cgroup: rename css_tryget*() to css_tryget_online*()

[karo-tx-linux.git] / kernel / cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 7633703e9baf324e750412612fcb6f4bb70c2083..671d8a6dae37e011ea812ee6a6304c1bd633161e 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3771,7 +3771,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
 
        /*
         * We aren't being called from kernfs and there's no guarantee on
-        * @kn->priv's validity.  For this and css_tryget_from_dir(),
+        * @kn->priv's validity.  For this and css_tryget_online_from_dir(),
         * @kn->priv is RCU safe.  Let's do the RCU dancing.
         */
        rcu_read_lock();
@@ -4060,9 +4060,9 @@ err:
  *    Implemented in kill_css().
  *
  * 2. When the percpu_ref is confirmed to be visible as killed on all CPUs
- *    and thus css_tryget() is guaranteed to fail, the css can be offlined
- *    by invoking offline_css().  After offlining, the base ref is put.
- *    Implemented in css_killed_work_fn().
+ *    and thus css_tryget_online() is guaranteed to fail, the css can be
+ *    offlined by invoking offline_css().  After offlining, the base ref is
+ *    put.  Implemented in css_killed_work_fn().
  *
  * 3. When the percpu_ref reaches zero, the only possible remaining
  *    accessors are inside RCU read sections.  css_release() schedules the
@@ -4386,7 +4386,7 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
 
 /*
  * This is called when the refcnt of a css is confirmed to be killed.
- * css_tryget() is now guaranteed to fail.
+ * css_tryget_online() is now guaranteed to fail.
  */
 static void css_killed_work_fn(struct work_struct *work)
 {
@@ -4398,8 +4398,8 @@ static void css_killed_work_fn(struct work_struct *work)
        mutex_lock(&cgroup_mutex);
 
        /*
-        * css_tryget() is guaranteed to fail now.  Tell subsystems to
-        * initate destruction.
+        * css_tryget_online() is guaranteed to fail now.  Tell subsystems
+        * to initate destruction.
         */
        offline_css(css);
 
@@ -4440,8 +4440,8 @@ static void css_killed_ref_fn(struct percpu_ref *ref)
  *
  * This function initiates destruction of @css by removing cgroup interface
  * files and putting its base reference.  ->css_offline() will be invoked
- * asynchronously once css_tryget() is guaranteed to fail and when the
- * reference count reaches zero, @css will be released.
+ * asynchronously once css_tryget_online() is guaranteed to fail and when
+ * the reference count reaches zero, @css will be released.
  */
 static void kill_css(struct cgroup_subsys_state *css)
 {
@@ -4462,7 +4462,7 @@ static void kill_css(struct cgroup_subsys_state *css)
        /*
         * cgroup core guarantees that, by the time ->css_offline() is
         * invoked, no new css reference will be given out via
-        * css_tryget().  We can't simply call percpu_ref_kill() and
+        * css_tryget_online().  We can't simply call percpu_ref_kill() and
         * proceed to offlining css's because percpu_ref_kill() doesn't
         * guarantee that the ref is seen as killed on all CPUs on return.
         *
@@ -4478,9 +4478,9 @@ static void kill_css(struct cgroup_subsys_state *css)
  *
  * css's make use of percpu refcnts whose killing latency shouldn't be
  * exposed to userland and are RCU protected.  Also, cgroup core needs to
- * guarantee that css_tryget() won't succeed by the time ->css_offline() is
- * invoked.  To satisfy all the requirements, destruction is implemented in
- * the following two steps.
+ * guarantee that css_tryget_online() won't succeed by the time
+ * ->css_offline() is invoked.  To satisfy all the requirements,
+ * destruction is implemented in the following two steps.
  *
  * s1. Verify @cgrp can be destroyed and mark it dying.  Remove all
  *     userland visible parts and start killing the percpu refcnts of
@@ -4574,9 +4574,9 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
        /*
         * There are two control paths which try to determine cgroup from
         * dentry without going through kernfs - cgroupstats_build() and
-        * css_tryget_from_dir().  Those are supported by RCU protecting
-        * clearing of cgrp->kn->priv backpointer, which should happen
-        * after all files under it have been removed.
+        * css_tryget_online_from_dir().  Those are supported by RCU
+        * protecting clearing of cgrp->kn->priv backpointer, which should
+        * happen after all files under it have been removed.
         */
        kernfs_remove(cgrp->kn);        /* @cgrp has an extra ref on its kn */
        RCU_INIT_POINTER(*(void __rcu __force **)&cgrp->kn->priv, NULL);
@@ -5173,7 +5173,7 @@ static int __init cgroup_disable(char *str)
 __setup("cgroup_disable=", cgroup_disable);
 
 /**
- * css_tryget_from_dir - get corresponding css from the dentry of a cgroup dir
+ * css_tryget_online_from_dir - get corresponding css from a cgroup dentry
  * @dentry: directory dentry of interest
  * @ss: subsystem of interest
  *
@@ -5181,8 +5181,8 @@ __setup("cgroup_disable=", cgroup_disable);
  * to get the corresponding css and return it.  If such css doesn't exist
  * or can't be pinned, an ERR_PTR value is returned.
  */
-struct cgroup_subsys_state *css_tryget_from_dir(struct dentry *dentry,
-                                               struct cgroup_subsys *ss)
+struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
+                                                      struct cgroup_subsys *ss)
 {
        struct kernfs_node *kn = kernfs_node_from_dentry(dentry);
        struct cgroup_subsys_state *css = NULL;
@@ -5204,7 +5204,7 @@ struct cgroup_subsys_state *css_tryget_from_dir(struct dentry *dentry,
        if (cgrp)
                css = cgroup_css(cgrp, ss);
 
-       if (!css || !css_tryget(css))
+       if (!css || !css_tryget_online(css))
                css = ERR_PTR(-ENOENT);
 
        rcu_read_unlock();