cgroup: misc changes
Misc trivial changes to prepare for future changes. No functional
difference.
* Expose cgroup_get(), cgroup_tryget() and cgroup_parent().
* Implement task_dfl_cgroup() which dereferences css_set->dfl_cgrp.
* Rename cgroup_stats_show() to cgroup_stat_show() for consistency
with the file name.
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 79faa64..085056e 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -398,6 +398,16 @@ static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n)
percpu_ref_put_many(&css->refcnt, n);
}
+static inline void cgroup_get(struct cgroup *cgrp)
+{
+ css_get(&cgrp->self);
+}
+
+static inline bool cgroup_tryget(struct cgroup *cgrp)
+{
+ return css_tryget(&cgrp->self);
+}
+
static inline void cgroup_put(struct cgroup *cgrp)
{
css_put(&cgrp->self);
@@ -510,6 +520,20 @@ static inline struct cgroup *task_cgroup(struct task_struct *task,
return task_css(task, subsys_id)->cgroup;
}
+static inline struct cgroup *task_dfl_cgroup(struct task_struct *task)
+{
+ return task_css_set(task)->dfl_cgrp;
+}
+
+static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
+{
+ struct cgroup_subsys_state *parent_css = cgrp->self.parent;
+
+ if (parent_css)
+ return container_of(parent_css, struct cgroup, self);
+ return NULL;
+}
+
/**
* cgroup_is_descendant - test ancestry
* @cgrp: the cgroup to be tested