mac80211: add interface list lock
Using only the RTNL has a number of problems, most notably that
ieee80211_iterate_active_interfaces() and other interface list
traversals cannot be done from the internal workqueue because it
needs to be flushed under the RTNL.
This patch introduces a new mutex that protects the interface list
against modifications. A more detailed explanation is part of the
code change.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index fc30f29..73c7d73 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -468,7 +468,7 @@
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata;
- rtnl_lock();
+ mutex_lock(&local->iflist_mtx);
list_for_each_entry(sdata, &local->interfaces, list) {
switch (sdata->vif.type) {
@@ -489,7 +489,7 @@
&sdata->vif);
}
- rtnl_unlock();
+ mutex_unlock(&local->iflist_mtx);
}
EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);