FUSE_IOCTL_COMPAT
unsigned int flags = FUSE_IOCTL_COMPAT;
FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR);
if (flags & FUSE_IOCTL_COMPAT) {
(flags & FUSE_IOCTL_COMPAT) != 0);
return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);