[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, 16 insertions, 3 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index b65b8cfbdf30..04418e10d1dc 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1976,7 +1976,7 @@ static int raid1_resize(mddev_t *mddev, sector_t sectors)
         return 0;
 }
 
-static int raid1_reshape(mddev_t *mddev, int raid_disks)
+static int raid1_reshape(mddev_t *mddev)
 {
         /* We need to:
          * 1/ resize the r1bio_pool
@@ -1993,10 +1993,22 @@ static int raid1_reshape(mddev_t *mddev, int raid_disks)
         struct pool_info *newpoolinfo;
         mirror_info_t *newmirrors;
         conf_t *conf = mddev_to_conf(mddev);
-        int cnt;
+        int cnt, raid_disks;
 
         int d, d2;
 
+        /* Cannot change chunk_size, layout, or level */
+        if (mddev->chunk_size != mddev->new_chunk ||
+            mddev->layout != mddev->new_layout ||
+            mddev->level != mddev->new_level) {
+                mddev->new_chunk = mddev->chunk_size;
+                mddev->new_layout = mddev->layout;
+                mddev->new_level = mddev->level;
+                return -EINVAL;
+        }
+
+        raid_disks = mddev->raid_disks + mddev->delta_disks;
+
         if (raid_disks < conf->raid_disks) {
                 cnt=0;
                 for (d= 0; d < conf->raid_disks; d++)
@@ -2043,6 +2055,7 @@ static int raid1_reshape(mddev_t *mddev, int raid_disks)
 
         mddev->degraded += (raid_disks - conf->raid_disks);
         conf->raid_disks = mddev->raid_disks = raid_disks;
+        mddev->delta_disks = 0;
 
         conf->last_used = 0; /* just make sure it is in-range */
         lower_barrier(conf);
@@ -2084,7 +2097,7 @@ static struct mdk_personality raid1_personality =
         .spare_active   = raid1_spare_active,
         .sync_request   = sync_request,
         .resize         = raid1_resize,
-        .reshape        = raid1_reshape,
+        .check_reshape  = raid1_reshape,
         .quiesce        = raid1_quiesce,
 };