AT_HANDLE_FID
if (flag & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH | AT_HANDLE_FID |
flag & (AT_HANDLE_FID | AT_EMPTY_PATH))
else if (flag & AT_HANDLE_FID)
#ifndef AT_HANDLE_FID
ASSERT_EQ(name_to_handle_at(self->child_pidfd2, "", fh, &mnt_id, AT_EMPTY_PATH | AT_HANDLE_FID), 0);