device busy -- no locks?

[Jo Rhett]

Thanks for the super-quick reply!  Responses are inline...

On Thu, Jul 20, 2006 at 07:16:07PM -0500, Rick C. Petty wrote:
> > root at scapa 47# fstat /dev/ttyd0
> > USER     CMD          PID   FD MOUNT      INUM MODE         SZ|DV R/W NAME
> 
> What about "fstat /dev/cuad0" ?  Anyway, I've found that fstat is useless,
> try using sysutils/lsof instead.
 
Sorry, yes. Same results.  And if lsof shows things that fstat doesn't, 
then this is a bug in FreeBSD.

But anyway,
root at scapa 63# lsof /dev/cuad0
root at scapa 64# lsof /dev/ttyd0

Nada.

Also note that this system is pretty bone stock.  Standard install, plus
mysql and apache.  Nothing else would be using the port.  It's something
that left it locked, and really only "login" could be the culprit.

> > root at scapa 48# ps -ajwx |grep d0
> > root      12     0     0     0    0 WL    ??    0:00.05 [irq1: atkbd0]
> > root     372     0     0     0    0 DL    ??    0:00.24 [md0]
> 
> try "-axww" instead..  I've noticed that processes with long command lines
> don't match a regular grep.
 
Same result.

> > No locks? No processes using it.  Okay, this is uncool.
> > And yet "ktrace tip com1" and "kdump -f ktrace.out" clearly show:
> > 
> >  50461 tip      CALL  open(0x8059030,0x6,0)
> >  50461 tip      NAMI  "/dev/cuad0"
> >  50461 tip      RET   open -1 errno 16 Device busy
> 
> This isn't very useful.  A ktrace on the process that's locking the file
> would be.  :-P

See above.  I can't find it. :-(

> > NOTE: at this time I am suspecting that CD is being misread (it's not
> > present - I have a break out box on the line) and that this problem is
> > somehow tied to that.  This problem appears at random after login has
> > exerted itself on the system.  I've disabled the getty on ttyd0 and login
> > has timed out, but it continues to show "device busy".
> 
> How did you disable the getty?  Was this prior to or after a restart?  It
> sounds like /etc/ttys is maybe running a process on it.  You need to
> "killall -HUP init" after changing /etc/ttys.  But you probably already
> know that.

Yes, I change "on" to "off" in /etc/ttys and "kill -1 1" :-)
 
-- 
Jo Rhett
senior geek
SVcolo : Silicon Valley Colocation