We should not call cgroup_unload_subsys() if online_css() fails, because
online_css() does not assign css to cgroup on failure, while
offline_css() called from cgroup_unload_subsys() expects it is assigned.
So let's call everything we need to rollback inline without involving
cgroup_unload_subsys().
Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Li Zefan <lizefan@xxxxxxxxxx>
---
kernel/cgroup.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 8b729c2..3cd7247 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4861,10 +4861,8 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
*/
css = ss->css_alloc(cgroup_css(cgroup_dummy_top, ss));
if (IS_ERR(css)) {
- /* failure case - need to deassign the cgroup_subsys[] slot. */
- cgroup_subsys[ss->subsys_id] = NULL;
- mutex_unlock(&cgroup_mutex);
- return PTR_ERR(css);
+ ret = PTR_ERR(css);
+ goto out_err;
}
list_add(&ss->sibling, &cgroup_dummy_root.subsys_list);
@@ -4873,6 +4871,10 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
/* our new subsystem will be attached to the dummy hierarchy. */
init_css(css, ss, cgroup_dummy_top);
+ ret = online_css(css);
+ if (ret)
+ goto free_css;
+
/*
* Now we need to entangle the css into the existing css_sets. unlike
* in cgroup_init_subsys, there are now multiple css_sets, so each one
@@ -4896,18 +4898,17 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
}
write_unlock(&css_set_lock);
- ret = online_css(css);
- if (ret)
- goto err_unload;
-
/* success! */
mutex_unlock(&cgroup_mutex);
return 0;
-err_unload:
+free_css:
+ list_del(&ss->sibling);
+ ss->css_free(css);
+out_err:
+ /* failure case - need to deassign the cgroup_subsys[] slot. */
+ cgroup_subsys[ss->subsys_id] = NULL;
mutex_unlock(&cgroup_mutex);
- /* @ss can't be mounted here as try_module_get() would fail */
- cgroup_unload_subsys(ss);
return ret;
}
EXPORT_SYMBOL_GPL(cgroup_load_subsys);
--
1.7.10.4
--
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