1 files changed, 4 insertions, 1 deletions

diff --git a/lib/idr.c b/lib/idr.c
index 422a9d5069c..c1a20690176 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -445,6 +445,7 @@ EXPORT_SYMBOL(idr_remove);
 void idr_remove_all(struct idr *idp)
 {
         int n, id, max;
+        int bt_mask;
         struct idr_layer *p;
         struct idr_layer *pa[MAX_LEVEL];
         struct idr_layer **paa = &pa[0];
@@ -462,8 +463,10 @@ void idr_remove_all(struct idr *idp)
                         p = p->ary[(id >> n) & IDR_MASK];
                 }
 
+                bt_mask = id;
                 id += 1 << n;
-                while (n < fls(id)) {
+                /* Get the highest bit that the above add changed from 0->1. */
+                while (n < fls(id ^ bt_mask)) {
                         if (p)
                                 free_layer(p);
                         n += IDR_BITS;