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

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Date:	Tue, 11 Jan 2011 12:16:51 +0200
From:	Amir Goldstein <amir73il@...il.com>
To:	"Theodore Ts'o" <tytso@....edu>
Cc:	Ext4 Developers List <linux-ext4@...r.kernel.org>,
	hughd@...gle.com, stable@...nel.org
Subject: Re: [PATCH] ext4: fix memory leak in ext4_free_branches

On Mon, Jan 10, 2011 at 7:56 PM, Theodore Ts'o <tytso@....edu> 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.

My bad... what I should have done was to pass 'bh' to ext4_free_blocks.
this would make the code equivalent to ext3 code.

Ted's fix is probably as good, but I think it is nicer to fix it by passing bh.

>
> Thanks to Hugh Dickins for pointing this out.
>
> Cc: stable@...nel.org
> Signed-off-by: "Theodore Ts'o" <tytso@....edu>
> ---
>  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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