[linux-lvm] Snapshot LE to PE Mapping

[<bowmailtmp-lvm yahoo com>]

I am using LVM to debug a custom ASIC virtualization
chip  for my company.  I have found it quite useful.

One queston though, I have written scripts to convert 
lvdisplay -vv table output into our own mapping
structures, but found this to be of limited use for
snapshots.

Is there a way to find out where the changed snapshot
data actually resides physically?
if you do lvdisplay for a snapshot volume, it only
gives you the LE->PE maps for the *original* LV.  it
does not show you what extents the *changed* data got
moved to, so i don't know how to track it down and
verify it.  is there another way to do this or is it a
possible enhancement to lvdisplay for snapshot
volumes?

Thanks,
Dave