+/*
+ * The on-disk (optional) layout structure.
+ * sits in an EXOFS_ATTR_INODE_FILE_LAYOUT or EXOFS_ATTR_INODE_DIR_LAYOUT
+ * attribute, attached to any inode, usually to a directory.
+ */
+
+enum exofs_inode_layout_gen_functions {
+ LAYOUT_MOVING_WINDOW = 0,
+ LAYOUT_IMPLICT = 1,
+};
+
+struct exofs_on_disk_inode_layout {
+ __le16 gen_func; /* One of enum exofs_inode_layout_gen_functions */
+ __le16 pad;
+ union {
+ /* gen_func == LAYOUT_MOVING_WINDOW (default) */
+ struct exofs_layout_sliding_window {
+ __le32 num_devices; /* first n devices in global-table*/
+ } sliding_window __packed;
+
+ /* gen_func == LAYOUT_IMPLICT */
+ struct exofs_layout_implict_list {
+ struct exofs_dt_data_map data_map;
+ /* Variable array of size data_map.cb_num_comps. These
+ * are device indexes of the devices in the global table
+ */
+ __le32 dev_indexes[];
+ } implict __packed;
+ };
+} __packed;
+
+static inline size_t exofs_on_disk_inode_layout_size(unsigned max_devs)
+{
+ return sizeof(struct exofs_on_disk_inode_layout) +
+ max_devs * sizeof(__le32);
+}
+