1 files changed, 14 insertions, 2 deletions

diff --git a/lib/idr.c b/lib/idr.c
index 305117c..7b5a59c 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -100,10 +100,11 @@ static int sub_alloc(struct idr *idp, void *ptr, int *starting_id)
 	int n, m, sh;
 	struct idr_layer *p, *new;
 	struct idr_layer *pa[MAX_LEVEL];
-	int l, id;
+	int l, id, oid;
 	long bm;
 
 	id = *starting_id;
+ restart:
 	p = idp->top;
 	l = idp->layers;
 	pa[l--] = NULL;
@@ -117,12 +118,23 @@ static int sub_alloc(struct idr *idp, void *ptr, int *starting_id)
 		if (m == IDR_SIZE) {
 			/* no space available go back to previous layer. */
 			l++;
+			oid = id;
 			id = (id | ((1 << (IDR_BITS * l)) - 1)) + 1;
+
+			/* if already at the top layer, we need to grow */
 			if (!(p = pa[l])) {
 				*starting_id = id;
 				return -2;
 			}
-			continue;
+
+			/* If we need to go up one layer, continue the
+			 * loop; otherwise, restart from the top.
+			 */
+			sh = IDR_BITS * (l + 1);
+			if (oid >> sh == id >> sh)
+				continue;
+			else
+				goto restart;
 		}
 		if (m != n) {
 			sh = IDR_BITS*l;