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
sourceMockTransportService.addSendBehavior(targetMockTransportService, (connection, requestId, action, request, options) -> {
            assertNotEquals(PeerRecoveryTargetService.Actions.FILE_CHUNK, action);
            connection.sendRequest(requestId, action, request, options);
        });
        assertAcked(
            client().admin()
                .indices()
                .prepareUpdateSettings(indexName)
                .setSettings(Settings.builder().put("index.routing.allocation.require._name", targetNode))
                .get()
        );
        ensureGreen();
        RecoveryState recoveryState = getLatestPeerRecoveryStateForShard(indexName, 0);
        assertPeerRecoveryWasSuccessful(recoveryState, sourceNode, targetNode);
        RepositoriesService repositoriesService = internalCluster().getInstance(RepositoriesService.class, targetNode);
        InstrumentedRepo repository = (InstrumentedRepo) repositoriesService.repository(repoName);
        
        long expectedRecoveredBytesFromRepo = 0;
        long totalBytesRecoveredFromSnapshot = 0;
        for (RecoveryState.FileDetail fileDetail : recoveryState.getIndex().fileDetails()) {
            totalBytesRecoveredFromSnapshot += fileDetail.recoveredFromSnapshot();
            if (fileDetail.name().startsWith("segments") || fileDetail.name().endsWith(".si")) {
                continue;
            }
            expectedRecoveredBytesFromRepo += fileDetail.recovered();
        }
        assertThat(repository.totalBytesRead.get(), is(equalTo(expectedRecoveredBytesFromRepo)));
        long snapshotSizeForIndex = getSnapshotSizeForIndex(repoName, snapshot, indexName);
        assertThat(repository.totalBytesRead.get(), is(greaterThan(0L)));
        assertThat(repository.totalBytesRead.get(), is(lessThanOrEqualTo(snapshotSizeForIndex)));