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
final StoreFileMetadata md;
        final ReleasableBytesReference content;
        final long position;
        final boolean lastChunk;
        FileChunk(StoreFileMetadata md, ReleasableBytesReference content, long position, boolean lastChunk) {
            this.md = md;
            this.content = content.retain();
            this.position = position;
            this.lastChunk = lastChunk;
        }
        @Override
        public void close() {
            content.decRef();
        }
    }
    private final class FileChunkWriter implements Releasable {
        
        final PriorityQueue<FileChunk> pendingChunks = new PriorityQueue<>(Comparator.comparing(fc -> fc.position));
        long lastPosition = 0;
        void writeChunk(FileChunk newChunk) throws IOException {
            synchronized (this) {
                pendingChunks.add(newChunk);
            }