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.
Signed-off-by: Brendan Jackman jackmanb@google.com --- 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 5c8a53869b1bd287b09a250edf628a66c25c2439..433e54fb634f793f2eb4c53ba6b791045c9f4986 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,