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
flush(new FlushRequest().waitIfOngoing(true));
        SetOnce<Engine> newEngineReference = new SetOnce<>();
        final long globalCheckpoint = getLastKnownGlobalCheckpoint();
        assert globalCheckpoint == getLastSyncedGlobalCheckpoint();
        synchronized (engineMutex) {
            verifyNotClosed();
            
            
            final Engine readOnlyEngine = new ReadOnlyEngine(
                newEngineConfig(replicationTracker),
                seqNoStats,
                translogStats,
                false,
                Function.identity(),
                true,
                false
            ) {
                @Override
                public IndexCommitRef acquireLastIndexCommit(boolean flushFirst) {
                    synchronized (engineMutex) {
                        if (newEngineReference.get() == null) {
                            throw new AlreadyClosedException("engine was closed");
                        }
                        
                        return newEngineReference.get().acquireLastIndexCommit(false);
                    }
                }
                @Override
                public IndexCommitRef acquireSafeIndexCommit() {