The visa (TRV) only allows him to travel to Canada. The work permit is one type of temporary resident permit. If he wants to continue working in Canada, he has to renew the work permit. In most cases, this requires that his employer obtain a new Labour Market Impact Assessment (LMIA) before he can apply for a work permit.
Applying for permanent residence does not give any status in the country. If he applies for CEC and gets his AOR (Acknowledgement of receipt, usually takes about 2 months) before his current work permit expires, then he would be eligible for a bridging open work permit (BOWP), but he would have to apply for that before the current permit expires.