[DataLoader] Add mode to LoadFilesFromDisk (#57056)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/57056
Test Plan: Imported from OSS
Reviewed By: zou3519
Differential Revision: D28059776
Pulled By: ejguan
fbshipit-source-id: 0be511f196bedf6eab3cd0bded35096c17a473bf
