On Mon, 27 Jul 2026 10:52:17 +0100 Muhammad Usama Anjum <[email protected]> wrote:
> The tmpfile-backed COW cases allocate a one-page file with fallocate() > before exercising private and shared mappings. When the filesystem > backing tmpfile() does not implement fallocate(), setup fails with > EOPNOTSUPP and no COW behavior is exercised. > > This occurs when the temporary directory resides on a filesystem with > limited allocation support, such as NFSv3. Reporting a failure adds > noise because the test prerequisite is absent rather than the COW > implementation being broken. > > Report EOPNOTSUPP as a skip. Continue treating every other fallocate() > error as a failure so unexpected setup regressions remain visible. > > Tested-by: Sarthak Sharma <[email protected]> > Signed-off-by: Muhammad Usama Anjum <[email protected]> > --- > tools/testing/selftests/mm/cow.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/mm/cow.c > b/tools/testing/selftests/mm/cow.c > index 0c627ea89ff7b..c1b8920e29342 100644 > --- a/tools/testing/selftests/mm/cow.c > +++ b/tools/testing/selftests/mm/cow.c > @@ -1718,8 +1718,13 @@ static void run_with_tmpfile(non_anon_test_fn fn, > const char *desc) > > /* File consists of a single page filled with zeroes. */ > if (fallocate(fd, 0, 0, pagesize)) { > - ksft_perror("fallocate() failed"); > - log_test_result(KSFT_FAIL); > + if (errno == EOPNOTSUPP) { > + ksft_print_msg("fallocate() not supported by > filesystem\n"); > + log_test_result(KSFT_SKIP); > + } else { > + ksft_perror("fallocate() failed"); > + log_test_result(KSFT_FAIL); > + } Correctly skips only unsupported fallocate() setup Acked-by: Usama Arif <[email protected]> > goto close; > } > > -- > 2.47.3 > >
