1 files changed, 7 insertions, 1 deletions

diff --git a/lib/idr.c b/lib/idr.c
index 7a785a0c2ea0..1c4f9281f412 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -220,8 +220,14 @@ build_up:
          */
         while ((layers < (MAX_LEVEL - 1)) && (id >= (1 << (layers*IDR_BITS)))) {
                 layers++;
-                if (!p->count)
+                if (!p->count) {
+                        /* special case: if the tree is currently empty,
+                         * then we grow the tree by moving the top node
+                         * upwards.
+                         */
+                        p->layer++;
                         continue;
+                }
                 if (!(new = get_from_free_list(idp))) {
                         /*
                          * The allocation failed.  If we built part of