Hi,

The function crush_adjust_tree_bucket_item_weight in 
ceph-0.41/src/crush/builder.c seem to  have a bug. The argument weight 
is no use, because it is assigned .
--------------------------------------------------------------------
int crush_adjust_tree_bucket_item_weight(struct crush_bucket_tree 
*bucket, int item, int weight)
{
     int diff;
     int node;
     unsigned i, j;
     unsigned depth = calc_depth(bucket->h.size);

     for (i = 0; i < bucket->h.size; i++) {
         if (bucket->h.items[i] == item)
             break;
     }
     if (i == bucket->h.size)
         return 0;

     node = crush_calc_tree_node(i);
     diff = weight = bucket->node_weights[node];
     bucket->node_weights[node] = weight;
     bucket->h.weight += diff;

     for (j=1; j<depth; j++) {
         node = parent(node);
         bucket->node_weights[node] += diff;
     }

     return diff;

--------------------------------------------------------------------
The function crush_adjust_list_bucket_item_weight also have a same problem.

-ZhuRongze