[PATCH 1/3] mac80211: move some RCU locking into an if branch

[Johannes Berg <johannes@sipsolutions.net>]

The if itself doesn't need to be protected, so move in the RCU
locking to avoid doing anything at all when the condition isn't
true.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
 net/mac80211/mlme.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

--- everything.orig/net/mac80211/mlme.c	2008-09-08 10:20:25.000000000 +0200
+++ everything/net/mac80211/mlme.c	2008-09-08 10:21:09.000000000 +0200
@@ -2613,13 +2613,12 @@ static void ieee80211_rx_bss_info(struct
 				      mesh_peer_accepts_plinks(elems));
 	}
 
-	rcu_read_lock();
-
 	if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS && elems->supp_rates &&
 	    memcmp(mgmt->bssid, sdata->u.sta.bssid, ETH_ALEN) == 0) {
-
 		supp_rates = ieee80211_sta_get_rates(local, elems, band);
 
+		rcu_read_lock();
+
 		sta = sta_info_get(local, mgmt->sa);
 		if (sta) {
 			u64 prev_rates;
@@ -2643,9 +2642,9 @@ static void ieee80211_rx_bss_info(struct
 			ieee80211_ibss_add_sta(sdata, NULL, mgmt->bssid,
 					       mgmt->sa, supp_rates);
 		}
-	}
 
-	rcu_read_unlock();
+		rcu_read_unlock();
+	}
 
 	if (elems->ds_params && elems->ds_params_len == 1)
 		freq = ieee80211_channel_to_frequency(elems->ds_params[0]);

--