From 84ad0a66d0161562bb8fbce70be7e36f7a74520e Mon Sep 17 00:00:00 2001
From: Kirk McKusick <mckusick@FreeBSD.org>
Date: Thu, 23 Dec 2010 00:38:57 +0000
Subject: [PATCH] This patch fixes a soft update panic while running perl 5.12
 tests which produced:

    panic: indir_trunc: Index out of range -148 parent -2061 lbn -305164

Reported by: Dimitry Andric
Fixed by: Jeff Roberson
---
 sys/ufs/ffs/ffs_softdep.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sys/ufs/ffs/ffs_softdep.c b/sys/ufs/ffs/ffs_softdep.c
index 8ed68c329524..3278d6c7b8e3 100644
--- a/sys/ufs/ffs/ffs_softdep.c
+++ b/sys/ufs/ffs/ffs_softdep.c
@@ -6153,7 +6153,8 @@ indir_trunc(freework, dbn, lbn)
 		if (jnewblk->jn_lbn > 0)
 			i = (jnewblk->jn_lbn - -lbn) / lbnadd;
 		else
-			i = (jnewblk->jn_lbn - (lbn + 1)) / lbnadd;
+			i = (-(jnewblk->jn_lbn + level - 1) - -(lbn + level)) /
+			    lbnadd;
 		KASSERT(i >= 0 && i < NINDIR(fs),
 		    ("indir_trunc: Index out of range %d parent %jd lbn %jd",
 		    i, lbn, jnewblk->jn_lbn));