md: fix v1.x metadata update when a disk is missing.

If an array with 1.x metadata is assembled with the last disk missing,
md doesn't properly record the fact that the disk was missing.

This is unlikely to cause a real problem as the event count will be
different to the count on the missing disk so it won't be included in
the array.  However it could still cause confusion.

So make sure we clear all the relevant slots, not just the early ones.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index bdd9bba577b076addf1c1c9e880fd8c4498aac1b..f20d13e717d55e0a04de747f62384d2ce4b0b310 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1643,7 +1643,9 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
                bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
                if (rdev->sb_size & bmask)
                        rdev->sb_size = (rdev->sb_size | bmask) + 1;
-       }
+       } else
+               max_dev = le32_to_cpu(sb->max_dev);
+
        for (i=0; i<max_dev;i++)
                sb->dev_roles[i] = cpu_to_le16(0xfffe);