From 9402b746e7ba0f317ffa465a4c5128c7c220f27b Mon Sep 17 00:00:00 2001 From: dingtianhong Date: Tue, 23 Jul 2013 15:25:39 +0800 Subject: [PATCH] bonding: add rtnl protection for bonding_store_fail_over_mac We need rtnl protection while reading slave_cnt and updating the .fail_over_mac, and it also follows the logic "don't change anything slave-related without rtnl". :) Signed-off-by: Ding Tianhong Cc: Jay Vosburgh Cc: Andy Gospodarek Signed-off-by: David S. Miller --- drivers/net/bonding/bond_sysfs.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c index 984ca02cfe75..ae02c194c01b 100644 --- a/drivers/net/bonding/bond_sysfs.c +++ b/drivers/net/bonding/bond_sysfs.c @@ -501,20 +501,25 @@ static ssize_t bonding_store_fail_over_mac(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(); + if (bond->slave_cnt != 0) { pr_err("%s: Can't alter fail_over_mac with slaves in bond.\n", bond->dev->name); - return -EPERM; + ret = -EPERM; + goto out; } new_value = bond_parse_parm(buf, fail_over_mac_tbl); if (new_value < 0) { pr_err("%s: Ignoring invalid fail_over_mac value %s.\n", bond->dev->name, buf); - return -EINVAL; + ret = -EINVAL; + goto out; } bond->params.fail_over_mac = new_value; @@ -522,7 +527,9 @@ static ssize_t bonding_store_fail_over_mac(struct device *d, bond->dev->name, fail_over_mac_tbl[new_value].modename, new_value); - return count; +out: + rtnl_unlock(); + return ret; } static DEVICE_ATTR(fail_over_mac, S_IRUGO | S_IWUSR, -- 2.20.1