public inbox for linux-xfs@vger.kernel.org
 help / color / mirror / Atom feed
From: Dave Chinner <david@fromorbit.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: xfs@oss.sgi.com
Subject: Re: [PATCH] xfs: work around bogus gcc warning in xfs_allocbt_init_cursor
Date: Tue, 21 Jun 2011 10:05:57 +1000	[thread overview]
Message-ID: <20110621000557.GG32466@dastard> (raw)
In-Reply-To: <20110617131214.GA2141@infradead.org>

On Fri, Jun 17, 2011 at 09:12:14AM -0400, Christoph Hellwig wrote:
> GCC 4.6 complains about an array subscript is above array bounds when
> using the btree index to index into the agf_levels array.  The only
> two indices passed in are 0 and 1, and we have an assert insuring that.
> 
> Replace the trick of using the array index directly with using constants
> in the already existing branch for assigning the XFS_BTREE_LASTREC_UPDATE
> flag.

Ugh.

> Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Index: xfs/fs/xfs/xfs_alloc_btree.c
> ===================================================================
> --- xfs.orig/fs/xfs/xfs_alloc_btree.c	2011-06-17 14:16:27.929065669 +0200
> +++ xfs/fs/xfs/xfs_alloc_btree.c	2011-06-17 14:17:22.145729599 +0200
> @@ -427,13 +427,16 @@ xfs_allocbt_init_cursor(
>  
>  	cur->bc_tp = tp;
>  	cur->bc_mp = mp;
> -	cur->bc_nlevels = be32_to_cpu(agf->agf_levels[btnum]);
>  	cur->bc_btnum = btnum;
>  	cur->bc_blocklog = mp->m_sb.sb_blocklog;
> -
>  	cur->bc_ops = &xfs_allocbt_ops;
> -	if (btnum == XFS_BTNUM_CNT)
> +
> +	if (btnum == XFS_BTNUM_CNT) {
> +		cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
>  		cur->bc_flags = XFS_BTREE_LASTREC_UPDATE;
> +	} else {
> +		cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
> +	}
>  
>  	cur->bc_private.a.agbp = agbp;
>  	cur->bc_private.a.agno = agno;

Looks fine.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

-- 
Dave Chinner
david@fromorbit.com

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

      reply	other threads:[~2011-06-21  0:06 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-17 13:12 [PATCH] xfs: work around bogus gcc warning in xfs_allocbt_init_cursor Christoph Hellwig
2011-06-21  0:05 ` Dave Chinner [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20110621000557.GG32466@dastard \
    --to=david@fromorbit.com \
    --cc=hch@infradead.org \
    --cc=xfs@oss.sgi.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox