Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760699Ab0GSRCQ (ORCPT ); Mon, 19 Jul 2010 13:02:16 -0400 Received: from smtp-outbound-1.vmware.com ([65.115.85.69]:16329 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755167Ab0GSRCO (ORCPT ); Mon, 19 Jul 2010 13:02:14 -0400 Date: Mon, 19 Jul 2010 10:02:13 -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: <20100717.163538.137865264.davem@davemloft.net> Message-ID: References: <20100715.183210.226762655.davem@davemloft.net> <20100717.163538.137865264.davem@davemloft.net> User-Agent: Alpine 2.00 (LRH 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2606 Lines: 84 On Sat, 17 Jul 2010, David Miller wrote: > From: Shreyas Bhatewara > Date: Fri, 16 Jul 2010 01:17:29 -0700 (PDT) > > > > > > > On Thu, 15 Jul 2010, David Miller wrote: > > > >> From: Shreyas Bhatewara > >> Date: Thu, 15 Jul 2010 18:20:52 -0700 (PDT) > >> > >> > Is this what you suggest : > >> > > >> > --- > >> > > >> > Hold rtnl_lock to get the right link state. > >> > >> It ought to work, but make sure that it is legal to take the > >> RTNL semaphore in all contexts in which this code block > >> might be called. > >> > > > > This code block is called only from the workqueue handler, which runs in > > process context, so it is legal to take rtnl semaphore. > > Tested this code by simulating event interrupts (which schedule this > > code) at considerable frequency while the interface was brought up and > > down in a loop. Similar stress testing had revealed the bug originally. > > Awesome, please submit this formally. The copy you sent lacked a commit > message and signoff. > Reposting the patch formally. David, Thanks for your coperation. ->Shreyas --- From: Shreyas Bhatewara 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. Signed-off-by: Shreyas Bhatewara --- drivers/net/vmxnet3/vmxnet3_drv.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) 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); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/