Merge remote-tracking branch 'device-mapper/for-next'
[karo-tx-linux.git] / drivers / md / persistent-data / dm-btree-remove.c
index 4d7617f..21ea537 100644 (file)
@@ -298,11 +298,16 @@ static void redistribute3(struct dm_btree_info *info, struct btree_node *parent,
 {
        int s;
        uint32_t max_entries = le32_to_cpu(left->header.max_entries);
-       unsigned target = (nr_left + nr_center + nr_right) / 3;
-       BUG_ON(target > max_entries);
+       unsigned total = nr_left + nr_center + nr_right;
+       unsigned target_right = total / 3;
+       unsigned remainder = (target_right * 3) != total;
+       unsigned target_left = target_right + remainder;
+
+       BUG_ON(target_left > max_entries);
+       BUG_ON(target_right > max_entries);
 
        if (nr_left < nr_right) {
-               s = nr_left - target;
+               s = nr_left - target_left;
 
                if (s < 0 && nr_center < -s) {
                        /* not enough in central node */
@@ -313,10 +318,10 @@ static void redistribute3(struct dm_btree_info *info, struct btree_node *parent,
                } else
                        shift(left, center, s);
 
-               shift(center, right, target - nr_right);
+               shift(center, right, target_right - nr_right);
 
        } else {
-               s = target - nr_right;
+               s = target_right - nr_right;
                if (s > 0 && nr_center < s) {
                        /* not enough in central node */
                        shift(center, right, nr_center);
@@ -326,7 +331,7 @@ static void redistribute3(struct dm_btree_info *info, struct btree_node *parent,
                } else
                        shift(center, right, s);
 
-               shift(left, center, nr_left - target);
+               shift(left, center, nr_left - target_left);
        }
 
        *key_ptr(parent, c->index) = center->keys[0];