diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 5eeb24a8082f..f60de54d2042 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -525,6 +525,13 @@ void wbc_attach_and_unlock_inode(struct writeback_control *wbc,
 
 	wb_get(wbc->wb);
 	spin_unlock(&inode->i_lock);
+
+	/*
+	 * A dying wb indicates that the memcg-blkcg mapping has changed
+	 * and a new wb is already serving the memcg.  Switch immediately.
+	 */
+	if (unlikely(wb_dying(wbc->wb)))
+		inode_switch_wbs(inode, wbc->wb_id);
 }
 
 /**
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
index e047b496a0b9..a48d90e3bcbb 100644
--- a/include/linux/backing-dev-defs.h
+++ b/include/linux/backing-dev-defs.h
@@ -219,6 +219,17 @@ static inline void wb_put(struct bdi_writeback *wb)
 		percpu_ref_put(&wb->refcnt);
 }
 
+/**
+ * wb_dying - is a wb dying?
+ * @wb: bdi_writeback of interest
+ *
+ * Returns whether @wb is unlinked and being drained.
+ */
+static inline bool wb_dying(struct bdi_writeback *wb)
+{
+	return percpu_ref_is_dying(&wb->refcnt);
+}
+
 #else	/* CONFIG_CGROUP_WRITEBACK */
 
 static inline bool wb_tryget(struct bdi_writeback *wb)
@@ -234,6 +245,11 @@ static inline void wb_put(struct bdi_writeback *wb)
 {
 }
 
+static inline bool wb_dying(struct bdi_writeback *wb)
+{
+	return false;
+}
+
 #endif	/* CONFIG_CGROUP_WRITEBACK */
 
 #endif	/* __LINUX_BACKING_DEV_DEFS_H */