+/*
+ * DELTA: describe a change to the in-core extent list.
+ *
+ * Internally the use of xed_blockount is somewhat funky.
+ * xed_blockcount contains an offset much of the time because this
+ * makes merging changes easier. (xfs_fileoff_t and xfs_filblks_t are
+ * the same underlying type).
+ */
+typedef struct xfs_extdelta
+{
+ xfs_fileoff_t xed_startoff; /* offset of range */
+ xfs_filblks_t xed_blockcount; /* blocks in range */
+} xfs_extdelta_t;
+