mac80211: optimise mixed AP/VLAN station removal

Teach sta_info_flush() to optionally also remove stations
from all VLANs associated with an AP interface to optimise
the station removal (in particular, synchronize_net().)

To not have to add the vlans argument throughout, do some
refactoring.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 14 insertions, 6 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index e11bdb63167a..18b56fb7911e 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1097,9 +1097,7 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev)
         if (old_probe_resp)
                 kfree_rcu(old_probe_resp, rcu_head);
 
-        list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
-                sta_info_flush(vlan);
-        sta_info_flush(sdata);
+        __sta_info_flush(sdata, true);
         synchronize_net();
         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
                 ieee80211_free_keys(vlan);
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 89d449d0de6d..4576ba0ff221 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -960,7 +960,7 @@ void sta_info_stop(struct ieee80211_local *local)
 }
 
 
-int sta_info_flush(struct ieee80211_sub_if_data *sdata)
+int __sta_info_flush(struct ieee80211_sub_if_data *sdata, bool vlans)
 {
         struct ieee80211_local *local = sdata->local;
         struct sta_info *sta, *tmp;
@@ -969,9 +969,13 @@ int sta_info_flush(struct ieee80211_sub_if_data *sdata)
 
         might_sleep();
 
+        WARN_ON(vlans && sdata->vif.type != NL80211_IFTYPE_AP);
+        WARN_ON(vlans && !sdata->bss);
+
         mutex_lock(&local->sta_mtx);
         list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
-                if (sdata == sta->sdata) {
+                if (sdata == sta->sdata ||
+                    (vlans && sdata->bss == sta->sdata->bss)) {
                         if (!WARN_ON(__sta_info_destroy_part1(sta)))
                                 list_add(&sta->free_list, &free_list);
                         ret++;
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index f6081e574a28..d77ff7090630 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -613,8 +613,14 @@ void sta_info_stop(struct ieee80211_local *local);
  * Returns the number of removed STA entries.
  *
  * @sdata: sdata to remove all stations from
+ * @vlans: if the given interface is an AP interface, also flush VLANs
  */
-int sta_info_flush(struct ieee80211_sub_if_data *sdata);
+int __sta_info_flush(struct ieee80211_sub_if_data *sdata, bool vlans);
+
+static inline int sta_info_flush(struct ieee80211_sub_if_data *sdata)
+{
+        return __sta_info_flush(sdata, false);
+}
 
 void sta_set_rate_info_tx(struct sta_info *sta,
                           const struct ieee80211_tx_rate *rate,