From 83d5cc012441531ab0bf6f99881958e964e9cf11 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 12 Jan 2012 09:31:10 +0100 Subject: 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 Signed-off-by: John W. Linville --- net/mac80211/sta_info.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) (limited to 'net/mac80211/sta_info.c') diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index f28fa02b6e54..df8f0a2f0dee 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -403,6 +403,8 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU) 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 @@ static bool sta_info_cleanup_expire_buffered(struct ieee80211_local *local, 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 @@ static int __must_check __sta_info_destroy(struct sta_info *sta) 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 @@ static int __must_check __sta_info_destroy(struct sta_info *sta) 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 @@ void ieee80211_sta_set_buffered(struct ieee80211_sta *pubsta, } 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(); -- cgit v1.2.3