1 files changed, 7 insertions, 5 deletions

diff --git a/lib/idr.c b/lib/idr.c
index 1cac726c44bc..2eb1dca03681 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -156,10 +156,12 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa)
                         id = (id | ((1 << (IDR_BITS * l)) - 1)) + 1;
 
                         /* if already at the top layer, we need to grow */
-                        if (!(p = pa[l])) {
+                        if (id >= 1 << (idp->layers * IDR_BITS)) {
                                 *starting_id = id;
                                 return IDR_NEED_TO_GROW;
                         }
+                        p = pa[l];
+                        BUG_ON(!p);
 
                         /* If we need to go up one layer, continue the
                          * loop; otherwise, restart from the top.
@@ -502,7 +504,7 @@ void *idr_find(struct idr *idp, int id)
         int n;
         struct idr_layer *p;
 
-        p = rcu_dereference(idp->top);
+        p = rcu_dereference_raw(idp->top);
         if (!p)
                 return NULL;
         n = (p->layer+1) * IDR_BITS;
@@ -517,7 +519,7 @@ void *idr_find(struct idr *idp, int id)
         while (n > 0 && p) {
                 n -= IDR_BITS;
                 BUG_ON(n != p->layer*IDR_BITS);
-                p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]);
+                p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
         }
         return((void *)p);
 }
@@ -550,7 +552,7 @@ int idr_for_each(struct idr *idp,
         struct idr_layer **paa = &pa[0];
 
         n = idp->layers * IDR_BITS;
-        p = rcu_dereference(idp->top);
+        p = rcu_dereference_raw(idp->top);
         max = 1 << n;
 
         id = 0;
@@ -558,7 +560,7 @@ int idr_for_each(struct idr *idp,
                 while (n > 0 && p) {
                         n -= IDR_BITS;
                         *paa++ = p;
-                        p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]);
+                        p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
                 }
 
                 if (p) {