The Linux SCSI Target Wiki
The source files can be view via kernel.org gitweb at lio-core-2.6.git/drivers/target/tcm_loop/
What is tcm_loop..?
TCM_Loop is a Target_Core_Mod/ConfigFS fabric module that provides locally accessable virtual Linux/SCSI devices from TCM storage objects such as IBLOCK and FILEIO. It allows TCM SPC-3 and above SCSI emulation to accessed via Linux/SCSI LLD driver, and provides CDB-level SAS emulation