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>
This commit is contained in:
Heinz Mauelshagen 2016-08-17 15:36:44 +02:00 committed by Mike Snitzer
parent a3c06a3897
commit 9e7d9367e6

View File

@ -860,6 +860,9 @@ static int validate_region_size(struct raid_set *rs, unsigned long region_size)
{
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 @@ static int validate_raid_redundancy(struct raid_set *rs)
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 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
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);