* If idr init fails, cgroup_load_subsys() cleared dummytop->subsys[]
before calilng ->destroy() making CSS inaccessible to the callback,
and didn't unlink ss->sibling. As no modular controller uses
->use_id, this doesn't cause any actual problems.
* cgroup_unload_subsys() was forgetting to free idr, call
->pre_destroy() and clear ->active. As there currently is no
modular controller which uses ->use_id, ->pre_destroy() or ->active,
this doesn't cause any actual problems.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
kernel/cgroup.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 76f1a01..c5368c0 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4420,9 +4420,10 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
if (ss->use_id) {
int ret = cgroup_init_idr(ss, css);
if (ret) {
- dummytop->subsys[ss->subsys_id] = NULL;
ss->destroy(dummytop);
+ dummytop->subsys[ss->subsys_id] = NULL;
subsys[ss->subsys_id] = NULL;
+ list_del_init(&ss->sibling);
mutex_unlock(&cgroup_mutex);
return ret;
}
@@ -4490,7 +4491,19 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
*/
BUG_ON(ss->root != &rootnode);
+ /* ->pre_destroy() should be called outside cgroup_mutex for now */
+ if (ss->pre_destroy)
+ ss->pre_destroy(dummytop);
+
mutex_lock(&cgroup_mutex);
+
+ ss->active = 0;
+
+ if (ss->use_id) {
+ idr_remove_all(&ss->idr);
+ idr_destroy(&ss->idr);
+ }
+
/* deassign the subsys_id */
subsys[ss->subsys_id] = NULL;
--
1.7.11.7
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