From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [net-2.6 PATCH 08/13] e1000: remove races when changing mtu Date: Fri, 25 Sep 2009 15:19:02 -0700 Message-ID: <20090925221901.26715.21741.stgit@localhost.localdomain> References: <20090925221613.26715.66796.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, gospo@redhat.com, Jesse Brandeburg , Don Skidmore , Jeff Kirsher To: davem@davemloft.net Return-path: Received: from qmta09.westchester.pa.mail.comcast.net ([76.96.62.96]:40913 "EHLO QMTA09.westchester.pa.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753019AbZIYWTS (ORCPT ); Fri, 25 Sep 2009 18:19:18 -0400 In-Reply-To: <20090925221613.26715.66796.stgit@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: From: Jesse Brandeburg this patch fixes a bug that occurs when routing packets and simultaneously changing the mtu. the rx_buffer_len variable is used during the rx cleanup and if that changes on the fly without stopping traffic bad things happen Signed-off-by: Jesse Brandeburg Signed-off-by: Don Skidmore Signed-off-by: Jeff Kirsher --- drivers/net/e1000/e1000_main.c | 16 ++++++++++++++-- 1 files changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c index cdbf4fb..2178e0d 100644 --- a/drivers/net/e1000/e1000_main.c +++ b/drivers/net/e1000/e1000_main.c @@ -3141,6 +3141,13 @@ static int e1000_change_mtu(struct net_device *netdev, int new_mtu) break; } + while (test_and_set_bit(__E1000_RESETTING, &adapter->flags)) + msleep(1); + /* e1000_down has a dependency on max_frame_size */ + hw->max_frame_size = max_frame; + if (netif_running(netdev)) + e1000_down(adapter); + /* NOTE: netdev_alloc_skb reserves 16 bytes, and typically NET_IP_ALIGN * means we reserve 2 more, this pushes us to allocate from the next * larger slab size. @@ -3169,11 +3176,16 @@ static int e1000_change_mtu(struct net_device *netdev, int new_mtu) (max_frame == MAXIMUM_ETHERNET_VLAN_SIZE))) adapter->rx_buffer_len = MAXIMUM_ETHERNET_VLAN_SIZE; + printk(KERN_INFO "e1000: %s changing MTU from %d to %d\n", + netdev->name, netdev->mtu, new_mtu); netdev->mtu = new_mtu; - hw->max_frame_size = max_frame; if (netif_running(netdev)) - e1000_reinit_locked(adapter); + e1000_up(adapter); + else + e1000_reset(adapter); + + clear_bit(__E1000_RESETTING, &adapter->flags); return 0; }