From owner-freebsd-current  Mon Feb  4  8:35:33 2002
Delivered-To: freebsd-current@freebsd.org
Received: from mailman.zeta.org.au (mailman.zeta.org.au [203.26.10.16])
	by hub.freebsd.org (Postfix) with ESMTP
	id 2D96037B4A4; Mon,  4 Feb 2002 08:35:11 -0800 (PST)
Received: from bde.zeta.org.au (bde.zeta.org.au [203.2.228.102])
	by mailman.zeta.org.au (8.9.3/8.8.7) with ESMTP id DAA24848;
	Tue, 5 Feb 2002 03:35:03 +1100
Date: Tue, 5 Feb 2002 03:37:26 +1100 (EST)
From: Bruce Evans <bde@zeta.org.au>
X-X-Sender:  <bde@gamplex.bde.org>
To: Alfred Perlstein <bright@mu.org>
Cc: John Polstra <jdp@polstra.com>, <current@FreeBSD.ORG>,
	<markm@FreeBSD.ORG>
Subject: Re: Panics in ffs_clusteracct with todays -current
In-Reply-To: <20020204080336.A95852@elvis.mu.org>
Message-ID: <20020205031909.L23629-100000@gamplex.bde.org>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: owner-freebsd-current@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-current.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-current>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-current>
X-Loop: FreeBSD.ORG

On Mon, 4 Feb 2002, Alfred Perlstein wrote:

> * Bruce Evans <bde@zeta.org.au> [020204 05:26] wrote:
> > This patch just backs out the change to NBBY.
>
> Wouldn't this make more sense:
>
> Index: ffs/ffs_alloc.c
> ===================================================================
> RCS file: /home/ncvs/src/sys/ufs/ffs/ffs_alloc.c,v
> retrieving revision 1.86
> diff -u -r1.86 ffs_alloc.c
> --- ffs/ffs_alloc.c	2 Feb 2002 01:42:44 -0000	1.86
> +++ ffs/ffs_alloc.c	4 Feb 2002 16:08:34 -0000
> @@ -1790,7 +1790,7 @@
>  	end = start + fs->fs_contigsumsize;
>  	if (end >= cgp->cg_nclusterblks)
>  		end = cgp->cg_nclusterblks;
> -	mapp = &freemapp[start / NBBY];
> +	mapp = &freemapp[start < 0 ? 0 : start / NBBY];
>  	map = *mapp++;
>  	bit = 1 << (start % NBBY);
>  	for (i = start; i < end; i++) {
>

Except it doesn't fix the potentially millions of other lines that are
affected by the fix, and leaves at best confusing code: mapp, map and
bit are unitialized to bogus values.  This seems to be harmless because
they are not used (the loop is iterated 0 times if start < 0).

Bruce


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message