diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 9620d452d030..ae94f3beb5fc 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -268,6 +268,31 @@ static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
 			if (page->index == bitmap->file_pages-1)
 				size = roundup(bitmap->last_page_size,
 					       bdev_hardsect_size(rdev->bdev));
+			/* Just make sure we aren't corrupting data or
+			 * metadata
+			 */
+			if (bitmap->offset < 0) {
+				/* DATA  BITMAP METADATA  */
+				if (bitmap->offset
+				    + page->index * (PAGE_SIZE/512)
+				    + size/512 > 0)
+					/* bitmap runs in to metadata */
+					return -EINVAL;
+				if (rdev->data_offset + mddev->size*2
+				    > rdev->sb_offset*2 + bitmap->offset)
+					/* data runs in to bitmap */
+					return -EINVAL;
+			} else if (rdev->sb_offset*2 < rdev->data_offset) {
+				/* METADATA BITMAP DATA */
+				if (rdev->sb_offset*2
+				    + bitmap->offset
+				    + page->index*(PAGE_SIZE/512) + size/512
+				    > rdev->data_offset)
+					/* bitmap runs in to data */
+					return -EINVAL;
+			} else {
+				/* DATA METADATA BITMAP - no problems */
+			}
 			md_super_write(mddev, rdev,
 				       (rdev->sb_offset<<1) + bitmap->offset
 				       + page->index * (PAGE_SIZE/512),
@@ -287,8 +312,14 @@ static int write_page(struct bitmap *bitmap, struct page *page, int wait)
 {
 	struct buffer_head *bh;
 
-	if (bitmap->file == NULL)
-		return write_sb_page(bitmap, page, wait);
+	if (bitmap->file == NULL) {
+		switch (write_sb_page(bitmap, page, wait)) {
+		case -EINVAL:
+			bitmap->flags |= BITMAP_WRITE_ERROR;
+			return -EIO;
+		}
+		return 0;
+	}
 
 	bh = page_buffers(page);
 
diff --git a/drivers/md/md.c b/drivers/md/md.c
index bae42331182d..36c05ba7855a 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3176,13 +3176,33 @@ static int do_md_run(mddev_t * mddev)
 	 * 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);