question: public void flush ( LogSeqNum lsn ) { logMgrLock . lock ( ) ; try { if ( lsn . compareTo ( lastFlushedLsn ) >= 0 ) flush ( ) ; } finally { logMgrLock . unlock ( ) ; } }
target:  Ensures that the log records corresponding to the specified LSN has been written to disk. All earlier log records will also be written to disk.