On Wed, May 20, 2015 at 08:21:59PM +0300, Cyrill Gorcunov wrote:
> While been playing with c/r of a container with IP assigned I found that
> VE exit (ve_drop_context) is happening earlier than venet::exit
> routine which means the ve::ve_netns = nil when we enter into
> ip releasing procedure.
>
> | zap_pid_ns_processes
> | ve_stop_ns
> | ve_exit_ns
> | ve_drop_context(ve);
> | put_net(ve->ve_netns);
> | ve->ve_netns = NULL;
>
> Releasing ve context that early looks logical because ve::ve_netns
> is a part of ve structure itself, in turn ip address and venet device
> is rather a side feature provided by venet module.
>
> So because we do not create nested venet devices and adding
> some additional ioctl makes code only harder to read I propose
> to use VE exit hook to cleanup ip address.
>
> With the patch applied I can checkpoint/restore container
> with venet configured.
Is it posibale to unload the venet module? Is it ok with this patch?
>
> Signed-off-by: Cyrill Gorcunov <gorcu...@odin.com>
> CC: Vladimir Davydov <vdavy...@odin.com>
> CC: Konstantin Khorenko <khore...@odin.com>
> CC: Pavel Emelyanov <xe...@odin.com>
> CC: Andrey Vagin <ava...@odin.com>
> ---
>
> If there some better idea, please share.
>
> drivers/net/venetdev.c | 71
> ++++++++++++++++++++++---------------------------
> 1 file changed, 32 insertions(+), 39 deletions(-)
>
> Index: linux-pcs7.git/drivers/net/venetdev.c
> ===================================================================
> --- linux-pcs7.git.orig/drivers/net/venetdev.c
> +++ linux-pcs7.git/drivers/net/venetdev.c
> @@ -881,9 +881,13 @@ static int do_ve_ip_map(struct ve_struct
> switch (op)
> {
> case VE_IP_ADD:
> - err = -ESRCH;
> - if (ve->is_running)
> - err = veip_entry_add(ve, addr);
> + /*
> + * FIXME We should check if VE
> + * is either running or in restore
> + * state instead of allowing adding
> + * address arbitrary.
> + */
> + err = veip_entry_add(ve, addr);
> break;
>
> case VE_IP_DEL:
> @@ -1113,51 +1117,39 @@ err:
> return err;
> }
>
> -static __net_exit void venet_exit_net(struct list_head *net_exit_list)
> +static struct pernet_operations venet_net_ops = {
> + .init = venet_init_net,
> +};
> +
> +/*
> + * VE context dropping is happening earlier than
> + * pernet_operations::exit method so we can't
> + * rely on it and do the cleanup earlier.
> + */
> +static void venet_stop_notifier(void *data)
> {
> - struct net *net;
> - struct ve_struct *env;
> - struct net_device *dev;
> - LIST_HEAD(netdev_kill_list);
> + struct ve_struct *env = data;
>
> - list_for_each_entry(net, net_exit_list, exit_list) {
> - env = net->owner_ve;
> - if (env->ve_netns != net)
> - continue;
> + if (env->ve_netns) {
> + struct net_device *dev = env->_venet_dev;
>
> venet_ext_clean(env);
> veip_stop(env);
>
> - dev = env->_venet_dev;
> - if (dev == NULL)
> - continue;
> -
> - rtnl_lock();
> - unregister_netdevice_queue(dev, &netdev_kill_list);
> - rtnl_unlock();
> - }
> -
> - rtnl_lock();
> - unregister_netdevice_many(&netdev_kill_list);
> - rtnl_unlock();
> -
> - list_for_each_entry(net, net_exit_list, exit_list) {
> - env = net->owner_ve;
> - if (env->ve_netns != net)
> - continue;
> -
> - dev = env->_venet_dev;
> - if (dev == NULL)
> - continue;
> -
> - env->_venet_dev = NULL;
> - free_netdev(dev);
> + if (dev) {
> + env->_venet_dev = NULL;
> + rtnl_lock();
> + unregister_netdevice(dev);
> + rtnl_unlock();
> + free_netdev(dev);
> + }
> }
> }
>
> -static struct pernet_operations venet_net_ops = {
> - .init = venet_init_net,
> - .exit_batch = venet_exit_net,
> +static struct ve_hook venet_stop_hook = {
> + .fini = venet_stop_notifier,
> + .priority = HOOK_PRIO_FINISHING,
> + .owner = THIS_MODULE,
> };
>
> static int venet_changelink(struct net_device *dev, struct nlattr *tb[],
> @@ -1241,6 +1233,7 @@ __init int venet_init(void)
>
> vzioctl_register(&venetcalls);
> vzmon_register_veaddr_print_cb(veaddr_seq_print);
> + ve_hook_register(VE_SS_CHAIN, &venet_stop_hook);
>
> return rtnl_link_register(&venet_link_ops);
>
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