+#ifdef EXT2FS_DEBUG
+
+static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
+
+unsigned long ext2_count_free (struct buffer_head * map, unsigned int numchars)
+{
+ unsigned int i;
+ unsigned long sum = 0;
+
+ if (!map)
+ return (0);
+ for (i = 0; i < numchars; i++)
+ sum += nibblemap[map->b_data[i] & 0xf] +
+ nibblemap[(map->b_data[i] >> 4) & 0xf];
+ return (sum);
+}
+
+#endif /* EXT2FS_DEBUG */
+