team: fix mtu setting

[ Upstream commit 9d0d68faea6962d62dd501cd6e71ce5cc8ed262b ]

Now it is not possible to set mtu to team device which has a port
enslaved to it. The reason is that when team_change_mtu() calls
dev_set_mtu() for port device, notificator for NETDEV_PRECHANGEMTU
event is called and team_device_event() returns NOTIFY_BAD forbidding
the change. So fix this by returning NOTIFY_DONE here in case team is
changing mtu in team_change_mtu().

Introduced-by: 3d249d4c "net: introduce ethernet teaming device"
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index fe3fd77..1222229 100644 (file)
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -1542,6 +1542,7 @@ static int team_change_mtu(struct net_device *dev, int new_mtu)
         * to traverse list in reverse under rcu_read_lock
         */
        mutex_lock(&team->lock);
+       team->port_mtu_change_allowed = true;
        list_for_each_entry(port, &team->port_list, list) {
                err = dev_set_mtu(port->dev, new_mtu);
                if (err) {
@@ -1550,6 +1551,7 @@ static int team_change_mtu(struct net_device *dev, int new_mtu)
                        goto unwind;
                }
        }
+       team->port_mtu_change_allowed = false;
        mutex_unlock(&team->lock);
 
        dev->mtu = new_mtu;
@@ -1559,6 +1561,7 @@ static int team_change_mtu(struct net_device *dev, int new_mtu)
 unwind:
        list_for_each_entry_continue_reverse(port, &team->port_list, list)
                dev_set_mtu(port->dev, dev->mtu);
+       team->port_mtu_change_allowed = false;
        mutex_unlock(&team->lock);
 
        return err;
@@ -2678,7 +2681,9 @@ static int team_device_event(struct notifier_block *unused,
                break;
        case NETDEV_CHANGEMTU:
                /* Forbid to change mtu of underlaying device */
-               return NOTIFY_BAD;
+               if (!port->team->port_mtu_change_allowed)
+                       return NOTIFY_BAD;
+               break;
        case NETDEV_PRE_TYPE_CHANGE:
                /* Forbid to change type of underlaying device */
                return NOTIFY_BAD;

diff --git a/include/linux/if_team.h b/include/linux/if_team.h
index 16fae64..25b8b15 100644 (file)
--- a/include/linux/if_team.h
+++ b/include/linux/if_team.h
@@ -193,6 +193,7 @@ struct team {
        bool user_carrier_enabled;
        bool queue_override_enabled;
        struct list_head *qom_lists; /* array of queue override mapping lists */
+       bool port_mtu_change_allowed;
        long mode_priv[TEAM_MODE_PRIV_LONGS];
 };