mac80211: station state transition error handling
In the future, when we start notifying drivers,
state transitions could potentially fail. To make
it easier to distinguish between programming bugs
and driver failures:
* rename sta_info_move_state() to
sta_info_pre_move_state() which can only be
called before the station is inserted (and
check this with a new station flag).
* rename sta_info_move_state_checked() to just
plain sta_info_move_state(), as it will be
the regular function that can fail for more
than just one reason (bad transition or an
error from the driver)
This makes the programming model easier -- one of
the functions can only be called before insertion
and can't fail, the other can fail.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index f28fa02..df8f0a2 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -403,6 +403,8 @@
sta_info_hash_add(local, sta);
list_add(&sta->list, &local->sta_list);
+
+ set_sta_flag(sta, WLAN_STA_INSERTED);
} else {
sta->dummy = false;
}
@@ -707,7 +709,7 @@
return have_buffered;
}
-static int __must_check __sta_info_destroy(struct sta_info *sta)
+int __must_check __sta_info_destroy(struct sta_info *sta)
{
struct ieee80211_local *local;
struct ieee80211_sub_if_data *sdata;
@@ -722,6 +724,8 @@
local = sta->local;
sdata = sta->sdata;
+ lockdep_assert_held(&local->sta_mtx);
+
/*
* Before removing the station from the driver and
* rate control, it might still start new aggregation
@@ -763,8 +767,13 @@
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
RCU_INIT_POINTER(sdata->u.vlan.sta, NULL);
- while (sta->sta_state > IEEE80211_STA_NONE)
- sta_info_move_state(sta, sta->sta_state - 1);
+ while (sta->sta_state > IEEE80211_STA_NONE) {
+ int err = sta_info_move_state(sta, sta->sta_state - 1);
+ if (err) {
+ WARN_ON_ONCE(1);
+ break;
+ }
+ }
if (sta->uploaded) {
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
@@ -1391,8 +1400,8 @@
}
EXPORT_SYMBOL(ieee80211_sta_set_buffered);
-int sta_info_move_state_checked(struct sta_info *sta,
- enum ieee80211_sta_state new_state)
+int sta_info_move_state(struct sta_info *sta,
+ enum ieee80211_sta_state new_state)
{
might_sleep();