| Message ID | 20201206052127.21450-2-ljp@linux.ibm.com (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | lockless version of | expand |
| Context | Check | Description |
|---|---|---|
| netdev/apply | fail | Patch does not apply to net-next |
| netdev/tree_selection | success | Clearly marked for net-next |
On Sat, 5 Dec 2020 23:21:25 -0600 Lijun Pan wrote: > There are some use cases for netdev_notify_peers in the context > when rtnl lock is already held. Introduce lockless version > of netdev_notify_peers call to save the extra code to call > call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev); > call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev); > > Suggested-by: Nathan Lynch <nathanl@linux.ibm.com> > Signed-off-by: Lijun Pan <ljp@linux.ibm.com> > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -1488,6 +1488,25 @@ void netdev_notify_peers(struct net_device *dev) > } > EXPORT_SYMBOL(netdev_notify_peers); Why not convert netdev_notify_peers to call the new helper? That way the chance they will get out of sync is way smaller. > +/** > + * netdev_notify_peers_locked - notify network peers about existence of @dev, > + * to be called in the context when rtnl lock is already held. > + * @dev: network device > + * > + * Generate traffic such that interested network peers are aware of > + * @dev, such as by generating a gratuitous ARP. This may be used when > + * a device wants to inform the rest of the network about some sort of > + * reconfiguration such as a failover event or virtual machine > + * migration. > + */ > +void netdev_notify_peers_locked(struct net_device *dev) I think __netdev_notify_peers() would be a more typical name for a core kernel function like this. > +{ > + ASSERT_RTNL(); > + call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev); > + call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev); > +} > +EXPORT_SYMBOL(netdev_notify_peers_locked); Otherwise LGTM, seems like a good cleanup.
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 964b494b0e8d..dec16d462672 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4492,6 +4492,7 @@ int dev_set_promiscuity(struct net_device *dev, int inc); int dev_set_allmulti(struct net_device *dev, int inc); void netdev_state_change(struct net_device *dev); void netdev_notify_peers(struct net_device *dev); +void netdev_notify_peers_locked(struct net_device *dev); void netdev_features_change(struct net_device *dev); /* Load a device via the kmod */ void dev_load(struct net *net, const char *name); diff --git a/net/core/dev.c b/net/core/dev.c index 82dc6b48e45f..20c1ab886222 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1488,6 +1488,25 @@ void netdev_notify_peers(struct net_device *dev) } EXPORT_SYMBOL(netdev_notify_peers); +/** + * netdev_notify_peers_locked - notify network peers about existence of @dev, + * to be called in the context when rtnl lock is already held. + * @dev: network device + * + * Generate traffic such that interested network peers are aware of + * @dev, such as by generating a gratuitous ARP. This may be used when + * a device wants to inform the rest of the network about some sort of + * reconfiguration such as a failover event or virtual machine + * migration. + */ +void netdev_notify_peers_locked(struct net_device *dev) +{ + ASSERT_RTNL(); + call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev); + call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev); +} +EXPORT_SYMBOL(netdev_notify_peers_locked); + static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack) { const struct net_device_ops *ops = dev->netdev_ops;
There are some use cases for netdev_notify_peers in the context when rtnl lock is already held. Introduce lockless version of netdev_notify_peers call to save the extra code to call call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev); call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev); Suggested-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Lijun Pan <ljp@linux.ibm.com> --- include/linux/netdevice.h | 1 + net/core/dev.c | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+)