md: Fix removal of extra drives when converting RAID6 to RAID5

When a RAID6 is converted to a RAID5, the extra drive should
be discarded.  However it isn't due to a typo in a comparison.

This bug was introduced in commit e93f68a1fc6 in 2.6.35-rc4
and is suitable for any -stable since than.

As the extra drive is not removed, the 'degraded' counter is wrong and
so the RAID5 will not respond correctly to a subsequent failure.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 665851308818..3194a80f3620 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3126,7 +3126,7 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
                 char nm[20];
                 if (rdev->raid_disk < 0)
                         continue;
-                if (rdev->new_raid_disk > mddev->raid_disks)
+                if (rdev->new_raid_disk >= mddev->raid_disks)
                         rdev->new_raid_disk = -1;
                 if (rdev->new_raid_disk == rdev->raid_disk)
                         continue;