Messages in this thread | | | Date | Mon, 5 Nov 2012 13:36:14 +0800 | From | Li Zefan <> | Subject | Re: [PATCH 3/8] cgroup: use cgroup_lock_live_group(parent) in cgroup_create() |
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On 2012/11/1 3:44, Tejun Heo wrote: > This patch makes cgroup_create() fail if @parent is marked removed. > This is to prepare for further updates to cgroup_rmdir() path. > > Note that this change isn't strictly necessary. cgroup can only be > created via mkdir and the removed marking and dentry removal happen > without releasing cgroup_mutex, so cgroup_create() can never race with > cgroup_rmdir(). Even after the scheduled updates to cgroup_rmdir(), > cgroup_mkdir() and cgroup_rmdir() are synchronized by i_mutex > rendering the added liveliness check unnecessary. > > Do it anyway such that locking is contained inside cgroup proper and > we don't get nasty surprises if we ever grow another caller of > cgroup_create(). > > Signed-off-by: Tejun Heo <tj@kernel.org> > Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Li Zefan <lizefan@huawei.com>
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