Re: [PATCH] vsock: Make transport the proto owner

Andy King
2014-05-01T22:10:19Z

Oh just shoot me now, doesn't even pass checkpatch *hangs head in shame*
Dave/Greg, flame away if you like...

- Andy

----- Original Message -----
> Right now the core vsock module is the owner of the proto family. This
> means there's nothing preventing the transport module from unloading if
> there are open sockets, which results in a panic. Fix that by allowing
> the transport to be the owner, which will refcount it properly.
>
> Includes version bump to 1.0.1.0-k
>
> Cc: stable@vger.kernel.org
> Acked-by: Dmitry Torokhov <dtor@vmware.com>
> Signed-off-by: Andy King <acking@vmware.com>
> ---
> include/net/af_vsock.h | 6 +++++-
> net/vmw_vsock/af_vsock.c | 46
> +++++++++++++++++++++-------------------------
> 2 files changed, 26 insertions(+), 26 deletions(-)
>
> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
> index 7d64d36..8f02e5c 100644
> --- a/include/net/af_vsock.h
> +++ b/include/net/af_vsock.h
> @@ -155,7 +155,11 @@ struct vsock_transport {
>
> /**** CORE ****/
>
> -int vsock_core_init(const struct vsock_transport *t);
> +int __vsock_core_init(const struct vsock_transport *t, struct module
> *owner);
> +static inline int vsock_core_init(const struct vsock_transport *t)
> +{
> + return __vsock_core_init(t, THIS_MODULE);
> +}
> void vsock_core_exit(void);
>
> /**** UTILS ****/
> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> index 5adfd94..5743553 100644
> --- a/net/vmw_vsock/af_vsock.c
> +++ b/net/vmw_vsock/af_vsock.c
> @@ -1925,9 +1925,22 @@ static struct miscdevice vsock_device = {
> .fops = &vsock_device_ops,
> };
>
> -static int __vsock_core_init(void)
> +int __vsock_core_init(const struct vsock_transport *t, struct module *owner)
> {
> - int err;
> + int err = mutex_lock_interruptible(&vsock_register_mutex);
> + if (err)
> + return err;
> +
> + if (transport) {
> + err = -EBUSY;
> + goto err_busy;
> + }
> +
> + /* Transport must be the owner of the protocol so that it can't
> + * unload while there are open sockets.
> + */
> + vsock_proto.owner = owner;
> + transport = t;
>
> vsock_init_tables();
>
> @@ -1951,36 +1964,19 @@ static int __vsock_core_init(void)
> goto err_unregister_proto;
> }
>
> + mutex_unlock(&vsock_register_mutex);
> return 0;
>
> err_unregister_proto:
> proto_unregister(&vsock_proto);
> err_misc_deregister:
> misc_deregister(&vsock_device);
> - return err;
> -}
> -
> -int vsock_core_init(const struct vsock_transport *t)
> -{
> - int retval = mutex_lock_interruptible(&vsock_register_mutex);
> - if (retval)
> - return retval;
> -
> - if (transport) {
> - retval = -EBUSY;
> - goto out;
> - }
> -
> - transport = t;
> - retval = __vsock_core_init();
> - if (retval)
> - transport = NULL;
> -
> -out:
> + transport = NULL;
> +err_busy:
> mutex_unlock(&vsock_register_mutex);
> - return retval;
> + return err;
> }
> -EXPORT_SYMBOL_GPL(vsock_core_init);
> +EXPORT_SYMBOL_GPL(__vsock_core_init);
>
> void vsock_core_exit(void)
> {
> @@ -2000,5 +1996,5 @@ EXPORT_SYMBOL_GPL(vsock_core_exit);
>
> MODULE_AUTHOR("VMware, Inc.");
> MODULE_DESCRIPTION("VMware Virtual Socket Family");
> -MODULE_VERSION("1.0.0.0-k");
> +MODULE_VERSION("1.0.1.0-k");
> MODULE_LICENSE("GPL v2");
> --
> 1.7.4.1
>