[RFC][PATCH] Do not set /proc inode->pid for non-pid-related inodes

[Eric W. Biederman]

Cedric Le Goater <clg at fr.ibm.com> writes:

> Eric W. Biederman wrote:
>> "Serge E. Hallyn" <serue at us.ibm.com> writes:
>> 
>>> So how do you see us enforcing pid1's existance?  Somehow keep it from
>>> fully exiting, or just kill all the processes in it's namespace if it
>>> exits?
>
> what about a kthread that would be spawned when a task is cloned in an 
> unshared pid namespace ? This is an extra cost in term of tasks.

If you use kernel_thread this can happen. (Die kernel_thread).
If you use the kthread interface keventd will be the parent process and
we won't have problems.  Thus most users of kernel_thread need to be fixed
to use the kthread interface.

Thanks for the reminder of this one, I had forgotten that bit of
reasoning for updating kernel_thread users.

>> Killing all other processes in the namespace when pid1 exits is what
>> I implemented last time around.
>
> this looks like a sane thing to do.

Eric