diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 069bc20..63c3cd4 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -925,6 +925,14 @@
 	.css_free = blkcg_css_free,
 	.can_attach = blkcg_can_attach,
 	.base_cftypes = blkcg_files,
+#ifdef CONFIG_MEMCG
+	/*
+	 * This ensures that, if available, memcg is automatically enabled
+	 * together on the default hierarchy so that the owner cgroup can
+	 * be retrieved from writeback pages.
+	 */
+	.depends_on = 1 << memory_cgrp_id,
+#endif
 };
 EXPORT_SYMBOL_GPL(blkio_cgrp_subsys);
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a2c7bcb..db536e9 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6407,6 +6407,29 @@
 	__mem_cgroup_free(memcg);
 }
 
+/**
+ * mem_cgroup_css_reset - reset the states of a mem_cgroup
+ * @css: the target css
+ *
+ * Reset the states of the mem_cgroup associated with @css.  This is
+ * invoked when the userland requests disabling on the default hierarchy
+ * but the memcg is pinned through dependency.  The memcg should stop
+ * applying policies and should revert to the vanilla state as it may be
+ * made visible again.
+ *
+ * The current implementation only resets the essential configurations.
+ * This needs to be expanded to cover all the visible parts.
+ */
+static void mem_cgroup_css_reset(struct cgroup_subsys_state *css)
+{
+	struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+	mem_cgroup_resize_limit(memcg, ULLONG_MAX);
+	mem_cgroup_resize_memsw_limit(memcg, ULLONG_MAX);
+	memcg_update_kmem_limit(memcg, ULLONG_MAX);
+	res_counter_set_soft_limit(&memcg->res, ULLONG_MAX);
+}
+
 #ifdef CONFIG_MMU
 /* Handlers for move charge at task migration. */
 #define PRECHARGE_COUNT_AT_ONCE	256
@@ -7019,6 +7042,7 @@
 	.css_online = mem_cgroup_css_online,
 	.css_offline = mem_cgroup_css_offline,
 	.css_free = mem_cgroup_css_free,
+	.css_reset = mem_cgroup_css_reset,
 	.can_attach = mem_cgroup_can_attach,
 	.cancel_attach = mem_cgroup_cancel_attach,
 	.attach = mem_cgroup_move_task,