"ST7 USB FS DFU Demo" from ST Micro
This code shows the Bulk-Only Transport (BOT) method on USB Mass Storage Class (MSC) for Compact FLASH, MMC, Smart Card and Memory Stick.
"USB Storage - FAQ for Driver and Hardware Developers" from WHDC
This is one of (or sole ?) poor documents for Usbstor.sys, built-in SMC driver, from Microsoft.
"AN10039_1 "ISP1582/83 Firmware Programming Guide" from Philips
"Chapter 4. Mass storage application" explains MSC BOT handling for encapsulated ATA/ATAPI protocol with flow charts. Though this explanation is for ATAPI bridge, the code flow is almost same as the FLASH media.
And also next original specifications will be needed to realize the protocol.
"USB Mass Storage Class Specification Overview" from USB.org
"USB Mass Storage Class Bulk-Only Transport" specification from USB.org

As MSC BOT accesses to media in primitive level, such as ATAPI protocol, a file system driver is not needed for its implementation.

Tsuneo