From 245f46c2c221ef09c7db892f0e3fc2149be42052 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 31 Mar 2009 14:39:39 +1100 Subject: md: add ->takeover method to support changing the personality managing an array Implement this for RAID6 to be able to 'takeover' a RAID5 array. The new RAID6 will use a layout which places Q on the last device, and that device will be missing. If there are any available spares, one will immediately have Q recovered onto it. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 59 insertions(+), 5 deletions(-) (limited to 'drivers/md/raid5.c') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 81789fa7a02..5b346b41e51 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -933,8 +933,10 @@ static int grow_stripes(raid5_conf_t *conf, int num) struct kmem_cache *sc; int devs = conf->raid_disks; - sprintf(conf->cache_name[0], "raid5-%s", mdname(conf->mddev)); - sprintf(conf->cache_name[1], "raid5-%s-alt", mdname(conf->mddev)); + sprintf(conf->cache_name[0], + "raid%d-%s", conf->level, mdname(conf->mddev)); + sprintf(conf->cache_name[1], + "raid%d-%s-alt", conf->level, mdname(conf->mddev)); conf->active_name = 0; sc = kmem_cache_create(conf->cache_name[conf->active_name], sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), @@ -4361,10 +4363,12 @@ static int run(mddev_t *mddev) BUG_ON(mddev->chunk_size != mddev->new_chunk); BUG_ON(mddev->delta_disks != 0); } - conf = setup_conf(mddev); - if (conf == NULL) - return -EIO; + if (mddev->private == NULL) + conf = setup_conf(mddev); + else + conf = mddev->private; + if (IS_ERR(conf)) return PTR_ERR(conf); @@ -4880,6 +4884,55 @@ static void raid5_quiesce(mddev_t *mddev, int state) } } +static struct mdk_personality raid5_personality; + +static void *raid6_takeover(mddev_t *mddev) +{ + /* Currently can only take over a raid5. We map the + * personality to an equivalent raid6 personality + * with the Q block at the end. + */ + int new_layout; + + if (mddev->pers != &raid5_personality) + return ERR_PTR(-EINVAL); + if (mddev->degraded > 1) + return ERR_PTR(-EINVAL); + if (mddev->raid_disks > 253) + return ERR_PTR(-EINVAL); + if (mddev->raid_disks < 3) + return ERR_PTR(-EINVAL); + + switch (mddev->layout) { + case ALGORITHM_LEFT_ASYMMETRIC: + new_layout = ALGORITHM_LEFT_ASYMMETRIC_6; + break; + case ALGORITHM_RIGHT_ASYMMETRIC: + new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6; + break; + case ALGORITHM_LEFT_SYMMETRIC: + new_layout = ALGORITHM_LEFT_SYMMETRIC_6; + break; + case ALGORITHM_RIGHT_SYMMETRIC: + new_layout = ALGORITHM_RIGHT_SYMMETRIC_6; + break; + case ALGORITHM_PARITY_0: + new_layout = ALGORITHM_PARITY_0_6; + break; + case ALGORITHM_PARITY_N: + new_layout = ALGORITHM_PARITY_N; + break; + default: + return ERR_PTR(-EINVAL); + } + mddev->new_level = 6; + mddev->new_layout = new_layout; + mddev->delta_disks = 1; + mddev->raid_disks += 1; + return setup_conf(mddev); +} + + static struct mdk_personality raid6_personality = { .name = "raid6", @@ -4900,6 +4953,7 @@ static struct mdk_personality raid6_personality = .start_reshape = raid5_start_reshape, #endif .quiesce = raid5_quiesce, + .takeover = raid6_takeover, }; static struct mdk_personality raid5_personality = { -- cgit v1.2.3