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hv_netvsc: rework link status change handling 

There are several issues in hv_netvsc driver with regards to link status
change handling:
- RNDIS_STATUS_NETWORK_CHANGE results in calling userspace helper doing
  '/etc/init.d/network restart' and this is inappropriate and broken for
  many reasons.
- link_watch infrastructure only sends one notification per second and
  in case of e.g. paired disconnect/connect events we get only one
  notification with last status. This makes it impossible to handle such
  situations in userspace.

Redo link status changes handling in the following way:
- Create a list of reconfig events in network device context.
- On a reconfig event add it to the list of events and schedule
  netvsc_link_change().
- In netvsc_link_change() ensure 2-second delay between link status
  changes.
- Handle RNDIS_STATUS_NETWORK_CHANGE as a paired disconnect/connect event.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Vitaly Kuznetsov 2015-11-27 11:39:55 +01:00 committed by David S. Miller
parent 77b75f4d8c
commit 27a70af3f4
2 changed files with 109 additions and 49 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/net/hyperv/hyperv_net.h
View File

@ -177,7 +177,6 @@ struct rndis_device {
enum rndis_device_state state;
bool link_state;
bool link_change;
atomic_t new_req_id;
spinlock_t request_lock;
@ -644,11 +643,24 @@ struct netvsc_stats {
struct u64_stats_sync syncp;
};
struct netvsc_reconfig {
struct list_head list;
u32 event;
};
/* The context of the netvsc device */
struct net_device_context {
/* point back to our device context */
struct hv_device *device_ctx;
/* reconfigure work */
struct delayed_work dwork;
/* last reconfig time */
unsigned long last_reconfig;
/* reconfig events */
struct list_head reconfig_events;
/* list protection */
spinlock_t lock;
struct work_struct work;
u32 msg_enable; /* debug level */

144
drivers/net/hyperv/netvsc_drv.c
View File

@ -42,6 +42,7 @@
#define RING_SIZE_MIN 64
#define LINKCHANGE_INT (2 * HZ)
static int ring_size = 128;
module_param(ring_size, int, S_IRUGO);
MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
@ -647,37 +648,33 @@ void netvsc_linkstatus_callback(struct hv_device *device_obj,
struct net_device *net;
struct net_device_context *ndev_ctx;
struct netvsc_device *net_device;
struct rndis_device *rdev;
struct netvsc_reconfig *event;
unsigned long flags;
/* Handle link change statuses only */
if (indicate->status != RNDIS_STATUS_NETWORK_CHANGE &&
indicate->status != RNDIS_STATUS_MEDIA_CONNECT &&
indicate->status != RNDIS_STATUS_MEDIA_DISCONNECT)
return;
net_device = hv_get_drvdata(device_obj);
rdev = net_device->extension;
switch (indicate->status) {
case RNDIS_STATUS_MEDIA_CONNECT:
rdev->link_state = false;
break;
case RNDIS_STATUS_MEDIA_DISCONNECT:
rdev->link_state = true;
break;
case RNDIS_STATUS_NETWORK_CHANGE:
rdev->link_change = true;
break;
default:
return;
}
net = net_device->ndev;
if (!net || net->reg_state != NETREG_REGISTERED)
return;
ndev_ctx = netdev_priv(net);
if (!rdev->link_state) {
schedule_delayed_work(&ndev_ctx->dwork, 0);
schedule_delayed_work(&ndev_ctx->dwork, msecs_to_jiffies(20));
} else {
schedule_delayed_work(&ndev_ctx->dwork, 0);
}
event = kzalloc(sizeof(*event), GFP_ATOMIC);
if (!event)
return;
event->event = indicate->status;
spin_lock_irqsave(&ndev_ctx->lock, flags);
list_add_tail(&event->list, &ndev_ctx->reconfig_events);
spin_unlock_irqrestore(&ndev_ctx->lock, flags);
schedule_delayed_work(&ndev_ctx->dwork, 0);
}
/*
@ -1009,12 +1006,9 @@ static const struct net_device_ops device_ops = {
};
/*
* Send GARP packet to network peers after migrations.
* After Quick Migration, the network is not immediately operational in the
* current context when receiving RNDIS_STATUS_MEDIA_CONNECT event. So, add
* another netif_notify_peers() into a delayed work, otherwise GARP packet
* will not be sent after quick migration, and cause network disconnection.
* Also, we update the carrier status here.
* Handle link status changes. For RNDIS_STATUS_NETWORK_CHANGE emulate link
* down/up sequence. In case of RNDIS_STATUS_MEDIA_CONNECT when carrier is
* present send GARP packet to network peers with netif_notify_peers().
*/
static void netvsc_link_change(struct work_struct *w)
{
@ -1022,36 +1016,89 @@ static void netvsc_link_change(struct work_struct *w)
struct net_device *net;
struct netvsc_device *net_device;
struct rndis_device *rdev;
bool notify, refresh = false;
char *argv[] = { "/etc/init.d/network", "restart", NULL };
char *envp[] = { "HOME=/", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
rtnl_lock();
struct netvsc_reconfig *event = NULL;
bool notify = false, reschedule = false;
unsigned long flags, next_reconfig, delay;
ndev_ctx = container_of(w, struct net_device_context, dwork.work);
net_device = hv_get_drvdata(ndev_ctx->device_ctx);
rdev = net_device->extension;
net = net_device->ndev;
if (rdev->link_state) {
netif_carrier_off(net);
notify = false;
} else {
netif_carrier_on(net);
notify = true;
if (rdev->link_change) {
rdev->link_change = false;
refresh = true;
next_reconfig = ndev_ctx->last_reconfig + LINKCHANGE_INT;
if (time_is_after_jiffies(next_reconfig)) {
/* link_watch only sends one notification with current state
* per second, avoid doing reconfig more frequently. Handle
* wrap around.
*/
delay = next_reconfig - jiffies;
delay = delay < LINKCHANGE_INT ? delay : LINKCHANGE_INT;
schedule_delayed_work(&ndev_ctx->dwork, delay);
return;
}
ndev_ctx->last_reconfig = jiffies;
spin_lock_irqsave(&ndev_ctx->lock, flags);
if (!list_empty(&ndev_ctx->reconfig_events)) {
event = list_first_entry(&ndev_ctx->reconfig_events,
struct netvsc_reconfig, list);
list_del(&event->list);
reschedule = !list_empty(&ndev_ctx->reconfig_events);
}
spin_unlock_irqrestore(&ndev_ctx->lock, flags);
if (!event)
return;
rtnl_lock();
switch (event->event) {
/* Only the following events are possible due to the check in
* netvsc_linkstatus_callback()
*/
case RNDIS_STATUS_MEDIA_CONNECT:
if (rdev->link_state) {
rdev->link_state = false;
netif_carrier_on(net);
netif_tx_wake_all_queues(net);
} else {
notify = true;
}
kfree(event);
break;
case RNDIS_STATUS_MEDIA_DISCONNECT:
if (!rdev->link_state) {
rdev->link_state = true;
netif_carrier_off(net);
netif_tx_stop_all_queues(net);
}
kfree(event);
break;
case RNDIS_STATUS_NETWORK_CHANGE:
/* Only makes sense if carrier is present */
if (!rdev->link_state) {
rdev->link_state = true;
netif_carrier_off(net);
netif_tx_stop_all_queues(net);
event->event = RNDIS_STATUS_MEDIA_CONNECT;
spin_lock_irqsave(&ndev_ctx->lock, flags);
list_add_tail(&event->list, &ndev_ctx->reconfig_events);
spin_unlock_irqrestore(&ndev_ctx->lock, flags);
reschedule = true;
}
break;
}
rtnl_unlock();
if (refresh)
call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
if (notify)
netdev_notify_peers(net);
/* link_watch only sends one notification with current state per
* second, handle next reconfig event in 2 seconds.
*/
if (reschedule)
schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
}
static void netvsc_free_netdev(struct net_device *netdev)
@ -1106,6 +1153,9 @@ static int netvsc_probe(struct hv_device *dev,
INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
INIT_WORK(&net_device_ctx->work, do_set_multicast);
spin_lock_init(&net_device_ctx->lock);
INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
net->netdev_ops = &device_ops;
net->hw_features = NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_IP_CSUM |
@ -1145,8 +1195,6 @@ static int netvsc_probe(struct hv_device *dev,
pr_err("Unable to register netdev.\n");
rndis_filter_device_remove(dev);
netvsc_free_netdev(net);
} else {
schedule_delayed_work(&net_device_ctx->dwork, 0);
}
return ret;