Re: [PATCH 1/4] tcm_vhost: Add missed lock in vhost_scsi_clear_endpoint()

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Mar 12, 2013 at 10:42:48AM +0800, Asias He wrote:
> tv_tpg->tv_tpg_vhost_count should be protected by tv_tpg->tv_tpg_mutex.
> 
> Signed-off-by: Asias He <asias@redhat.com>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  drivers/vhost/tcm_vhost.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
> index 9951297..b3e50d7 100644
> --- a/drivers/vhost/tcm_vhost.c
> +++ b/drivers/vhost/tcm_vhost.c
> @@ -860,9 +860,11 @@ static int vhost_scsi_clear_endpoint(
>  		if (!tv_tpg)
>  			continue;
>  
> +		mutex_lock(&tv_tpg->tv_tpg_mutex);
>  		tv_tport = tv_tpg->tport;
>  		if (!tv_tport) {
>  			ret = -ENODEV;
> +			mutex_unlock(&tv_tpg->tv_tpg_mutex);
>  			goto err;
>  		}
>  
> @@ -872,11 +874,13 @@ static int vhost_scsi_clear_endpoint(
>  				tv_tport->tport_name, tv_tpg->tport_tpgt,
>  				t->vhost_wwpn, t->vhost_tpgt);
>  			ret = -EINVAL;
> +			mutex_unlock(&tv_tpg->tv_tpg_mutex);
>  			goto err;
>  		}
>  		tv_tpg->tv_tpg_vhost_count--;
>  		vs->vs_tpg[target] = NULL;
>  		vs->vs_endpoint = false;
> +		mutex_unlock(&tv_tpg->tv_tpg_mutex);
>  	}
>  	mutex_unlock(&vs->dev.mutex);
>  	return 0;

Does the error handling have to be so messy?
How about another label which does unlock and goto there?

> -- 
> 1.8.1.4