Re: udev rules for new firewire driver stack

[Stefan Richter <stefanr@s5r6.in-berlin.de>]

David Moore wrote:
> On Wed, 2008-08-20 at 21:39 +0200, Stefan Richter wrote:
>> 3.e)  Aliases for firewire character devices (symlinks)
...
>> I spotted the following in udev/rules/redhat/40-redhat.rules:
>>
>> KERNEL="fw*", PROGRAM="fw_unit_symlinks.sh %k %n", SYMLINK+="$result"
...
>> this will create symlinks like iidc3, sbp2-7, avc5 end the likes.
>> These aren't persistent (only unique), because %n will change all the
>> time.  Since they provide symlinks which encode the types of available
>> units on the node, these symlinks may be of (some limited) use in the
>> future, provided that they would be available on all distributions.
> 
>> So, all things considered, I think we don't need any of such symlinks at
>> all.
>>
> 
> Yes, I think it was me who originally came up with this symlink script.
> See here:
> 
> https://bugzilla.redhat.com/show_bug.cgi?id$0770
> 
> It was created because udev rules could not see the spec_id of the
> devices and we wanted to selectively chgrp iidc and avc devices to the
> console owner.  Thus, this script would create named symlinks and then
> udev could simply chgrp based on the filename.
> 
> Now that ACLs are used in Fedora for dealing with console ownership,
> this script and its udev rule are probably not very useful to anyone.

So, to summarize the need of symlink rules:

   - We don't need symlinks (aliases) for application support,
     neither type-oriented aliases, nor persistently named aliases.

   - Symlinks may be needed to fit the firewire device files into a
     distro's file permissions scheme though.  (This was actually the
     intent behind redhat/40-redhat.rules, which wasn't apparent to
     me when I read the rules files out of context.)

Ergo, there may be distro-specific symlinks but applications/libraries 
will not rely on any of those.  (Right?)
-- 
Stefan Richter
-===-=--- =--- =-=-http://arcgraph.de/sr/