We saw a case where the recovery stats reported `recovered_bytes` greater than `length_in_bytes` for one file:

```
GET /_recovery?detailed

200 OK
...
{
  "name": "_buk.fdt",
  "length_in_bytes": 26891307173,
  "reused": false,
  "recovered_in_bytes": 35324928266,
  "recovered_from_snapshot_in_bytes": 8433621093
}
...
```

NB `35324928266 == 26891307173 + 8433621093`

This causes Elasticsearch to compute a negative value for the reserved space on the target node of this recovery, which prevents stats APIs from working. This appears to be caused by a network-level failure which triggers a retry without first cancelling an ongoing download of a different file with the same name from the snapshot repository.

---

### Workaround

Restart the target node to clear these stats.
server/src/main/java/org/elasticsearch/index/shard/IndexShard.java
/**
     * Returns the latest cluster routing entry received with this shard.
     */
    @Override
    public ShardRouting routingEntry() {
        return this.shardRouting;
    }
    public QueryCachingPolicy getQueryCachingPolicy() {
        return cachingPolicy;
    }
    @Override
    public void updateShardState(
        final ShardRouting newRouting,
        final long newPrimaryTerm,
        final BiConsumer<IndexShard, ActionListener<ResyncTask>> primaryReplicaSyncer,
        final long applyingClusterStateVersion,
        final Set<String> inSyncAllocationIds,
        final IndexShardRoutingTable routingTable
    ) throws IOException {
        final ShardRouting currentRouting;
        synchronized (mutex) {
            currentRouting = this.shardRouting;
            assert currentRouting != null;
            if (newRouting.shardId().equals(shardId()) == false) {
                throw new IllegalArgumentException(
                    "Trying to set a routing entry with shardId " + newRouting.shardId() + " on a shard with shardId " + shardId()
                );
            }
            if (newRouting.isSameAllocation(currentRouting) == false) {
                throw new IllegalArgumentException(