cgroup: add css_parent()

Currently, controllers have to explicitly follow the cgroup hierarchy to find the parent of a given css. cgroup is moving towards using cgroup_subsys_state as the main controller interface construct, so let's provide a way to climb the hierarchy using just csses. This patch implements css_parent() which, given a css, returns its parent. The function is guarnateed to valid non-NULL parent css as long as the target css is not at the top of the hierarchy. freezer, cpuset, cpu, cpuacct, hugetlb, memory, net_cls and devices are converted to use css_parent() instead of accessing cgroup->parent directly. * __parent_ca() is dropped from cpuacct and its usage is replaced with parent_ca(). The only difference between the two was NULL test on cgroup->parent which is now embedded in css_parent() making the distinction moot. Note that eventually a css->parent field will be added to css and the NULL check in css_parent() will go away. This patch shouldn't cause any behavior differences. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
author: Tejun Heo <tj@kernel.org> 2013-08-08 20:11:23 -0400
committer: Tejun Heo <tj@kernel.org> 2013-08-08 20:11:23 -0400
commit: 6387698699afd72d6304566fb6ccf84bffe07c56 (patch)
tree: 9440e96fa8e5adce62409a5b0e40984dfedaada3
parent: a7c6d554aa01236ac2a9f851ab0f75704f76dfa2 (diff)
10 files changed, 46 insertions, 78 deletions
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 8e5863e900bf..b6802c46d68f 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -209,9 +209,7 @@ static inline struct blkcg *bio_blkcg(struct bio *bio)
 */
 static inline struct blkcg *blkcg_parent(struct blkcg *blkcg)
 {
-        struct cgroup *pcg = blkcg->css.cgroup->parent;
+        return css_to_blkcg(css_parent(&blkcg->css));
-        return pcg ? cgroup_to_blkcg(pcg) : NULL;
 }
 /**
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 821678aae4db..18112a3bb12b 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -647,6 +647,21 @@ struct cgroup_subsys {
 #undef SUBSYS
 /**
+ * css_parent - find the parent css
+ * @css: the target cgroup_subsys_state
+ *
+ * Return the parent css of @css.  This function is guaranteed to return
+ * non-NULL parent as long as @css isn't the root.
+ */
+static inline
+struct cgroup_subsys_state *css_parent(struct cgroup_subsys_state *css)
+{
+        struct cgroup *parent_cgrp = css->cgroup->parent;
+        return parent_cgrp ? parent_cgrp->subsys[css->ss->subsys_id] : NULL;
+}
+/**
 * cgroup_css - obtain a cgroup's css for the specified subsystem
 * @cgrp: the cgroup of interest
 * @subsys_id: the subsystem of interest
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 1db686e47a22..657a73cd44c4 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -62,11 +62,7 @@ static inline struct freezer *task_freezer(struct task_struct *task)
 static struct freezer *parent_freezer(struct freezer *freezer)
 {
-        struct cgroup *pcg = freezer->css.cgroup->parent;
+        return css_freezer(css_parent(&freezer->css));
-        if (pcg)
-                return cgroup_freezer(pcg);
-        return NULL;
 }
 bool cgroup_freezing(struct task_struct *task)
@@ -234,7 +230,7 @@ static void freezer_fork(struct task_struct *task)
         * The root cgroup is non-freezable, so we can skip the
         * following check.
         */
-        if (!freezer->css.cgroup->parent)
+        if (!parent_freezer(freezer))
                goto out;
        spin_lock_irq(&freezer->lock);
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 6e9cbdde25bd..259a4af37e69 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -133,11 +133,7 @@ static inline struct cpuset *task_cs(struct task_struct *task)
 static inline struct cpuset *parent_cs(struct cpuset *cs)
 {
-        struct cgroup *pcgrp = cs->css.cgroup->parent;
+        return css_cs(css_parent(&cs->css));
-        if (pcgrp)
-                return cgroup_cs(pcgrp);
-        return NULL;
 }
 #ifdef CONFIG_NUMA
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5bccb0277129..7a10742b389a 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7114,13 +7114,10 @@ static struct cgroup_subsys_state *cpu_cgroup_css_alloc(struct cgroup *cgrp)
 static int cpu_cgroup_css_online(struct cgroup *cgrp)
 {
        struct task_group *tg = cgroup_tg(cgrp);
-        struct task_group *parent;
+        struct task_group *parent = css_tg(css_parent(&tg->css));
-        if (!cgrp->parent)
+        if (parent)
-                return 0;
+                sched_online_group(tg, parent);
-        parent = cgroup_tg(cgrp->parent);
-        sched_online_group(tg, parent);
        return 0;
 }
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 8ccfa10cc89f..f6926a149a71 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -50,16 +50,9 @@ static inline struct cpuacct *task_ca(struct task_struct *tsk)
        return css_ca(task_css(tsk, cpuacct_subsys_id));
 }
-static inline struct cpuacct *__parent_ca(struct cpuacct *ca)
-{
-        return cgroup_ca(ca->css.cgroup->parent);
-}
 static inline struct cpuacct *parent_ca(struct cpuacct *ca)
 {
-        if (!ca->css.cgroup->parent)
+        return css_ca(css_parent(&ca->css));
-                return NULL;
-        return cgroup_ca(ca->css.cgroup->parent);
 }
 static DEFINE_PER_CPU(u64, root_cpuacct_cpuusage);
@@ -284,7 +277,7 @@ void cpuacct_account_field(struct task_struct *p, int index, u64 val)
        while (ca != &root_cpuacct) {
                kcpustat = this_cpu_ptr(ca->cpustat);
                kcpustat->cpustat[index] += val;
-                ca = __parent_ca(ca);
+                ca = parent_ca(ca);
        }
        rcu_read_unlock();
 }
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index 95585a0b9c8d..57ecb5d2513f 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -59,11 +59,7 @@ static inline bool hugetlb_cgroup_is_root(struct hugetlb_cgroup *h_cg)
 static inline struct hugetlb_cgroup *
 parent_hugetlb_cgroup(struct hugetlb_cgroup *h_cg)
 {
-        struct cgroup *parent = h_cg->css.cgroup->parent;
+        return hugetlb_cgroup_from_css(css_parent(&h_cg->css));
-        if (!parent)
-                return NULL;
-        return hugetlb_cgroup_from_cgroup(parent);
 }
 static inline bool hugetlb_cgroup_have_usage(struct hugetlb_cgroup *h_cg)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 11d659e3b08e..69b3e520f921 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1524,10 +1524,8 @@ static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
 int mem_cgroup_swappiness(struct mem_cgroup *memcg)
 {
-        struct cgroup *cgrp = memcg->css.cgroup;
        /* root ? */
-        if (cgrp->parent == NULL)
+        if (!css_parent(&memcg->css))
                return vm_swappiness;
        return memcg->swappiness;
@@ -5026,11 +5024,7 @@ static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
 {
        int retval = 0;
        struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
-        struct cgroup *parent = cont->parent;
+        struct mem_cgroup *parent_memcg = mem_cgroup_from_css(css_parent(&memcg->css));
-        struct mem_cgroup *parent_memcg = NULL;
-        if (parent)
-                parent_memcg = mem_cgroup_from_cont(parent);
        mutex_lock(&memcg_create_mutex);
@@ -5282,18 +5276,15 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
 static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
                unsigned long long *mem_limit, unsigned long long *memsw_limit)
 {
-        struct cgroup *cgroup;
        unsigned long long min_limit, min_memsw_limit, tmp;
        min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
        min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
-        cgroup = memcg->css.cgroup;
        if (!memcg->use_hierarchy)
                goto out;
-        while (cgroup->parent) {
+        while (css_parent(&memcg->css)) {
-                cgroup = cgroup->parent;
+                memcg = mem_cgroup_from_css(css_parent(&memcg->css));
-                memcg = mem_cgroup_from_cont(cgroup);
                if (!memcg->use_hierarchy)
                        break;
                tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
@@ -5523,16 +5514,11 @@ static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
                                       u64 val)
 {
        struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
-        struct mem_cgroup *parent;
+        struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
-        if (val > 100)
-                return -EINVAL;
-        if (cgrp->parent == NULL)
+        if (val > 100 || !parent)
                return -EINVAL;
-        parent = mem_cgroup_from_cont(cgrp->parent);
        mutex_lock(&memcg_create_mutex);
        /* If under hierarchy, only empty-root can set this value */
@@ -5861,14 +5847,12 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
        struct cftype *cft, u64 val)
 {
        struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
-        struct mem_cgroup *parent;
+        struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
        /* cannot set to root cgroup and only 0 and 1 are allowed */
-        if (!cgrp->parent || !((val == 0) || (val == 1)))
+        if (!parent || !((val == 0) || (val == 1)))
                return -EINVAL;
-        parent = mem_cgroup_from_cont(cgrp->parent);
        mutex_lock(&memcg_create_mutex);
        /* oom-kill-disable is a flag for subhierarchy. */
        if ((parent->use_hierarchy) || memcg_has_children(memcg)) {
@@ -6266,15 +6250,14 @@ free_out:
 static int
 mem_cgroup_css_online(struct cgroup *cont)
 {
-        struct mem_cgroup *memcg, *parent;
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+        struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
        int error = 0;
-        if (!cont->parent)
+        if (!parent)
                return 0;
        mutex_lock(&memcg_create_mutex);
-        memcg = mem_cgroup_from_cont(cont);
-        parent = mem_cgroup_from_cont(cont->parent);
        memcg->use_hierarchy = parent->use_hierarchy;
        memcg->oom_kill_disable = parent->oom_kill_disable;
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index af412ab2b477..9e6b75e5efce 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -50,9 +50,11 @@ static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp)
 static int cgrp_css_online(struct cgroup *cgrp)
 {
-        if (cgrp->parent)
+        struct cgroup_cls_state *cs = cgrp_cls_state(cgrp);
-                cgrp_cls_state(cgrp)->classid =
+        struct cgroup_cls_state *parent = css_cls_state(css_parent(&cs->css));
-                        cgrp_cls_state(cgrp->parent)->classid;
+        if (parent)
+                cs->classid = parent->classid;
        return 0;
 }
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 90953648c643..635a49db005d 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -198,13 +198,11 @@ static inline bool is_devcg_online(const struct dev_cgroup *devcg)
 */
 static int devcgroup_online(struct cgroup *cgroup)
 {
-        struct dev_cgroup *dev_cgroup, *parent_dev_cgroup = NULL;
+        struct dev_cgroup *dev_cgroup = cgroup_to_devcgroup(cgroup);
+        struct dev_cgroup *parent_dev_cgroup = css_to_devcgroup(css_parent(&dev_cgroup->css));
        int ret = 0;
        mutex_lock(&devcgroup_mutex);
-        dev_cgroup = cgroup_to_devcgroup(cgroup);
-        if (cgroup->parent)
-                parent_dev_cgroup = cgroup_to_devcgroup(cgroup->parent);
        if (parent_dev_cgroup == NULL)
                dev_cgroup->behavior = DEVCG_DEFAULT_ALLOW;
@@ -394,12 +392,10 @@ static bool may_access(struct dev_cgroup *dev_cgroup,
 static int parent_has_perm(struct dev_cgroup *childcg,
                                  struct dev_exception_item *ex)
 {
-        struct cgroup *pcg = childcg->css.cgroup->parent;
+        struct dev_cgroup *parent = css_to_devcgroup(css_parent(&childcg->css));
-        struct dev_cgroup *parent;
-        if (!pcg)
+        if (!parent)
                return 1;
-        parent = cgroup_to_devcgroup(pcg);
        return may_access(parent, ex, childcg->behavior);
 }
@@ -524,15 +520,11 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup,
        char temp[12];          /* 11 + 1 characters needed for a u32 */
        int count, rc = 0;
        struct dev_exception_item ex;
-        struct cgroup *p = devcgroup->css.cgroup;
+        struct dev_cgroup *parent = css_to_devcgroup(css_parent(&devcgroup->css));
-        struct dev_cgroup *parent = NULL;
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
-        if (p->parent)
-                parent = cgroup_to_devcgroup(p->parent);
        memset(&ex, 0, sizeof(ex));
        b = buffer;
author	Tejun Heo <tj@kernel.org>	2013-08-08 20:11:23 -0400
committer	Tejun Heo <tj@kernel.org>	2013-08-08 20:11:23 -0400
commit	6387698699afd72d6304566fb6ccf84bffe07c56 (patch)
tree	9440e96fa8e5adce62409a5b0e40984dfedaada3
parent	a7c6d554aa01236ac2a9f851ab0f75704f76dfa2 (diff)

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 8e5863e900bf..b6802c46d68f 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h
@@ -209,9 +209,7 @@ static inline struct blkcg bio_blkcg(struct bio bio)
209	*/	209	*/
210	static inline struct blkcg blkcg_parent(struct blkcg blkcg)	210	static inline struct blkcg blkcg_parent(struct blkcg blkcg)
211	{	211	{
212	struct cgroup *pcg = blkcg->css.cgroup->parent;	212	return css_to_blkcg(css_parent(&blkcg->css));
213
214	return pcg ? cgroup_to_blkcg(pcg) : NULL;
215	}	213	}
216		214
217	/**	215	/**


diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 821678aae4db..18112a3bb12b 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h
@@ -647,6 +647,21 @@ struct cgroup_subsys {
647	#undef SUBSYS	647	#undef SUBSYS
648		648
649	/**	649	/**
		650	* css_parent - find the parent css
		651	* @css: the target cgroup_subsys_state
		652	*
		653	* Return the parent css of @css. This function is guaranteed to return
		654	* non-NULL parent as long as @css isn't the root.
		655	*/
		656	static inline
		657	struct cgroup_subsys_state css_parent(struct cgroup_subsys_state css)
		658	{
		659	struct cgroup *parent_cgrp = css->cgroup->parent;
		660
		661	return parent_cgrp ? parent_cgrp->subsys[css->ss->subsys_id] : NULL;
		662	}
		663
		664	/**
650	* cgroup_css - obtain a cgroup's css for the specified subsystem	665	* cgroup_css - obtain a cgroup's css for the specified subsystem
651	* @cgrp: the cgroup of interest	666	* @cgrp: the cgroup of interest
652	* @subsys_id: the subsystem of interest	667	* @subsys_id: the subsystem of interest


diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index 1db686e47a22..657a73cd44c4 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c
@@ -62,11 +62,7 @@ static inline struct freezer task_freezer(struct task_struct task)
62		62
63	static struct freezer parent_freezer(struct freezer freezer)	63	static struct freezer parent_freezer(struct freezer freezer)
64	{	64	{
65	struct cgroup *pcg = freezer->css.cgroup->parent;	65	return css_freezer(css_parent(&freezer->css));
66
67	if (pcg)
68	return cgroup_freezer(pcg);
69	return NULL;
70	}	66	}
71		67
72	bool cgroup_freezing(struct task_struct *task)	68	bool cgroup_freezing(struct task_struct *task)
@@ -234,7 +230,7 @@ static void freezer_fork(struct task_struct *task)
234	* The root cgroup is non-freezable, so we can skip the	230	* The root cgroup is non-freezable, so we can skip the
235	* following check.	231	* following check.
236	*/	232	*/
237	if (!freezer->css.cgroup->parent)	233	if (!parent_freezer(freezer))
238	goto out;	234	goto out;
239		235
240	spin_lock_irq(&freezer->lock);	236	spin_lock_irq(&freezer->lock);


diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 6e9cbdde25bd..259a4af37e69 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c
@@ -133,11 +133,7 @@ static inline struct cpuset task_cs(struct task_struct task)
133		133
134	static inline struct cpuset parent_cs(struct cpuset cs)	134	static inline struct cpuset parent_cs(struct cpuset cs)
135	{	135	{
136	struct cgroup *pcgrp = cs->css.cgroup->parent;	136	return css_cs(css_parent(&cs->css));
137
138	if (pcgrp)
139	return cgroup_cs(pcgrp);
140	return NULL;
141	}	137	}
142		138
143	#ifdef CONFIG_NUMA	139	#ifdef CONFIG_NUMA


diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5bccb0277129..7a10742b389a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c
@@ -7114,13 +7114,10 @@ static struct cgroup_subsys_state cpu_cgroup_css_alloc(struct cgroup cgrp)
7114	static int cpu_cgroup_css_online(struct cgroup *cgrp)	7114	static int cpu_cgroup_css_online(struct cgroup *cgrp)
7115	{	7115	{
7116	struct task_group *tg = cgroup_tg(cgrp);	7116	struct task_group *tg = cgroup_tg(cgrp);
7117	struct task_group *parent;	7117	struct task_group *parent = css_tg(css_parent(&tg->css));
7118		7118
7119	if (!cgrp->parent)	7119	if (parent)
7120	return 0;	7120	sched_online_group(tg, parent);
7121
7122	parent = cgroup_tg(cgrp->parent);
7123	sched_online_group(tg, parent);
7124	return 0;	7121	return 0;
7125	}	7122	}
7126		7123


diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index 8ccfa10cc89f..f6926a149a71 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c
@@ -50,16 +50,9 @@ static inline struct cpuacct task_ca(struct task_struct tsk)
50	return css_ca(task_css(tsk, cpuacct_subsys_id));	50	return css_ca(task_css(tsk, cpuacct_subsys_id));
51	}	51	}
52		52
53	static inline struct cpuacct __parent_ca(struct cpuacct ca)
54	{
55	return cgroup_ca(ca->css.cgroup->parent);
56	}
57
58	static inline struct cpuacct parent_ca(struct cpuacct ca)	53	static inline struct cpuacct parent_ca(struct cpuacct ca)
59	{	54	{
60	if (!ca->css.cgroup->parent)	55	return css_ca(css_parent(&ca->css));
61	return NULL;
62	return cgroup_ca(ca->css.cgroup->parent);
63	}	56	}
64		57
65	static DEFINE_PER_CPU(u64, root_cpuacct_cpuusage);	58	static DEFINE_PER_CPU(u64, root_cpuacct_cpuusage);
@@ -284,7 +277,7 @@ void cpuacct_account_field(struct task_struct *p, int index, u64 val)
284	while (ca != &root_cpuacct) {	277	while (ca != &root_cpuacct) {
285	kcpustat = this_cpu_ptr(ca->cpustat);	278	kcpustat = this_cpu_ptr(ca->cpustat);
286	kcpustat->cpustat[index] += val;	279	kcpustat->cpustat[index] += val;
287	ca = __parent_ca(ca);	280	ca = parent_ca(ca);
288	}	281	}
289	rcu_read_unlock();	282	rcu_read_unlock();
290	}	283	}


diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index 95585a0b9c8d..57ecb5d2513f 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c
@@ -59,11 +59,7 @@ static inline bool hugetlb_cgroup_is_root(struct hugetlb_cgroup *h_cg)
59	static inline struct hugetlb_cgroup *	59	static inline struct hugetlb_cgroup *
60	parent_hugetlb_cgroup(struct hugetlb_cgroup *h_cg)	60	parent_hugetlb_cgroup(struct hugetlb_cgroup *h_cg)
61	{	61	{
62	struct cgroup *parent = h_cg->css.cgroup->parent;	62	return hugetlb_cgroup_from_css(css_parent(&h_cg->css));
63
64	if (!parent)
65	return NULL;
66	return hugetlb_cgroup_from_cgroup(parent);
67	}	63	}
68		64
69	static inline bool hugetlb_cgroup_have_usage(struct hugetlb_cgroup *h_cg)	65	static inline bool hugetlb_cgroup_have_usage(struct hugetlb_cgroup *h_cg)


diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 11d659e3b08e..69b3e520f921 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c
@@ -1524,10 +1524,8 @@ static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
1524		1524
1525	int mem_cgroup_swappiness(struct mem_cgroup *memcg)	1525	int mem_cgroup_swappiness(struct mem_cgroup *memcg)
1526	{	1526	{
1527	struct cgroup *cgrp = memcg->css.cgroup;
1528
1529	/* root ? */	1527	/* root ? */
1530	if (cgrp->parent == NULL)	1528	if (!css_parent(&memcg->css))
1531	return vm_swappiness;	1529	return vm_swappiness;
1532		1530
1533	return memcg->swappiness;	1531	return memcg->swappiness;
@@ -5026,11 +5024,7 @@ static int mem_cgroup_hierarchy_write(struct cgroup cont, struct cftype cft,
5026	{	5024	{
5027	int retval = 0;	5025	int retval = 0;
5028	struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);	5026	struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
5029	struct cgroup *parent = cont->parent;	5027	struct mem_cgroup *parent_memcg = mem_cgroup_from_css(css_parent(&memcg->css));
5030	struct mem_cgroup *parent_memcg = NULL;
5031
5032	if (parent)
5033	parent_memcg = mem_cgroup_from_cont(parent);
5034		5028
5035	mutex_lock(&memcg_create_mutex);	5029	mutex_lock(&memcg_create_mutex);
5036		5030
@@ -5282,18 +5276,15 @@ static int mem_cgroup_write(struct cgroup cont, struct cftype cft,
5282	static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,	5276	static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
5283	unsigned long long mem_limit, unsigned long long memsw_limit)	5277	unsigned long long mem_limit, unsigned long long memsw_limit)
5284	{	5278	{
5285	struct cgroup *cgroup;
5286	unsigned long long min_limit, min_memsw_limit, tmp;	5279	unsigned long long min_limit, min_memsw_limit, tmp;
5287		5280
5288	min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);	5281	min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
5289	min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);	5282	min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
5290	cgroup = memcg->css.cgroup;
5291	if (!memcg->use_hierarchy)	5283	if (!memcg->use_hierarchy)
5292	goto out;	5284	goto out;
5293		5285
5294	while (cgroup->parent) {	5286	while (css_parent(&memcg->css)) {
5295	cgroup = cgroup->parent;	5287	memcg = mem_cgroup_from_css(css_parent(&memcg->css));
5296	memcg = mem_cgroup_from_cont(cgroup);
5297	if (!memcg->use_hierarchy)	5288	if (!memcg->use_hierarchy)
5298	break;	5289	break;
5299	tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);	5290	tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
@@ -5523,16 +5514,11 @@ static int mem_cgroup_swappiness_write(struct cgroup cgrp, struct cftype cft,
5523	u64 val)	5514	u64 val)
5524	{	5515	{
5525	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);	5516	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
5526	struct mem_cgroup *parent;	5517	struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
5527
5528	if (val > 100)
5529	return -EINVAL;
5530		5518
5531	if (cgrp->parent == NULL)	5519	if (val > 100 \|\| !parent)
5532	return -EINVAL;	5520	return -EINVAL;
5533		5521
5534	parent = mem_cgroup_from_cont(cgrp->parent);
5535
5536	mutex_lock(&memcg_create_mutex);	5522	mutex_lock(&memcg_create_mutex);
5537		5523
5538	/* If under hierarchy, only empty-root can set this value */	5524	/* If under hierarchy, only empty-root can set this value */
@@ -5861,14 +5847,12 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
5861	struct cftype *cft, u64 val)	5847	struct cftype *cft, u64 val)
5862	{	5848	{
5863	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);	5849	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
5864	struct mem_cgroup *parent;	5850	struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
5865		5851
5866	/* cannot set to root cgroup and only 0 and 1 are allowed */	5852	/* cannot set to root cgroup and only 0 and 1 are allowed */
5867	if (!cgrp->parent \|\| !((val == 0) \|\| (val == 1)))	5853	if (!parent \|\| !((val == 0) \|\| (val == 1)))
5868	return -EINVAL;	5854	return -EINVAL;
5869		5855
5870	parent = mem_cgroup_from_cont(cgrp->parent);
5871
5872	mutex_lock(&memcg_create_mutex);	5856	mutex_lock(&memcg_create_mutex);
5873	/* oom-kill-disable is a flag for subhierarchy. */	5857	/* oom-kill-disable is a flag for subhierarchy. */
5874	if ((parent->use_hierarchy) \|\| memcg_has_children(memcg)) {	5858	if ((parent->use_hierarchy) \|\| memcg_has_children(memcg)) {
@@ -6266,15 +6250,14 @@ free_out:
6266	static int	6250	static int
6267	mem_cgroup_css_online(struct cgroup *cont)	6251	mem_cgroup_css_online(struct cgroup *cont)
6268	{	6252	{
6269	struct mem_cgroup memcg, parent;	6253	struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
		6254	struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
6270	int error = 0;	6255	int error = 0;
6271		6256
6272	if (!cont->parent)	6257	if (!parent)
6273	return 0;	6258	return 0;
6274		6259
6275	mutex_lock(&memcg_create_mutex);	6260	mutex_lock(&memcg_create_mutex);
6276	memcg = mem_cgroup_from_cont(cont);
6277	parent = mem_cgroup_from_cont(cont->parent);
6278		6261
6279	memcg->use_hierarchy = parent->use_hierarchy;	6262	memcg->use_hierarchy = parent->use_hierarchy;
6280	memcg->oom_kill_disable = parent->oom_kill_disable;	6263	memcg->oom_kill_disable = parent->oom_kill_disable;


diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c index af412ab2b477..9e6b75e5efce 100644 --- a/net/sched/cls_cgroup.c +++ b/net/sched/cls_cgroup.c
@@ -50,9 +50,11 @@ static struct cgroup_subsys_state cgrp_css_alloc(struct cgroup cgrp)
50		50
51	static int cgrp_css_online(struct cgroup *cgrp)	51	static int cgrp_css_online(struct cgroup *cgrp)
52	{	52	{
53	if (cgrp->parent)	53	struct cgroup_cls_state *cs = cgrp_cls_state(cgrp);
54	cgrp_cls_state(cgrp)->classid =	54	struct cgroup_cls_state *parent = css_cls_state(css_parent(&cs->css));
55	cgrp_cls_state(cgrp->parent)->classid;	55
		56	if (parent)
		57	cs->classid = parent->classid;
56	return 0;	58	return 0;
57	}	59	}
58		60


diff --git a/security/device_cgroup.c b/security/device_cgroup.c index 90953648c643..635a49db005d 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c
@@ -198,13 +198,11 @@ static inline bool is_devcg_online(const struct dev_cgroup *devcg)
198	*/	198	*/
199	static int devcgroup_online(struct cgroup *cgroup)	199	static int devcgroup_online(struct cgroup *cgroup)
200	{	200	{
201	struct dev_cgroup dev_cgroup, parent_dev_cgroup = NULL;	201	struct dev_cgroup *dev_cgroup = cgroup_to_devcgroup(cgroup);
		202	struct dev_cgroup *parent_dev_cgroup = css_to_devcgroup(css_parent(&dev_cgroup->css));
202	int ret = 0;	203	int ret = 0;
203		204
204	mutex_lock(&devcgroup_mutex);	205	mutex_lock(&devcgroup_mutex);
205	dev_cgroup = cgroup_to_devcgroup(cgroup);
206	if (cgroup->parent)
207	parent_dev_cgroup = cgroup_to_devcgroup(cgroup->parent);
208		206
209	if (parent_dev_cgroup == NULL)	207	if (parent_dev_cgroup == NULL)
210	dev_cgroup->behavior = DEVCG_DEFAULT_ALLOW;	208	dev_cgroup->behavior = DEVCG_DEFAULT_ALLOW;
@@ -394,12 +392,10 @@ static bool may_access(struct dev_cgroup *dev_cgroup,
394	static int parent_has_perm(struct dev_cgroup *childcg,	392	static int parent_has_perm(struct dev_cgroup *childcg,
395	struct dev_exception_item *ex)	393	struct dev_exception_item *ex)
396	{	394	{
397	struct cgroup *pcg = childcg->css.cgroup->parent;	395	struct dev_cgroup *parent = css_to_devcgroup(css_parent(&childcg->css));
398	struct dev_cgroup *parent;
399		396
400	if (!pcg)	397	if (!parent)
401	return 1;	398	return 1;
402	parent = cgroup_to_devcgroup(pcg);
403	return may_access(parent, ex, childcg->behavior);	399	return may_access(parent, ex, childcg->behavior);
404	}	400	}
405		401
@@ -524,15 +520,11 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup,
524	char temp[12]; /* 11 + 1 characters needed for a u32 */	520	char temp[12]; /* 11 + 1 characters needed for a u32 */
525	int count, rc = 0;	521	int count, rc = 0;
526	struct dev_exception_item ex;	522	struct dev_exception_item ex;
527	struct cgroup *p = devcgroup->css.cgroup;	523	struct dev_cgroup *parent = css_to_devcgroup(css_parent(&devcgroup->css));
528	struct dev_cgroup *parent = NULL;
529		524
530	if (!capable(CAP_SYS_ADMIN))	525	if (!capable(CAP_SYS_ADMIN))
531	return -EPERM;	526	return -EPERM;
532		527
533	if (p->parent)
534	parent = cgroup_to_devcgroup(p->parent);
535
536	memset(&ex, 0, sizeof(ex));	528	memset(&ex, 0, sizeof(ex));
537	b = buffer;	529	b = buffer;
538		530