Re: [PATCH net 2/3] selftests: net: lib: avoid error removing empty netns name

[Petr Machata <petrm@nvidia.com>]

Matthieu Baerts <matttbe@kernel.org> writes:

> Hi Petr,
>
> Thank you for the review!
>
> On 05/06/2024 12:38, Petr Machata wrote:
>> 
>> "Matthieu Baerts (NGI0)" <matttbe@kernel.org> writes:
>> 
>>> If there is an error to create the first netns with 'setup_ns()',
>>> 'cleanup_ns()' will be called with an empty string as first parameter.
>>>
>>> The consequences is that 'cleanup_ns()' will try to delete an invalid
>>> netns, and wait 20 seconds if the netns list is empty.
>>>
>>> Instead of just checking if the name is not empty, convert the string
>>> separated by spaces to an array. Manipulating the array is cleaner, and
>>> calling 'cleanup_ns()' with an empty array will be a no-op.
>>>
>>> Fixes: 25ae948b4478 ("selftests/net: add lib.sh")
>>> Cc: stable@vger.kernel.org
>>> Acked-by: Geliang Tang <geliang@kernel.org>
>>> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
>>> ---
>>>  tools/testing/selftests/net/lib.sh | 13 +++++++------
>>>  1 file changed, 7 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/tools/testing/selftests/net/lib.sh b/tools/testing/selftests/net/lib.sh
>>> index a422e10d3d3a..e2f51102d7e1 100644
>>> --- a/tools/testing/selftests/net/lib.sh
>>> +++ b/tools/testing/selftests/net/lib.sh
>>> @@ -15,7 +15,7 @@ ksft_xfail=2
>>>  ksft_skip=4
>>>  
>>>  # namespace list created by setup_ns
>>> -NS_LIST=""
>>> +NS_LIST=()
>>>  
>>>  ##############################################################################
>>>  # Helpers
>>> @@ -137,6 +137,7 @@ cleanup_ns()
>>>  	fi
>>>  
>>>  	for ns in "$@"; do
>>> +		[ -z "${ns}" ] && continue
>> 
>> I think this is now irrelevant though? Now cleanup_ns() will be called
>> with no arguments for an empty NS list, so the loop does not even kick in.
>
> If you don't mind, I think it is "safer" to keep it: some selftests are
> using 'cleanup_ns()' directly, not via 'cleanup_all_ns()', e.g.
> netns-name.sh, cmsg-*.sh, fib-*.sh, etc. which can call it with the
> variables not set if 'setup_ns' failed during the init phase.
>
> For the moment, all these selftests are calling 'cleanup_ns()' with
> parameters added without double quotes: so it is fine. Until someone
> changes that to please shellcheck, like we did on our side with MPTCP
> selftests. So this line will be useful soon when we will publish the
> rest of our patches to use 'lib.sh' [1] :)

All right.

Reviewed-by: Petr Machata <petrm@nvidia.com>