From patchwork Fri Jul 16 01:20:52 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shreyas Bhatewara X-Patchwork-Id: 59054 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 9E065B6F15 for ; Fri, 16 Jul 2010 11:21:16 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935202Ab0GPBUy (ORCPT ); Thu, 15 Jul 2010 21:20:54 -0400 Received: from smtp-outbound-1.vmware.com ([65.115.85.69]:56631 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935162Ab0GPBUw (ORCPT ); Thu, 15 Jul 2010 21:20:52 -0400 Received: from mailhost4.vmware.com (mailhost4.vmware.com [10.16.67.124]) by smtp-outbound-1.vmware.com (Postfix) with ESMTP id 8220712005; Thu, 15 Jul 2010 18:20:52 -0700 (PDT) Received: from promb-1s-dhcp85.eng.vmware.com (promb-1s-dhcp85.eng.vmware.com [10.20.84.85]) by mailhost4.vmware.com (Postfix) with ESMTP id 74DB7C9C2C; Thu, 15 Jul 2010 18:20:52 -0700 (PDT) Date: Thu, 15 Jul 2010 18:20:52 -0700 (PDT) From: Shreyas Bhatewara X-X-Sender: sbhatewara@localhost.localdomain To: David Miller cc: "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "pv-drivers@vmware.com" , Ronghua Zhang , Matthieu Bucchianeri Subject: Re: [PATCH 2.6.35-rc1] net-next: vmxnet3 fixes [4/5] Do not reset when the device is not opened In-Reply-To: <20100714.140718.115934967.davem@davemloft.net> Message-ID: References: <20100714.140718.115934967.davem@davemloft.net> User-Agent: Alpine 2.00 (LRH 1167 2008-08-23) MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 14 Jul 2010, David Miller wrote: > From: Shreyas Bhatewara > Date: Tue, 13 Jul 2010 17:49:52 -0700 (PDT) > > > > > Do not reset when the device is not opened > > > > If a reset is scheduled, and the device goes thru close and open, it > > may happen that reset and open may run in parallel. > > The reset code now bails out if the device is not opened. > > > > Signed-off-by: Ronghua Zang > > Signed-off-by: Matthieu Bucchianeri > > Signed-off-by: Shreyas Bhatewara > > Testing IFF_UP is just making your race hole a little smaller but > it isn't fixing the problem. > > In fact, there really isn't any legitimate reason for a driver > to test the IFF_UP state bit. netif_running() is the correct > test, and asynchronous work queue things like resets should > synchronize with open/close using the RTNL lock so that your > test of netif_running() is a stable one. > Is this what you suggest : --- Hold rtnl_lock to get the right link state. While asynchronously resetting the device, hold rtnl_lock to get the right value from netif_running. If a reset is scheduled, and the device goes thru close and open, it may happen that reset and open may run in parallel. Holding rtnl_lock will avoid this. --- drivers/net/vmxnet3/vmxnet3_drv.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c index 1b0ce8c..c4d7e42 100644 --- a/drivers/net/vmxnet3/vmxnet3_drv.c +++ b/drivers/net/vmxnet3/vmxnet3_drv.c @@ -2420,6 +2420,7 @@ vmxnet3_reset_work(struct work_struct *data) return; /* if the device is closed, we must leave it alone */ + rtnl_lock(); if (netif_running(adapter->netdev)) { printk(KERN_INFO "%s: resetting\n", adapter->netdev->name); vmxnet3_quiesce_dev(adapter); @@ -2428,6 +2429,7 @@ vmxnet3_reset_work(struct work_struct *data) } else { printk(KERN_INFO "%s: already closed\n", adapter->netdev->name); } + rtnl_unlock(); clear_bit(VMXNET3_STATE_BIT_RESETTING, &adapter->state); }