cae71ba91d
* Add a dkdevice; move sc_*openpart, sc_label, and sc_cpulabel into it. * Turn sc_wlabel into a flag, and don't set it automatically in DIOCWLABEL. * If there is no label, disallow all I/O except to the raw partition. * Don't allow I/O to `unused' partitions. * Beginnings of support for block sizes other than 512 bytes. Other minor changes.