drive VOP functions: use the PID of the original opener to fool the
lock manager.
open_drive: be quiet about failures (they're normal when scanning the
partitions).
close_drive: lock drive before closing.
remove_drive: lock drive before deallocating.
read_drive_label: set drive up when all is OK
check_drive:
Complete rewrite. Offload most of the code to the new
vinum_scandisk
format_config:
use snprintf and %qd options to make much less emetic.
Remove old supporting functions.
vinum_scandisk:
Moved here from vinum.c
Almost complete rewrite, incorporating much of what was check_drive.
We still don't have a general way to find the drives on a system, so
get the user to supply the names via the `read' command. For each
device, try each possible compatibility slice name (there's a danger
of finding both /dev/da1h and /dev/da0s1h otherwise). Sort the
partitions found in reverse order of last update time and read them
in, setting the `update' parameter to parse_config and descendents.
save_config: rename to daemon_save_config, since the function is now
called by the daemon. Create a new function save_config which queues
the request with the daemon.
daemon_save_config: some mods to allow for the unfamiliar
environment.