diff --git a/drivers/md/md.c b/drivers/md/md.c
index bae4233..36c05ba 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3176,13 +3176,33 @@
 	 * Drop all container device buffers, from now on
 	 * the only valid external interface is through the md
 	 * device.
-	 * Also find largest hardsector size
 	 */
 	ITERATE_RDEV(mddev,rdev,tmp) {
 		if (test_bit(Faulty, &rdev->flags))
 			continue;
 		sync_blockdev(rdev->bdev);
 		invalidate_bdev(rdev->bdev);
+
+		/* perform some consistency tests on the device.
+		 * We don't want the data to overlap the metadata,
+		 * Internal Bitmap issues has handled elsewhere.
+		 */
+		if (rdev->data_offset < rdev->sb_offset) {
+			if (mddev->size &&
+			    rdev->data_offset + mddev->size*2
+			    > rdev->sb_offset*2) {
+				printk("md: %s: data overlaps metadata\n",
+				       mdname(mddev));
+				return -EINVAL;
+			}
+		} else {
+			if (rdev->sb_offset*2 + rdev->sb_size/512
+			    > rdev->data_offset) {
+				printk("md: %s: metadata overlaps data\n",
+				       mdname(mddev));
+				return -EINVAL;
+			}
+		}
 	}
 
 	md_probe(mddev->unit, NULL, NULL);