JPMorgan Chase & Co.’s EMC Mortgage, facing homeowner lawsuits over foreclosures, was sued by the trustee of a mortgage portfolio for refusing to turn over documents detailing the quality of loans bought by the trust. Wells Fargo & Co., the trustee, is seeking access to files for more than 2,000 underlying mortgages in the Bear Stearns Mortgage Funding Trust 2007-AR2, according to the complaint filed today in Delaware Chancery Court in Wilmington.