51:14 -0500 X-IronPort-AV: E=Sophos;i="5.33,320,1477958400"; d="scan'208";a="412383267" From: Ross Lagerwall To: CC: , Boris Ostrovsky , Juergen Gross , , , Ross Lagerwall Subject: [PATCH] xen-netfront: Improve error handling during initialization Date: Wed, 1 Feb 2017 15:50:22 +0000 Message-ID: <1485964222-1501-1-git-send-email-ross.lagerwall@citrix.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 --- 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; }