Quoting Aditya Kali (adityakali@xxxxxxxxxx): > On Thu, Oct 16, 2014 at 2:12 PM, Serge E. Hallyn <serge@xxxxxxxxxx> wrote: > > Quoting Aditya Kali (adityakali@xxxxxxxxxx): > >> setns on a cgroup namespace is allowed only if > >> * task has CAP_SYS_ADMIN in its current user-namespace and > >> over the user-namespace associated with target cgroupns. > >> * task's current cgroup is descendent of the target cgroupns-root > >> cgroup. > > > > What is the point of this? > > > > If I'm a user logged into > > /lxc/c1/user.slice/user-1000.slice/session-c12.scope and I start > > a container which is in > > /lxc/c1/user.slice/user-1000.slice/session-c12.scope/x1 > > then I will want to be able to enter the container's cgroup. > > The container's cgroup root is under my own (satisfying the > > below condition0 but my cgroup is not a descendent of the > > container's cgroup. > > > This condition is there because we don't want to do implicit cgroup > changes when a process attaches to another cgroupns. cgroupns tries to > preserve the invariant that at any point, your current cgroup is > always under the cgroupns-root of your cgroup namespace. But in your > example, if we allow a process in "session-c12.scope" container to > attach to cgroupns root'ed at "session-c12.scope/x1" container > (without implicitly moving its cgroup), then this invariant won't > hold. Oh, I see. Guess that should be workable. Thanks. -serge -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
