--- a/mpffs/common.c	Mon Jul 01 06:28:30 2013 +0000
+++ b/mpffs/common.c	Mon Jul 01 06:49:50 2013 +0000
@@ -335,6 +335,39 @@
 	chi->len = chi->end - chi->start;
 }
 
+iterate_extra_chunks(first_extra_chunk, callback, callback_data)
+	void (*callback)();
+	u_long callback_data;
+{
+	int ent;
+	struct objinfo obj;
+
+	for (ent = first_extra_chunk; ent != 0xFFFF; ent = obj.descend) {
+loop:		obj.entryno = ent;
+		get_index_entry(&obj);
+		switch (obj.type) {
+		case 0xF4:
+			validate_chunk(&obj);
+			callback(&obj, callback_data);
+			continue;
+		case 0x00:
+			if (obj.sibling == 0xFFFF) {
+				fprintf(stderr,
+"file continuation object at index %x: marked deleted, but no sibling\n",
+					ent);
+				exit(1);
+			}
+			ent = obj.sibling;
+			goto loop;
+		default:
+			fprintf(stderr,
+		"file continuation object at index %x: unexpected type %02X\n",
+				ent, obj.type);
+			exit(1);
+		}
+	}
+}
+
 find_root_node()
 {
 	struct objinfo obj;

--- a/mpffs/ls.c	Mon Jul 01 06:28:30 2013 +0000
+++ b/mpffs/ls.c	Mon Jul 01 06:49:50 2013 +0000
@@ -18,34 +18,29 @@
 
 char workpath[512];
 
+void
+extra_chunk_callback(obj, opaque)
+	struct objinfo *obj;
+	u_long opaque;
+{
+	size_t *accump = (size_t *) opaque;
+	struct chunkinfo chi;
+
+	size_extra_chunk(obj, &chi);
+	*accump += chi.len;
+}
+
 size_t
 get_file_size(head)
 	struct objinfo *head;
 {
-	int ent;
-	struct objinfo ch;
 	struct chunkinfo chi;
 	size_t accum;
 
 	size_head_chunk(head, &chi);
 	accum = chi.len;
-	for (ent = head->descend; ent != 0xFFFF; ent = ch.descend) {
-		ch.entryno = ent;
-		get_index_entry(&ch);
-		if (ch.type != 0xF4) {
-			fprintf(stderr,
-	"file continuation object at index %x: type %02X != expected F4\n",
-				ent, ch.type);
-			break;
-		}
-		validate_chunk(&ch);
-		size_extra_chunk(&ch, &chi);
-		accum += chi.len;
-		if (ch.sibling != 0xFFFF)
-			fprintf(stderr,
-"warning: file continuation object (index %x) has a non-nil sibling pointer\n",
-				ent);
-	}
+	iterate_extra_chunks(head->descend, extra_chunk_callback,
+				(u_long) &accum);
 	return(accum);
 }