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/indices/recovery/RecoveryTarget.java
import org.elasticsearch.core.AbstractRefCounted;
import org.elasticsearch.core.Nullable;
import org.elasticsearch.core.Releasable;
import org.elasticsearch.index.engine.Engine;
import org.elasticsearch.index.mapper.MapperException;
import org.elasticsearch.index.seqno.ReplicationTracker;
import org.elasticsearch.index.seqno.RetentionLeases;
import org.elasticsearch.index.seqno.SequenceNumbers;
import org.elasticsearch.index.shard.IndexShard;
import org.elasticsearch.index.shard.IndexShardNotRecoveringException;
import org.elasticsearch.index.shard.IndexShardState;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.index.snapshots.blobstore.BlobStoreIndexShardSnapshot;
import org.elasticsearch.index.store.Store;
import org.elasticsearch.index.store.StoreFileMetadata;
import org.elasticsearch.index.translog.Translog;
import org.elasticsearch.repositories.IndexId;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Path;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;
import static org.elasticsearch.core.Strings.format;
/**
 * Represents a recovery where the current node is the target node of the recovery. To track recoveries in a central place, instances of
 * this class are created through {@link RecoveriesCollection}.
 */
public class RecoveryTarget extends AbstractRefCounted implements RecoveryTargetHandler {