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authorNeilBrown <neilb@suse.de>2009-03-31 14:39:39 +1100
committerNeilBrown <neilb@suse.de>2009-03-31 14:39:39 +1100
commit245f46c2c221ef09c7db892f0e3fc2149be42052 (patch)
treebe7e6f4b7b65b682c43e59ef17f7ed580bc8a82b /drivers/md/raid5.c
parent409c57f3801701dfee27a28103dda4831306cb20 (diff)
downloadop-kernel-dev-245f46c2c221ef09c7db892f0e3fc2149be42052.zip
op-kernel-dev-245f46c2c221ef09c7db892f0e3fc2149be42052.tar.gz
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 <neilb@suse.de>
Diffstat (limited to 'drivers/md/raid5.c')
-rw-r--r--drivers/md/raid5.c64
1 files changed, 59 insertions, 5 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 81789fa..5b346b4 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 =
{
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