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/RecoveryState.java
out.writeBoolean(reused);
            if (out.getVersion().onOrAfter(RecoverySettings.SNAPSHOT_RECOVERIES_SUPPORTED_VERSION)) {
                out.writeLong(recoveredFromSnapshot);
            }
        }
        void addRecoveredBytes(long bytes) {
            assert reused == false : "file is marked as reused, can't update recovered bytes";
            assert bytes >= 0 : "can't recovered negative bytes. got [" + bytes + "]";
            recovered += bytes;
        }
        void resetRecoveredBytes() {
            assert reused == false : "file is marked as reused, can't update recovered bytes";
            recovered = 0;
        }
        void addRecoveredFromSnapshotBytes(long bytes) {
            assert reused == false : "file is marked as reused, can't update recovered bytes";
            assert bytes >= 0 : "can't recovered negative bytes. got [" + bytes + "]";
            recoveredFromSnapshot += bytes;
            recovered += bytes;
        }
        /**
         * file name *
         */
        public String name() {
            return name;
        }
        /**
         * file length *
         */
        public long length() {