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 <dingtianhong@huawei.com>
Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 984ca02..ae02c19 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -501,20 +501,25 @@
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 @@
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,