Re: [linux-usb-devel] Re: 2.5.26 hotplug failure

[torvalds@transmeta.com (Linus Torvalds)]

In article <20020921033137.GA26017@kroah.com>, Greg KH  <greg@kroah.com> wrote:
>On Fri, Sep 20, 2002 at 07:55:22PM -0700, David Brownell wrote:
>> 
>> How about a facility to create the character (or block?) special file
>> node right there in the driverfs directory?  Optional of course.
>
>No, Linus has stated that this is not ok to do.  See the lkml archives
>for the whole discussion about this.

I'm not totally against it, it's just that it has some issues:

 - naming policy in general. Trivially handled by just always calling
   the special node something truly boring and nautral like "node", and
   be done with it. The _path_ is the real name, the "node" would be
   just an openable entity.

 - the issue of persistent permissions and ownership. 

The latter is the real problem.  And I personally think the only sane
policy is to just let "/sbin/hotplug" handle it, which definitely
implies _not_ having the kernel create the real device node. That way
user-space can have any policy it damn well pleases, including having
some default heuristics along with "a priori known nodes".

But clearly that user-space hotplug entity needs to know major and minor
numbers in order to create the real device node, and that's where the
"node" thing may be acceptable - as a template, nothing more.  Although
I suspect that there are other, simpler and more acceptable templates
(ie export the dang thing as just a "node" text-file, which describes
the majors and minors and "char vs block" issues)

		Linus