Re: [PATCH v2] selftests/efivarfs: skip write tests if efivarfs is mounted read-only

[Hui Wang <hui.wang@canonical.com>]

On 9/4/26 14:44, Ard Biesheuvel wrote:
>
> On Fri, 4 Sep 2026, at 04:06, Hui Wang wrote:
>> The previous mail was rejected by linux-kselftest maillist because the
>> html part is detected. Fixing it and re-sending the mail.
>>
>> On 9/3/26 17:34, Ard Biesheuvel wrote:
>>>>    run_test()
>>>> @@ -74,7 +82,7 @@ test_create_empty()
>>>>    {
>>>>    	local file=$efivarfs_mount/$FUNCNAME-$test_guid
>>>>
>>>> -	: > $file
>>>> +	: 2>/dev/null > $file
>>>>
>>> Why is this needed?
>> The test_create_empty() will be run on read-only efivarfs, and it will
>> print [PASS], but it will also print some noise message with read-only
>> filesystem like:
>>
>> --------------------
>> running test_create_empty
>> --------------------
>> $(TESTCASE_PATH)/efivarfs.sh: line 85:
>> /sys/firmware/efi/efivars/test_create_empty-210be57c-9849-4fc7-a635-e6382d1aec27:
>> Read-only file system
>>     [PASS]
>>
>> This change is for suppressing the noise message and make the output
>> clean like below:
>>
>> --------------------
>> running test_create_empty
>> --------------------
>>     [PASS]
>>
> That does not make sense.
>
> If the file does not exist after attempting to create it, the test has failed.
> But I suspect that this fails even on a read-write efivarfs, given that EFI
> does not support zero-length variables.
>
> Please fix this in a separate patch, or leave it alone. Don't paper over it
> like this.

OK, got it.

Thanks.