[dm-devel] [PATCH 1/5] dm raid: validate current raid sets redundancy

[Heinz Mauelshagen]

Verifying the current raid sets redundancy based on retrieved
superblock content has to use the raid level as of superblock
content (e.g. raid0), not the constructor requested one (e.g. raid10).

Using the requested raid level of raid10 lead to a "divide error"
on raid0 which defines data copies divided by to be zero.

Also check for bogus data copies.

Signed-off-by: Heinz Mauelshagen <heinzm at redhat.com>
---
 drivers/md/dm-raid.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index dfbc2bd787c1..c9287666ee5a 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -1007,7 +1007,7 @@ static int validate_raid_redundancy(struct raid_set *rs)
 		    !rs->dev[i].rdev.sb_page)
 			rebuild_cnt++;
 
-	switch (rs->raid_type->level) {
+	switch (rs->md.level) {
 	case 0:
 		break;
 	case 1:
@@ -1022,6 +1022,11 @@ static int validate_raid_redundancy(struct raid_set *rs)
 		break;
 	case 10:
 		copies = raid10_md_layout_to_copies(rs->md.new_layout);
+		if (copies < 2) {
+			DMERR("Bogus raid10 data copies < 2!");
+			return -EINVAL;
+		}
+
 		if (rebuild_cnt < copies)
 			break;
 
-- 
2.13.6