From a31f2d3ff7fe20cbe2a143515a7d7c408b29dd0d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 19 Nov 2012 08:13:37 -0800 Subject: cgroup: introduce CSS_ONLINE flag and on/offline_css() helpers New helpers on/offline_css() respectively wrap ->post_create() and ->pre_destroy() invocations. online_css() sets CSS_ONLINE after ->post_create() is complete and offline_css() invokes ->pre_destroy() iff CSS_ONLINE is set and clears it while also handling the temporary dropping of cgroup_mutex. This patch doesn't introduce any behavior change at the moment but will be used to improve cgroup_create() failure path and allow ->post_create() to fail. Signed-off-by: Tejun Heo Acked-by: Li Zefan --- include/linux/cgroup.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index a0fc64167129..f4a9c9836906 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -82,6 +82,7 @@ struct cgroup_subsys_state { /* bits in struct cgroup_subsys_state flags field */ enum { CSS_ROOT = (1 << 0), /* this CSS is the root of the subsystem */ + CSS_ONLINE = (1 << 1), /* between ->post_create() and ->pre_destroy() */ }; /* Caller must verify that the css is not for root cgroup */ -- cgit v1.2.3