md: check that internal bitmap does not overlap other data

[cascardo/linux.git] / drivers / md / md.c

diff --git a/drivers/md/md.c b/drivers/md/md.c
index bae4233..36c05ba 100644 (file)
--- 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);