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>

1 files changed, 4 insertions, 18 deletions

diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index d997d0f0c54a..e7c6e862580d 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -72,7 +72,6 @@ int cfg80211_wext_siwmode(struct net_device *dev, struct iw_request_info *info,
         struct cfg80211_registered_device *rdev;
         struct vif_params vifparams;
         enum nl80211_iftype type;
-        int ret;
 
         rdev = wiphy_to_dev(wdev->wiphy);
 
@@ -98,11 +97,7 @@ int cfg80211_wext_siwmode(struct net_device *dev, struct iw_request_info *info,
 
         memset(&vifparams, 0, sizeof(vifparams));
 
-        cfg80211_lock_rdev(rdev);
-        ret = cfg80211_change_iface(rdev, dev, type, NULL, &vifparams);
-        cfg80211_unlock_rdev(rdev);
-
-        return ret;
+        return cfg80211_change_iface(rdev, dev, type, NULL, &vifparams);
 }
 EXPORT_SYMBOL_GPL(cfg80211_wext_siwmode);
 
@@ -579,13 +574,10 @@ static int cfg80211_set_encryption(struct cfg80211_registered_device *rdev,
 {
         int err;
 
-        /* devlist mutex needed for possible IBSS re-join */
-        mutex_lock(&rdev->devlist_mtx);
         wdev_lock(dev->ieee80211_ptr);
         err = __cfg80211_set_encryption(rdev, dev, pairwise, addr,
                                         remove, tx_key, idx, params);
         wdev_unlock(dev->ieee80211_ptr);
-        mutex_unlock(&rdev->devlist_mtx);
 
         return err;
 }
@@ -787,7 +779,7 @@ static int cfg80211_wext_siwfreq(struct net_device *dev,
         struct cfg80211_chan_def chandef = {
                 .width = NL80211_CHAN_WIDTH_20_NOHT,
         };
-        int freq, err;
+        int freq;
 
         switch (wdev->iftype) {
         case NL80211_IFTYPE_STATION:
@@ -804,10 +796,7 @@ static int cfg80211_wext_siwfreq(struct net_device *dev,
                 chandef.chan = ieee80211_get_channel(&rdev->wiphy, freq);
                 if (!chandef.chan)
                         return -EINVAL;
-                mutex_lock(&rdev->devlist_mtx);
-                err = cfg80211_set_monitor_channel(rdev, &chandef);
-                mutex_unlock(&rdev->devlist_mtx);
-                return err;
+                return cfg80211_set_monitor_channel(rdev, &chandef);
         case NL80211_IFTYPE_MESH_POINT:
                 freq = cfg80211_wext_freq(wdev->wiphy, wextfreq);
                 if (freq < 0)
@@ -818,10 +807,7 @@ static int cfg80211_wext_siwfreq(struct net_device *dev,
                 chandef.chan = ieee80211_get_channel(&rdev->wiphy, freq);
                 if (!chandef.chan)
                         return -EINVAL;
-                mutex_lock(&rdev->devlist_mtx);
-                err = cfg80211_set_mesh_channel(rdev, wdev, &chandef);
-                mutex_unlock(&rdev->devlist_mtx);
-                return err;
+                return cfg80211_set_mesh_channel(rdev, wdev, &chandef);
         default:
                 return -EOPNOTSUPP;
         }