Re: [dpdk-dev] [PATCH] vhost: fix passing destroyed device to destroy callback

[Tiwei Bie <tiwei.bie@intel.com>]

On Tue, Apr 09, 2019 at 04:36:22PM +0300, Ilya Maximets wrote:
> Application should be able to obtain information like 'ifname' from
> the 'vid' passed to 'destroy_connection' callback. Currently, all the
> API calls with passed 'vid' fails with 'device not found'.
> 
> Fixes: efba12a78ddf ("vhost: add user callbacks for socket open/close")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
> ---
>  lib/librte_vhost/socket.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
> index 3da9de62c..43f091d10 100644
> --- a/lib/librte_vhost/socket.c
> +++ b/lib/librte_vhost/socket.c
> @@ -297,11 +297,12 @@ vhost_user_read_cb(int connfd, void *dat, int *remove)
>  	if (ret < 0) {
>  		close(connfd);
>  		*remove = 1;
> -		vhost_destroy_device(conn->vid);
>  
>  		if (vsocket->notify_ops->destroy_connection)
>  			vsocket->notify_ops->destroy_connection(conn->vid);
>  
> +		vhost_destroy_device(conn->vid);

By design, notify_ops->destroy_device() should be called before
notify_ops->destroy_connection(). I.e. something like:

	vhost_destroy_device_notify(...); // device stop

	if (vsocket->notify_ops->destroy_connection) // socket close
		vsocket->notify_ops->destroy_connection(conn->vid);

	vhost_destroy_device(conn->vid); // free

As destroy_device() callback means device stop (which also
happens in e.g. GET_VRING_BASE).


> +
>  		pthread_mutex_lock(&vsocket->conn_mutex);
>  		TAILQ_REMOVE(&vsocket->conn_list, conn, next);
>  		pthread_mutex_unlock(&vsocket->conn_mutex);
> -- 
> 2.17.1
>