Revert "cgroup/cpuset: Change cpuset_rwsem and hotplug lock order"

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6TI3Y
CVE: NA

--------------------------------

This reverts commit c831178a.
Signed-off-by: NCai Xinchen <caixinchen1@huawei.com>
Reviewed-by: NWang Weiyang <wangweiyang2@huawei.com>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

include/linux/cpuset.h

@@ -40,14 +40,14 @@ static inline bool cpusets_enabled(void)
 
 static inline void cpuset_inc(void)
 {
-	static_branch_inc_cpuslocked(&cpusets_pre_enable_key);
-	static_branch_inc_cpuslocked(&cpusets_enabled_key);
+	static_branch_inc(&cpusets_pre_enable_key);
+	static_branch_inc(&cpusets_enabled_key);
 }
 
 static inline void cpuset_dec(void)
 {
-	static_branch_dec_cpuslocked(&cpusets_enabled_key);
-	static_branch_dec_cpuslocked(&cpusets_pre_enable_key);
+	static_branch_dec(&cpusets_enabled_key);
+	static_branch_dec(&cpusets_pre_enable_key);
 }
 
 extern int cpuset_init(void);

kernel/cgroup/cpuset.c

@@ -914,8 +914,8 @@ static void rebuild_sched_domains_locked(void)
 	cpumask_var_t *doms;
 	int ndoms;
 
-	lockdep_assert_cpus_held();
 	lockdep_assert_held(&cpuset_mutex);
+	get_online_cpus();
 
 	/*
 	 * We have raced with CPU hotplug. Don't do anything to avoid
@@ -923,13 +923,15 @@ 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))
-		return;
+		goto out;
 
 	/* 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)
@@ -939,11 +941,9 @@ static void rebuild_sched_domains_locked(void)
 
 void rebuild_sched_domains(void)
 {
-	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 	rebuild_sched_domains_locked();
 	mutex_unlock(&cpuset_mutex);
-	put_online_cpus();
 }
 
 /**
@@ -1612,13 +1612,13 @@ static void cpuset_attach(struct cgroup_taskset *tset)
 	cgroup_taskset_first(tset, &css);
 	cs = css_cs(css);
 
+	mutex_lock(&cpuset_mutex);
+
 	/*
 	 * It should hold cpus lock because a cpu offline event can
 	 * cause set_cpus_allowed_ptr() failed.
 	 */
 	get_online_cpus();
-	mutex_lock(&cpuset_mutex);
-
 	/* prepare for attach */
 	if (cs == &top_cpuset)
 		cpumask_copy(cpus_attach, cpu_possible_mask);
@@ -1644,6 +1644,7 @@ static void cpuset_attach(struct cgroup_taskset *tset)
 		cpuset_change_task_nodemask(task, &cpuset_attach_nodemask_to);
 		cpuset_update_task_spread_flag(cs, task);
 	}
+       put_online_cpus();
 
 	/*
 	 * Change mm for all threadgroup leaders. This is expensive and may
@@ -1679,7 +1680,6 @@ static void cpuset_attach(struct cgroup_taskset *tset)
 		wake_up(&cpuset_attach_wq);
 
 	mutex_unlock(&cpuset_mutex);
-	put_online_cpus();
 }
 
 /* The various types of files and directories in a cpuset file system */
@@ -1711,7 +1711,6 @@ 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;
@@ -1749,7 +1748,6 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
 	}
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
-	put_online_cpus();
 	return retval;
 }
 
@@ -1760,7 +1758,6 @@ 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;
@@ -1775,7 +1772,6 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
 	}
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
-	put_online_cpus();
 	return retval;
 }
 
@@ -1814,7 +1810,6 @@ 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;
@@ -1845,7 +1840,6 @@ 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);
@@ -2114,7 +2108,6 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
 	if (!parent)
 		return 0;
 
-	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 
 	set_bit(CS_ONLINE, &cs->flags);
@@ -2168,7 +2161,6 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
 	spin_unlock_irq(&callback_lock);
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
-	put_online_cpus();
 	return 0;
 }
 
@@ -2182,7 +2174,6 @@ 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))
@@ -2192,7 +2183,6 @@ 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)