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
long globalCheckpoint,
        ActionListener<ReplicationResponse> listener
    ) {
        assert assertPrimaryMode();
        
        assert indexSettings.getIndexVersionCreated().before(Version.V_7_4_0) || indexSettings.isSoftDeleteEnabled() == false;
        return replicationTracker.addPeerRecoveryRetentionLease(nodeId, globalCheckpoint, listener);
    }
    public RetentionLease cloneLocalPeerRecoveryRetentionLease(String nodeId, ActionListener<ReplicationResponse> listener) {
        assert assertPrimaryMode();
        return replicationTracker.cloneLocalPeerRecoveryRetentionLease(nodeId, listener);
    }
    public void removePeerRecoveryRetentionLease(String nodeId, ActionListener<ReplicationResponse> listener) {
        assert assertPrimaryMode();
        replicationTracker.removePeerRecoveryRetentionLease(nodeId, listener);
    }
    /**
     * Returns a list of retention leases for peer recovery installed in this shard copy.
     */
    public List<RetentionLease> getPeerRecoveryRetentionLeases() {
        return replicationTracker.getPeerRecoveryRetentionLeases();
    }
    public boolean useRetentionLeasesInPeerRecovery() {
        return useRetentionLeasesInPeerRecovery;
    }
    private SafeCommitInfo getSafeCommitInfo() {
        final Engine engine = getEngineOrNull();
        return engine == null ? SafeCommitInfo.EMPTY : engine.getSafeCommitInfo();
    }
    class ShardEventListener implements Engine.EventListener {