[MAC80211]: improve locking of sta_info related structures

The sta_info code has some awkward locking which prevents some driver callbacks from being allowed to sleep. This patch makes the locking more focused so code that calls driver callbacks are allowed to sleep. It also converts sta_lock to a rwlock. Signed-off-by: Michael Wu <flamingice@sourmilk.net> Signed-off-by: Jiri Benc <jbenc@suse.cz> Signed-off-by: John W. Linville <linville@tuxdriver.com>
git-mirror · Oct 10, 2007 · be8755e · be8755e
1 parent c2d1560
commit be8755e
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Showing 8 changed files with 109 additions and 136 deletions.
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
@@ -626,8 +626,7 @@ struct ieee80211_ops {
 	 * station hwaddr for individual keys. aid of the station is given
 	 * to help low-level driver in selecting which key->hw_key_idx to use
 	 * for this key. TX control data will use the hw_key_idx selected by
-	 * the low-level driver.
-	 * Must be atomic. */
+	 * the low-level driver. */
 	int (*set_key)(struct ieee80211_hw *hw, set_key_cmd cmd,
 		       u8 *addr, struct ieee80211_key_conf *key, int aid);
 

diff --git a/net/mac80211/ieee80211.c b/net/mac80211/ieee80211.c
@@ -628,8 +628,8 @@ int ieee80211_if_update_wds(struct net_device *dev, u8 *remote_addr)
 	/* Remove STA entry for the old peer */
 	sta = sta_info_get(local, sdata->u.wds.remote_addr);
 	if (sta) {
+		sta_info_free(sta);
 		sta_info_put(sta);
-		sta_info_free(sta, 0);
 	} else {
 		printk(KERN_DEBUG "%s: could not find STA entry for WDS link "
 		       "peer " MAC_FMT "\n",
@@ -776,13 +776,13 @@ static void ieee80211_stat_refresh(unsigned long data)
 		return;
 
 	/* go through all stations */
-	spin_lock_bh(&local->sta_lock);
+	read_lock_bh(&local->sta_lock);
 	list_for_each_entry(sta, &local->sta_list, list) {
 		sta->channel_use = (sta->channel_use_raw / local->stat_time) /
 			CHAN_UTIL_PER_10MS;
 		sta->channel_use_raw = 0;
 	}
-	spin_unlock_bh(&local->sta_lock);
+	read_unlock_bh(&local->sta_lock);
 
 	/* go through all subinterfaces */
 	read_lock(&local->sub_if_lock);

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
@@ -417,10 +417,9 @@ struct ieee80211_local {
 	struct sk_buff_head skb_queue_unreliable;
 
 	/* Station data structures */
-	spinlock_t sta_lock; /* mutex for STA data structures */
+	rwlock_t sta_lock; /* protects STA data structures */
 	int num_sta; /* number of stations in sta_list */
 	struct list_head sta_list;
-	struct list_head deleted_sta_list;
 	struct sta_info *sta_hash[STA_HASH_SIZE];
 	struct timer_list sta_cleanup;
 
@@ -669,9 +668,9 @@ static inline void __bss_tim_set(struct ieee80211_if_ap *bss, int aid)
 static inline void bss_tim_set(struct ieee80211_local *local,
 			       struct ieee80211_if_ap *bss, int aid)
 {
-	spin_lock_bh(&local->sta_lock);
+	read_lock_bh(&local->sta_lock);
 	__bss_tim_set(bss, aid);
-	spin_unlock_bh(&local->sta_lock);
+	read_unlock_bh(&local->sta_lock);
 }
 
 static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, int aid)
@@ -686,9 +685,9 @@ static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, int aid)
 static inline void bss_tim_clear(struct ieee80211_local *local,
 				 struct ieee80211_if_ap *bss, int aid)
 {
-	spin_lock_bh(&local->sta_lock);
+	read_lock_bh(&local->sta_lock);
 	__bss_tim_clear(bss, aid);
-	spin_unlock_bh(&local->sta_lock);
+	read_unlock_bh(&local->sta_lock);
 }
 
 /**

diff --git a/net/mac80211/ieee80211_iface.c b/net/mac80211/ieee80211_iface.c
@@ -272,8 +272,8 @@ void ieee80211_if_reinit(struct net_device *dev)
 	case IEEE80211_IF_TYPE_WDS:
 		sta = sta_info_get(local, sdata->u.wds.remote_addr);
 		if (sta) {
+			sta_info_free(sta);
 			sta_info_put(sta);
-			sta_info_free(sta, 0);
 		} else {
 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 			printk(KERN_DEBUG "%s: Someone had deleted my STA "

diff --git a/net/mac80211/ieee80211_sta.c b/net/mac80211/ieee80211_sta.c
@@ -773,7 +773,7 @@ static void ieee80211_associated(struct net_device *dev,
 				       "range\n",
 				       dev->name, MAC_ARG(ifsta->bssid));
 				disassoc = 1;
-				sta_info_free(sta, 0);
+				sta_info_free(sta);
 				ifsta->probereq_poll = 0;
 			} else {
 				ieee80211_send_probe_req(dev, ifsta->bssid,
@@ -1890,7 +1890,7 @@ static int ieee80211_sta_active_ibss(struct net_device *dev)
 	int active = 0;
 	struct sta_info *sta;
 
-	spin_lock_bh(&local->sta_lock);
+	read_lock_bh(&local->sta_lock);
 	list_for_each_entry(sta, &local->sta_list, list) {
 		if (sta->dev == dev &&
 		    time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
@@ -1899,7 +1899,7 @@ static int ieee80211_sta_active_ibss(struct net_device *dev)
 			break;
 		}
 	}
-	spin_unlock_bh(&local->sta_lock);
+	read_unlock_bh(&local->sta_lock);
 
 	return active;
 }
@@ -1909,16 +1909,24 @@ static void ieee80211_sta_expire(struct net_device *dev)
 {
 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 	struct sta_info *sta, *tmp;
+	LIST_HEAD(tmp_list);
 
-	spin_lock_bh(&local->sta_lock);
+	write_lock_bh(&local->sta_lock);
 	list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
 		if (time_after(jiffies, sta->last_rx +
 			       IEEE80211_IBSS_INACTIVITY_LIMIT)) {
 			printk(KERN_DEBUG "%s: expiring inactive STA " MAC_FMT
 			       "\n", dev->name, MAC_ARG(sta->addr));
-			sta_info_free(sta, 1);
+			__sta_info_get(sta);
+			sta_info_remove(sta);
+			list_add(&sta->list, &tmp_list);
 		}
-	spin_unlock_bh(&local->sta_lock);
+	write_unlock_bh(&local->sta_lock);
+
+	list_for_each_entry_safe(sta, tmp, &tmp_list, list) {
+		sta_info_free(sta);
+		sta_info_put(sta);
+	}
 }