2 files changed, 40 insertions, 0 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 2a64cba9ea72..22c630b7ba6c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3017,6 +3017,20 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
                         mddev->to_remove = &md_redundancy_group;
         }
 
+        if (mddev->pers->sync_request == NULL &&
+            mddev->external) {
+                /* We are converting from a no-redundancy array
+                 * to a redundancy array and metadata is managed
+                 * externally so we need to be sure that writes
+                 * won't block due to a need to transition
+                 *      clean->dirty
+                 * until external management is started.
+                 */
+                mddev->in_sync = 0;
+                mddev->safemode_delay = 0;
+                mddev->safemode = 0;
+        }
+
         module_put(mddev->pers->owner);
         /* Invalidate devices that are now superfluous */
         list_for_each_entry(rdev, &mddev->disks, same_set)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 10af3715b1fc..bb28fd6b44fe 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -52,6 +52,7 @@
 #include <linux/cpu.h>
 #include "md.h"
 #include "raid5.h"
+#include "raid0.h"
 #include "bitmap.h"
 
 /*
@@ -5619,6 +5620,21 @@ static void raid5_quiesce(mddev_t *mddev, int state)
 }
 
 
+static void *raid5_takeover_raid0(mddev_t *mddev)
+{
+
+        mddev->new_level = 5;
+        mddev->new_layout = ALGORITHM_PARITY_N;
+        mddev->new_chunk_sectors = mddev->chunk_sectors;
+        mddev->raid_disks += 1;
+        mddev->delta_disks = 1;
+        /* make sure it will be not marked as dirty */
+        mddev->recovery_cp = MaxSector;
+
+        return setup_conf(mddev);
+}
+
+
 static void *raid5_takeover_raid1(mddev_t *mddev)
 {
         int chunksect;
@@ -5748,6 +5764,16 @@ static void *raid5_takeover(mddev_t *mddev)
          *  raid4 - trivial - just use a raid4 layout.
          *  raid6 - Providing it is a *_6 layout
          */
+        if (mddev->level == 0) {
+                /* for raid0 takeover only one zone is supported */
+                struct raid0_private_data *raid0_priv
+                        = mddev->private;
+                if (raid0_priv->nr_strip_zones > 1) {
+                        printk(KERN_ERR "md: cannot takeover raid 0 with more than one zone.\n");
+                        return ERR_PTR(-EINVAL);
+                }
+                return raid5_takeover_raid0(mddev);
+        }
 
         if (mddev->level == 1)
                 return raid5_takeover_raid1(mddev);