[no subject]

From: Tejun Heo
Date: Fri Aug 11 2017 - 08:49:01 EST


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@xxxxxxxxxx>
---
Applied to cgroup/for-4.14.

Thanks.

include/linux/cgroup.h | 24 ++++++++++++++++++++++++
kernel/cgroup/cgroup.c | 23 ++---------------------
2 files changed, 26 insertions(+), 21 deletions(-)

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
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index f5ca55d..c038ccf 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -319,15 +319,6 @@ static void cgroup_idr_remove(struct idr *idr, int id)
spin_unlock_bh(&cgroup_idr_lock);
}

-static 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;
-}
-
static bool cgroup_has_tasks(struct cgroup *cgrp)
{
return cgrp->nr_populated_csets;
@@ -534,22 +525,12 @@ struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgrp,
return css;
}

-static void __maybe_unused cgroup_get(struct cgroup *cgrp)
-{
- css_get(&cgrp->self);
-}
-
static void cgroup_get_live(struct cgroup *cgrp)
{
WARN_ON_ONCE(cgroup_is_dead(cgrp));
css_get(&cgrp->self);
}

-static bool cgroup_tryget(struct cgroup *cgrp)
-{
- return css_tryget(&cgrp->self);
-}
-
struct cgroup_subsys_state *of_css(struct kernfs_open_file *of)
{
struct cgroup *cgrp = of->kn->parent->priv;
@@ -3306,7 +3287,7 @@ static int cgroup_events_show(struct seq_file *seq, void *v)
return 0;
}

-static int cgroup_stats_show(struct seq_file *seq, void *v)
+static int cgroup_stat_show(struct seq_file *seq, void *v)
{
struct cgroup *cgroup = seq_css(seq)->cgroup;

@@ -4423,7 +4404,7 @@ static struct cftype cgroup_base_files[] = {
},
{
.name = "cgroup.stat",
- .seq_show = cgroup_stats_show,
+ .seq_show = cgroup_stat_show,
},
{ } /* terminate */
};
--
2.9.3