Re: [PATCH v2 5/5] test: add test for full FAT16 directory

Heinrich Schuchardt
2022-08-01T06:14:24Z

On 8/1/22 03:50, AKASHI Takahiro wrote:
> On Sun, Jul 31, 2022 at 01:58:37PM +0200, Heinrich Schuchardt wrote:
>> Add a unit test checking that a full FAT16 directory leads to an error
>> when trying to add an additional entry.
>
> Thank you for adding this test case, but
> why do you restrict this test to fat16 and the root directory?
> The root directory on fat16 is a very much special case and differently
> implemented from others. So the test scenario doesn't do what we expect
> for fulfilling the whole disk.
>
> I think we should use other sub directories (and other file systems as well).

No other filesystem but FAT supports mkdir in U-Boot currently.

Creating the maximum 512 directory entries for the root directory of
FAT16 can be done in a reasonable time.

Otherwise "The maximum valid directory size is 2**21 bytes." Creating
65536 entries takes far too long to be done in a regular test. Even a
bash script in Linux needs more than half an hour for this on my laptop.

The 2 MiB limit is not implemented in U-Boot. So the test would fail
after a few days or weeks.

>
>> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
>> ---
>> v2:
>> new patch
>> ---
>> test/py/tests/test_fs/test_mkdir.py | 17 +++++++++++++++++
>> 1 file changed, 17 insertions(+)
>>
>> diff --git a/test/py/tests/test_fs/test_mkdir.py b/test/py/tests/test_fs/test_mkdir.py
>> index f5cc308362..e3a9e3ed27 100644
>> --- a/test/py/tests/test_fs/test_mkdir.py
>> +++ b/test/py/tests/test_fs/test_mkdir.py
>> @@ -119,3 +119,20 @@ class TestMkdir(object):
>> assert('0123456789abcdef00/' in output)
>> assert('0123456789abcdef13/' in output)
>> assert_fs_integrity(fs_ubtype, fs_img)
>> +
>> + def test_mkdir7(self, u_boot_console, fs_obj_mkdir):
>> + """ Test Case 7 - max out number of root directory entries
>> + """
>> + _, _, fs_type = fs_obj_mkdir
>
> Why not use fs_ubtype, _, fs_type = ..., then
>
>> + if fs_type != 'fat16':
>> + return
>> + with u_boot_console.log.section('Test Case 7 - mkdir (max out)'):
>> + for i in range(0, 512):
>> + output = u_boot_console.run_command(
>> + f'fatmkdir host 0:0 /U-Boot-mkdir-max-out-test-directory-{i:05d}')
>
> '%smkdir ...'.format(fs_ubtype, i)

We know it is FAT.

Best regards

Heinrich
>
> -Takahiro Akashi
>
>> + if 'Can\'t create directory entry' in output:
>> + break
>> + # A directory was created
>> + assert i > 0
>> + # The FAT16 root directory has only 512 directory entries
>> + assert i <= 512 / 5
>> --
>> 2.36.1
>>