Re: [PATCH 7/9] s390/block/dcssblk: add error handling support for add_disk()

[Heiko Carstens]

On Thu, Sep 02, 2021 at 10:41:03AM -0700, Luis Chamberlain wrote:
> We never checked for errors on add_disk() as this function
> returned void. Now that this is fixed, use the shiny new
> error handling.
> 
> Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> ---
>  drivers/s390/block/dcssblk.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
> index 5be3d1c39a78..b0fd5009a12e 100644
> --- a/drivers/s390/block/dcssblk.c
> +++ b/drivers/s390/block/dcssblk.c
> @@ -696,7 +696,9 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
>  	}
>  
>  	get_device(&dev_info->dev);
> -	device_add_disk(&dev_info->dev, dev_info->gd, NULL);
> +	rc = device_add_disk(&dev_info->dev, dev_info->gd, NULL);
> +	if (rc)
> +		goto put_dev;

This looks not correct to me. We seem to have now in case of an error:

- reference count imbalance (= memory leak)
- dax cleanup is missing