diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 8847e8c5d5b4..974ecf5e0d95 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -2944,9 +2944,10 @@ static void dbAdjTree(dmtree_t *tp, int leafno, int newval, bool is_ctl)
 static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl)
 {
 	int ti, n = 0, k, x = 0;
-	int max_size;
+	int max_size, max_idx;
 
 	max_size = is_ctl ? CTLTREESIZE : TREESIZE;
+	max_idx = is_ctl ? LPERCTL : LPERDMAP;
 
 	/* first check the root of the tree to see if there is
 	 * sufficient free space.
@@ -2978,6 +2979,8 @@ static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl)
 		 */
 		assert(n < 4);
 	}
+	if (le32_to_cpu(tp->dmt_leafidx) >= max_idx)
+		return -ENOSPC;
 
 	/* set the return to the leftmost leaf describing sufficient
 	 * free space.