1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/md/persistent-data/dm-array.c b/drivers/md/persistent-data/dm-array.c
index 172147eb1d40..1d75b1dc1e2e 100644
--- a/drivers/md/persistent-data/dm-array.c
+++ b/drivers/md/persistent-data/dm-array.c
@@ -317,8 +317,16 @@ static int shadow_ablock(struct dm_array_info *info, dm_block_t *root,
          * The shadow op will often be a noop.  Only insert if it really
          * copied data.
          */
-        if (dm_block_location(*block) != b)
+        if (dm_block_location(*block) != b) {
+                /*
+                 * dm_tm_shadow_block will have already decremented the old
+                 * block, but it is still referenced by the btree.  We
+                 * increment to stop the insert decrementing it below zero
+                 * when overwriting the old value.
+                 */
+                dm_tm_inc(info->btree_info.tm, b);
                 r = insert_ablock(info, index, *block, root);
+        }
 
         return r;
 }
@@ -509,15 +517,18 @@ static int grow_add_tail_block(struct resize *resize)
 static int grow_needs_more_blocks(struct resize *resize)
 {
         int r;
+        unsigned old_nr_blocks = resize->old_nr_full_blocks;
 
         if (resize->old_nr_entries_in_last_block > 0) {
+                old_nr_blocks++;
+
                 r = grow_extend_tail_block(resize, resize->max_entries);
                 if (r)
                         return r;
         }
 
         r = insert_full_ablocks(resize->info, resize->size_of_block,
-                                resize->old_nr_full_blocks,
+                                old_nr_blocks,
                                 resize->new_nr_full_blocks,
                                 resize->max_entries, resize->value,
                                 &resize->root);