From: tytso@mit.edu
Subject: Re: [PATCH] ext4: group cache is added in
 ext4_mb_discard_preallocations()
Date: Tue, 6 Apr 2010 14:49:52 -0400
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Cc: Andreas Dilger <adilger@sun.com>,
	linux-ext4 <linux-ext4@vger.kernel.org>,
	Dave Kleikamp <shaggy@linux.vnet.ibm.com>,
	"Aneesh Kumar K. V" <aneesh.kumar@linux.vnet.ibm.com>
To: jing zhang <zj.barak@gmail.com>
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On Thu, Apr 01, 2010 at 08:34:41PM +0800, jing zhang wrote:
> 
> --- linux-2.6.32/fs/ext4/mballoc.c	2009-12-03 11:51:22.000000000 +0800
> +++ ext4_mm_leak/mballoc-14.c	2010-04-01 20:35:58.000000000 +0800
> @@ -4299,7 +4299,7 @@ repeat:
>  		}
>  	} else {
>  		freed  = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
> -		if (freed)
> +		if (freed && freed >= ac->ac_o_ex.fe_len)
>  			goto repeat;
>  		*errp = -ENOSPC;
>  		ac->ac_b_ex.fe_len = 0;

This is just wrong.   

Since you didn't give a justification, I'm not sure why you think it
is correct.

						- Ted