--- fs/super.c.mount_p_opt	2009-11-22 05:03:04.000000000 +0100
+++ fs/super.c	2009-11-26 16:38:26.000000000 +0100
@@ -650,7 +650,8 @@
 enum {
 	Opt_err_cont, Opt_err_panic, Opt_err_ro,
 	Opt_barrier, Opt_snapshot, Opt_order,
-	Opt_err,
+	Opt_protperiod,
+	Opt_err, 
 };
 
 static match_table_t tokens = {
@@ -660,6 +661,7 @@
 	{Opt_barrier, "barrier=%s"},
 	{Opt_snapshot, "cp=%u"},
 	{Opt_order, "order=%s"},
+	{Opt_protperiod, "pp=%s"},
 	{Opt_err, NULL}
 };
 
@@ -728,6 +730,10 @@
 			sbi->s_snapshot_cno = option;
 			nilfs_set_opt(sbi, SNAPSHOT);
 			break;
+		case Opt_protperiod:
+			if (match_int(&args[0], &option) || option <= 0)
+				return 0;
+			break;
 		default:
 			printk(KERN_ERR
 			       "NILFS: Unrecognized mount option \"%s\"\n", p);