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
delegatedListener.onResponse(releasable);
            }
        });
        if (requirePrimaryTermUpdate(opPrimaryTerm, allowCombineOperationWithPrimaryTermUpdate)) {
            synchronized (mutex) {
                if (requirePrimaryTermUpdate(opPrimaryTerm, allowCombineOperationWithPrimaryTermUpdate)) {
                    final IndexShardState shardState = state();
                    
                    
                    
                    
                    if (shardState != IndexShardState.POST_RECOVERY && shardState != IndexShardState.STARTED) {
                        throw new IndexShardNotStartedException(shardId, shardState);
                    }
                    bumpPrimaryTerm(opPrimaryTerm, () -> {
                        updateGlobalCheckpointOnReplica(globalCheckpoint, "primary term transition");
                        final long currentGlobalCheckpoint = getLastKnownGlobalCheckpoint();
                        final long maxSeqNo = seqNoStats().getMaxSeqNo();
                        logger.info(
                            "detected new primary with primary term [{}], global checkpoint [{}], max_seq_no [{}]",
                            opPrimaryTerm,
                            currentGlobalCheckpoint,
                            maxSeqNo
                        );
                        if (currentGlobalCheckpoint < maxSeqNo) {
                            resetEngineToGlobalCheckpoint();
                        } else {
                            getEngine().rollTranslogGeneration();
                        }
                    }, allowCombineOperationWithPrimaryTermUpdate ? operationListener : null);