Re: [PATCH] sysfs: add necessary Null check in sysfs_do_create_link_sd

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Dec 03, 2013 at 09:38:47AM +0800, Rui Xiang wrote:
> While target_sd or sd are null, it won't need sysfs_put and
> should return -ENOENT directly. Here add null check for
> target_sd and sd.
> 
> Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
> ---
>  fs/sysfs/symlink.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
> index 3ae3f1b..d69b786 100644
> --- a/fs/sysfs/symlink.c
> +++ b/fs/sysfs/symlink.c
> @@ -83,8 +83,10 @@ static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd,
>  	return 0;
>  
>   out_put:
> -	sysfs_put(target_sd);
> -	sysfs_put(sd);
> +	if (target_sd)
> +		sysfs_put(target_sd);
> +	if (sd)
> +		sysfs_put(sd);

This change does nothing at all, why is it needed?

greg k-h