Re: [PATCH v2 12/13] selftests/fs/mount-notify-ns: Fix build warning

[Amir Goldstein]

On Fri, Dec 5, 2025 at 6:12 PM Guenter Roeck <li...@roeck-us.net> wrote:
>
> Fix
>
> mount-notify_test_ns.c: In function ‘fanotify_rmdir’:
> mount-notify_test_ns.c:494:17: warning:
>         ignoring return value of ‘chdir’ declared with attribute 
> ‘warn_unused_result’
>
> by checking the return value of chdir() and displaying an error message
> if it returns an error.
>
> Fixes: 781091f3f5945 ("selftests/fs/mount-notify: add a test variant running 
> inside userns")
> Cc: Amir Goldstein <amir7...@gmail.com>
> Signed-off-by: Guenter Roeck <li...@roeck-us.net>
> ---
> v2: Update subject and description to reflect that the patch fixes a build
>     warning.
>     Use perror() to display an error message if chdir() returns an error.
>
>  .../selftests/filesystems/mount-notify/mount-notify_test_ns.c  | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> 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 9f57ca46e3af..90bec6faf64e 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
> @@ -491,7 +491,8 @@ TEST_F(fanotify, rmdir)
>         ASSERT_GE(ret, 0);
>
>         if (ret == 0) {
> -               chdir("/");
> +               if (chdir("/"))
> +                       perror("chdir()");

ASSERT_EQ(0, chdir("/"));

and there is another one like this in mount-notify_test.c

Thanks,
Amir.