kern/41756: cgd unloading doesn't release resources

[pooka%iki.fi@localhost]

>Number:         41756
>Category:       kern
>Synopsis:       cgd unloading doesn't release resources
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jul 20 16:10:00 +0000 2009
>Originator:     Antti Kantee
>Release:        
>Organization:
yup, it's monday
>Environment:
>Description:
in cgd_modcmd:

        case MODULE_CMD_INIT:
                cgdattach(4);
                
                return devsw_attach("cgd", &cgd_bdevsw, &bmajor,
                    &cgd_cdevsw, &cmajor);
                break;

        case MODULE_CMD_FINI:
                return devsw_detach(&cgd_bdevsw, &cgd_cdevsw);
                break;

I cannot find where cgdattach() is undone.  If it is done through
a non-obvious hyperspace pointer maneuver, the resource releasing
code is indeed very well hidden.
>How-To-Repeat:

>Fix: