Data race condition

The value of the shared data will be determined by the interleaving of thread execution. Thread shared data is accessed without holding an appropriate lock, possibly causing a race condition
/src/mongo/db/modules/enterprise/src/fcbis/backup_file_cloner.cpp:333: MISSING_LOCK 154916 Accessing "this->start" without holding lock "mongo::repl::BaseCloner._mutex". Elsewhere, "mongo::repl::BackupFileCloner::Stats.start" is written to with "BaseCloner._mutex" held 1 out of 1 times (1 of these accesses strongly imply that it is necessary).