[PATCH 3.4 05/26] team: fix mtu setting

Greg Kroah-Hartman
2014-06-24T16:56:42Z

From: Jiri Pirko <jiri@resnulli.us>

[ 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>
---
drivers/net/team/team.c | 7 ++++++-
include/linux/if_team.h | 1 +
2 files changed, 7 insertions(+), 1 deletion(-)

--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -889,6 +889,7 @@ static int team_change_mtu(struct net_de
* 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) {
@@ -897,6 +898,7 @@ static int team_change_mtu(struct net_de
goto unwind;
}
}
+ team->port_mtu_change_allowed = false;
mutex_unlock(&team->lock);

dev->mtu = new_mtu;
@@ -906,6 +908,7 @@ static int team_change_mtu(struct net_de
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;
@@ -1671,7 +1674,9 @@ static int team_device_event(struct noti
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;
--- a/include/linux/if_team.h
+++ b/include/linux/if_team.h
@@ -113,6 +113,7 @@ struct team {

const struct team_mode *mode;
struct team_mode_ops ops;
+ bool port_mtu_change_allowed;
long mode_priv[TEAM_MODE_PRIV_LONGS];
};