1137a1138,1192
>
> int
> fzap_count_write(zap_name_t *zn, int add, uint64_t *towrite,
> uint64_t *tooverwrite)
> {
> zap_t *zap = zn->zn_zap;
> zap_leaf_t *l;
> int err;
>
> /*
> * Account for the header block of the fatzap.
> */
> if (!add && dmu_buf_freeable(zap->zap_dbuf)) {
> *tooverwrite += zap->zap_dbuf->db_size;
> } else {
> *towrite += zap->zap_dbuf->db_size;
> }
>
> /*
> * Account for the pointer table blocks.
> * If we are adding we need to account for the following cases :
> * - If the pointer table is embedded, this operation could force an
> * external pointer table.
> * - If this already has an external pointer table this operation
> * could extend the table.
> */
> if (add) {
> if (zap->zap_f.zap_phys->zap_ptrtbl.zt_blk == 0)
> *towrite += zap->zap_dbuf->db_size;
> else
> *towrite += (zap->zap_dbuf->db_size * 3);
> }
>
> /*
> * Now, check if the block containing leaf is freeable
> * and account accordingly.
> */
> err = zap_deref_leaf(zap, zn->zn_hash, NULL, RW_READER, &l);
> if (err != 0) {
> return (err);
> }
>
> if (!add && dmu_buf_freeable(l->l_dbuf)) {
> *tooverwrite += l->l_dbuf->db_size;
> } else {
> /*
> * If this an add operation, the leaf block could split.
> * Hence, we need to account for an additional leaf block.
> */
> *towrite += (add ? 2 : 1) * l->l_dbuf->db_size;
> }
>
> zap_put_leaf(l);
> return (0);
> }