The mortgage discharge just means you aren't responsible for it, it doesn't mean the loan evaporated. The security is still there and the bankruptcy doesn't have any affect on foreclosures other than a temporary stay while things are being sorted out.
How fast the bank starts foreclosure is really up to them. The foreclosure tends to run 180 days or so at the earliest from the time it is initiated. You can booted out about twenty days after that.

