The RAID1 must have two drives and be a suitable size to
be a multiple of a chunksize that isn't too small.
---
drivers/md/raid5.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 67 insertions(+), 5 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 89ce65d..8847c14 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -4151,7 +4151,8 @@ static struct attribute_group raid5_attrs_group = {
.attrs = raid5_attrs,
};
-static raid5_conf_t *setup_conf(mddev_t *mddev, int raid_disks, int level, int layout)
+static raid5_conf_t *setup_conf(mddev_t *mddev, int raid_disks,
+ int level, int layout, int chunksize)
{
raid5_conf_t *conf;
int raid_disk, memory;
@@ -4170,7 +4171,7 @@ static raid5_conf_t *setup_conf(mddev_t *mddev, int raid_disks, int level, int l
return ERR_PTR(-EIO);
}
- if (mddev->chunk_size < PAGE_SIZE) {
+ if (chunksize < PAGE_SIZE) {
printk(KERN_ERR "md/raid5: chunk_size must be at least "
"PAGE_SIZE but %d < %ld\n",
mddev->chunk_size, PAGE_SIZE);
@@ -4237,7 +4238,7 @@ static raid5_conf_t *setup_conf(mddev_t *mddev, int raid_disks, int level, int l
conf->fullsync = 1;
}
- conf->chunk_size = mddev->chunk_size;
+ conf->chunk_size = chunksize;
conf->level = level;
if (conf->level == 6)
conf->max_degraded = 2;
@@ -4330,11 +4331,13 @@ static int run(mddev_t *mddev)
}
if (mddev->private == NULL)
- conf = setup_conf(mddev, mddev->raid_disks, mddev->level, mddev->layout);
+ conf = setup_conf(mddev, mddev->raid_disks, mddev->level,
+ mddev->layout, mddev->chunk_size);
else {
conf = mddev->private;
mddev->raid_disks = conf->raid_disks;
mddev->layout = conf->algorithm;
+ mddev->chunk_size = conf->chunk_size;
}
if (IS_ERR(conf))
@@ -4869,6 +4872,63 @@ static void raid5_quiesce(mddev_t *mddev, int state)
}
}
+
+static void *raid5_takeover_raid1(mddev_t *mddev)
+{
+ int chunksect;
+ raid5_conf_t *conf;
+
+ 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);
+
+ conf = setup_conf(mddev, 2, 5, ALGORITHM_LEFT_SYMMETRIC,
+ chunksect << 9);
+ if (IS_ERR(conf))
+ return conf;
+
+ conf->thread = md_register_thread(raid5d, mddev, "%s_raid5");
+ if (conf->thread)
+ return conf;
+
+ safe_put_page(conf->spare_page);
+ kfree(conf->disks);
+ kfree(conf->stripe_hashtbl);
+ kfree(conf);
+
+ return ERR_PTR(-ENOMEM);
+
+}
+
+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)
@@ -4911,7 +4971,8 @@ static void *raid6_takeover(mddev_t *mddev)
default:
return ERR_PTR(-EINVAL);
}
- conf = setup_conf(mddev, mddev->raid_disks + 1, 6, new_layout);
+ conf = setup_conf(mddev, mddev->raid_disks + 1, 6, new_layout,
+ mddev->chunk_size);
if (IS_ERR(conf))
return conf;
@@ -4970,6 +5031,7 @@ static struct mdk_personality raid5_personality =
.start_reshape = raid5_start_reshape,
#endif
.quiesce = raid5_quiesce,
+ .takeover = raid5_takeover,
};
static struct mdk_personality raid4_personality =
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