Re: [RFC PATCH v2 net-next 07/16] net: dsa: sync ageing time when joining the bridge

Florian Fainelli
2021-03-19T22:13:50Z

On 3/18/2021 4:18 PM, Vladimir Oltean wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
>
> The SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME attribute is only emitted from:
>
> sysfs/ioctl/netlink
> -> br_set_ageing_time
> -> __set_ageing_time
>
> therefore not at bridge port creation time, so:
> (a) drivers had to hardcode the initial value for the address ageing time,
> because they didn't get any notification
> (b) that hardcoded value can be out of sync, if the user changes the
> ageing time before enslaving the port to the bridge
>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
> include/linux/if_bridge.h | 6 ++++++
> net/bridge/br_stp.c | 13 +++++++++++++
> net/dsa/port.c | 10 ++++++++++
> 3 files changed, 29 insertions(+)
>
> diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
> index 920d3a02cc68..ebd16495459c 100644
> --- a/include/linux/if_bridge.h
> +++ b/include/linux/if_bridge.h
> @@ -137,6 +137,7 @@ struct net_device *br_fdb_find_port(const struct net_device *br_dev,
> void br_fdb_clear_offload(const struct net_device *dev, u16 vid);
> bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag);
> u8 br_port_get_stp_state(const struct net_device *dev);
> +clock_t br_get_ageing_time(struct net_device *br_dev);
> #else
> static inline struct net_device *
> br_fdb_find_port(const struct net_device *br_dev,
> @@ -160,6 +161,11 @@ static inline u8 br_port_get_stp_state(const struct net_device *dev)
> {
> return BR_STATE_DISABLED;
> }
> +
> +static inline clock_t br_get_ageing_time(struct net_device *br_dev)
> +{
> + return 0;
> +}
> #endif
>
> #endif
> diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c
> index 86b5e05d3f21..3dafb6143cff 100644
> --- a/net/bridge/br_stp.c
> +++ b/net/bridge/br_stp.c
> @@ -639,6 +639,19 @@ int br_set_ageing_time(struct net_bridge *br, clock_t ageing_time)
> return 0;
> }
>
> +clock_t br_get_ageing_time(struct net_device *br_dev)
> +{
> + struct net_bridge *br;
> +
> + if (!netif_is_bridge_master(br_dev))
> + return 0;
> +
> + br = netdev_priv(br_dev);
> +
> + return jiffies_to_clock_t(br->ageing_time);

Don't you want an ASSERT_RTNL() in this function as well?
--
Florian