public BucketSizeInfo roundUpToBucketSizeInfo(int blockSize) {
    for (int i = 0; i < bucketSizes.length; ++i)
      if (blockSize <= bucketSizes[i]) return bucketSizeInfos[i];
    return null;
  }
Round up the given block size to bucket size, and get the corresponding BucketSizeInfo
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketAllocator.java