Re: [PATCH 3/3] net/virtio_user: fix dev not freed after init error

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri,  5 Aug 2016 11:36:43 +0000
Jianfeng Tan <jianfeng.tan@intel.com> wrote:

> diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
> index daef09b..62ccb0b 100644
> --- a/drivers/net/virtio/virtio_user_ethdev.c
> +++ b/drivers/net/virtio/virtio_user_ethdev.c
> @@ -313,6 +313,17 @@ virtio_user_eth_dev_alloc(const char *name)
>  	return eth_dev;
>  }
>  
> +static void
> +virtio_user_eth_dev_free(struct rte_eth_dev *eth_dev)
> +{
> +	struct rte_eth_dev_data *data = eth_dev->data;
> +	struct virtio_hw *hw = data->dev_private;
> +
> +	rte_free(hw->virtio_user_dev);
> +	rte_free(hw);
> +	rte_eth_dev_release_port(eth_dev);
> +}
> +
>  /* Dev initialization routine. Invoked once for each virtio vdev at
>   * EAL init time, see rte_eal_dev_init().
>   * Returns 0 on success.
> @@ -328,7 +339,7 @@ virtio_user_pmd_devinit(const char *name, const char *params)
>  	uint64_t queue_size = VIRTIO_USER_DEF_Q_SZ;
>  	char *path = NULL;
>  	char *mac_addr = NULL;
> -	int ret = -1;
> +	int result = -1, ret;

It is not clear why two return value variables are needed?
>  
>  	if (!params || params[0] == '\0') {
>  		PMD_INIT_LOG(ERR, "arg %s is mandatory for virtio_user",
> @@ -411,15 +422,19 @@ virtio_user_pmd_devinit(const char *name, const char *params)
>  
>  	hw = eth_dev->data->dev_private;
>  	if (virtio_user_dev_init(hw->virtio_user_dev, path, queues, cq,
> -				 queue_size, mac_addr) < 0)
> +				 queue_size, mac_addr) < 0) {
> +		PMD_INIT_LOG(ERR, "virtio_user_dev_init fails");
> +		virtio_user_eth_dev_free(eth_dev);
>  		goto end;
> +	}
>  
>  	/* previously called by rte_eal_pci_probe() for physical dev */
>  	if (eth_virtio_dev_init(eth_dev) < 0) {
>  		PMD_INIT_LOG(ERR, "eth_virtio_dev_init fails");
> +		virtio_user_eth_dev_free(eth_dev);
>  		goto end;
>  	}
> -	ret = 0;
> +	result = 0;
>  
>  end:
>  	if (kvlist)
> @@ -428,7 +443,7 @@ end:
>  		free(path);
>  	if (mac_addr)
>  		free(mac_addr);

Unrelated, but this code could eliminate those if () tests.

> -	return ret;
> +	return result;
>  }