From 5a5990d3090b03745a9548a6f5edef02095675cf Mon Sep 17 00:00:00 2001
From: Stephen Hemminger <shemminger@vyatta.com>
Date: Thu, 26 Feb 2009 06:49:24 +0000
Subject: [PATCH] net: Avoid race between network down and sysfs

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/core/net-sysfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 6ac29a46e23e..484f58750eba 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -77,7 +77,9 @@ static ssize_t netdev_store(struct device *dev, struct device_attribute *attr,
 	if (endp == buf)
 		goto err;
 
-	rtnl_lock();
+	if (!rtnl_trylock())
+		return -ERESTARTSYS;
+
 	if (dev_isalive(net)) {
 		if ((ret = (*set)(net, new)) == 0)
 			ret = len;