From 23d154c0d071468aadbebb57a0d73e93bd1aff0e Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Thu, 20 Feb 2020 09:07:54 +0200 Subject: [PATCH] mlxsw: spectrum_router: Do not assume RTNL is taken during RIF teardown IPv6 addresses are deleted in an atomic context, so the driver defers the potential teardown of the associated router interface (RIF) to a work item that takes RTNL. The RIF is only destroyed if the associated netdev does not have any IP addresses (both IPv4 and IPv6). The IPv4 device ('struct in_device') is currently fetched via __in_dev_get_rtnl() which assumes RTNL is taken. Since RTNL is going to be removed, convert it to use __in_dev_get_rcu() from an RCU read-side critical section. Note that the IPv6 device ('struct inet6_dev') is fetched via __in6_dev_get(), which does not require RTNL. Signed-off-by: Ido Schimmel Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c index 28dca7aa4ce0..21e8539727be 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c @@ -6285,7 +6285,8 @@ mlxsw_sp_rif_should_config(struct mlxsw_sp_rif *rif, struct net_device *dev, case NETDEV_UP: return rif == NULL; case NETDEV_DOWN: - idev = __in_dev_get_rtnl(dev); + rcu_read_lock(); + idev = __in_dev_get_rcu(dev); if (idev && idev->ifa_list) addr_list_empty = false; @@ -6293,6 +6294,7 @@ mlxsw_sp_rif_should_config(struct mlxsw_sp_rif *rif, struct net_device *dev, if (addr_list_empty && inet6_dev && !list_empty(&inet6_dev->addr_list)) addr_list_empty = false; + rcu_read_unlock(); /* macvlans do not have a RIF, but rather piggy back on the * RIF of their lower device.