We were leaking file descriptors when coll/ml was in use. It turn out
this was because basesmuma was failing to unmap files it had previously
mapped. This commit cleans up the setup code to ensure that we only
attempt to map the control files once per module and then ensures the
files are unmapped when the module is released.
cmr=v1.8.2:reviewer=manjugv
This commit was SVN r31737.