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.
x-pack/plugin/snapshot-based-recoveries/src/internalClusterTest/java/org/elasticsearch/xpack/snapshotbasedrecoveries/recovery/SnapshotBasedIndexRecoveryIT.java
String replicaNodeIdAfterFailOver = shardRoutingTableAfterFailOver.replicaShards().get(0).currentNodeId();
        String replicaNodeNameAfterFailOver = clusterStateAfterPrimaryFailOver.nodes().resolveNode(replicaNodeIdAfterFailOver).getName();
        RecoveryState recoveryState = getLatestPeerRecoveryStateForShard(indexName, 0);
        assertPeerRecoveryWasSuccessful(recoveryState, primaryNodeNameAfterFailOver, replicaNodeNameAfterFailOver);
        assertDocumentsAreEqual(indexName, numDocs);
        if (repoType.equals(TestRepositoryPlugin.FAULTY_TYPE) == false) {
            for (RecoveryState.FileDetail fileDetail : recoveryState.getIndex().fileDetails()) {
                assertThat(fileDetail.recoveredFromSnapshot(), is(equalTo(fileDetail.length())));
            }
            Store.MetadataSnapshot replicaAfterFailoverMetadataSnapshot = getMetadataSnapshot(replicaNodeNameAfterFailOver, indexName);
            Store.RecoveryDiff recoveryDiff = primaryMetadataSnapshot.recoveryDiff(replicaAfterFailoverMetadataSnapshot);
            assertThat(recoveryDiff.identical, is(not(empty())));
        }
    }
    public void testRecoveryUsingSnapshotsIsThrottledPerNode() throws Exception {
        executeRecoveryWithSnapshotFileDownloadThrottled(
            (
                indices,
                sourceNode,
                targetNode,
                targetMockTransportService,
                recoverySnapshotFileRequests,
                awaitForRecoverSnapshotFileRequestReceived,
                respondToRecoverSnapshotFile) -> {
                String indexRecoveredFromSnapshot1 = indices.get(0);
                assertAcked(
                    client().admin()
                        .indices()
                        .prepareUpdateSettings(indexRecoveredFromSnapshot1)
                        .setSettings(Settings.builder().put("index.routing.allocation.require._name", targetNode))