net/mlx5: Fix return value when searching for existing flow group

When attempting to add a rule to an existing flow group, if a matching
flow group exists but is not active, the error code returned should be
EAGAIN, so that the rule can be added to the matching flow group once
it is active, rather than ENOENT, which indicates that no matching
flow group was found.

Fixes: bd71b08 ("net/mlx5: Support multiple updates of steering rules in parallel")
Signed-off-by: Gavi Teitz <[email protected]>
Signed-off-by: Roi Dayan <[email protected]>
Signed-off-by: Patrisious Haddad <[email protected]>
Reviewed-by: Tariq Toukan <[email protected]>
Signed-off-by: Mark Bloch <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: PatrisiousHaddad

drivers/net/ethernet/mellanox/mlx5/core/fs_core.c

@@ -2228,6 +2228,7 @@ try_add_to_existing_fg(struct mlx5_flow_table *ft,
 	struct mlx5_flow_handle *rule;
 	struct match_list *iter;
 	bool take_write = false;
+	bool try_again = false;
 	struct fs_fte *fte;
 	u64  version = 0;
 	int err;
@@ -2292,6 +2293,7 @@ try_add_to_existing_fg(struct mlx5_flow_table *ft,
 		nested_down_write_ref_node(&g->node, FS_LOCK_PARENT);
 
 		if (!g->node.active) {
+			try_again = true;
 			up_write_ref_node(&g->node, false);
 			continue;
 		}
@@ -2313,7 +2315,8 @@ try_add_to_existing_fg(struct mlx5_flow_table *ft,
 			tree_put_node(&fte->node, false);
 		return rule;
 	}
-	rule = ERR_PTR(-ENOENT);
+	err = try_again ? -EAGAIN : -ENOENT;
+	rule = ERR_PTR(err);
 out:
 	kmem_cache_free(steering->ftes_cache, fte);
 	return rule;