+static inline u64
+end_offset(u64 start, u64 len)
+{
+ u64 end;
+
+ end = start + len;
+ return end >= start ? end : NFS4_MAX_UINT64;
+}
+
+/* last octet in a range */
+static inline u64
+last_byte_offset(u64 start, u64 len)
+{
+ u64 end;
+
+ BUG_ON(!len);
+ end = start + len;
+ return end > start ? end - 1 : NFS4_MAX_UINT64;
+}
+
+/*
+ * is l2 fully contained in l1?
+ * start1 end1
+ * [----------------------------------)
+ * start2 end2
+ * [----------------)
+ */
+static inline int
+lo_seg_contained(struct pnfs_layout_range *l1,
+ struct pnfs_layout_range *l2)
+{
+ u64 start1 = l1->offset;
+ u64 end1 = end_offset(start1, l1->length);
+ u64 start2 = l2->offset;
+ u64 end2 = end_offset(start2, l2->length);
+
+ return (start1 <= start2) && (end1 >= end2);
+}
+
+/*
+ * is l1 and l2 intersecting?
+ * start1 end1
+ * [----------------------------------)
+ * start2 end2
+ * [----------------)
+ */
+static inline int
+lo_seg_intersecting(struct pnfs_layout_range *l1,
+ struct pnfs_layout_range *l2)
+{
+ u64 start1 = l1->offset;
+ u64 end1 = end_offset(start1, l1->length);
+ u64 start2 = l2->offset;
+ u64 end2 = end_offset(start2, l2->length);
+
+ return (end1 == NFS4_MAX_UINT64 || end1 > start2) &&
+ (end2 == NFS4_MAX_UINT64 || end2 > start1);
+}
+