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Commit f7df4923 authored by Ido Schimmel's avatar Ido Schimmel Committed by David S. Miller
Browse files

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: 6b75c480 ("mlxsw: spectrum_router: Add virtual router management")
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4f7bfb39

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

+20 −10
Original line number Diff line number Diff line
@@ -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,