Re: [Xen-devel] [PATCH] xen/xen-scsiback: Need go to fail after xenbus_dev_error()

[Juergen Gross <jgross@suse.com>]

On 09/26/2014 06:38 PM, Chen Gang wrote:
> When failure occurs, after xenbus_dev_error(), need go to fail to let
> upper caller know about it.
>
> Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
> ---
>   drivers/xen/xen-scsiback.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
> index 847bc9c..3e430e1 100644
> --- a/drivers/xen/xen-scsiback.c
> +++ b/drivers/xen/xen-scsiback.c
> @@ -1222,8 +1222,10 @@ static int scsiback_probe(struct xenbus_device *dev,
>
>   	err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
>   			    SG_ALL);
> -	if (err)
> +	if (err) {
>   		xenbus_dev_error(dev, err, "writing feature-sg-grant");
> +		goto fail;
> +	}
>
>   	xenbus_switch_state(dev, XenbusStateInitWait);
>   	return 0;
>

Hmm, not testing for failure was on purpose. Advertising this feature
is just for tuning purposes, not mandatory.

OTOH it would really be a strange error if this xenbus_printf() fails
but all other operations are working, and signaling an error at the
time when it first shows up is a good thing. So:

Acked-by: Juergen Gross <jgross@suse.com>