From owner-freebsd-current@FreeBSD.ORG  Sun Oct 16 22:11:48 2005
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
X-Original-To: freebsd-current@freebsd.org
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 3746D16A41F;
	Sun, 16 Oct 2005 22:11:48 +0000 (GMT)
	(envelope-from dillon@apollo.backplane.com)
Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 023EC43D46;
	Sun, 16 Oct 2005 22:11:47 +0000 (GMT)
	(envelope-from dillon@apollo.backplane.com)
Received: from apollo.backplane.com (localhost [127.0.0.1])
	by apollo.backplane.com (8.13.4/8.13.4) with ESMTP id j9GMBZI9037256;
	Sun, 16 Oct 2005 15:11:35 -0700 (PDT)
Received: (from dillon@localhost)
	by apollo.backplane.com (8.13.4/8.13.4/Submit) id j9GMBZED037255;
	Sun, 16 Oct 2005 15:11:35 -0700 (PDT)
Date: Sun, 16 Oct 2005 15:11:35 -0700 (PDT)
From: Matthew Dillon <dillon@apollo.backplane.com>
Message-Id: <200510162211.j9GMBZED037255@apollo.backplane.com>
To: obrien@freebsd.org, freebsd-current@freebsd.org
References: <20050926152952.GA1670@dragon.NUXI.org>
	<20050926160808.GB1649@dragon.NUXI.org>
	<200510141940.j9EJeYsn024832@apollo.backplane.com>
Cc: 
Subject: Re: [PANIC] ufs_dirbad: bad dir
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 16 Oct 2005 22:11:48 -0000

    Going through all this badly documented filesystem code is 
    aweful.

    Could someone check the reallocblks code?  Specifically this:

        /*
         * If the block range spans two block maps, get the second map.
         */
        if (end_lvl == 0 || (idp = &end_ap[end_lvl - 1])->in_off + 1 >= len) {
                ssize = len;
        } else {
#ifdef DIAGNOSTIC
                if (start_ap[start_lvl-1].in_lbn == idp->in_lbn)
                        panic("ffs_reallocblk: start == end");
#endif
                ssize = len - (idp->in_off + 1);
			^^^^^^^^^^^^^^^^^^^^^
			This doesn't look right.  It kinda seems to me
			that it should be (len - idp->in_off).


                if (bread(vp, idp->in_lbn, (int)fs->fs_bsize, &ebp))
                        goto fail;
                ebap = (ufs_daddr_t *)ebp->b_data;
        }

    I went through about 3 or 4 false alarms earlier today, and this could
    be another one.   But if it is wrong it would fit the symptoms....
    the first indirect block in the inode getting blown to bits.

					-Matt
					Matthew Dillon 
					<dillon@backplane.com>