Re: [PATCH] ext4: fix memory leak in ext4_free_branches

Hugh Dickins
2011-01-11T00:02:17Z

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@kernel.org
> Signed-off-by: "Theodore Ts'o" <tytso@mit.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
>
>