9 files changed, 28 insertions, 29 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 4b40640240a4..54ad00292edf 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -891,7 +891,7 @@ static int blkcg_can_attach(struct cgroup_subsys_state *css,
         int ret = 0;
 
         /* task_lock() is needed to avoid races with exit_io_context() */
-        cgroup_taskset_for_each(task, css->cgroup, tset) {
+        cgroup_taskset_for_each(task, css, tset) {
                 task_lock(task);
                 ioc = task->io_context;
                 if (ioc && atomic_read(&ioc->nr_tasks) > 1)
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index b065d24486e6..d9a970568be9 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -562,20 +562,22 @@ int cgroup_task_count(const struct cgroup *cgrp);
 struct cgroup_taskset;
 struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset);
 struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset);
-struct cgroup *cgroup_taskset_cur_cgroup(struct cgroup_taskset *tset);
+struct cgroup_subsys_state *cgroup_taskset_cur_css(struct cgroup_taskset *tset,
+                                                   int subsys_id);
 int cgroup_taskset_size(struct cgroup_taskset *tset);
 
 /**
  * cgroup_taskset_for_each - iterate cgroup_taskset
  * @task: the loop cursor
- * @skip_cgrp: skip if task's cgroup matches this, %NULL to iterate through all
+ * @skip_css: skip if task's css matches this, %NULL to iterate through all
  * @tset: taskset to iterate
  */
-#define cgroup_taskset_for_each(task, skip_cgrp, tset)                  \
+#define cgroup_taskset_for_each(task, skip_css, tset)                   \
         for ((task) = cgroup_taskset_first((tset)); (task);             \
              (task) = cgroup_taskset_next((tset)))                      \
-                if (!(skip_cgrp) ||                                     \
-                    cgroup_taskset_cur_cgroup((tset)) != (skip_cgrp))
+                if (!(skip_css) ||                                      \
+                    cgroup_taskset_cur_css((tset),                      \
+                        (skip_css)->ss->subsys_id) != (skip_css))
 
 /*
  * Control Group subsystem type.
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index a71f2e0f9711..e5bfb2a81dcb 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1907,18 +1907,20 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset)
 EXPORT_SYMBOL_GPL(cgroup_taskset_next);
 
 /**
- * cgroup_taskset_cur_cgroup - return the matching cgroup for the current task
+ * cgroup_taskset_cur_css - return the matching css for the current task
  * @tset: taskset of interest
+ * @subsys_id: the ID of the target subsystem
  *
- * Return the cgroup for the current (last returned) task of @tset.  This
- * function must be preceded by either cgroup_taskset_first() or
- * cgroup_taskset_next().
+ * Return the css for the current (last returned) task of @tset for
+ * subsystem specified by @subsys_id.  This function must be preceded by
+ * either cgroup_taskset_first() or cgroup_taskset_next().
  */
-struct cgroup *cgroup_taskset_cur_cgroup(struct cgroup_taskset *tset)
+struct cgroup_subsys_state *cgroup_taskset_cur_css(struct cgroup_taskset *tset,
+                                                   int subsys_id)
 {
-        return tset->cur_cgrp;
+        return cgroup_css(tset->cur_cgrp, subsys_id);
 }
-EXPORT_SYMBOL_GPL(cgroup_taskset_cur_cgroup);
+EXPORT_SYMBOL_GPL(cgroup_taskset_cur_css);
 
 /**
  * cgroup_taskset_size - return the number of tasks in taskset
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 5cd2b6d55243..224da9aa27f5 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -189,7 +189,7 @@ static void freezer_attach(struct cgroup_subsys_state *new_css,
          * current state before executing the following - !frozen tasks may
          * be visible in a FROZEN cgroup and frozen tasks in a THAWED one.
          */
-        cgroup_taskset_for_each(task, new_css->cgroup, tset) {
+        cgroup_taskset_for_each(task, new_css, tset) {
                 if (!(freezer->state & CGROUP_FREEZING)) {
                         __thaw_task(task);
                 } else {
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 39e52175f4af..bf69717325b4 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -119,12 +119,6 @@ static inline struct cpuset *css_cs(struct cgroup_subsys_state *css)
         return css ? container_of(css, struct cpuset, css) : NULL;
 }
 
-/* Retrieve the cpuset for a cgroup */
-static inline struct cpuset *cgroup_cs(struct cgroup *cgrp)
-{
-        return css_cs(cgroup_css(cgrp, cpuset_subsys_id));
-}
-
 /* Retrieve the cpuset for a task */
 static inline struct cpuset *task_cs(struct task_struct *task)
 {
@@ -1459,7 +1453,7 @@ static int cpuset_can_attach(struct cgroup_subsys_state *css,
             (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)))
                 goto out_unlock;
 
-        cgroup_taskset_for_each(task, css->cgroup, tset) {
+        cgroup_taskset_for_each(task, css, tset) {
                 /*
                  * Kthreads which disallow setaffinity shouldn't be moved
                  * to a new cpuset; we don't want to change their cpu
@@ -1511,9 +1505,10 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
         struct mm_struct *mm;
         struct task_struct *task;
         struct task_struct *leader = cgroup_taskset_first(tset);
-        struct cgroup *oldcgrp = cgroup_taskset_cur_cgroup(tset);
+        struct cgroup_subsys_state *oldcss = cgroup_taskset_cur_css(tset,
+                                                        cpuset_subsys_id);
         struct cpuset *cs = css_cs(css);
-        struct cpuset *oldcs = cgroup_cs(oldcgrp);
+        struct cpuset *oldcs = css_cs(oldcss);
         struct cpuset *cpus_cs = effective_cpumask_cpuset(cs);
         struct cpuset *mems_cs = effective_nodemask_cpuset(cs);
 
@@ -1527,7 +1522,7 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
 
         guarantee_online_mems(mems_cs, &cpuset_attach_nodemask_to);
 
-        cgroup_taskset_for_each(task, css->cgroup, tset) {
+        cgroup_taskset_for_each(task, css, tset) {
                 /*
                  * can_attach beforehand should guarantee that this doesn't
                  * fail.  TODO: have a better way to handle failure here
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 9705a0ed1dce..c199c4f24910 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7816,7 +7816,7 @@ static void perf_cgroup_attach(struct cgroup_subsys_state *css,
 {
         struct task_struct *task;
 
-        cgroup_taskset_for_each(task, css->cgroup, tset)
+        cgroup_taskset_for_each(task, css, tset)
                 task_function_call(task, __perf_cgroup_move, task);
 }
 
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index cc9a49266382..a7122d5b8310 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7135,7 +7135,7 @@ static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css,
 {
         struct task_struct *task;
 
-        cgroup_taskset_for_each(task, css->cgroup, tset) {
+        cgroup_taskset_for_each(task, css, tset) {
 #ifdef CONFIG_RT_GROUP_SCHED
                 if (!sched_rt_can_attach(css_tg(css), task))
                         return -EINVAL;
@@ -7153,7 +7153,7 @@ static void cpu_cgroup_attach(struct cgroup_subsys_state *css,
 {
         struct task_struct *task;
 
-        cgroup_taskset_for_each(task, css->cgroup, tset)
+        cgroup_taskset_for_each(task, css, tset)
                 sched_move_task(task);
 }
 
diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index e00f60e5baea..d9cd627e6a16 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -224,7 +224,7 @@ static void net_prio_attach(struct cgroup_subsys_state *css,
         struct task_struct *p;
         void *v;
 
-        cgroup_taskset_for_each(p, css->cgroup, tset) {
+        cgroup_taskset_for_each(p, css, tset) {
                 task_lock(p);
                 v = (void *)(unsigned long)task_netprioidx(p);
                 iterate_fd(p->files, 0, update_netprio, v);
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 8ea1184cec92..867b4a3e3980 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -74,7 +74,7 @@ static void cgrp_attach(struct cgroup_subsys_state *css,
         struct task_struct *p;
         void *v;
 
-        cgroup_taskset_for_each(p, css->cgroup, tset) {
+        cgroup_taskset_for_each(p, css, tset) {
                 task_lock(p);
                 v = (void *)(unsigned long)task_cls_classid(p);
                 iterate_fd(p->files, 0, update_classid, v);