dm raid: support raid0 with missing metadata devices
The raid0 MD personality does not start a raid0 array with any of its
data devices missing.
dm-raid was removing data/metadata device pairs unconditionally if it
failed to read a superblock off the respective metadata device of such
pair, resulting in failure to start arrays with the raid0 personality.
Avoid removing any data/metadata device pairs in case of raid0
(e.g. lvm2 segment type 'raid0_meta') thus allowing MD to start the
array.
Also, avoid region size validation for raid0.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index b1c251872..8abde6b 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -860,6 +860,9 @@
{
unsigned long min_region_size = rs->ti->len / (1 << 21);
+ if (rs_is_raid0(rs))
+ return 0;
+
if (!region_size) {
/*
* Choose a reasonable default. All figures in sectors.
@@ -929,6 +932,8 @@
rebuild_cnt++;
switch (rs->raid_type->level) {
+ case 0:
+ break;
case 1:
if (rebuild_cnt >= rs->md.raid_disks)
goto too_many;
@@ -2334,6 +2339,13 @@
case 0:
break;
default:
+ /*
+ * We have to keep any raid0 data/metadata device pairs or
+ * the MD raid0 personality will fail to start the array.
+ */
+ if (rs_is_raid0(rs))
+ continue;
+
dev = container_of(rdev, struct raid_dev, rdev);
if (dev->meta_dev)
dm_put_device(ti, dev->meta_dev);
