diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 6b838d3ae7c2..baa97bda1c7a 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -2730,7 +2730,9 @@ static int dbBackSplit(dmtree_t * tp, int leafno)
  *	leafno	- the number of the leaf to be updated.
  *	newval	- the new value for the leaf.
  *
- * RETURN VALUES: none
+ * RETURN VALUES:
+ *  0		- success
+ *	-EIO	- i/o error
  */
 static int dbJoin(dmtree_t * tp, int leafno, int newval)
 {
@@ -2757,6 +2759,10 @@ static int dbJoin(dmtree_t * tp, int leafno, int newval)
 		 * get the buddy size (number of words covered) of
 		 * the new value.
 		 */
+
+		if ((newval - tp->dmt_budmin) < BUDMIN)
+			return -EIO;
+
 		budsz = BUDSIZE(newval, tp->dmt_budmin);
 
 		/* try to join.