The Irishman has been one of the Spotland club's best performers in a run of two wins and a draw in four games under new boss John Coleman that has seen Dale move off the bottom of npower League One.
The 21-year-old defender joined on an initial month-long loan in January but will now stay for the maximum 93-day period.
Rochdale will now have Long available for all but one of their games in their bid to avoid the drop.
Long spent the first half of the season on loan at Accrington under the guidance of then Stanley boss Coleman.
Burnley last week