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
startTime,
            autoGeneratedIdTimestamp,
            isRetry,
            ifSeqNo,
            ifPrimaryTerm
        );
    }
    private Engine.IndexResult index(Engine engine, Engine.Index index) throws IOException {
        active.set(true);
        final Engine.IndexResult result;
        final Engine.Index preIndex = indexingOperationListeners.preIndex(shardId, index);
        try {
            if (logger.isTraceEnabled()) {
                
                logger.trace(
                    "index [{}] seq# [{}] allocation-id [{}] primaryTerm [{}] operationPrimaryTerm [{}] origin [{}]",
                    preIndex.id(),
                    preIndex.seqNo(),
                    routingEntry().allocationId(),
                    preIndex.primaryTerm(),
                    getOperationPrimaryTerm(),
                    preIndex.origin()
                );
            }
            result = engine.index(preIndex);
            if (logger.isTraceEnabled()) {
                logger.trace(
                    "index-done [{}] seq# [{}] allocation-id [{}] primaryTerm [{}] operationPrimaryTerm [{}] origin [{}] "
                        + "result-seq# [{}] result-term [{}] failure [{}]",
                    preIndex.id(),