mac80211: fix mesh deadlock
The patch "cfg80211/mac80211: use cfg80211 wdev mutex in
mac80211" introduced several deadlocks by converting the
ifmsh->mtx to wdev->mtx. Solve these by:
1. drop the cancel_work_sync() in ieee80211_stop_mesh().
Instead make the mesh work conditional on whether the mesh
is running or not.
2. lock the mesh work with sdata_lock() to protect beacon
updates and prevent races with wdev->mesh_id_len or
cfg80211.
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index 6c4da99..09bebed 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -517,9 +517,7 @@
ieee80211_mps_frame_release(sta, elems);
out:
rcu_read_unlock();
- sdata_lock(sdata);
ieee80211_mbss_info_change_notify(sdata, changed);
- sdata_unlock(sdata);
}
static void mesh_plink_timer(unsigned long data)
@@ -1070,9 +1068,6 @@
rcu_read_unlock();
- if (changed) {
- sdata_lock(sdata);
+ if (changed)
ieee80211_mbss_info_change_notify(sdata, changed);
- sdata_unlock(sdata);
- }
}