diff options
| -rw-r--r-- | drivers/md/raid5.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 5b346b41e51..611ea7bbf47 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4884,6 +4884,53 @@ static void raid5_quiesce(mddev_t *mddev, int state) } } + +static void *raid5_takeover_raid1(mddev_t *mddev) +{ + int chunksect; + + if (mddev->raid_disks != 2 || + mddev->degraded > 1) + return ERR_PTR(-EINVAL); + + /* Should check if there are write-behind devices? */ + + chunksect = 64*2; /* 64K by default */ + + /* The array must be an exact multiple of chunksize */ + while (chunksect && (mddev->array_sectors & (chunksect-1))) + chunksect >>= 1; + + if ((chunksect<<9) < STRIPE_SIZE) + /* array size does not allow a suitable chunk size */ + return ERR_PTR(-EINVAL); + + mddev->new_level = 5; + mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC; + mddev->new_chunk = chunksect << 9; + + return setup_conf(mddev); +} + + +static void *raid5_takeover(mddev_t *mddev) +{ + /* raid5 can take over: + * raid0 - if all devices are the same - make it a raid4 layout + * raid1 - if there are two drives. We need to know the chunk size + * raid4 - trivial - just use a raid4 layout. + * raid6 - Providing it is a *_6 layout + * + * For now, just do raid1 + */ + + if (mddev->level == 1) + return raid5_takeover_raid1(mddev); + + return ERR_PTR(-EINVAL); +} + + static struct mdk_personality raid5_personality; static void *raid6_takeover(mddev_t *mddev) @@ -4975,6 +5022,7 @@ static struct mdk_personality raid5_personality = .start_reshape = raid5_start_reshape, #endif .quiesce = raid5_quiesce, + .takeover = raid5_takeover, }; static struct mdk_personality raid4_personality = |