ntfs_acl
static_assert(sizeof(struct ntfs_acl) == 8);
struct ntfs_acl *acl;
(sizeof(struct ntfs_sid) + 8) + sizeof(struct ntfs_acl) +
acl = (struct ntfs_acl *)((u8 *)sid + sizeof(struct ntfs_sid) + 8);
acl->size = cpu_to_le16(sizeof(struct ntfs_acl) + sizeof(struct ntfs_ace) + 4);
ace = (struct ntfs_ace *)((u8 *)acl + sizeof(struct ntfs_acl));