linux-ext4 - Re: [PATCH] ext4: fix memory leak in ext4_free

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Message-ID: <alpine.LSU.2.00.1101101557400.21100@tigran.mtv.corp.google.com>
Date:	Mon, 10 Jan 2011 16:02:11 -0800 (PST)
From:	Hugh Dickins <hughd@...gle.com>
To:	"Theodore Ts'o" <tytso@....edu>
cc:	Ext4 Developers List <linux-ext4@...r.kernel.org>,
	stable@...nel.org
Subject: Re: [PATCH] ext4: fix memory leak in ext4_free_branches

On Mon, 10 Jan 2011, Theodore Ts'o wrote:

> Commit 40389687 moved a call to ext4_forget() out of
> ext4_free_branches and let ext4_free_blocks() handle calling
> bforget().  But that change unfortunately did not replace the call to
> ext4_forget() with brelse(), which was needed to drop the in-use count
> of the indirect block's buffer head, which lead to a memory leak when
> deleting files that used indirect blocks.  Fix this.
> 
> Thanks to Hugh Dickins for pointing this out.
> 
> Cc: stable@...nel.org
> Signed-off-by: "Theodore Ts'o" <tytso@....edu>

Many thanks: I've given that a run with the added debug I'd put in,
and it fixes the problems nicely.  I thought it would be a brelse(bh)
somewhere, but wouldn't dare trust my data to my own guesses of where!

Hugh

> ---
>  fs/ext4/inode.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 84b6162..e80fc51 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -4378,6 +4378,7 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
>  					(__le32 *) bh->b_data,
>  					(__le32 *) bh->b_data + addr_per_block,
>  					depth);
> +			brelse(bh);
>  
>  			/*
>  			 * Everything below this this pointer has been
> -- 
> 1.7.3.1
> 
> 
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