--- y/fs/namespace.c
+++ x/fs/namespace.c
@@ -1801,6 +1801,9 @@ int path_umount(struct path *path, int f
 	if (!ret)
 		ret = do_umount(mnt, flags);
 
+	if (ret)
+		return ret;
+
 	/* we mustn't call path_put() as that would clear mnt_expiry_mark */
 	dput(path->dentry);
 	mntput_no_expire(mnt);
--- y/include/linux/cgroup-defs.h
+++ x/include/linux/cgroup-defs.h
@@ -179,7 +179,7 @@ struct cgroup_subsys_state {
 	atomic_t online_cnt;
 
 	/* percpu_ref killing and RCU release */
-	struct work_struct destroy_work;
+	struct work_struct destroy_work, release_work;
 	struct rcu_work destroy_rwork;
 
 	/*
--- y/kernel/cgroup/cgroup.c
+++ x/kernel/cgroup/cgroup.c
@@ -5154,7 +5154,7 @@ static void css_free_rwork_fn(struct wor
 static void css_release_work_fn(struct work_struct *work)
 {
 	struct cgroup_subsys_state *css =
-		container_of(work, struct cgroup_subsys_state, destroy_work);
+		container_of(work, struct cgroup_subsys_state, release_work);
 	struct cgroup_subsys *ss = css->ss;
 	struct cgroup *cgrp = css->cgroup;
 
@@ -5210,8 +5210,8 @@ static void css_release(struct percpu_re
 	struct cgroup_subsys_state *css =
 		container_of(ref, struct cgroup_subsys_state, refcnt);
 
-	INIT_WORK(&css->destroy_work, css_release_work_fn);
-	queue_work(cgroup_destroy_wq, &css->destroy_work);
+	INIT_WORK(&css->release_work, css_release_work_fn);
+	queue_work(cgroup_destroy_wq, &css->release_work);
 }
 
 static void init_and_link_css(struct cgroup_subsys_state *css,