mac80211: add interface list lock
Using only the RTNL has a number of problems, most notably that
ieee80211_iterate_active_interfaces() and other interface list
traversals cannot be done from the internal workqueue because it
needs to be flushed under the RTNL.
This patch introduces a new mutex that protects the interface list
against modifications. A more detailed explanation is part of the
code change.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index c1e8261..8e65adf 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -928,9 +928,8 @@
* @workqueue: single threaded workqueue available for driver use,
* allocated by mac80211 on registration and flushed when an
* interface is removed.
- * NOTICE: All work performed on this workqueue should NEVER
- * acquire the RTNL lock (i.e. Don't use the function
- * ieee80211_iterate_active_interfaces())
+ * NOTICE: All work performed on this workqueue must not
+ * acquire the RTNL lock.
*
* @priv: pointer to private area that was allocated for driver use
* along with this structure.