2014-10-12 17:21:36

by gene heskett

[permalink] [raw]
Subject: reboot housekeeping, lack thereof, is messing with me

To whomever is in charge of the supposedly volatile LCK.. files in
/var/lock:

Its my understanding that these files should be volatile when they
represent a USB usage, because a USB device can be unplugged instantly and
at any time. The device nicely and dutifully disappears from an 'ls /dev'
listing when a device is unplugged.

Why is it then that the /var/lock/LCK..ttyUSB1 file is always left behind,
so it screws up any possibility of doing a nice clean reboot and restart
of the program that uses it?

/var/lock is not now nor has it ever been volatile storage since its on
the drive forever, or until one becomes root, deletes it, and then reboots
the machine. That just cost me a days work, testing usb cables etc with a
digital storage scope and a chip replacement on the other systems
motherboard that in all likelyhood wasn't needed.

Is this fixable?

Thanks.

Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS


2014-10-13 06:55:44

by Clemens Ladisch

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Subject: Re: reboot housekeeping, lack thereof, is messing with me

Gene Heskett wrote:
> To whomever is in charge of the supposedly volatile LCK.. files in
> /var/lock:

Whoever that may be, it's not the kernel.

> Its my understanding that these files should be volatile when they
> represent a USB usage, because a USB device can be unplugged instantly and
> at any time. The device nicely and dutifully disappears from an 'ls /dev'
> listing when a device is unplugged.
>
> Why is it then that the /var/lock/LCK..ttyUSB1 file is always left behind,
> so it screws up any possibility of doing a nice clean reboot and restart
> of the program that uses it?

What program leaves this file behind? (The pid in there is no longer
helpful, unless it got logged due to a segfault, but what was the last
program used for serial stuff?)

Anyway, it appears some programs automatically delete this file when the
pid is not valid.


Regards,
Clemens