Re: [RFC PATCH] fs: call_usermodehelper_root helper introduced

From: Stanislav Kinsbursky
Date: Thu May 23 2013 - 04:11:58 EST


22.05.2013 22:35, Eric W. Biederman пишет:
ebiederm@xxxxxxxxxxxx (Eric W. Biederman) writes:

I am missing a lot of context here and capturing the context of a
process at time time we mount the filesystem and reconstituing it in
call user mode helper seems like something we could do.

If we want to do something like this the only sane thing I can see is to
have a per container version of kthread call it uthread. That the user
mode helper code would use to launch a new process.


The main point here, is that a container can have it's own root, different
to kthread's one (another mount or at least chroot result).

Anything else and I expect we will be tearing our hair out for the rest
of our lives with weird corner cases or unexpected semantics.

At first glace I would exepct uthread to be per pid namespace in
implementation.


Having a per-pidnamespace kernel thread would be really great.
But regrettably doesn't solve the root swapping problem.

Eric




--
Best regards,
Stanislav Kinsbursky
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