Re: [PATCH] Btrfs: fix memory leak in do_walk_down

["Holger Hoffstätte" <holger@applied-asynchrony.com>]

On 09/14/16 04:02, Liu Bo wrote:
> The extent buffer 'next' needs to be free'd conditionally.
> 
> Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
> ---
>  fs/btrfs/extent-tree.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 5a940ab..779fd72 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -8882,6 +8882,7 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
>  				       &wc->flags[level - 1]);
>  	if (ret < 0) {
>  		btrfs_tree_unlock(next);
> +		free_extent_buffer(next);
>  		return ret;
>  	}
>  
> 

This was fixed a long time ago by the following patch by Josef:

"Btrfs: don't BUG() during drop snapshot"
https://patchwork.kernel.org/patch/7002791/

..which never got merged. I've been using it since 4.1.x until today
without problems.

Note that apparently Patchwork got confused here: downloading only the
"patch" fragment won't work; you'll need the full "mbox" attachment.
It also seems to have been sorted into the wrong list bucket for some
reason.

-h