Re: [PATCH net] selftests: forwarding: skip if kernel not support setting bridge fdb learning limit

[Nikolay Aleksandrov <razor@blackwall.org>]

On 23/07/2024 11:22, Hangbin Liu wrote:
> If the testing kernel doesn't support setting fdb_max_learned or show
> fdb_n_learned, just skip it. Or we will get errors like
> 
> ./bridge_fdb_learning_limit.sh: line 218: [: null: integer expression expected
> ./bridge_fdb_learning_limit.sh: line 225: [: null: integer expression expected
> 
> Fixes: 6f84090333bb ("selftests: forwarding: bridge_fdb_learning_limit: Add a new selftest")
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> ---
>  .../forwarding/bridge_fdb_learning_limit.sh    | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/tools/testing/selftests/net/forwarding/bridge_fdb_learning_limit.sh b/tools/testing/selftests/net/forwarding/bridge_fdb_learning_limit.sh
> index 0760a34b7114..a21b7085da2e 100755
> --- a/tools/testing/selftests/net/forwarding/bridge_fdb_learning_limit.sh
> +++ b/tools/testing/selftests/net/forwarding/bridge_fdb_learning_limit.sh
> @@ -178,6 +178,22 @@ fdb_del()
>  	check_err $? "Failed to remove a FDB entry of type ${type}"
>  }
>  
> +check_fdb_n_learned_support()
> +{
> +	if ! ip link help bridge 2>&1 | grep -q "fdb_max_learned"; then
> +		echo "SKIP: iproute2 too old, missing bridge max learned support"
> +		exit $ksft_skip
> +	fi
> +
> +	ip link add dev br0 type bridge
> +	local learned=$(fdb_get_n_learned)
> +	ip link del dev br0
> +	if [ "$learned" == "null" ]; then
> +		echo "SKIP: kernel too old; bridge fdb_n_learned feature not supported."
> +		exit $ksft_skip
> +	fi
> +}
> +
>  check_accounting_one_type()
>  {
>  	local type=$1 is_counted=$2 overrides_learned=$3
> @@ -274,6 +290,8 @@ check_limit()
>  	done
>  }
>  
> +check_fdb_n_learned_support
> +
>  trap cleanup EXIT
>  
>  setup_prepare

Isn't the selftest supposed to be added after the feature was included?

I don't understand why this one is special, we should have the same
issue with all new features.