FSH_FINDDUPHVPB - Locate equivalent hVPB

This function provides the mechanism to identify a previous instance of a 
volume during the FS_MOUNT process. 
Calling Sequence   

int far pascal FSH_FINDDUPHVPB(hVPB, phVPB)

unsigned short hVPB;
unsigned short far * phVPB;

hVPB is the handle to the volume to be found. 
phVPB is the pointer to where the handle of matching volume will be stored 
If no error is detected, a zero error code is returned. If an error is 
detected, one of the following error codes is returned: 
indicates there is no matching hVPB. 
When OS/2 is recognizing a volume, it calls the FSD to mount the volume. 
At this point, the FSD may elect to allocate storage and buffer data for 
that volume. The mount process will allocate a new VPB whenever the media 
becomes uncertain, that is, when the device driver recognizes it can no 
longer be certain the media is unchanged. This VPB cannot be collapsed 
with a previously allocated VPB, because of a reinsertion of media, until 
the FS_MOUNT call returns. The previous VPB, however, may have some cached 
data that must be updated from the media (the media may have been written 
while it was removed) FSH_FINDDUPHVPB allows the FSD to find this previous 
occurrence of the volume in order to update the cached information for the 
old VPB. Remember the newly created VPB will be unmounted if there is 
another, older VPB for that volume. 
Note:   OS/2 does not validate input parameters. An FSD, therefore, should 
call FSH_PROBEBUF where appropriate. 

Created using Inf-PHP v.2 (c) 2003 Yuri Prokushev
Created using Inf-HTML v.0.9b (c) 1995 Peter Childs