struct xfs_mount        *mp = ip->i_mount;
        struct xfs_ifork        *ifp;
        struct xfs_btree_cur    *cur = NULL;
-       xfs_fsblock_t           firstblock = NULLFSBLOCK;
        struct xfs_bmbt_irec    got;
        struct xfs_iext_cursor  icur;
        int                     whichfork = xfs_bmapi_whichfork(flags);
 
        if (ifp->if_flags & XFS_IFBROOT) {
                cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
-               cur->bc_private.b.firstblock = firstblock;
+               cur->bc_private.b.firstblock = tp->t_firstblock;
                cur->bc_private.b.flags = 0;
        }
 
                got.br_state = XFS_EXT_NORM;
 
        error = xfs_bmap_add_extent_hole_real(tp, ip, whichfork, &icur,
-                       &cur, &got, &firstblock, &logflags, flags);
+                       &cur, &got, &tp->t_firstblock, &logflags, flags);
        if (error)
                goto error0;