+enum {
+ IAM_IDLE_HEADER_MAGIC = 0x7903,
+};
+
+/*
+ * Header structure to record idle blocks.
+ */
+struct iam_idle_head {
+ __le16 iih_magic;
+ __le16 iih_count; /* how many idle blocks in this head */
+ __le32 iih_next; /* next head for idle blocks */
+ __le32 iih_blks[0];
+};
+