I am in Shanghai and have been given an S2 visa, as my British passport is full and no blank pages

The S2 says ..."Permitted to stay until 10 MAR 2015 for this time... and to stay for 30 days each time since the next entry"....I need to go to UK to renew my passport ... will I be allowed to re enter Shanghai with this S2 type?

Please reply asap... thank you