From f7df4923fa986247e93ec2cdff5ca168fff14dcf Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Tue, 28 Feb 2017 08:55:40 +0100 Subject: [PATCH] mlxsw: spectrum_router: Avoid potential packets loss When the structure of the LPM tree changes (f.e., due to the addition of a new prefix), we unbind the old tree and then bind the new one. This may result in temporary packet loss. Instead, overwrite the old binding with the new one. Fixes: 6b75c4807db3 ("mlxsw: spectrum_router: Add virtual router management") Signed-off-by: Ido Schimmel Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- .../ethernet/mellanox/mlxsw/spectrum_router.c | 30 ++++++++++++------- 1 file changed, 20 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c index d7ac22d7f940..bd8de6b9be71 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c @@ -441,30 +441,40 @@ static int mlxsw_sp_vr_lpm_tree_check(struct mlxsw_sp *mlxsw_sp, struct mlxsw_sp_vr *vr, struct mlxsw_sp_prefix_usage *req_prefix_usage) { - struct mlxsw_sp_lpm_tree *lpm_tree; + struct mlxsw_sp_lpm_tree *lpm_tree = vr->lpm_tree; + struct mlxsw_sp_lpm_tree *new_tree; + int err; - if (mlxsw_sp_prefix_usage_eq(req_prefix_usage, - &vr->lpm_tree->prefix_usage)) + if (mlxsw_sp_prefix_usage_eq(req_prefix_usage, &lpm_tree->prefix_usage)) return 0; - lpm_tree = mlxsw_sp_lpm_tree_get(mlxsw_sp, req_prefix_usage, + new_tree = mlxsw_sp_lpm_tree_get(mlxsw_sp, req_prefix_usage, vr->proto, false); - if (IS_ERR(lpm_tree)) { + if (IS_ERR(new_tree)) { /* We failed to get a tree according to the required * prefix usage. However, the current tree might be still good * for us if our requirement is subset of the prefixes used * in the tree. */ if (mlxsw_sp_prefix_usage_subset(req_prefix_usage, - &vr->lpm_tree->prefix_usage)) + &lpm_tree->prefix_usage)) return 0; - return PTR_ERR(lpm_tree); + return PTR_ERR(new_tree); } - mlxsw_sp_vr_lpm_tree_unbind(mlxsw_sp, vr); - mlxsw_sp_lpm_tree_put(mlxsw_sp, vr->lpm_tree); + /* Prevent packet loss by overwriting existing binding */ + vr->lpm_tree = new_tree; + err = mlxsw_sp_vr_lpm_tree_bind(mlxsw_sp, vr); + if (err) + goto err_tree_bind; + mlxsw_sp_lpm_tree_put(mlxsw_sp, lpm_tree); + + return 0; + +err_tree_bind: vr->lpm_tree = lpm_tree; - return mlxsw_sp_vr_lpm_tree_bind(mlxsw_sp, vr); + mlxsw_sp_lpm_tree_put(mlxsw_sp, new_tree); + return err; } static struct mlxsw_sp_vr *mlxsw_sp_vr_get(struct mlxsw_sp *mlxsw_sp,