to remove 'b'lock devices. The agreement is, essentially, that
block devices will be collapsed into character devices as a first
step (though I don't particularly agree), and raw device names 'rxxx'
will become simply 'xxx' in devfs in the second step (i.e. no 'rxxx'
names will exist). The renaming will not effect the original /dev
and the expectation is that devfs will eventually (but not immediately)
become the standard way to access devices in the system.
If it is determined that a reimplementation of block device access
characteristics is beneficial, a number of alternatives will
be possible that do not involve resurrecting the 'b'lock device class.
For example, an ioctl() that might be made on an open character device
descriptor or a generic buffered overlay device.
This commit removes the blockdev disablement sysctl which does not
apply to the solution that was reached.
dfbdd7d2b3