On Thu, Oct 16, 2025 at 12:20 AM Andrii Nakryiko
<[email protected]> wrote:
>
> On Tue, Oct 14, 2025 at 7:50 PM Xing Guo <[email protected]> wrote:
> >
> > Recently, I noticed a selftest failure in my local environment. The
> > test_parse_test_list_file writes some data to
> > /tmp/bpf_arg_parsing_test.XXXXXX and parse_test_list_file() will read
> > the data back. However, after writing data to that file, we forget to
> > call fsync() and it's causing testing failure in my laptop. This patch
> > helps fix it by adding the missing fsync() call.
> >
> > Signed-off-by: Xing Guo <[email protected]>
> > ---
> > tools/testing/selftests/bpf/prog_tests/arg_parsing.c | 10 +++++-----
> > 1 file changed, 5 insertions(+), 5 deletions(-)
> >
>
> I accidentally applied it to bpf-next tree and had to drop it from there.
>
> It actually doesn't apply to bpf tree cleanly, so please rebase and resend.
>
> But first, did you validate that fclose() actually fixes the issue for
> you? Because I don't think fclose() will call fsync(), will it?
> fclose() will basically do the same thing as should be done with
> fflush() anyways, so I have my doubts.
Thanks for pointing this out. Adding fclose() resolves the issue on
my laptop too.
I prefer switching back to using fsync() according to your comment.
Best Regards,
Xing.
>
> Furthermore, your commit message doesn't correspond to your patch.
> There is no fsync() call here, please fix that as well.
>
> > diff --git a/tools/testing/selftests/bpf/prog_tests/arg_parsing.c
> > b/tools/testing/selftests/bpf/prog_tests/arg_parsing.c
> > index bb143de68875..0f99f06116ea 100644
> > --- a/tools/testing/selftests/bpf/prog_tests/arg_parsing.c
> > +++ b/tools/testing/selftests/bpf/prog_tests/arg_parsing.c
> > @@ -140,9 +140,11 @@ static void test_parse_test_list_file(void)
> > fprintf(fp, "testA/subtest2\n");
> > fprintf(fp, "testC_no_eof_newline");
> > fflush(fp);
> > -
> > - if (!ASSERT_OK(ferror(fp), "prepare tmp"))
> > - goto out_fclose;
> > + if (!ASSERT_OK(ferror(fp), "prepare tmp")) {
> > + fclose(fp);
> > + goto out_remove;
> > + }
> > + fclose(fp);
> >
> > init_test_filter_set(&set);
> >
> > @@ -160,8 +162,6 @@ static void test_parse_test_list_file(void)
> >
> > free_test_filter_set(&set);
> >
> > -out_fclose:
> > - fclose(fp);
> > out_remove:
> > remove(tmpfile);
> > }
> > --
> > 2.51.0
> >
