Re: Idea: a way to use /dev/modem symlinks safely

[Avery Pennarun <apenwarr@worldvisions.ca>]

On Thu, Apr 08, 1999 at 12:13:43PM +0300, Fabrizio Polacco wrote:

> On Wed, Apr 07, 1999 at 12:26:52PM -0400, Avery Pennarun wrote:
>
> > I think there are advantages to using /dev/modem, however, there is a big
> > disadvantage that we already know about: if some programs use /dev/modem and
> > others use /dev/ttySx, their lock files have different names and locking
> > doesn't work correctly.  This means that mgetty conflicts with minicom,
> > diald conflicts with efax, etc.
> 
> The solution is to use liblockdev library for implementing the lock.
> Not only it is able to handle the /dev/modem -> /dev/ttyS? symlink, but
> it is also able to handle the case when /dev/modem is created by mknod,
> making a new device with the same major and minor numbers.
> 
> This library has been created for the purpose to standardize the lock of
> devices (not only ttys) and superate the limits of the algorithm
> suggested (or mandated) by FSSTND. It is compatible with that algorithm.

Wow, I didn't know about this one.  (I knew about liblockfile, but not
liblockdev.) It looks like the perfect solution!  Why isn't it part of
policy?

Have fun,

Avery