6 files changed, 41 insertions, 35 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 4edcda8f4869..4869128bf742 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3001,6 +3001,9 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
                 return -EINVAL;
         }
 
+        list_for_each_entry(rdev, &mddev->disks, same_set)
+                rdev->new_raid_disk = rdev->raid_disk;
+
         /* ->takeover must set new_* and/or delta_disks
          * if it succeeds, and may set them when it fails.
          */
@@ -3051,13 +3054,35 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
                 mddev->safemode = 0;
         }
 
-        module_put(mddev->pers->owner);
-        /* Invalidate devices that are now superfluous */
-        list_for_each_entry(rdev, &mddev->disks, same_set)
-                if (rdev->raid_disk >= mddev->raid_disks) {
-                        rdev->raid_disk = -1;
+        list_for_each_entry(rdev, &mddev->disks, same_set) {
+                char nm[20];
+                if (rdev->raid_disk < 0)
+                        continue;
+                if (rdev->new_raid_disk > mddev->raid_disks)
+                        rdev->new_raid_disk = -1;
+                if (rdev->new_raid_disk == rdev->raid_disk)
+                        continue;
+                sprintf(nm, "rd%d", rdev->raid_disk);
+                sysfs_remove_link(&mddev->kobj, nm);
+        }
+        list_for_each_entry(rdev, &mddev->disks, same_set) {
+                if (rdev->raid_disk < 0)
+                        continue;
+                if (rdev->new_raid_disk == rdev->raid_disk)
+                        continue;
+                rdev->raid_disk = rdev->new_raid_disk;
+                if (rdev->raid_disk < 0)
                         clear_bit(In_sync, &rdev->flags);
+                else {
+                        char nm[20];
+                        sprintf(nm, "rd%d", rdev->raid_disk);
+                        if(sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
+                                printk("md: cannot register %s for %s after level change\n",
+                                       nm, mdname(mddev));
                 }
+        }
+
+        module_put(mddev->pers->owner);
         mddev->pers = pers;
         mddev->private = priv;
         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 7ab5ea155452..10597bfec000 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -78,6 +78,9 @@ struct mdk_rdev_s
 
         int desc_nr;                    /* descriptor index in the superblock */
         int raid_disk;                  /* role of device in array */
+        int new_raid_disk;              /* role that the device will have in
+                                         * the array after a level-change completes.
+                                         */
         int saved_raid_disk;            /* role that device used to have in the
                                          * array and could again if we did a partial
                                          * resync from the bitmap
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index e70f004c99e8..7c7c38058bc2 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -173,9 +173,11 @@ static int create_strip_zones(mddev_t *mddev, raid0_conf_t **private_conf)
         list_for_each_entry(rdev1, &mddev->disks, same_set) {
                 int j = rdev1->raid_disk;
 
-                if (mddev->level == 10)
+                if (mddev->level == 10) {
                         /* taking over a raid10-n2 array */
                         j /= 2;
+                        rdev1->new_raid_disk = j;
+                }
 
                 if (j < 0 || j >= mddev->raid_disks) {
                         printk(KERN_ERR "md/raid0:%s: bad disk number %d - "
@@ -361,12 +363,6 @@ static int raid0_run(mddev_t *mddev)
                 mddev->private = conf;
         }
         conf = mddev->private;
-        if (conf->scale_raid_disks) {
-                int i;
-                for (i=0; i < conf->strip_zone[0].nb_dev; i++)
-                        conf->devlist[i]->raid_disk /= conf->scale_raid_disks;
-                /* FIXME update sysfs rd links */
-        }
 
         /* calculate array device size */
         md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
@@ -643,7 +639,6 @@ static void *raid0_takeover_raid10(mddev_t *mddev)
         mddev->recovery_cp = MaxSector;
 
         create_strip_zones(mddev, &priv_conf);
-        priv_conf->scale_raid_disks = 2;
         return priv_conf;
 }
 
diff --git a/drivers/md/raid0.h b/drivers/md/raid0.h
index d724e664ca4d..91f8e876ee64 100644
--- a/drivers/md/raid0.h
+++ b/drivers/md/raid0.h
@@ -13,9 +13,6 @@ struct raid0_private_data
         struct strip_zone *strip_zone;
         mdk_rdev_t **devlist; /* lists of rdevs, pointed to by strip_zone->dev */
         int nr_strip_zones;
-        int scale_raid_disks; /* divide rdev->raid_disks by this in run()
-                               * to handle conversion from raid10
-                               */
 };
 
 typedef struct raid0_private_data raid0_conf_t;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 6d420cb487b5..1bab3559f3e2 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2241,7 +2241,6 @@ static conf_t *setup_conf(mddev_t *mddev)
         if (!conf->thread)
                 goto out;
 
-        conf->scale_disks = 0;
         conf->mddev = mddev;
         return conf;
 
@@ -2300,11 +2299,6 @@ static int run(mddev_t *mddev)
                 if (disk_idx >= conf->raid_disks
                     || disk_idx < 0)
                         continue;
-                if (conf->scale_disks) {
-                        disk_idx *= conf->scale_disks;
-                        rdev->raid_disk = disk_idx;
-                        /* MOVE 'rd%d' link !! */
-                }
                 disk = conf->mirrors + disk_idx;
 
                 disk->rdev = rdev;
@@ -2435,13 +2429,6 @@ static void *raid10_takeover_raid0(mddev_t *mddev)
                 return ERR_PTR(-EINVAL);
         }
 
-        /* Update slot numbers to obtain
-         * degraded raid10 with missing mirrors
-         */
-        list_for_each_entry(rdev, &mddev->disks, same_set) {
-                rdev->raid_disk *= 2;
-        }
-
         /* Set new parameters */
         mddev->new_level = 10;
         /* new layout: far_copies = 1, near_copies = 2 */
@@ -2454,7 +2441,11 @@ static void *raid10_takeover_raid0(mddev_t *mddev)
         mddev->recovery_cp = MaxSector;
 
         conf = setup_conf(mddev);
-        conf->scale_disks = 2;
+        if (!IS_ERR(conf))
+                list_for_each_entry(rdev, &mddev->disks, same_set)
+                        if (rdev->raid_disk >= 0)
+                                rdev->new_raid_disk = rdev->raid_disk * 2;
+                
         return conf;
 }
 
diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h
index 3824a087e17c..2316ac2e8e21 100644
--- a/drivers/md/raid10.h
+++ b/drivers/md/raid10.h
@@ -38,11 +38,6 @@ struct r10_private_data_s {
         int chunk_shift; /* shift from chunks to sectors */
         sector_t chunk_mask;
 
-        int                     scale_disks;  /* When starting array, multiply
-                                               * each ->raid_disk by this.
-                                               * Need for raid0->raid10 migration
-                                               */
-
         struct list_head        retry_list;
         /* queue pending writes and submit them on unplug */
         struct bio_list         pending_bio_list;