cfg80211: vastly simplify locking
Virtually all code paths in cfg80211 already (need to) hold
the RTNL. As such, there's little point in having another
four mutexes for various parts of the code, they just cause
lock ordering issues (and much of the time, the RTNL and a
few of the others need thus be held.)
Simplify all this by getting rid of the extra four mutexes
and just use the RTNL throughout. Only a few code changes
were needed to do this and we can get rid of a work struct
for bonus points.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index 3ed35c3..4dbf314 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -43,35 +43,29 @@
struct wireless_dev *wdev;
bool is_all_idle = true;
- mutex_lock(&cfg80211_mutex);
-
/*
* All devices must be idle as otherwise if you are actively
* scanning some new beacon hints could be learned and would
* count as new regulatory hints.
*/
list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
- cfg80211_lock_rdev(rdev);
list_for_each_entry(wdev, &rdev->wdev_list, list) {
wdev_lock(wdev);
if (wdev->sme_state != CFG80211_SME_IDLE)
is_all_idle = false;
wdev_unlock(wdev);
}
- cfg80211_unlock_rdev(rdev);
}
- mutex_unlock(&cfg80211_mutex);
-
return is_all_idle;
}
static void disconnect_work(struct work_struct *work)
{
- if (!cfg80211_is_all_idle())
- return;
-
- regulatory_hint_disconnect();
+ rtnl_lock();
+ if (cfg80211_is_all_idle())
+ regulatory_hint_disconnect();
+ rtnl_unlock();
}
static DECLARE_WORK(cfg80211_disconnect_work, disconnect_work);
@@ -85,7 +79,6 @@
ASSERT_RTNL();
ASSERT_RDEV_LOCK(rdev);
ASSERT_WDEV_LOCK(wdev);
- lockdep_assert_held(&rdev->sched_scan_mtx);
if (rdev->scan_req)
return -EBUSY;
@@ -226,9 +219,6 @@
u8 bssid_buf[ETH_ALEN], *bssid = NULL;
rtnl_lock();
- cfg80211_lock_rdev(rdev);
- mutex_lock(&rdev->devlist_mtx);
- mutex_lock(&rdev->sched_scan_mtx);
list_for_each_entry(wdev, &rdev->wdev_list, list) {
if (!wdev->netdev)
@@ -256,9 +246,6 @@
wdev_unlock(wdev);
}
- mutex_unlock(&rdev->sched_scan_mtx);
- mutex_unlock(&rdev->devlist_mtx);
- cfg80211_unlock_rdev(rdev);
rtnl_unlock();
}
@@ -931,14 +918,9 @@
{
int err;
- mutex_lock(&rdev->devlist_mtx);
- /* might request scan - scan_mtx -> wdev_mtx dependency */
- mutex_lock(&rdev->sched_scan_mtx);
wdev_lock(dev->ieee80211_ptr);
err = __cfg80211_connect(rdev, dev, connect, connkeys, NULL);
wdev_unlock(dev->ieee80211_ptr);
- mutex_unlock(&rdev->sched_scan_mtx);
- mutex_unlock(&rdev->devlist_mtx);
return err;
}