Re: [PATCH for-9.0 1/3] qtest/virtio-9p-test.c: consolidate create dir, file and symlink tests

[Daniel Henrique Barboza <dbarboza@ventanamicro.com>]

On 3/27/24 05:47, Christian Schoenebeck wrote:
> On Tuesday, March 26, 2024 6:47:17 PM CET Daniel Henrique Barboza wrote:
>> On 3/26/24 14:05, Greg Kurz wrote:
>>> On Tue, 26 Mar 2024 10:26:04 -0300
>>> Daniel Henrique Barboza <dbarboza@ventanamicro.com> wrote:
>>>
>>>> The local 9p driver in virtio-9p-test.c its temporary dir right at the
>>>> start of qos-test (via virtio_9p_create_local_test_dir()) and only
>>>> deletes it after qos-test is finished (via
>>>> virtio_9p_remove_local_test_dir()).
>>>>
>>>> This means that any qos-test machine that ends up running virtio-9p-test local
>>>> tests more than once will end up re-using the same temp dir. This is
>>>> what's happening in [1] after we introduced the riscv machine nodes: if
>>>> we enable slow tests with the '-m slow' flag using qemu-system-riscv64,
>>>> this is what happens:
>>>>
>>>> - a temp dir is created, e.g. qtest-9p-local-WZLDL2;
>>>>
>>>> - virtio-9p-device tests will run virtio-9p-test successfully;
>>>>
>>>> - virtio-9p-pci tests will run virtio-9p-test, and fail right at the
>>>>     first slow test at fs_create_dir() because the "01" file was already
>>>>     created by fs_create_dir() test when running with the virtio-9p-device.
>>>>
>>>> We can fix it by making every test clean up their changes in the
>>>> filesystem after they're done. But we don't need every test either:
>>>> what fs_create_file() does is already exercised in fs_unlinkat_dir(),
>>>> i.e. a dir is created, verified to be created, and then removed. Fixing
>>>> fs_create_file() would turn it into fs_unlikat_dir(), so we don't need
>>>> both. The same theme follows every test in virtio-9p-test.c, where the
>>>> 'unlikat' variant does the same thing the 'create' does but with some
>>>> cleaning in the end.
>>>>
>>>> Consolide some tests as follows:
>>>>
>>>> - fs_create_dir() is removed. fs_unlinkat_dir() is renamed to
>>>>     fs_create_unlinkat_dir();
>>>>
>>>> - fs_create_file() is removed. fs_unlinkat_file() is renamed to
>>>>     fs_create_unlinkat_file(). The "04" dir it uses is now being removed;
>>>>
>>>> - fs_symlink_file() is removed. fs_unlinkat_symlink() is renamed to
>>>>     fs_create_unlinkat_symlink(). Both "real_file" and the "06" dir it
>>>>     creates is now being removed.
>>>>
>>>
>>> The  change looks good functionally but it breaks the legitimate assumption
>>> that files "06/*" come from test #6 and so on... I think you should consider
>>> renumbering to avoid confusion when debugging logs.
>>>
>>> Since this will bring more hunks, please split this in enough reviewable
>>> patches.
>>
>> Fair enough. Let me cook a v2. Thanks,
> 
> Wouldn't it be much simpler to just change the name of the temporary
> directory, such that it contains the device name as well? Then these tests
> runs would run on independent directories and won't interfere with each other
> and that wouldn't need much changes I guess.

That's true. If we were just trying to fix the issue then I would go with this
approach since it's simpler. But given that we're also cutting half the tests while
retaining the coverage I think this approach is worth the extra code.


Thanks,


Daniel



> 
> /Christian
> 
>