Re: [PATCH v4 13/18] xen/pvcalls: implement release command

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

> +
> +static int pvcalls_back_release_passive(struct xenbus_device *dev,
> +					struct pvcalls_fedata *fedata,
> +					struct sockpass_mapping *mappass)
> +{
> +	if (mappass->sock->sk != NULL) {
> +		write_lock_bh(&mappass->sock->sk->sk_callback_lock);
> +		mappass->sock->sk->sk_user_data = NULL;
> +		mappass->sock->sk->sk_data_ready = mappass->saved_data_ready;
> +		write_unlock_bh(&mappass->sock->sk->sk_callback_lock);
> +	}
> +	down(&fedata->socket_lock);
> +	radix_tree_delete(&fedata->socketpass_mappings, mappass->id);
> +	sock_release(mappass->sock);
> +	flush_workqueue(mappass->wq);
> +	destroy_workqueue(mappass->wq);
> +	kfree(mappass);
> +	up(&fedata->socket_lock);

Can you raise the semaphore earlier, once the mapping is deleted from
the tree?

Also, why are you not locking the tree in pvcalls_back_accept()?

-boris