diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index b604c7e0cfc6d1cf75732950e3b97e5a221f3944..e66b9ee5ecc1a104b8493fc23cd43ffa6ba54a49 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -338,16 +338,24 @@ struct cgrp_cset_link {
struct list_head cgrp_link;
};
-/* The default css_set - used by init and its children prior to any
+/*
+ * The default css_set - used by init and its children prior to any
* hierarchies being mounted. It contains a pointer to the root state
* for each subsystem. Also used to anchor the list of css_sets. Not
* reference-counted, to improve performance when child cgroups
* haven't been created.
*/
+static struct css_set init_css_set = {
+ .refcount = ATOMIC_INIT(1),
+ .cgrp_links = LIST_HEAD_INIT(init_css_set.cgrp_links),
+ .tasks = LIST_HEAD_INIT(init_css_set.tasks),
+ .mg_tasks = LIST_HEAD_INIT(init_css_set.mg_tasks),
+ .mg_preload_node = LIST_HEAD_INIT(init_css_set.mg_preload_node),
+ .mg_node = LIST_HEAD_INIT(init_css_set.mg_node),
+};
-static struct css_set init_css_set;
static struct cgrp_cset_link init_cgrp_cset_link;
-static int css_set_count;
+static int css_set_count = 1; /* 1 for init_css_set */
/*
* hash table for cgroup groups. This improves the performance to find
@@ -1352,7 +1360,8 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
cgrp->dummy_css.cgroup = cgrp;
}
-static void init_cgroup_root(struct cgroupfs_root *root)
+static void init_cgroup_root(struct cgroupfs_root *root,
+ struct cgroup_sb_opts *opts)
{
struct cgroup *cgrp = &root->top_cgroup;
@@ -1361,20 +1370,6 @@ static void init_cgroup_root(struct cgroupfs_root *root)
cgrp->root = root;
init_cgroup_housekeeping(cgrp);
idr_init(&root->cgroup_idr);
-}
-
-static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts)
-{
- struct cgroupfs_root *root;
-
- if (!opts->subsys_mask && !opts->none)
- return ERR_PTR(-EINVAL);
-
- root = kzalloc(sizeof(*root), GFP_KERNEL);
- if (!root)
- return ERR_PTR(-ENOMEM);
-
- init_cgroup_root(root);
root->flags = opts->flags;
if (opts->release_agent)
@@ -1383,7 +1378,6 @@ static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts)
strcpy(root->name, opts->name);
if (opts->cpuset_clone_children)
set_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->top_cgroup.flags);
- return root;
}
static int cgroup_setup_root(struct cgroupfs_root *root, unsigned long ss_mask)
@@ -1548,13 +1542,24 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
goto out_unlock;
}
- /* no such thing, create a new one */
- root = cgroup_root_from_opts(&opts);
- if (IS_ERR(root)) {
- ret = PTR_ERR(root);
+ /*
+ * No such thing, create a new one. name= matching without subsys
+ * specification is allowed for already existing hierarchies but we
+ * can't create new one without subsys specification.
+ */
+ if (!opts.subsys_mask && !opts.none) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ root = kzalloc(sizeof(*root), GFP_KERNEL);
+ if (!root) {
+ ret = -ENOMEM;
goto out_unlock;
}
+ init_cgroup_root(root, &opts);
+
ret = cgroup_setup_root(root, opts.subsys_mask);
if (ret)
cgroup_free_root(root);
@@ -4030,26 +4035,13 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
*/
int __init cgroup_init_early(void)
{
+ static struct cgroup_sb_opts __initdata opts = { };
struct cgroup_subsys *ss;
int i;
- atomic_set(&init_css_set.refcount, 1);
- INIT_LIST_HEAD(&init_css_set.cgrp_links);
- INIT_LIST_HEAD(&init_css_set.tasks);
- INIT_LIST_HEAD(&init_css_set.mg_tasks);
- INIT_LIST_HEAD(&init_css_set.mg_preload_node);
- INIT_LIST_HEAD(&init_css_set.mg_node);
- INIT_HLIST_NODE(&init_css_set.hlist);
- css_set_count = 1;
- init_cgroup_root(&cgroup_dummy_root);
- cgroup_root_count = 1;
+ init_cgroup_root(&cgroup_dummy_root, &opts);
RCU_INIT_POINTER(init_task.cgroups, &init_css_set);
- init_cgrp_cset_link.cset = &init_css_set;
- init_cgrp_cset_link.cgrp = cgroup_dummy_top;
- list_add(&init_cgrp_cset_link.cset_link, &cgroup_dummy_top->cset_links);
- list_add(&init_cgrp_cset_link.cgrp_link, &init_css_set.cgrp_links);
-
for_each_subsys(ss, i) {
WARN(!ss->css_alloc || !ss->css_free || ss->name || ss->id,
"invalid cgroup_subsys %d:%s css_alloc=%p css_free=%p name:id=%d:%s\n",
@@ -4077,22 +4069,10 @@ int __init cgroup_init(void)
{
struct cgroup_subsys *ss;
unsigned long key;
- int i, err;
+ int ssid, err;
BUG_ON(cgroup_init_cftypes(NULL, cgroup_base_files));
- for_each_subsys(ss, i) {
- if (!ss->early_init)
- cgroup_init_subsys(ss);
-
- /*
- * cftype registration needs kmalloc and can't be done
- * during early_init. Register base cftypes separately.
- */
- if (ss->base_cftypes)
- WARN_ON(cgroup_add_cftypes(ss, ss->base_cftypes));
- }
-
/* allocate id for the dummy hierarchy */
mutex_lock(&cgroup_mutex);
@@ -4106,8 +4086,26 @@ int __init cgroup_init(void)
0, 1, GFP_KERNEL);
BUG_ON(err < 0);
+ cgroup_root_count = 1;
+ init_cgrp_cset_link.cset = &init_css_set;
+ init_cgrp_cset_link.cgrp = cgroup_dummy_top;
+ list_add(&init_cgrp_cset_link.cset_link, &cgroup_dummy_top->cset_links);
+ list_add(&init_cgrp_cset_link.cgrp_link, &init_css_set.cgrp_links);
+
mutex_unlock(&cgroup_mutex);
+ for_each_subsys(ss, ssid) {
+ if (!ss->early_init)
+ cgroup_init_subsys(ss);
+
+ /*
+ * cftype registration needs kmalloc and can't be done
+ * during early_init. Register base cftypes separately.
+ */
+ if (ss->base_cftypes)
+ WARN_ON(cgroup_add_cftypes(ss, ss->base_cftypes));
+ }
+
cgroup_kobj = kobject_create_and_add("cgroup", fs_kobj);
if (!cgroup_kobj)
return -ENOMEM;