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-rw-r--r--drivers/md/md.c101
-rw-r--r--drivers/md/md.h10
-rw-r--r--drivers/md/raid5.c64
3 files changed, 161 insertions, 14 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 6cb31f8da14..05b613b5e4b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2649,18 +2649,101 @@ level_show(mddev_t *mddev, char *page)
static ssize_t
level_store(mddev_t *mddev, const char *buf, size_t len)
{
+ char level[16];
ssize_t rv = len;
- if (mddev->pers)
+ struct mdk_personality *pers;
+ void *priv;
+
+ if (mddev->pers == NULL) {
+ if (len == 0)
+ return 0;
+ if (len >= sizeof(mddev->clevel))
+ return -ENOSPC;
+ strncpy(mddev->clevel, buf, len);
+ if (mddev->clevel[len-1] == '\n')
+ len--;
+ mddev->clevel[len] = 0;
+ mddev->level = LEVEL_NONE;
+ return rv;
+ }
+
+ /* request to change the personality. Need to ensure:
+ * - array is not engaged in resync/recovery/reshape
+ * - old personality can be suspended
+ * - new personality will access other array.
+ */
+
+ if (mddev->sync_thread || mddev->reshape_position != MaxSector)
return -EBUSY;
- if (len == 0)
- return 0;
- if (len >= sizeof(mddev->clevel))
- return -ENOSPC;
- strncpy(mddev->clevel, buf, len);
- if (mddev->clevel[len-1] == '\n')
+
+ if (!mddev->pers->quiesce) {
+ printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
+ mdname(mddev), mddev->pers->name);
+ return -EINVAL;
+ }
+
+ /* Now find the new personality */
+ if (len == 0 || len >= sizeof(level))
+ return -EINVAL;
+ strncpy(level, buf, len);
+ if (level[len-1] == '\n')
len--;
- mddev->clevel[len] = 0;
- mddev->level = LEVEL_NONE;
+ level[len] = 0;
+
+ request_module("md-%s", level);
+ spin_lock(&pers_lock);
+ pers = find_pers(LEVEL_NONE, level);
+ if (!pers || !try_module_get(pers->owner)) {
+ spin_unlock(&pers_lock);
+ printk(KERN_WARNING "md: personality %s not loaded\n", level);
+ return -EINVAL;
+ }
+ spin_unlock(&pers_lock);
+
+ if (pers == mddev->pers) {
+ /* Nothing to do! */
+ module_put(pers->owner);
+ return rv;
+ }
+ if (!pers->takeover) {
+ module_put(pers->owner);
+ printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
+ mdname(mddev), level);
+ return -EINVAL;
+ }
+
+ /* ->takeover must set new_* and/or delta_disks
+ * if it succeeds, and may set them when it fails.
+ */
+ priv = pers->takeover(mddev);
+ if (IS_ERR(priv)) {
+ mddev->new_level = mddev->level;
+ mddev->new_layout = mddev->layout;
+ mddev->new_chunk = mddev->chunk_size;
+ mddev->raid_disks -= mddev->delta_disks;
+ mddev->delta_disks = 0;
+ module_put(pers->owner);
+ printk(KERN_WARNING "md: %s: %s would not accept array\n",
+ mdname(mddev), level);
+ return PTR_ERR(priv);
+ }
+
+ /* Looks like we have a winner */
+ mddev_suspend(mddev);
+ mddev->pers->stop(mddev);
+ module_put(mddev->pers->owner);
+ mddev->pers = pers;
+ mddev->private = priv;
+ strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
+ mddev->level = mddev->new_level;
+ mddev->layout = mddev->new_layout;
+ mddev->chunk_size = mddev->new_chunk;
+ mddev->delta_disks = 0;
+ pers->run(mddev);
+ mddev_resume(mddev);
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ md_wakeup_thread(mddev->thread);
return rv;
}
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 84b22d67ba1..8034f62a9d2 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -321,6 +321,16 @@ struct mdk_personality
* others - reserved
*/
void (*quiesce) (mddev_t *mddev, int state);
+ /* takeover is used to transition an array from one
+ * personality to another. The new personality must be able
+ * to handle the data in the current layout.
+ * e.g. 2drive raid1 -> 2drive raid5
+ * ndrive raid5 -> degraded n+1drive raid6 with special layout
+ * If the takeover succeeds, a new 'private' structure is returned.
+ * This needs to be installed and then ->run used to activate the
+ * array.
+ */
+ void *(*takeover) (mddev_t *mddev);
};
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 =
{
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-23 17:39:15 +0000