On 6/20/25 7:55 PM, Chen Linxuan wrote:
> On Fri, Jun 20, 2025 at 10:46 PM Muhammad Usama Anjum
> <usama.an...@collabora.com> wrote:
>>
>> On 6/20/25 8:50 AM, Chen Linxuan wrote:
>>> When running `make kselftest`, the following compilation warning was
>>> encountered:
>>>
>>> mount-notify_test.c: In function ‘fanotify_rmdir’:
>>> mount-notify_test.c:490:17: warning: ignoring return value of ‘chdir’
>>> declared with attribute ‘warn_unused_result’ [-Wunused-result]
>>> 490 | chdir("/");
>>> | ^~~~~~~~~~
>>>
>>> Signed-off-by: Chen Linxuan <chenlinx...@uniontech.com>
>>> ---
>>> Changes in v2:
>>> - Apply changes suggested by Shuah Khan
>>> - Link to v1:
>>> https://lore.kernel.org/all/20250610020758.2798787-2-chenlinx...@uniontech.com/
>>> ---
>>> .../filesystems/mount-notify/mount-notify_test.c | 15 ++++++++++-----
>>> .../mount-notify/mount-notify_test_ns.c | 15 ++++++++++-----
>>> 2 files changed, 20 insertions(+), 10 deletions(-)
>>>
>>> diff --git
>>> a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
>>> b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
>>> index 5a3b0ace1a88c..f8e0c6b06e2d9 100644
>>> --- a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
>>> +++ b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
>>> @@ -458,12 +458,17 @@ TEST_F(fanotify, rmdir)
>>> ASSERT_GE(ret, 0);
>>>
>>> if (ret == 0) {
>>> - chdir("/");
>>> - unshare(CLONE_NEWNS);
>>> - mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
>>> - umount2("/a", MNT_DETACH);
>>> + if (chdir("/"))
>> Please use the APIs provided by the kselftest_harness.h instead of checking
>> return types manually. For example:
>> use ASSERT_EQ(chdir("/", 0)).
>
> Are you sure？We're in a forked sub process here.
ASSERT_* are macros. They can be used anywhere. Please give it a try.
>
>>
>>> + exit(-1);
>>> + if (unshare(CLONE_NEWNS))
>>> + exit(-1);
>>> + if (mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL))
>>> + exit(-1);
>>> + if (umount2("/a", MNT_DETACH))
>>> + exit(-1);
>>> // This triggers a detach in the other namespace
>>> - rmdir("/a");
>>> + if (rmdir("/a"))
>>> + exit(-1);
>>> exit(0);
>>> }
>>> wait(NULL);
>>> diff --git
>>> a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
>>> b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
>>> index d91946e69591a..d6a6a7ee87028 100644
>>> ---
>>> a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
>>> +++
>>> b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
>>> @@ -486,12 +486,17 @@ TEST_F(fanotify, rmdir)
>>> ASSERT_GE(ret, 0);
>>>
>>> if (ret == 0) {
>>> - chdir("/");
>>> - unshare(CLONE_NEWNS);
>>> - mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
>>> - umount2("/a", MNT_DETACH);
>>> + if (chdir("/"))
>>> + exit(-1);
>>> + if (unshare(CLONE_NEWNS))
>>> + exit(-1);
>>> + if (mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL))
>>> + exit(-1);
>>> + if (umount2("/a", MNT_DETACH))
>>> + exit(-1);
>>> // This triggers a detach in the other namespace
>>> - rmdir("/a");
>>> + if (rmdir("/a"))
>>> + exit(-1);
>>> exit(0);
>>> }
>>> wait(NULL);
>>
>>
>>
