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authorJohannes Berg <johannes.berg@intel.com>2013-08-21 22:07:20 +0200
committerJohannes Berg <johannes.berg@intel.com>2013-09-26 13:21:37 +0200
commitc7c71066c27f2bafb2ce3b10c407c0285f56acfa (patch)
tree183c3557d596a8ae69bf3ae9219e7ef49456052e /net/mac80211
parent272b98c6455f00884f0350f775c5342358ebb73f (diff)
mac80211: add ieee80211_iterate_active_interfaces_rtnl()
If it is needed to disconnect multiple virtual interfaces after (WoWLAN-) suspend, the most obvious approach would be to iterate all interfaces by calling ieee80211_iterate_active_interfaces() and then call ieee80211_resume_disconnect() for each one. This is what the iwlmvm driver does. Unfortunately, this causes a locking dependency from mac80211's iflist_mtx to the key_mtx. This is problematic as the former is intentionally never held while calling any driver operation to allow drivers to iterate with their own locks held. The key_mtx is held while installing a key into the driver though, so this new lock dependency means drivers implementing the logic above can no longer hold their own lock while iterating. To fix this, add a new ieee80211_iterate_active_interfaces_rtnl() function that iterates while the RTNL is already held. This is true during suspend/resume, so that then the locking dependency isn't introduced. While at it, also refactor the various interface iterators and keep only a single implementation called by the various cases. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211')
-rw-r--r--net/mac80211/util.c71
1 files changed, 34 insertions, 37 deletions
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index e1b34a18b243..75a16853fb45 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -567,18 +567,15 @@ void ieee80211_flush_queues(struct ieee80211_local *local,
IEEE80211_QUEUE_STOP_REASON_FLUSH);
}
-void ieee80211_iterate_active_interfaces(
- struct ieee80211_hw *hw, u32 iter_flags,
- void (*iterator)(void *data, u8 *mac,
- struct ieee80211_vif *vif),
- void *data)
+static void __iterate_active_interfaces(struct ieee80211_local *local,
+ u32 iter_flags,
+ void (*iterator)(void *data, u8 *mac,
+ struct ieee80211_vif *vif),
+ void *data)
{
- struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata;
- mutex_lock(&local->iflist_mtx);
-
- list_for_each_entry(sdata, &local->interfaces, list) {
+ list_for_each_entry_rcu(sdata, &local->interfaces, list) {
switch (sdata->vif.type) {
case NL80211_IFTYPE_MONITOR:
if (!(sdata->u.mntr_flags & MONITOR_FLAG_ACTIVE))
@@ -597,13 +594,25 @@ void ieee80211_iterate_active_interfaces(
&sdata->vif);
}
- sdata = rcu_dereference_protected(local->monitor_sdata,
- lockdep_is_held(&local->iflist_mtx));
+ sdata = rcu_dereference_check(local->monitor_sdata,
+ lockdep_is_held(&local->iflist_mtx) ||
+ lockdep_rtnl_is_held());
if (sdata &&
(iter_flags & IEEE80211_IFACE_ITER_RESUME_ALL ||
sdata->flags & IEEE80211_SDATA_IN_DRIVER))
iterator(data, sdata->vif.addr, &sdata->vif);
+}
+void ieee80211_iterate_active_interfaces(
+ struct ieee80211_hw *hw, u32 iter_flags,
+ void (*iterator)(void *data, u8 *mac,
+ struct ieee80211_vif *vif),
+ void *data)
+{
+ struct ieee80211_local *local = hw_to_local(hw);
+
+ mutex_lock(&local->iflist_mtx);
+ __iterate_active_interfaces(local, iter_flags, iterator, data);
mutex_unlock(&local->iflist_mtx);
}
EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);
@@ -615,38 +624,26 @@ void ieee80211_iterate_active_interfaces_atomic(
void *data)
{
struct ieee80211_local *local = hw_to_local(hw);
- struct ieee80211_sub_if_data *sdata;
rcu_read_lock();
+ __iterate_active_interfaces(local, iter_flags, iterator, data);
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic);
- list_for_each_entry_rcu(sdata, &local->interfaces, list) {
- switch (sdata->vif.type) {
- case NL80211_IFTYPE_MONITOR:
- if (!(sdata->u.mntr_flags & MONITOR_FLAG_ACTIVE))
- continue;
- break;
- case NL80211_IFTYPE_AP_VLAN:
- continue;
- default:
- break;
- }
- if (!(iter_flags & IEEE80211_IFACE_ITER_RESUME_ALL) &&
- !(sdata->flags & IEEE80211_SDATA_IN_DRIVER))
- continue;
- if (ieee80211_sdata_running(sdata))
- iterator(data, sdata->vif.addr,
- &sdata->vif);
- }
+void ieee80211_iterate_active_interfaces_rtnl(
+ struct ieee80211_hw *hw, u32 iter_flags,
+ void (*iterator)(void *data, u8 *mac,
+ struct ieee80211_vif *vif),
+ void *data)
+{
+ struct ieee80211_local *local = hw_to_local(hw);
- sdata = rcu_dereference(local->monitor_sdata);
- if (sdata &&
- (iter_flags & IEEE80211_IFACE_ITER_RESUME_ALL ||
- sdata->flags & IEEE80211_SDATA_IN_DRIVER))
- iterator(data, sdata->vif.addr, &sdata->vif);
+ ASSERT_RTNL();
- rcu_read_unlock();
+ __iterate_active_interfaces(local, iter_flags, iterator, data);
}
-EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic);
+EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_rtnl);
/*
* Nothing should have been stuffed into the workqueue during