1 files changed, 49 insertions, 18 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 1c90005ab343..f102e88fc785 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3253,26 +3253,64 @@ static void calc_sectors(struct r10conf *conf, sector_t size)
         }
 }
 
+enum geo_type {geo_new, geo_old, geo_start};
+static int setup_geo(struct geom *geo, struct mddev *mddev, enum geo_type new)
+{
+        int nc, fc, fo;
+        int layout, chunk, disks;
+        switch (new) {
+        case geo_old:
+                layout = mddev->layout;
+                chunk = mddev->chunk_sectors;
+                disks = mddev->raid_disks - mddev->delta_disks;
+                break;
+        case geo_new:
+                layout = mddev->new_layout;
+                chunk = mddev->new_chunk_sectors;
+                disks = mddev->raid_disks;
+                break;
+        default: /* avoid 'may be unused' warnings */
+        case geo_start: /* new when starting reshape - raid_disks not
+                         * updated yet. */
+                layout = mddev->new_layout;
+                chunk = mddev->new_chunk_sectors;
+                disks = mddev->raid_disks + mddev->delta_disks;
+                break;
+        }
+        if (layout >> 17)
+                return -1;
+        if (chunk < (PAGE_SIZE >> 9) ||
+            !is_power_of_2(chunk))
+                return -2;
+        nc = layout & 255;
+        fc = (layout >> 8) & 255;
+        fo = layout & (1<<16);
+        geo->raid_disks = disks;
+        geo->near_copies = nc;
+        geo->far_copies = fc;
+        geo->far_offset = fo;
+        geo->chunk_mask = chunk - 1;
+        geo->chunk_shift = ffz(~chunk);
+        return nc*fc;
+}
+
 static struct r10conf *setup_conf(struct mddev *mddev)
 {
         struct r10conf *conf = NULL;
-        int nc, fc, fo;
         int err = -EINVAL;
+        struct geom geo;
+        int copies;
+
+        copies = setup_geo(&geo, mddev, geo_new);
 
-        if (mddev->new_chunk_sectors < (PAGE_SIZE >> 9) ||
-            !is_power_of_2(mddev->new_chunk_sectors)) {
+        if (copies == -2) {
                 printk(KERN_ERR "md/raid10:%s: chunk size must be "
                        "at least PAGE_SIZE(%ld) and be a power of 2.\n",
                        mdname(mddev), PAGE_SIZE);
                 goto out;
         }
 
-        nc = mddev->new_layout & 255;
-        fc = (mddev->new_layout >> 8) & 255;
-        fo = mddev->new_layout & (1<<16);
-
-        if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
-            (mddev->new_layout >> 17)) {
+        if (copies < 2 || copies > mddev->raid_disks) {
                 printk(KERN_ERR "md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
                        mdname(mddev), mddev->new_layout);
                 goto out;
@@ -3292,15 +3330,8 @@ static struct r10conf *setup_conf(struct mddev *mddev)
         if (!conf->tmppage)
                 goto out;
 
-
-        conf->geo.raid_disks = mddev->raid_disks;
-        conf->geo.near_copies = nc;
-        conf->geo.far_copies = fc;
-        conf->copies = nc*fc;
-        conf->geo.far_offset = fo;
-        conf->geo.chunk_mask = mddev->new_chunk_sectors - 1;
-        conf->geo.chunk_shift = ffz(~mddev->new_chunk_sectors);
-
+        conf->geo = geo;
+        conf->copies = copies;
         conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
                                            r10bio_pool_free, conf);
         if (!conf->r10bio_pool)