+ ret = algo->hash_init(algo, &ctx);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < region_count - 1; i++) {
+ ret = algo->hash_update(algo, ctx, region[i].data,
+ region[i].size, 0);
+ if (ret)
+ return ret;
+ }
+
+ ret = algo->hash_update(algo, ctx, region[i].data, region[i].size, 1);
+ if (ret)
+ return ret;
+ ret = algo->hash_finish(algo, ctx, checksum, algo->digest_size);
+ if (ret)
+ return ret;