1 files changed, 42 insertions, 30 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index db86d6b609b6..2ce1a5297b92 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -99,7 +99,7 @@ struct cpuset {
 
 	/* user-configured CPUs and Memory Nodes allow to tasks */
 	cpumask_var_t cpus_allowed;
-	cpumask_var_t cpus_requested;
+	cpumask_var_t cpus_requested;   /* CPUS requested, but not used because of hotplug */
 	nodemask_t mems_allowed;
 
 	/* effective CPUs and Memory Nodes allow to tasks */
@@ -419,14 +419,19 @@ static struct cpuset *alloc_trial_cpuset(struct cpuset *cs)
 
 	if (!alloc_cpumask_var(&trial->cpus_allowed, GFP_KERNEL))
 		goto free_cs;
+	if (!alloc_cpumask_var(&trial->cpus_requested, GFP_KERNEL))
+		goto free_allowed;
 	if (!alloc_cpumask_var(&trial->effective_cpus, GFP_KERNEL))
 		goto free_cpus;
 
 	cpumask_copy(trial->cpus_allowed, cs->cpus_allowed);
+	cpumask_copy(trial->cpus_requested, cs->cpus_requested);
 	cpumask_copy(trial->effective_cpus, cs->effective_cpus);
 	return trial;
 
 free_cpus:
+	free_cpumask_var(trial->cpus_requested);
+free_allowed:
 	free_cpumask_var(trial->cpus_allowed);
 free_cs:
 	kfree(trial);
@@ -440,6 +445,7 @@ free_cs:
 static void free_trial_cpuset(struct cpuset *trial)
 {
 	free_cpumask_var(trial->effective_cpus);
+	free_cpumask_var(trial->cpus_requested);
 	free_cpumask_var(trial->cpus_allowed);
 	kfree(trial);
 }
@@ -807,16 +813,15 @@ done:
  * 'cpus' is removed, then call this routine to rebuild the
  * scheduler's dynamic sched domains.
  *
- * Call with cpuset_mutex held.  Takes get_online_cpus().
  */
-static void rebuild_sched_domains_locked(void)
+static void rebuild_sched_domains_unlocked(void)
 {
 	struct sched_domain_attr *attr;
 	cpumask_var_t *doms;
 	int ndoms;
 
+	cpu_hotplug_mutex_held();
 	lockdep_assert_held(&cpuset_mutex);
-	get_online_cpus();
 
 	/*
 	 * We have raced with CPU hotplug. Don't do anything to avoid
@@ -824,27 +829,27 @@ static void rebuild_sched_domains_locked(void)
 	 * Anyways, hotplug work item will rebuild sched domains.
 	 */
 	if (!cpumask_equal(top_cpuset.effective_cpus, cpu_active_mask))
-		goto out;
+		return;
 
 	/* Generate domain masks and attrs */
 	ndoms = generate_sched_domains(&doms, &attr);
 
 	/* Have scheduler rebuild the domains */
 	partition_sched_domains(ndoms, doms, attr);
-out:
-	put_online_cpus();
 }
 #else /* !CONFIG_SMP */
-static void rebuild_sched_domains_locked(void)
+static void rebuild_sched_domains_unlocked(void)
 {
 }
 #endif /* CONFIG_SMP */
 
 void rebuild_sched_domains(void)
 {
+	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
-	rebuild_sched_domains_locked();
+	rebuild_sched_domains_unlocked();
 	mutex_unlock(&cpuset_mutex);
+	put_online_cpus();
 }
 
 /**
@@ -876,7 +881,6 @@ static void update_tasks_cpumask(struct cpuset *cs)
  *
  * On legacy hierachy, effective_cpus will be the same with cpu_allowed.
  *
- * Called with cpuset_mutex held
  */
 static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus)
 {
@@ -931,7 +935,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus)
 	rcu_read_unlock();
 
 	if (need_rebuild_sched_domains)
-		rebuild_sched_domains_locked();
+		rebuild_sched_domains_unlocked();
 }
 
 /**
@@ -950,23 +954,23 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
 		return -EACCES;
 
 	/*
-	 * An empty cpus_allowed is ok only if the cpuset has no tasks.
+	 * An empty cpus_requested is ok only if the cpuset has no tasks.
 	 * Since cpulist_parse() fails on an empty mask, we special case
 	 * that parsing.  The validate_change() call ensures that cpusets
 	 * with tasks have cpus.
 	 */
 	if (!*buf) {
-		cpumask_clear(trialcs->cpus_allowed);
+		cpumask_clear(trialcs->cpus_requested);
 	} else {
 		retval = cpulist_parse(buf, trialcs->cpus_requested);
 		if (retval < 0)
 			return retval;
+	}
 
-		if (!cpumask_subset(trialcs->cpus_requested, cpu_present_mask))
-			return -EINVAL;
+	if (!cpumask_subset(trialcs->cpus_requested, cpu_present_mask))
+		return -EINVAL;
 
-		cpumask_and(trialcs->cpus_allowed, trialcs->cpus_requested, cpu_active_mask);
-	}
+	cpumask_and(trialcs->cpus_allowed, trialcs->cpus_requested, cpu_active_mask);
 
 	/* Nothing to do if the cpus didn't change */
 	if (cpumask_equal(cs->cpus_requested, trialcs->cpus_requested))
@@ -1290,7 +1294,7 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val)
 		cs->relax_domain_level = val;
 		if (!cpumask_empty(cs->cpus_allowed) &&
 		    is_sched_load_balance(cs))
-			rebuild_sched_domains_locked();
+			rebuild_sched_domains_unlocked();
 	}
 
 	return 0;
@@ -1321,7 +1325,6 @@ static void update_tasks_flags(struct cpuset *cs)
  * cs:		the cpuset to update
  * turning_on: 	whether the flag is being set or cleared
  *
- * Call with cpuset_mutex held.
  */
 
 static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
@@ -1356,7 +1359,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
 	spin_unlock_irq(&callback_lock);
 
 	if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed)
-		rebuild_sched_domains_locked();
+		rebuild_sched_domains_unlocked();
 
 	if (spread_flag_changed)
 		update_tasks_flags(cs);
@@ -1621,6 +1624,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
 	cpuset_filetype_t type = cft->private;
 	int retval = 0;
 
+	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 	if (!is_cpuset_online(cs)) {
 		retval = -ENODEV;
@@ -1658,6 +1662,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
 	}
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
+	put_online_cpus();
 	return retval;
 }
 
@@ -1668,6 +1673,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
 	cpuset_filetype_t type = cft->private;
 	int retval = -ENODEV;
 
+	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 	if (!is_cpuset_online(cs))
 		goto out_unlock;
@@ -1682,6 +1688,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
 	}
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
+	put_online_cpus();
 	return retval;
 }
 
@@ -1720,6 +1727,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
 	kernfs_break_active_protection(of->kn);
 	flush_work(&cpuset_hotplug_work);
 
+	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 	if (!is_cpuset_online(cs))
 		goto out_unlock;
@@ -1745,6 +1753,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
 	free_trial_cpuset(trialcs);
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
+	put_online_cpus();
 	kernfs_unbreak_active_protection(of->kn);
 	css_put(&cs->css);
 	flush_workqueue(cpuset_migrate_mm_wq);
@@ -1958,11 +1967,11 @@ cpuset_css_alloc(struct cgroup_subsys_state *parent_css)
 	if (!cs)
 		return ERR_PTR(-ENOMEM);
 	if (!alloc_cpumask_var(&cs->cpus_allowed, GFP_KERNEL))
-		goto free_cs;
-	if (!alloc_cpumask_var(&cs->cpus_requested, GFP_KERNEL))
-		goto free_allowed;
+		goto error_allowed;
 	if (!alloc_cpumask_var(&cs->effective_cpus, GFP_KERNEL))
-		goto free_requested;
+		goto error_effective;
+	if (!alloc_cpumask_var(&cs->cpus_requested, GFP_KERNEL))
+		goto error_requested;
 
 	set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
 	cpumask_clear(cs->cpus_allowed);
@@ -1975,11 +1984,11 @@ cpuset_css_alloc(struct cgroup_subsys_state *parent_css)
 
 	return &cs->css;
 
-free_requested:
-	free_cpumask_var(cs->cpus_requested);
-free_allowed:
+error_requested:
+	free_cpumask_var(cs->effective_cpus);
+error_effective:
 	free_cpumask_var(cs->cpus_allowed);
-free_cs:
+error_allowed:
 	kfree(cs);
 	return ERR_PTR(-ENOMEM);
 }
@@ -2051,13 +2060,14 @@ out_unlock:
 /*
  * If the cpuset being removed has its flag 'sched_load_balance'
  * enabled, then simulate turning sched_load_balance off, which
- * will call rebuild_sched_domains_locked().
+ * will call rebuild_sched_domains_unlocked().
  */
 
 static void cpuset_css_offline(struct cgroup_subsys_state *css)
 {
 	struct cpuset *cs = css_cs(css);
 
+	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 
 	if (is_sched_load_balance(cs))
@@ -2067,6 +2077,7 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css)
 	clear_bit(CS_ONLINE, &cs->flags);
 
 	mutex_unlock(&cpuset_mutex);
+	put_online_cpus();
 }
 
 static void cpuset_css_free(struct cgroup_subsys_state *css)
@@ -2278,7 +2289,8 @@ retry:
 		goto retry;
 	}
 
-	cpumask_and(&new_cpus, cs->cpus_requested, parent_cs(cs)->effective_cpus);
+	cpumask_and(&new_cpus, cs->cpus_requested,
+						parent_cs(cs)->effective_cpus);
 	nodes_and(new_mems, cs->mems_allowed, parent_cs(cs)->effective_mems);
 
 	cpus_updated = !cpumask_equal(&new_cpus, cs->effective_cpus);