From 571a4b62ed63cace383619b0b4ef0c7e012237e1 Mon Sep 17 00:00:00 2001 From: Brendan Jackman Date: Tue, 11 Mar 2025 13:18:18 +0000 Subject: [PATCH] selftests/mm: skip map_populate on weird filesystems It seems that 9pfs does not allow truncating unlinked files, Mark Brown has noted that NFS may also behave this way. It doesn't seem quite right to call this a "bug" but it's probably a special enough case that it makes sense for the test to just SKIP if it happens. Link: https://lkml.kernel.org/r/20250311-mm-selftests-v4-7-dec210a658f5@google.com Signed-off-by: Brendan Jackman Cc: Dev Jain Cc: Lorenzo Stoakes Cc: Mateusz Guzik Cc: Shuah Khan Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/map_populate.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/tools/testing/selftests/mm/map_populate.c b/tools/testing/selftests/mm/map_populate.c index 5c8a53869b1b..433e54fb634f 100644 --- a/tools/testing/selftests/mm/map_populate.c +++ b/tools/testing/selftests/mm/map_populate.c @@ -87,6 +87,13 @@ int main(int argc, char **argv) BUG_ON(!ftmp, "tmpfile()"); ret = ftruncate(fileno(ftmp), MMAP_SZ); + if (ret < 0 && errno == ENOENT) { + /* + * This probably means tmpfile() made a file on a filesystem + * that doesn't handle temporary files the way we want. + */ + ksft_exit_skip("ftruncate(fileno(tmpfile())) gave ENOENT, weird filesystem?\n"); + } BUG_ON(ret, "ftruncate()"); smap = mmap(0, MMAP_SZ, PROT_READ | PROT_WRITE, -- 2.50.1