struct xfs_ifork                *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
        struct xfs_bmbt_irec            got, del;
        struct xfs_iext_cursor          icur;
-       xfs_fsblock_t                   firstfsb;
        struct xfs_defer_ops            dfops;
        struct xfs_defer_ops            *odfops = (*tpp)->t_dfops;
        int                             error = 0;
                        if (error)
                                break;
                } else if (del.br_state == XFS_EXT_UNWRITTEN || cancel_real) {
-                       xfs_defer_init(*tpp, &dfops, &firstfsb);
+                       xfs_defer_init(*tpp, &dfops, &(*tpp)->t_firstblock);
 
                        /* Free the CoW orphan record. */
                        error = xfs_refcount_free_cow_extent(ip->i_mount,