+/**
+ * target_find_device - find a se_device by its dev_index
+ * @id: dev_index
+ * @do_depend: true if caller needs target_depend_item to be done
+ *
+ * If do_depend is true, the caller must do a target_undepend_item
+ * when finished using the device.
+ *
+ * If do_depend is false, the caller must be called in a configfs
+ * callback or during removal.
+ */
+struct se_device *target_find_device(int id, bool do_depend)
+{
+ struct se_device *dev;
+
+ mutex_lock(&device_mutex);
+ dev = idr_find(&devices_idr, id);
+ if (dev && do_depend && target_depend_item(&dev->dev_group.cg_item))
+ dev = NULL;
+ mutex_unlock(&device_mutex);
+ return dev;
+}
+EXPORT_SYMBOL(target_find_device);
+
+struct devices_idr_iter {
+ int (*fn)(struct se_device *dev, void *data);
+ void *data;
+};
+
+static int target_devices_idr_iter(int id, void *p, void *data)
+{
+ struct devices_idr_iter *iter = data;
+ struct se_device *dev = p;
+
+ /*
+ * We add the device early to the idr, so it can be used
+ * by backend modules during configuration. We do not want
+ * to allow other callers to access partially setup devices,
+ * so we skip them here.
+ */
+ if (!(dev->dev_flags & DF_CONFIGURED))
+ return 0;
+
+ return iter->fn(dev, iter->data);
+}
+
+/**
+ * target_for_each_device - iterate over configured devices
+ * @fn: iterator function
+ * @data: pointer to data that will be passed to fn
+ *
+ * fn must return 0 to continue looping over devices. non-zero will break
+ * from the loop and return that value to the caller.
+ */
+int target_for_each_device(int (*fn)(struct se_device *dev, void *data),
+ void *data)
+{
+ struct devices_idr_iter iter;
+ int ret;
+
+ iter.fn = fn;
+ iter.data = data;
+
+ mutex_lock(&device_mutex);
+ ret = idr_for_each(&devices_idr, target_devices_idr_iter, &iter);
+ mutex_unlock(&device_mutex);
+ return ret;
+}
+