From: Mingming Cao <cmm@us.ibm.com>
Subject: Re: [PATCH] ext4:fix invariant checking in
	ext4_rebalance_reservation
Date: Mon, 18 Jun 2007 14:09:39 -0700
Message-ID: <1182200979.3711.6.camel@dyn9047017103.beaverton.ibm.com>
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Cc: Alex Tomas <alex@clusterfs.com>, linux-ext4@vger.kernel.org
To: Dmitriy Monakhov <dmonakhov@sw.ru>
In-Reply-To: <20070616080200.GA14349@localhost.sw.ru>
Sender: linux-ext4-owner@vger.kernel.org

On Sat, 2007-06-16 at 12:02 +0400, Dmitriy Monakhov wrote:
> Variable "free" was declarated as __u64 so conidition (free < 0) always
> false, even if free was overflowed during substraction.

Agreed. 

Can you add your Signed-off to this patch? I can add mine after yours.

Thanks,
Mingming
> ---
>  fs/ext4/balloc.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
> index 43ae8f8..a9655f1 100644
> --- a/fs/ext4/balloc.c
> +++ b/fs/ext4/balloc.c
> @@ -1909,8 +1909,8 @@ void ext4_rebalance_reservation(struct ext4_reservation_slot *rs, __u64 free)
>  			chunk = free;
>  		if (rs[i].rs_reserved || i == smp_processor_id()) {
>  			rs[i].rs_reserved = chunk;
> +			BUG_ON(free < chunk);
>  			free -= chunk;
> -			BUG_ON(free < 0);
>  		}
>  	}
>  	BUG_ON(free);