cgroup/cpuset: move validate_change_legacy to cpuset-v1.c

The validate_change_legacy functions is used for v1, move it to
cpuset-v1.c. And two micro 'cpuset_for_each_child' and
'cpuset_for_each_descendant_pre' are common for v1 and v2, move them to
cpuset-internal.h.

Signed-off-by: Chen Ridong <[email protected]>
Acked-by: Waiman Long <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>

Author: Chen Ridong

kernel/cgroup/cpuset-internal.h

@@ -238,6 +238,34 @@ static inline int is_spread_slab(const struct cpuset *cs)
 	return test_bit(CS_SPREAD_SLAB, &cs->flags);
 }
 
+/**
+ * cpuset_for_each_child - traverse online children of a cpuset
+ * @child_cs: loop cursor pointing to the current child
+ * @pos_css: used for iteration
+ * @parent_cs: target cpuset to walk children of
+ *
+ * Walk @child_cs through the online children of @parent_cs.  Must be used
+ * with RCU read locked.
+ */
+#define cpuset_for_each_child(child_cs, pos_css, parent_cs)		\
+	css_for_each_child((pos_css), &(parent_cs)->css)		\
+		if (is_cpuset_online(((child_cs) = css_cs((pos_css)))))
+
+/**
+ * cpuset_for_each_descendant_pre - pre-order walk of a cpuset's descendants
+ * @des_cs: loop cursor pointing to the current descendant
+ * @pos_css: used for iteration
+ * @root_cs: target cpuset to walk ancestor of
+ *
+ * Walk @des_cs through the online descendants of @root_cs.  Must be used
+ * with RCU read locked.  The caller may modify @pos_css by calling
+ * css_rightmost_descendant() to skip subtree.  @root_cs is included in the
+ * iteration and the first node to be visited.
+ */
+#define cpuset_for_each_descendant_pre(des_cs, pos_css, root_cs)	\
+	css_for_each_descendant_pre((pos_css), &(root_cs)->css)		\
+		if (is_cpuset_online(((des_cs) = css_cs((pos_css)))))
+
 void rebuild_sched_domains_locked(void);
 void callback_lock_irq(void);
 void callback_unlock_irq(void);
@@ -258,5 +286,6 @@ void update_tasks_flags(struct cpuset *cs);
 void hotplug_update_tasks_legacy(struct cpuset *cs,
 			    struct cpumask *new_cpus, nodemask_t *new_mems,
 			    bool cpus_updated, bool mems_updated);
+int validate_change_legacy(struct cpuset *cur, struct cpuset *trial);
 
 #endif /* __CPUSET_INTERNAL_H */

kernel/cgroup/cpuset-v1.c

@@ -327,3 +327,48 @@ void hotplug_update_tasks_legacy(struct cpuset *cs,
 		schedule_work(&s->work);
 	}
 }
+
+/*
+ * is_cpuset_subset(p, q) - Is cpuset p a subset of cpuset q?
+ *
+ * One cpuset is a subset of another if all its allowed CPUs and
+ * Memory Nodes are a subset of the other, and its exclusive flags
+ * are only set if the other's are set.  Call holding cpuset_mutex.
+ */
+
+static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
+{
+	return	cpumask_subset(p->cpus_allowed, q->cpus_allowed) &&
+		nodes_subset(p->mems_allowed, q->mems_allowed) &&
+		is_cpu_exclusive(p) <= is_cpu_exclusive(q) &&
+		is_mem_exclusive(p) <= is_mem_exclusive(q);
+}
+
+/*
+ * validate_change_legacy() - Validate conditions specific to legacy (v1)
+ *                            behavior.
+ */
+int validate_change_legacy(struct cpuset *cur, struct cpuset *trial)
+{
+	struct cgroup_subsys_state *css;
+	struct cpuset *c, *par;
+	int ret;
+
+	WARN_ON_ONCE(!rcu_read_lock_held());
+
+	/* Each of our child cpusets must be a subset of us */
+	ret = -EBUSY;
+	cpuset_for_each_child(c, css, cur)
+		if (!is_cpuset_subset(c, trial))
+			goto out;
+
+	/* On legacy hierarchy, we must be a subset of our parent cpuset. */
+	ret = -EACCES;
+	par = parent_cs(cur);
+	if (par && !is_cpuset_subset(trial, par))
+		goto out;
+
+	ret = 0;
+out:
+	return ret;
+}

kernel/cgroup/cpuset.c

@@ -186,34 +186,6 @@ static struct cpuset top_cpuset = {
 	.remote_sibling = LIST_HEAD_INIT(top_cpuset.remote_sibling),
 };
 
-/**
- * cpuset_for_each_child - traverse online children of a cpuset
- * @child_cs: loop cursor pointing to the current child
- * @pos_css: used for iteration
- * @parent_cs: target cpuset to walk children of
- *
- * Walk @child_cs through the online children of @parent_cs.  Must be used
- * with RCU read locked.
- */
-#define cpuset_for_each_child(child_cs, pos_css, parent_cs)		\
-	css_for_each_child((pos_css), &(parent_cs)->css)		\
-		if (is_cpuset_online(((child_cs) = css_cs((pos_css)))))
-
-/**
- * cpuset_for_each_descendant_pre - pre-order walk of a cpuset's descendants
- * @des_cs: loop cursor pointing to the current descendant
- * @pos_css: used for iteration
- * @root_cs: target cpuset to walk ancestor of
- *
- * Walk @des_cs through the online descendants of @root_cs.  Must be used
- * with RCU read locked.  The caller may modify @pos_css by calling
- * css_rightmost_descendant() to skip subtree.  @root_cs is included in the
- * iteration and the first node to be visited.
- */
-#define cpuset_for_each_descendant_pre(des_cs, pos_css, root_cs)	\
-	css_for_each_descendant_pre((pos_css), &(root_cs)->css)		\
-		if (is_cpuset_online(((des_cs) = css_cs((pos_css)))))
-
 /*
  * There are two global locks guarding cpuset structures - cpuset_mutex and
  * callback_lock. We also require taking task_lock() when dereferencing a
@@ -409,22 +381,6 @@ static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask)
 	nodes_and(*pmask, cs->effective_mems, node_states[N_MEMORY]);
 }
 
-/*
- * is_cpuset_subset(p, q) - Is cpuset p a subset of cpuset q?
- *
- * One cpuset is a subset of another if all its allowed CPUs and
- * Memory Nodes are a subset of the other, and its exclusive flags
- * are only set if the other's are set.  Call holding cpuset_mutex.
- */
-
-static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
-{
-	return	cpumask_subset(p->cpus_allowed, q->cpus_allowed) &&
-		nodes_subset(p->mems_allowed, q->mems_allowed) &&
-		is_cpu_exclusive(p) <= is_cpu_exclusive(q) &&
-		is_mem_exclusive(p) <= is_mem_exclusive(q);
-}
-
 /**
  * alloc_cpumasks - allocate three cpumasks for cpuset
  * @cs:  the cpuset that have cpumasks to be allocated.
@@ -555,35 +511,6 @@ static inline bool cpusets_are_exclusive(struct cpuset *cs1, struct cpuset *cs2)
 	return true;
 }
 
-/*
- * validate_change_legacy() - Validate conditions specific to legacy (v1)
- *                            behavior.
- */
-static int validate_change_legacy(struct cpuset *cur, struct cpuset *trial)
-{
-	struct cgroup_subsys_state *css;
-	struct cpuset *c, *par;
-	int ret;
-
-	WARN_ON_ONCE(!rcu_read_lock_held());
-
-	/* Each of our child cpusets must be a subset of us */
-	ret = -EBUSY;
-	cpuset_for_each_child(c, css, cur)
-		if (!is_cpuset_subset(c, trial))
-			goto out;
-
-	/* On legacy hierarchy, we must be a subset of our parent cpuset. */
-	ret = -EACCES;
-	par = parent_cs(cur);
-	if (par && !is_cpuset_subset(trial, par))
-		goto out;
-
-	ret = 0;
-out:
-	return ret;
-}
-
 /*
  * validate_change() - Used to validate that any proposed cpuset change
  *		       follows the structural rules for cpusets.