From 31057979cdadfee9f934746fd84046b43506ba61 Mon Sep 17 00:00:00 2001 From: Patrisious Haddad Date: Thu, 25 Dec 2025 15:27:13 +0200 Subject: [PATCH] net/mlx5: Lag, multipath, give priority for routes with smaller network prefix Today multipath offload is controlled by a single route and the route controlling is selected if it meets one of the following criteria: 1. No controlling route is set. 2. New route destination is the same as old one. 3. New route metric is lower than old route metric. This can cause unwanted behaviour in case a new route is added with a smaller network prefix which should get the priority. Fix this by adding a new criteria to give priority to new route with a smaller network prefix. Fixes: ad11c4f1d8fd ("net/mlx5e: Lag, Only handle events from highest priority multipath entry") Signed-off-by: Patrisious Haddad Signed-off-by: Mark Bloch Link: https://patch.msgid.link/20251225132717.358820-2-mbloch@nvidia.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/mellanox/mlx5/core/lag/mp.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag/mp.c b/drivers/net/ethernet/mellanox/mlx5/core/lag/mp.c index aee17fcf3b36c..cdc99fe5c9568 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/lag/mp.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/lag/mp.c @@ -173,10 +173,15 @@ static void mlx5_lag_fib_route_event(struct mlx5_lag *ldev, unsigned long event, } /* Handle multipath entry with lower priority value */ - if (mp->fib.mfi && mp->fib.mfi != fi && + if (mp->fib.mfi && (mp->fib.dst != fen_info->dst || mp->fib.dst_len != fen_info->dst_len) && - fi->fib_priority >= mp->fib.priority) + mp->fib.dst_len <= fen_info->dst_len && + !(mp->fib.dst_len == fen_info->dst_len && + fi->fib_priority < mp->fib.priority)) { + mlx5_core_dbg(ldev->pf[idx].dev, + "Multipath entry with lower priority was rejected\n"); return; + } nh_dev0 = mlx5_lag_get_next_fib_dev(ldev, fi, NULL); nh_dev1 = mlx5_lag_get_next_fib_dev(ldev, fi, nh_dev0); -- 2.47.3