On Dienstag, 12. Juli 2016 14:33:09 CEST Sven Eckelmann wrote: [....]
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-
interface.c
index 478977b..6324474 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c
[...]
+struct net_device *batadv_get_real_netdev(struct net_device *net_device) +{
[...]
- net = dev_net(hard_iface->soft_iface);
- ifindex = dev_get_iflink(net_device);
- real_netdev = dev_get_by_index(net, ifindex);
Andrew provided a patch [1] which gets the correct namespace of a link. You should consider to first accept his patch and then use batadv_getlink_net to get the correct namespace for the device instead of just assuming that it
will
be in the same netns as the batman-adv interface.
Something like this:
net = dev_net(hard_iface->soft_iface); ifindex = dev_get_iflink(net_device); real_net = = batadv_getlink_net(net_device, net); real_netdev = dev_get_by_index(real_net, ifindex);Could it also be that this has to be done with the rtnl lock held? Otherwise some of the the information may change while we are going through all the steps to get the real interface.
Maybe you can add ASSERT_RTNL(); in this function. The caller of these functions (see patch 3) have to make sure that they take the rtnl_lock().
batadv_is_cfg80211_netdev could get the rtnl_lock because it is used for the elp code (which isn't inside the rtnl_lock, right?). But the call to batadv_get_real_netdev in batadv_v_elp_get_throughput from Patch 3 still has to be protected.
Or you could create an extra function which takes care of getting the real device for batadv_v_elp_get_throughput when it is a cfg80211 based one (otherwise returning NULL). This function can take care of getting the lock. Then you can also drop this batadv_is_cfg80211_netdev -> _batadv_is_cfg80211_netdev change. Of course, you have to re-arrange many things in your patchset.
1. create batadv_is_cfg80211_netdev 2. introduce function that returns the device when it is a cfg80211 * make use of it in batadv_v_elp_get_throughput and use it instead of batadv_is_cfg80211_netdev 3. introduce batadv_get_real_netdev * make use of it in your newly created function of patch 2 * don't use batadv_get_real_netdev directly in batadv_v_elp_get_throughput
Kind regards, Sven