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
}
    private boolean hasUncommittedOperations() throws IOException {
        long localCheckpointOfCommit = Long.parseLong(indexShard.commitStats().getUserData().get(SequenceNumbers.LOCAL_CHECKPOINT_KEY));
        return indexShard.countChanges("peer-recovery", localCheckpointOfCommit + 1, Long.MAX_VALUE) > 0;
    }
    @Override
    public void handoffPrimaryContext(final ReplicationTracker.PrimaryContext primaryContext, ActionListener<Void> listener) {
        ActionListener.completeWith(listener, () -> {
            indexShard.activateWithPrimaryContext(primaryContext);
            return null;
        });
    }
    @Override
    public void indexTranslogOperations(
        final List<Translog.Operation> operations,
        final int totalTranslogOps,
        final long maxSeenAutoIdTimestampOnPrimary,
        final long maxSeqNoOfDeletesOrUpdatesOnPrimary,
        final RetentionLeases retentionLeases,
        final long mappingVersionOnPrimary,
        final ActionListener<Long> listener
    ) {
        ActionListener.completeWith(listener, () -> {
            final RecoveryState.Translog translog = state().getTranslog();
            translog.totalOperations(totalTranslogOps);
            assert indexShard().recoveryState() == state();
            if (indexShard().state() != IndexShardState.RECOVERING) {
                throw new IndexShardNotRecoveringException(shardId, indexShard().state());
            }
            /*