cpuset: initialize top_cpuset's configured masks at mount

We now have to support different behaviors for default hierachy and
legacy hiearchy, top_cpuset's configured masks need to be initialized
accordingly.

Suppose we've offlined cpu1.

On default hierarchy:

	# mount -t cgroup -o __DEVEL__sane_behavior xxx /cpuset
	# cat /cpuset/cpuset.cpus
	0-15

On legacy hierarchy:

	# mount -t cgroup xxx /cpuset
	# cat /cpuset/cpuset.cpus
	0,2-15

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 28 insertions, 9 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 60577ccdbfc7..e4c31e6b8716 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2015,16 +2015,35 @@ static void cpuset_css_free(struct cgroup_subsys_state *css)
         kfree(cs);
 }
 
+static void cpuset_bind(struct cgroup_subsys_state *root_css)
+{
+        mutex_lock(&cpuset_mutex);
+        mutex_lock(&callback_mutex);
+
+        if (cgroup_on_dfl(root_css->cgroup)) {
+                cpumask_copy(top_cpuset.cpus_allowed, cpu_possible_mask);
+                top_cpuset.mems_allowed = node_possible_map;
+        } else {
+                cpumask_copy(top_cpuset.cpus_allowed,
+                             top_cpuset.effective_cpus);
+                top_cpuset.mems_allowed = top_cpuset.effective_mems;
+        }
+
+        mutex_unlock(&callback_mutex);
+        mutex_unlock(&cpuset_mutex);
+}
+
 struct cgroup_subsys cpuset_cgrp_subsys = {
-        .css_alloc = cpuset_css_alloc,
-        .css_online = cpuset_css_online,
-        .css_offline = cpuset_css_offline,
-        .css_free = cpuset_css_free,
-        .can_attach = cpuset_can_attach,
-        .cancel_attach = cpuset_cancel_attach,
-        .attach = cpuset_attach,
-        .base_cftypes = files,
-        .early_init = 1,
+        .css_alloc      = cpuset_css_alloc,
+        .css_online     = cpuset_css_online,
+        .css_offline    = cpuset_css_offline,
+        .css_free       = cpuset_css_free,
+        .can_attach     = cpuset_can_attach,
+        .cancel_attach  = cpuset_cancel_attach,
+        .attach         = cpuset_attach,
+        .bind           = cpuset_bind,
+        .base_cftypes   = files,
+        .early_init     = 1,
 };
 
 /**