[PATCH] selftest/mm: Skip if fallocate() is unsupported in gup_longterm

[PATCH] selftest/mm: Skip if fallocate() is unsupported in gup_longterm

[Mark Brown]

Currently gup_longterm assumes that filesystems support fallocate() and uses
that to allocate space in files, however this is an optional feature and is
in particular not implemented by NFSv3 which is commonly used in CI systems
leading to spurious failures. Check for lack of support and report a skip
instead for that case.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/mm/gup_longterm.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/mm/gup_longterm.c b/tools/testing/selftests/mm/gup_longterm.c
index 8a97ac5176a4..0e99494268ed 100644
--- a/tools/testing/selftests/mm/gup_longterm.c
+++ b/tools/testing/selftests/mm/gup_longterm.c
@@ -114,7 +114,15 @@ static void do_test(int fd, size_t size, enum test_type type, bool shared)
 	}
 
 	if (fallocate(fd, 0, 0, size)) {
-		if (size == pagesize) {
+		/*
+		 * Some filesystems (eg, NFSv3) don't support
+		 * fallocate(), report this as a skip rather than a
+		 * test failure.
+		 */
+		if (errno == EOPNOTSUPP) {
+			ksft_print_msg("fallocate() not supported by filesystem\n");
+			result = KSFT_SKIP;
+		} else if (size == pagesize) {
 			ksft_print_msg("fallocate() failed (%s)\n", strerror(errno));
 			result = KSFT_FAIL;
 		} else {

---
base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
change-id: 20250610-selftest-mm-gup-longterm-fallocate-nfs-21ef54627ef2

Best regards,
-- 
Mark Brown <broonie@kernel.org>