Messages in this thread | | | Date | Mon, 16 Jul 2012 09:45:27 -0700 | From | Tejun Heo <> | Subject | Re: [PATCH] cgroup: fix dentry still in use bug when dropping css refs after umount |
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Hello,
On Tue, Jul 10, 2012 at 10:11:05AM +0800, Li Zefan wrote: > Right, but that should be safe. The css objects of the root cgroup are > allocated at boot, and won't be destroyed at umount. > > Furthermore when a cgroup hierarchy is going to be unmounted, those css's > will be made to point to a cgroup named dummytop in rebind_subsystems(), > and there's a syncronize_rcu() in the end of the function, so accessing > css->cgroup is always safe. > > In this case, dummytop->dentry is NULL, and that's safe too, because > cgroup_path() is aware of this case.
I see. Thanks for the explanation.
-- tejun
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