[9fans] Re: M device?

[9fans] Re: M device?

[jmk]

	Trivial question, but I can't find the answer anywhere I'd expect to see
	it; what's the M device?  It comes up in an ls -l listing of my root
	directory (single machine, 386, standard install from the Plan 9 CDROM).

	d-rwxrwxr-x M 3 sys sys     0 Jun 22  1997 /3210
	d-rwxrwxr-x M 3 sys sys     0 Jun 22  1997 /386
	d-rwxrwxr-x M 3 sys sys     0 Jun 22  1997 /68020
	d-rwxrwxr-x M 3 sys sys     0 Jun 22  1997 /960
	--r--r--r-- M 3 sys sys 63707 Apr  5  1995 /_conform.map
	d-rwxrwxr-x M 3 sys sys     0 Jun 22  1997 /acme
	d-rwxrwxrwx M 3 adm adm     0 Jun 22  1997 /adm
	d-rwxrwxrwx / 0 cwr cwr     0 Apr  4  1995 /bin
	d-rwxrwxr-x M 3 sys sys     0 Apr  5  1995 /bin
	--r-xr-xr-x / 0 cwr cwr 34080 Apr  4  1995 /boot
	--r-xr-xr-x / 0 cwr cwr 38432 Apr  4  1995 /cfs

	etc.

	The sys-owned stuff is the ordinary root fs, so M must be some sort
	of server, but I can't find the relevant letter in man(3).


	Will
	cwr@crash.cts.com

Brazil has the '#c/drivers' file to make finding out which drivers are loaded
with the kernel a bit easier. The devtab table changed from being an array of
Dev to an array of pointers to Dev and Dev acquired a couple of new elements to
describe the entry; devchar went away.

	% tail -20 /sys/src/brazil/port/devmnt.c
	Dev mntdevtab = {
		'M',
		"mnt",

		mntreset,
		devinit,
		mntattach,
		mntclone,
		mntwalk,
		mntstat,
		mntopen,
		mntcreate,
		mntclose,
		mntread,
		devbread,
		mntwrite,
		devbwrite,
		mntremove,
		mntwstat,
	};
	% cat /dev/drivers
	#/ root
	#c cons
	#e env
	#| pipe
	#p proc
	#M mnt
	#s srv
	#d dup
	#r rtc
	#D ssl
	#z mntstats
	#l ether
	#I ip
	#i draw
	#m mouse
	#v vga
	#S scsi
	#W cd
	#w sd
	#H ata
	#f floppy
	#A audio
	#y i82365
	#L lpt
	#t ns16552
	% 

[9fans] Re: M device?

[Will]

Markus Friedl (Markus.Friedl@informatik.uni-erlangen.de) wrote:
: In <7cgbfs$r5a$1@nusku.cts.com> Will Rose <cwr@cts.com> writes:

: > what's the M device? 
: > [...]
: > d-rwxrwxr-x M 3 sys sys     0 Jun 22  1997 /386

: the 'mount-device'. it multiplexes access to namespaces
: attached via bind/mount (see /lib/namespace, /bin/termrc),
: like sending 9fs RPCs to 'remote' servers.

: the character-to-device mapping can be found in
: /sys/src/9/port/master (-> /sys/src/9/port/devmnt.c).

Thanks - and it's in the man pages, too; mnt(3).  I don't know
how I missed it.


Will
cwr@crash.cts.com