What colour was the smoke?
Black smoke - excess fuel being injected, usual cause is a boost leak from the intake pipework, often split hose or split/damaged intercooler.
White smoke - excess fuel being leaked into a single cylinder by leaking injector or turbocharge oil seal failed leaking engine oil into the exhaust tract
Blue smoke - turbocharger oil seal leaking on the intake side meaning engine oil being burned in the combustion chambers (can turn to white if large quantities) *
The latter (*) is potentially dangerous as it can lead to "diesel runaway" which often results in a destroyed engine...
https://en.wikipedia.org/wiki/Diesel_engine_runaway