From f472321719787f3fdc9d5aa185d4453399475c72 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Fri, 6 Jul 2012 21:55:11 +0200
Subject: [PATCH] --- yaml --- r: 315539 b: refs/heads/master c:
 5260a5b2c3524f198ea062fe0a6a4faa724e6a9d h: refs/heads/master i:   315537:
 21d7e4b3a9b764e9084ed089e8ed53b683829cdb   315535:
 0db0a779e3cec78ca63dcc9bdcafd24c477dbff8 v: v3

---
 [refs]                           |  2 +-
 trunk/net/mac80211/ieee80211_i.h |  2 +-
 trunk/net/mac80211/main.c        |  3 ++-
 trunk/net/mac80211/rx.c          |  4 ++--
 trunk/net/mac80211/scan.c        | 20 ++++++++++----------
 5 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/[refs] b/[refs]
index 2ef26bac42c8..3f6859d4d5b0 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e2fd5dbc1c7031be5b5de043bcc0a18c7a59a68a
+refs/heads/master: 5260a5b2c3524f198ea062fe0a6a4faa724e6a9d
diff --git a/trunk/net/mac80211/ieee80211_i.h b/trunk/net/mac80211/ieee80211_i.h
index 9f2534a41243..e973a8f96c9b 100644
--- a/trunk/net/mac80211/ieee80211_i.h
+++ b/trunk/net/mac80211/ieee80211_i.h
@@ -965,9 +965,9 @@ struct ieee80211_local {
 	int scan_channel_idx;
 	int scan_ies_len;
 
-	bool sched_scanning;
 	struct ieee80211_sched_scan_ies sched_scan_ies;
 	struct work_struct sched_scan_stopped_work;
+	struct ieee80211_sub_if_data __rcu *sched_scan_sdata;
 
 	unsigned long leave_oper_channel_time;
 	enum mac80211_scan_state next_scan_state;
diff --git a/trunk/net/mac80211/main.c b/trunk/net/mac80211/main.c
index c794101f8987..c26e231c733a 100644
--- a/trunk/net/mac80211/main.c
+++ b/trunk/net/mac80211/main.c
@@ -322,7 +322,8 @@ static void ieee80211_restart_work(struct work_struct *work)
 
 	mutex_lock(&local->mtx);
 	WARN(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
-	     local->sched_scanning,
+	     rcu_dereference_protected(local->sched_scan_sdata,
+				       lockdep_is_held(&local->mtx)),
 		"%s called with hardware scan in progress\n", __func__);
 	mutex_unlock(&local->mtx);
 
diff --git a/trunk/net/mac80211/rx.c b/trunk/net/mac80211/rx.c
index f8cf9e7477a3..17a56151be7f 100644
--- a/trunk/net/mac80211/rx.c
+++ b/trunk/net/mac80211/rx.c
@@ -421,13 +421,13 @@ ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 	struct sk_buff *skb = rx->skb;
 
 	if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
-		   !local->sched_scanning))
+		   !rcu_access_pointer(local->sched_scan_sdata)))
 		return RX_CONTINUE;
 
 	if (test_bit(SCAN_HW_SCANNING, &local->scanning) ||
 	    test_bit(SCAN_SW_SCANNING, &local->scanning) ||
 	    test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning) ||
-	    local->sched_scanning)
+	    rcu_access_pointer(local->sched_scan_sdata))
 		return ieee80211_scan_rx(rx->sdata, skb);
 
 	/* scanning finished during invoking of handlers */
diff --git a/trunk/net/mac80211/scan.c b/trunk/net/mac80211/scan.c
index 704dcf847761..a619c1ea9bd5 100644
--- a/trunk/net/mac80211/scan.c
+++ b/trunk/net/mac80211/scan.c
@@ -930,9 +930,9 @@ int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
 	struct ieee80211_local *local = sdata->local;
 	int ret, i;
 
-	mutex_lock(&sdata->local->mtx);
+	mutex_lock(&local->mtx);
 
-	if (local->sched_scanning) {
+	if (rcu_access_pointer(local->sched_scan_sdata)) {
 		ret = -EBUSY;
 		goto out;
 	}
@@ -966,7 +966,7 @@ int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
 	ret = drv_sched_scan_start(local, sdata, req,
 				   &local->sched_scan_ies);
 	if (ret == 0) {
-		local->sched_scanning = true;
+		rcu_assign_pointer(local->sched_scan_sdata, sdata);
 		goto out;
 	}
 
@@ -974,7 +974,7 @@ int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
 	while (i > 0)
 		kfree(local->sched_scan_ies.ie[--i]);
 out:
-	mutex_unlock(&sdata->local->mtx);
+	mutex_unlock(&local->mtx);
 	return ret;
 }
 
@@ -983,22 +983,22 @@ int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
 	struct ieee80211_local *local = sdata->local;
 	int ret = 0, i;
 
-	mutex_lock(&sdata->local->mtx);
+	mutex_lock(&local->mtx);
 
 	if (!local->ops->sched_scan_stop) {
 		ret = -ENOTSUPP;
 		goto out;
 	}
 
-	if (local->sched_scanning) {
+	if (rcu_access_pointer(local->sched_scan_sdata)) {
 		for (i = 0; i < IEEE80211_NUM_BANDS; i++)
 			kfree(local->sched_scan_ies.ie[i]);
 
 		drv_sched_scan_stop(local, sdata);
-		local->sched_scanning = false;
+		rcu_assign_pointer(local->sched_scan_sdata, NULL);
 	}
 out:
-	mutex_unlock(&sdata->local->mtx);
+	mutex_unlock(&local->mtx);
 
 	return ret;
 }
@@ -1022,7 +1022,7 @@ void ieee80211_sched_scan_stopped_work(struct work_struct *work)
 
 	mutex_lock(&local->mtx);
 
-	if (!local->sched_scanning) {
+	if (!rcu_access_pointer(local->sched_scan_sdata)) {
 		mutex_unlock(&local->mtx);
 		return;
 	}
@@ -1030,7 +1030,7 @@ void ieee80211_sched_scan_stopped_work(struct work_struct *work)
 	for (i = 0; i < IEEE80211_NUM_BANDS; i++)
 		kfree(local->sched_scan_ies.ie[i]);
 
-	local->sched_scanning = false;
+	rcu_assign_pointer(local->sched_scan_sdata, NULL);
 
 	mutex_unlock(&local->mtx);