diff --git a/block/genhd.c b/block/genhd.c
index 0a536dc05f3b..666e11b83983 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -653,7 +653,6 @@ void del_gendisk(struct gendisk *disk)
 	disk->flags &= ~GENHD_FL_UP;
 
 	sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
-	bdi_unregister(&disk->queue->backing_dev_info);
 	blk_unregister_queue(disk);
 	blk_unregister_region(disk_devt(disk), disk->minors);
 
diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 85b8036deaa3..683dff272562 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -1750,6 +1750,7 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
 	struct nvme_iod *iod;
 	dma_addr_t meta_dma = 0;
 	void *meta = NULL;
+	void __user *metadata;
 
 	if (copy_from_user(&io, uio, sizeof(io)))
 		return -EFAULT;
@@ -1763,6 +1764,8 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
 		meta_len = 0;
 	}
 
+	metadata = (void __user *)(unsigned long)io.metadata;
+
 	write = io.opcode & 1;
 
 	switch (io.opcode) {
@@ -1786,13 +1789,13 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
 	if (meta_len) {
 		meta = dma_alloc_coherent(&dev->pci_dev->dev, meta_len,
 						&meta_dma, GFP_KERNEL);
+
 		if (!meta) {
 			status = -ENOMEM;
 			goto unmap;
 		}
 		if (write) {
-			if (copy_from_user(meta, (void __user *)io.metadata,
-								meta_len)) {
+			if (copy_from_user(meta, metadata, meta_len)) {
 				status = -EFAULT;
 				goto unmap;
 			}
@@ -1819,8 +1822,7 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
 	nvme_free_iod(dev, iod);
 	if (meta) {
 		if (status == NVME_SC_SUCCESS && !write) {
-			if (copy_to_user((void __user *)io.metadata, meta,
-								meta_len))
+			if (copy_to_user(metadata, meta, meta_len))
 				status = -EFAULT;
 		}
 		dma_free_coherent(&dev->pci_dev->dev, meta_len, meta, meta_dma);
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index aff923ae8c4b..d87d8eced064 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -116,7 +116,6 @@ __printf(3, 4)
 int bdi_register(struct backing_dev_info *bdi, struct device *parent,
 		const char *fmt, ...);
 int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);
-void bdi_unregister(struct backing_dev_info *bdi);
 int __must_check bdi_setup_and_register(struct backing_dev_info *, char *);
 void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
 			enum wb_reason reason);
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index 880dd7437172..c178d13d6f4c 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -250,7 +250,6 @@ DEFINE_EVENT(writeback_class, name, \
 DEFINE_WRITEBACK_EVENT(writeback_nowork);
 DEFINE_WRITEBACK_EVENT(writeback_wake_background);
 DEFINE_WRITEBACK_EVENT(writeback_bdi_register);
-DEFINE_WRITEBACK_EVENT(writeback_bdi_unregister);
 
 DECLARE_EVENT_CLASS(wbc_class,
 	TP_PROTO(struct writeback_control *wbc, struct backing_dev_info *bdi),
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 6dc4580df2af..000e7b3b9896 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -359,23 +359,6 @@ static void bdi_wb_shutdown(struct backing_dev_info *bdi)
 	flush_delayed_work(&bdi->wb.dwork);
 }
 
-/*
- * Called when the device behind @bdi has been removed or ejected.
- *
- * We can't really do much here except for reducing the dirty ratio at
- * the moment.  In the future we should be able to set a flag so that
- * the filesystem can handle errors at mark_inode_dirty time instead
- * of only at writeback time.
- */
-void bdi_unregister(struct backing_dev_info *bdi)
-{
-	if (WARN_ON_ONCE(!bdi->dev))
-		return;
-
-	bdi_set_min_ratio(bdi, 0);
-}
-EXPORT_SYMBOL(bdi_unregister);
-
 static void bdi_wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi)
 {
 	memset(wb, 0, sizeof(*wb));
@@ -443,6 +426,7 @@ void bdi_destroy(struct backing_dev_info *bdi)
 	int i;
 
 	bdi_wb_shutdown(bdi);
+	bdi_set_min_ratio(bdi, 0);
 
 	WARN_ON(!list_empty(&bdi->work_list));
 	WARN_ON(delayed_work_pending(&bdi->wb.dwork));