diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 49d7b23a7cfe..e8517ad677eb 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -225,6 +225,8 @@ void wb_wait_for_completion(struct wb_completion *done)
 					/* one round can affect upto 5 slots */
 #define WB_FRN_MAX_IN_FLIGHT	1024	/* don't queue too many concurrently */
 
+#define WB_MAX_INODES_PER_ISW	116	/* maximum inodes per isw */
+
 static atomic_t isw_nr_in_flight = ATOMIC_INIT(0);
 static struct workqueue_struct *isw_wq;
 
@@ -552,6 +554,72 @@ static void inode_switch_wbs(struct inode *inode, int new_wb_id)
 	kfree(isw);
 }
 
+/**
+ * cleanup_offline_cgwb - detach associated inodes
+ * @wb: target wb
+ *
+ * Switch all inodes attached to @wb to the bdi's root wb in order to eventually
+ * release the dying @wb.  Returns %true if not all inodes were switched and
+ * the function has to be restarted.
+ */
+bool cleanup_offline_cgwb(struct bdi_writeback *wb)
+{
+	struct inode_switch_wbs_context *isw;
+	struct inode *inode;
+	int nr;
+	bool restart = false;
+
+	isw = kzalloc(sizeof(*isw) + WB_MAX_INODES_PER_ISW *
+		      sizeof(struct inode *), GFP_KERNEL);
+	if (!isw)
+		return restart;
+
+	/* no need to call wb_get() here: bdi's root wb is not refcounted */
+	isw->new_wb = &wb->bdi->wb;
+
+	nr = 0;
+	spin_lock(&wb->list_lock);
+	list_for_each_entry(inode, &wb->b_attached, i_io_list) {
+		spin_lock(&inode->i_lock);
+		if (!(inode->i_sb->s_flags & SB_ACTIVE) ||
+		    inode->i_state & (I_WB_SWITCH | I_FREEING) ||
+		    inode_to_wb(inode) == isw->new_wb) {
+			spin_unlock(&inode->i_lock);
+			continue;
+		}
+		inode->i_state |= I_WB_SWITCH;
+		__iget(inode);
+		spin_unlock(&inode->i_lock);
+
+		isw->inodes[nr++] = inode;
+
+		if (nr >= WB_MAX_INODES_PER_ISW - 1) {
+			restart = true;
+			break;
+		}
+	}
+	spin_unlock(&wb->list_lock);
+
+	/* no attached inodes? bail out */
+	if (nr == 0) {
+		kfree(isw);
+		return restart;
+	}
+
+	/*
+	 * In addition to synchronizing among switchers, I_WB_SWITCH tells
+	 * the RCU protected stat update paths to grab the i_page
+	 * lock so that stat transfer can synchronize against them.
+	 * Let's continue after I_WB_SWITCH is guaranteed to be visible.
+	 */
+	INIT_RCU_WORK(&isw->work, inode_switch_wbs_work_fn);
+	queue_rcu_work(isw_wq, &isw->work);
+
+	atomic_inc(&isw_nr_in_flight);
+
+	return restart;
+}
+
 /**
  * wbc_attach_and_unlock_inode - associate wbc with target inode and unlock it
  * @wbc: writeback_control of interest
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
index e5dc238ebe4f..07d6b6d6dbdf 100644
--- a/include/linux/backing-dev-defs.h
+++ b/include/linux/backing-dev-defs.h
@@ -155,6 +155,7 @@ struct bdi_writeback {
 	struct list_head memcg_node;	/* anchored at memcg->cgwb_list */
 	struct list_head blkcg_node;	/* anchored at blkcg->cgwb_list */
 	struct list_head b_attached;	/* attached inodes, protected by list_lock */
+	struct list_head offline_node;	/* anchored at offline_cgwbs */
 
 	union {
 		struct work_struct release_work;
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 8e5c5bb16e2d..95de51c10248 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -221,6 +221,7 @@ void wbc_account_cgroup_owner(struct writeback_control *wbc, struct page *page,
 int cgroup_writeback_by_id(u64 bdi_id, int memcg_id, unsigned long nr_pages,
 			   enum wb_reason reason, struct wb_completion *done);
 void cgroup_writeback_umount(void);
+bool cleanup_offline_cgwb(struct bdi_writeback *wb);
 
 /**
  * inode_attach_wb - associate an inode with its wb
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 54c5dc4b8c24..f1fc04412bd7 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -371,12 +371,16 @@ static void wb_exit(struct bdi_writeback *wb)
 #include <linux/memcontrol.h>
 
 /*
- * cgwb_lock protects bdi->cgwb_tree, blkcg->cgwb_list, and memcg->cgwb_list.
- * bdi->cgwb_tree is also RCU protected.
+ * cgwb_lock protects bdi->cgwb_tree, blkcg->cgwb_list, offline_cgwbs and
+ * memcg->cgwb_list.  bdi->cgwb_tree is also RCU protected.
  */
 static DEFINE_SPINLOCK(cgwb_lock);
 static struct workqueue_struct *cgwb_release_wq;
 
+static LIST_HEAD(offline_cgwbs);
+static void cleanup_offline_cgwbs_workfn(struct work_struct *work);
+static DECLARE_WORK(cleanup_offline_cgwbs_work, cleanup_offline_cgwbs_workfn);
+
 static void cgwb_release_workfn(struct work_struct *work)
 {
 	struct bdi_writeback *wb = container_of(work, struct bdi_writeback,
@@ -395,6 +399,11 @@ static void cgwb_release_workfn(struct work_struct *work)
 
 	fprop_local_destroy_percpu(&wb->memcg_completions);
 	percpu_ref_exit(&wb->refcnt);
+
+	spin_lock_irq(&cgwb_lock);
+	list_del(&wb->offline_node);
+	spin_unlock_irq(&cgwb_lock);
+
 	wb_exit(wb);
 	WARN_ON_ONCE(!list_empty(&wb->b_attached));
 	kfree_rcu(wb, rcu);
@@ -414,6 +423,7 @@ static void cgwb_kill(struct bdi_writeback *wb)
 	WARN_ON(!radix_tree_delete(&wb->bdi->cgwb_tree, wb->memcg_css->id));
 	list_del(&wb->memcg_node);
 	list_del(&wb->blkcg_node);
+	list_add(&wb->offline_node, &offline_cgwbs);
 	percpu_ref_kill(&wb->refcnt);
 }
 
@@ -635,6 +645,48 @@ static void cgwb_bdi_unregister(struct backing_dev_info *bdi)
 	mutex_unlock(&bdi->cgwb_release_mutex);
 }
 
+/**
+ * cleanup_offline_cgwbs - try to release dying cgwbs
+ *
+ * Try to release dying cgwbs by switching attached inodes to the wb
+ * belonging to the root memory cgroup. Processed wbs are placed at the
+ * end of the list to guarantee the forward progress.
+ *
+ * Should be called with the acquired cgwb_lock lock, which might
+ * be released and re-acquired in the process.
+ */
+static void cleanup_offline_cgwbs_workfn(struct work_struct *work)
+{
+	struct bdi_writeback *wb;
+	LIST_HEAD(processed);
+
+	spin_lock_irq(&cgwb_lock);
+
+	while (!list_empty(&offline_cgwbs)) {
+		wb = list_first_entry(&offline_cgwbs, struct bdi_writeback,
+				      offline_node);
+		list_move(&wb->offline_node, &processed);
+
+		if (wb_has_dirty_io(wb))
+			continue;
+
+		if (!wb_tryget(wb))
+			continue;
+
+		spin_unlock_irq(&cgwb_lock);
+		while ((cleanup_offline_cgwb(wb)))
+			cond_resched();
+		spin_lock_irq(&cgwb_lock);
+
+		wb_put(wb);
+	}
+
+	if (!list_empty(&processed))
+		list_splice_tail(&processed, &offline_cgwbs);
+
+	spin_unlock_irq(&cgwb_lock);
+}
+
 /**
  * wb_memcg_offline - kill all wb's associated with a memcg being offlined
  * @memcg: memcg being offlined
@@ -651,6 +703,8 @@ void wb_memcg_offline(struct mem_cgroup *memcg)
 		cgwb_kill(wb);
 	memcg_cgwb_list->next = NULL;	/* prevent new wb's */
 	spin_unlock_irq(&cgwb_lock);
+
+	queue_work(system_unbound_wq, &cleanup_offline_cgwbs_work);
 }
 
 /**
