[PATCH 3/3] DDF: compare_super_ddf: fix sequence number check

[mwilck@arcor.de]

The sequence number check in compare_super_ddf was broken,
anchor sequence number is always -1.

With this patch, mdadm will refuse to add a disk with non-matching
sequence number.

This fixes Francis Moreau's problem reported with subject
"mdadm 3.3 fails to kick out non fresh disk".

FIXME: More work is needed here. Currently mdadm won't even add the
disk to the container, that's wrong. It should be added as a spare.
---
 super-ddf.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/super-ddf.c b/super-ddf.c
index 3673cb3..002b271 100644
--- a/super-ddf.c
+++ b/super-ddf.c
@@ -3892,10 +3892,10 @@ static int compare_super_ddf(struct supertype *st, struct supertype *tst)
 	if (memcmp(first->anchor.guid, second->anchor.guid, DDF_GUID_LEN) != 0)
 		return 2;
 
-	if (!be32_eq(first->anchor.seq, second->anchor.seq)) {
-		dprintf("%s: sequence number mismatch %u/%u\n", __func__,
-			be32_to_cpu(first->anchor.seq),
-			be32_to_cpu(second->anchor.seq));
+	if (!be32_eq(first->active->seq, second->active->seq)) {
+		dprintf("%s: sequence number mismatch %u<->%u\n", __func__,
+			be32_to_cpu(first->active->seq),
+			be32_to_cpu(second->active->seq));
 		return 3;
 	}
 	if (first->max_part != second->max_part ||
-- 
1.7.3.4