[BProc] Re: bproc+autofs: oz_pgrp problem

[hanzl at noel.feld.cvut.cz]

> >     static inline int autofs_oz_mode(struct autofs_sb_info *sbi) {
> >       return sbi->catatonic || current->pgrp == sbi->oz_pgrp;
> >     }
> >     ...
> 
> That should work.  bproc.masq->pgrp is the value returned by getpgrp.
> Make sure you check to make sure that current->bproc.masq is not null
> though.  It's null for all non-remotely managed processes.
> 
> - Erik

I tried this but things are probably different in older bproc used in
linux-2.4.18-lanl.16 which I wanted to fix. However I got working
autofs on node with this in fs/autofs/autofs_i.h:

...
#include <asm/uaccess.h>

/* Added by VH for bproc: */
#include <linux/bproc.h>
...

static inline int autofs_oz_mode(struct autofs_sb_info *sbi) {
/*	return sbi->catatonic || current->pgrp == sbi->oz_pgrp;
 * Changed by Vaclav Hanzl to let it work with bproc:
 */
   return sbi->catatonic ||
     bproc_hook_imv(current->pgrp,sys_getpgrp,()) == sbi->oz_pgrp;
}


I have little idea what it actually means, but it works :)
Any comments welcome, as always.


More exactly, I did this:

- edited /usr/src/linux-2.4.18-lanl.16/fs/autofs/autofs_i.h as
  indicated above

- make xconfig, load configs/kernel-2.4.18-i686.config, save without changes

- make dep

- make modules

- insmod --node 1 -f /usr/src/linux-2.4.18-lanl.16/fs/autofs/autofs.o


Any lover of risky games can take my autofs.o and autofs_i.h here:

  http://noel.feld.cvut.cz/magi/bproc-autofs

and use it at HIS/HER OWN BIG RISK.

>> - Start automount outside the distributed PID space. I am not sure how
>>   to do this, bproc is damn good in not letting you escape :-) - we
>>   could modify /etc/inittab on node and signal init process and have our
>>   automount process created this way?
>
>This is the easiest way to get around the problem although there are
>some drawbacks.  I've been pretty vehement about not providing hooks
>for things like daemons to escape.  The rationale there is basically
>that people would use those hooks if they were there. :)

Good rationale. Keep it. :-))

Little side-effect probably is that most people are not able to run
any daemons on bproc node. :-) But things are getting better...


Regards

Vaclav