diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 7c5036d..3a5ec76 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -339,9 +339,10 @@
 
 
 enum {
-	SKB_FCLONE_UNAVAILABLE,
-	SKB_FCLONE_ORIG,
-	SKB_FCLONE_CLONE,
+	SKB_FCLONE_UNAVAILABLE,	/* skb has no fclone (from head_cache) */
+	SKB_FCLONE_ORIG,	/* orig skb (from fclone_cache) */
+	SKB_FCLONE_CLONE,	/* companion fclone skb (from fclone_cache) */
+	SKB_FCLONE_FREE,	/* this companion fclone skb is available */
 };
 
 enum {