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.
x-pack/plugin/snapshot-based-recoveries/src/internalClusterTest/java/org/elasticsearch/xpack/snapshotbasedrecoveries/recovery/SnapshotBasedIndexRecoveryIT.java
return child;
                }
                @Override
                public InputStream readBlob(String blobName) throws IOException {
                    
                    if (blobName.startsWith("__") == false) {
                        return super.readBlob(blobName);
                    }
                    return new FilterInputStream(super.readBlob(blobName)) {
                        @Override
                        public int read(byte[] b, int off, int len) throws IOException {
                            if (randomBoolean()) {
                                
                                for (int i = 0; i < len; i++) {
                                    b[off + i] = randomByte();
                                }
                                return len;
                            } else {
                                if (randomBoolean()) {
                                    throw new IOException("Unable to read blob " + blobName);
                                } else {
                                    
                                    int read = super.read(b, off, len);
                                    return read / 2;
                                }
                            }
                        }
                    };
                }
            };