From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolay Aleksandrov Subject: [PATCH -net 1/2] bonding: fix store_arp_validate race with mode change Date: Fri, 6 Sep 2013 21:41:57 +0200 Message-ID: <1378496518-16104-2-git-send-email-nikolay@redhat.com> References: <1378496518-16104-1-git-send-email-nikolay@redhat.com> Cc: fubar@us.ibm.com, davem@davemloft.net, andy@greyhouse.net, mleitner@redhat.com To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:20654 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750810Ab3IFTpm (ORCPT ); Fri, 6 Sep 2013 15:45:42 -0400 In-Reply-To: <1378496518-16104-1-git-send-email-nikolay@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: We need to protect store_arp_validate via rtnl because it can race with mode changing and we can end up having arp_validate set in a mode different from active-backup. Signed-off-by: Nikolay Aleksandrov --- drivers/net/bonding/bond_sysfs.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c index ce46776..4e38683 100644 --- a/drivers/net/bonding/bond_sysfs.c +++ b/drivers/net/bonding/bond_sysfs.c @@ -419,27 +419,33 @@ static ssize_t bonding_store_arp_validate(struct device *d, struct device_attribute *attr, const char *buf, size_t count) { - int new_value; + int new_value, ret = count; struct bonding *bond = to_bond(d); + if (!rtnl_trylock()) + return restart_syscall(); new_value = bond_parse_parm(buf, arp_validate_tbl); if (new_value < 0) { pr_err("%s: Ignoring invalid arp_validate value %s\n", bond->dev->name, buf); - return -EINVAL; + ret = -EINVAL; + goto out; } if (new_value && (bond->params.mode != BOND_MODE_ACTIVEBACKUP)) { pr_err("%s: arp_validate only supported in active-backup mode.\n", bond->dev->name); - return -EINVAL; + ret = -EINVAL; + goto out; } pr_info("%s: setting arp_validate to %s (%d).\n", bond->dev->name, arp_validate_tbl[new_value].modename, new_value); bond->params.arp_validate = new_value; +out: + rtnl_unlock(); - return count; + return ret; } static DEVICE_ATTR(arp_validate, S_IRUGO | S_IWUSR, bonding_show_arp_validate, -- 1.8.1.4