Re: [PATCH 1/3] btrfs-progs: tests: check nullb index for the error case

[Naohiro Aota <Naohiro.Aota@wdc.com>]

On Tue Sep 2, 2025 at 6:11 PM JST, Qu Wenruo wrote:
>
>
> 在 2025/9/2 13:59, Naohiro Aota 写道:
>> "_find_free_index" can return "ERROR: ...". Check the return value for the
>> case and fail the test.
>> 
>> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>> ---
>>   tests/nullb | 3 +++
>>   1 file changed, 3 insertions(+)
>> 
>> diff --git a/tests/nullb b/tests/nullb
>> index 457ae0d8354a..bfc5640c4470 100755
>> --- a/tests/nullb
>> +++ b/tests/nullb
>> @@ -146,6 +146,9 @@ fi
>>   if [ "$CMD" = 'create' ]; then
>>   	_check_setup
>>   	index=$(_find_free_index)
>> +	if [[ "$index" = ERROR* ]]; then
>> +		_error "$index"
>> +	fi
>
> I think the bigger problem is that:
>
> - _error() output into stdout instead of stderr
>
> - the "exit 1" doesn't help in this case
>    It will only kill the child bash, not the calling one.
>
> So I'd prefer to make _error() to output the warning to stderr, so that 
> index will be empty on error.

Ah, yes. It's safer to do so. I'll revise the patch.

>
> Thanks,
> Qu
>
>>   	name="nullb$index"
>>   	# size in MB
>>   	size=$(_parse_device_size "$@")