[OpenAFS-devel] setgroups() fails to change pag under linux 2.6

[David Thompson]

Roland Kuhn wrote:
>On 9 Aug 2006, at 18:16, chas williams - CONTRACTOR wrote:
>
>> In message <FAE01A19-F876-471F-AB75-AF6D5B9C60DF@e18.physik.tu- 
>> muenchen.de>,Rol
>> and Kuhn writes:
>>> You got me curious. I should probably watched this thread more
>>> closely and maybe it would then be clear to me: Why should userspace
>>> ever see a PAG identifier? What should it be able to do with it?
>>
>> ideally, the userspace would be unaware of the pag and/or be able to
>> read/write it.  however, pags were stored in the group list which was
>> the only thing available at the time.  so users could see the pag and
>> do unwise things.  only root can change the group list so this atleast
>> kept ordinary users from manipulating their group list.
>>
>Okay, so PAG reuse should not be an issue, right? :-) If you do  
>"unwise things", you get to keep the pieces.

The problem (in our eyes) that brought all this up was the relative scarcity 
of pags over the execution time of the kernel.  I would love to have pags made 
invisible, provided that the current restrictions on obtaining them be 
eliminated.  To repeat for emphasis: it is the scarcity of pags, not how they 
are stored, that is the real issue for us.  To make them invisible without 
solving the scarcity problem leaves us with our original problem while taking 
away our workaround.

I would have no desire or need to reuse pags if there were 
"unlimited||sufficient" pags in the first place.  If I could obtain a new pag 
at will, without concern that I'm going to run out of pags or have performance 
issues, I would welcome a solution that would get the current overloading out 
of the group list.

Dave