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/MultiFileWriter.java
indexOutput = getOpenIndexOutput(name);
        }
        assert indexOutput.getFilePointer() == position : "file-pointer " + indexOutput.getFilePointer() + " != " + position;
        BytesRefIterator iterator = content.iterator();
        BytesRef scratch;
        while ((scratch = iterator.next()) != null) { 
            indexOutput.writeBytes(scratch.bytes, scratch.offset, scratch.length);
        }
        indexState.addRecoveredBytesToFile(name, content.length());
        if (indexOutput.getFilePointer() >= fileMetadata.length() || lastChunk) {
            try {
                Store.verify(indexOutput);
            } finally {
                
                indexOutput.close();
            }
            final String temporaryFileName = getTempNameForFile(name);
            assert Arrays.asList(store.directory().listAll()).contains(temporaryFileName)
                : "expected: [" + temporaryFileName + "] in " + Arrays.toString(store.directory().listAll());
            store.directory().sync(Collections.singleton(temporaryFileName));
            IndexOutput remove = removeOpenIndexOutputs(name);
            assert remove == null || remove == indexOutput; 
        }
    }
    @Override
    public void close() {
        if (closed.compareAndSet(false, true)) {
            decRef();
        }
    }