[PATCH] md: Split reshape handler in check_reshape and start_reshape

check_reshape checks validity and does things that can be done instantly -
like adding devices to raid1.  start_reshape initiates a restriping process to
convert the whole array.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index b9dfdfccdb78..1a637676a930 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2594,7 +2594,7 @@ static int do_md_run(mddev_t * mddev)
         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
 
         if (mddev->reshape_position != MaxSector &&
-            pers->reshape == NULL) {
+            pers->start_reshape == NULL) {
                 /* This personality cannot handle reshaping... */
                 mddev->pers = NULL;
                 module_put(pers->owner);
@@ -3556,14 +3556,16 @@ static int update_raid_disks(mddev_t *mddev, int raid_disks)
 {
         int rv;
         /* change the number of raid disks */
-        if (mddev->pers->reshape == NULL)
+        if (mddev->pers->check_reshape == NULL)
                 return -EINVAL;
         if (raid_disks <= 0 ||
             raid_disks >= mddev->max_disks)
                 return -EINVAL;
-        if (mddev->sync_thread)
+        if (mddev->sync_thread || mddev->reshape_position != MaxSector)
                 return -EBUSY;
-        rv = mddev->pers->reshape(mddev, raid_disks);
+        mddev->delta_disks = raid_disks - mddev->raid_disks;
+
+        rv = mddev->pers->check_reshape(mddev);
         return rv;
 }