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Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r--kernel/cgroup.c19
1 files changed, 9 insertions, 10 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 1ece8e20fdb5..f4ea4b6f3cf1 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4881,9 +4881,9 @@ void free_css_id(struct cgroup_subsys *ss, struct cgroup_subsys_state *css)
rcu_assign_pointer(id->css, NULL);
rcu_assign_pointer(css->id, NULL);
- write_lock(&ss->id_lock);
+ spin_lock(&ss->id_lock);
idr_remove(&ss->idr, id->id);
- write_unlock(&ss->id_lock);
+ spin_unlock(&ss->id_lock);
kfree_rcu(id, rcu_head);
}
EXPORT_SYMBOL_GPL(free_css_id);
@@ -4909,10 +4909,10 @@ static struct css_id *get_new_cssid(struct cgroup_subsys *ss, int depth)
error = -ENOMEM;
goto err_out;
}
- write_lock(&ss->id_lock);
+ spin_lock(&ss->id_lock);
/* Don't use 0. allocates an ID of 1-65535 */
error = idr_get_new_above(&ss->idr, newid, 1, &myid);
- write_unlock(&ss->id_lock);
+ spin_unlock(&ss->id_lock);
/* Returns error when there are no free spaces for new ID.*/
if (error) {
@@ -4927,9 +4927,9 @@ static struct css_id *get_new_cssid(struct cgroup_subsys *ss, int depth)
return newid;
remove_idr:
error = -ENOSPC;
- write_lock(&ss->id_lock);
+ spin_lock(&ss->id_lock);
idr_remove(&ss->idr, myid);
- write_unlock(&ss->id_lock);
+ spin_unlock(&ss->id_lock);
err_out:
kfree(newid);
return ERR_PTR(error);
@@ -4941,7 +4941,7 @@ static int __init_or_module cgroup_init_idr(struct cgroup_subsys *ss,
{
struct css_id *newid;
- rwlock_init(&ss->id_lock);
+ spin_lock_init(&ss->id_lock);
idr_init(&ss->idr);
newid = get_new_cssid(ss, 0);
@@ -5029,6 +5029,8 @@ css_get_next(struct cgroup_subsys *ss, int id,
return NULL;
BUG_ON(!ss->use_id);
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
/* fill start point for scan */
tmpid = id;
while (1) {
@@ -5036,10 +5038,7 @@ css_get_next(struct cgroup_subsys *ss, int id,
* scan next entry from bitmap(tree), tmpid is updated after
* idr_get_next().
*/
- read_lock(&ss->id_lock);
tmp = idr_get_next(&ss->idr, &tmpid);
- read_unlock(&ss->id_lock);
-
if (!tmp)
break;
if (tmp->depth >= depth && tmp->stack[depth] == rootid) {