diff --git a/block/bdev.c b/block/bdev.c
index ed022f8c48c7..96520fac7b2f 100644
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -860,10 +860,12 @@ void blkdev_put_no_open(struct block_device *bdev)
 	put_device(&bdev->bd_device);
 }
 
-static bool bdev_writes_blocked(struct block_device *bdev)
+bool bdev_writes_blocked(struct block_device *bdev)
 {
 	return bdev->bd_writers < 0;
 }
+EXPORT_SYMBOL_GPL(bdev_writes_blocked);
+
 
 static void bdev_block_writes(struct block_device *bdev)
 {
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 0000913f7efc..3f3a29abad1f 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1239,6 +1239,18 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
 		goto out_unlock;
 	}
 
+	/*
+	 * Changing lo_offset or lo_sizelimit on a mounted device is
+	 * equivalent to modifying the block device contents, block
+	 * this if writes are blocked on the device.
+	 */
+	if ((lo->lo_offset != info->lo_offset ||
+	     lo->lo_sizelimit != info->lo_sizelimit) &&
+	    bdev_writes_blocked(lo->lo_device)) {
+		err = -EBUSY;
+		goto out_unlock;
+	}
+
 	if (lo->lo_offset != info->lo_offset ||
 	    lo->lo_sizelimit != info->lo_sizelimit) {
 		size_changed = true;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d463b9b5a0a5..6b908e9dd035 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -820,6 +820,7 @@ static inline bool bdev_read_only(struct block_device *bdev)
 	return bdev_test_flag(bdev, BD_READ_ONLY) || get_disk_ro(bdev->bd_disk);
 }
 
+bool bdev_writes_blocked(struct block_device *bdev);
 bool set_capacity_and_notify(struct gendisk *disk, sector_t size);
 void disk_force_media_change(struct gendisk *disk);
 void bdev_mark_dead(struct block_device *bdev, bool surprise);