IFSMgr_SwapDrives

IFSMgr_SwapDrives(
 unsigned long VRP,
 unsigned long drive1,
 unsigned long drive2
 )
 

This service is provided to allow the drive letters of the host and child volumes to be swapped. Some compressed volume drivers do this. The FSD that manages the host and child volumes is also notified of the drive change.

VRP
Supplies the system volume handle for the parent and child drives. Both drives have to use the same system volume handle because they are logical mappings.
drive1
Supplies the 0-based drive number of one of the parent or child drives.
drive2
Supplies the 0-based drive number of the other drive in the pair.

Note that this function does not need to differentiate between the parent and child drives. It is irrelevant which is which as far as swapping them is concerned.