+ * idr_for_each - iterate through all stored pointers
+ * @idp: idr handle
+ * @fn: function to be called for each pointer
+ * @data: data passed back to callback function
+ *
+ * Iterate over the pointers registered with the given idr. The
+ * callback function will be called for each pointer currently
+ * registered, passing the id, the pointer and the data pointer passed
+ * to this function. It is not safe to modify the idr tree while in
+ * the callback, so functions such as idr_get_new and idr_remove are
+ * not allowed.
+ *
+ * We check the return of @fn each time. If it returns anything other
+ * than 0, we break out and return that value.
+ *
+ * The caller must serialize idr_for_each() vs idr_get_new() and idr_remove().
+ */
+int idr_for_each(struct idr *idp,
+ int (*fn)(int id, void *p, void *data), void *data)
+{
+ int n, id, max, error = 0;
+ struct idr_layer *p;
+ struct idr_layer *pa[MAX_LEVEL];
+ struct idr_layer **paa = &pa[0];
+
+ n = idp->layers * IDR_BITS;
+ p = rcu_dereference_raw(idp->top);
+ max = 1 << n;
+
+ id = 0;
+ while (id < max) {
+ while (n > 0 && p) {
+ n -= IDR_BITS;
+ *paa++ = p;
+ p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
+ }
+
+ if (p) {
+ error = fn(id, (void *)p, data);
+ if (error)
+ break;
+ }
+
+ id += 1 << n;
+ while (n < fls(id)) {
+ n += IDR_BITS;
+ p = *--paa;
+ }
+ }
+
+ return error;
+}
+EXPORT_SYMBOL(idr_for_each);
+
+/**
+ * idr_get_next - lookup next object of id to given id.
+ * @idp: idr handle
+ * @id: pointer to lookup key
+ *
+ * Returns pointer to registered object with id, which is next number to
+ * given id.
+ */
+
+void *idr_get_next(struct idr *idp, int *nextidp)
+{
+ struct idr_layer *p, *pa[MAX_LEVEL];
+ struct idr_layer **paa = &pa[0];
+ int id = *nextidp;
+ int n, max;
+
+ /* find first ent */
+ n = idp->layers * IDR_BITS;
+ max = 1 << n;
+ p = rcu_dereference(idp->top);
+ if (!p)
+ return NULL;
+
+ while (id < max) {
+ while (n > 0 && p) {
+ n -= IDR_BITS;
+ *paa++ = p;
+ p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]);
+ }
+
+ if (p) {
+ *nextidp = id;
+ return p;
+ }
+
+ id += 1 << n;
+ while (n < fls(id)) {
+ n += IDR_BITS;
+ p = *--paa;
+ }
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(idr_get_next);
+
+
+/**