From owner-freebsd-bugs  Mon Jan 20 09:20:04 1997
Return-Path: <owner-bugs>
Received: (from root@localhost)
          by freefall.freebsd.org (8.8.4/8.8.4) id JAA12793
          for bugs-outgoing; Mon, 20 Jan 1997 09:20:04 -0800 (PST)
Received: (from gnats@localhost)
          by freefall.freebsd.org (8.8.4/8.8.4) id JAA12762;
          Mon, 20 Jan 1997 09:20:02 -0800 (PST)
Resent-Date: Mon, 20 Jan 1997 09:20:02 -0800 (PST)
Resent-Message-Id: <199701201720.JAA12762@freefall.freebsd.org>
Resent-From: gnats (GNATS Management)
Resent-To: freebsd-bugs
Resent-Reply-To: FreeBSD-gnats@freefall.FreeBSD.org, fj@tfs.com
Received: from tfs.com (tfs.com [140.145.250.1])
          by freefall.freebsd.org (8.8.4/8.8.4) with SMTP id JAA12183
          for <FreeBSD-gnats-submit@freebsd.org>; Mon, 20 Jan 1997 09:10:26 -0800 (PST)
Received: from schizo.dk.tfs.com by tfs.com (smail3.1.28.1) with SMTP
	id m0vmNEJ-0003wqC; Mon, 20 Jan 97 09:09 PST
Received: (from fj@localhost) by schizo.dk.tfs.com (8.8.2/8.7.3) id SAA28651; Mon, 20 Jan 1997 18:09:53 +0100 (MET)
Message-Id: <199701201709.SAA28651@schizo.dk.tfs.com>
Date: Mon, 20 Jan 1997 18:09:53 +0100 (MET)
From: fj@tfs.com
Reply-To: fj@tfs.com
To: FreeBSD-gnats-submit@freebsd.org
X-Send-Pr-Version: 3.2
Subject: bin/2537: Fsck dies with floatingpoint exception
Sender: owner-bugs@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk


>Number:         2537
>Category:       bin
>Synopsis:       Fsck dies with floatingpoint exception
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Jan 20 09:20:01 PST 1997
>Last-Modified:
>Originator:     Flemming Jacobsen
>Organization:
>Release:        FreeBSD 2.2-RELEASE i386
>Environment:

	FreeBSD 2.2 beta, as generated by PHK 970114.

	System crashed (bad memory) during intense IO to disk.

>Description:

	At reboot automatic fsck failed with the message:
	  VALUES IN SUPER BLOCK DISAGREE WITH THOSE IN FIRST ALTERNATE
	(setup.c line 384)

	Running fsck by hand (on the primary superblock) resulted in a 
	floatingpoint exception (probably caused by the printf in main.c
	with [(float)(sblock.fs_cstotal.cs_nffree * 100) / sblock.fs_dsize)]).
	I did retry after setting the npx0 flags to 0x7 - same result.

	fsck -b 32  avoided the problem.

>How-To-Repeat:

	Good question ;-)

>Fix:
	
	fsck -b {better superblock copy}

	Fix fsck to check for divide by zero before trying.
>Audit-Trail:
>Unformatted: