mac80211: fix and simplify mesh locking
The locking in mesh_{mpath,mpp}_table_grow not only
has an rcu_read_unlock() missing, it's also racy
(though really only technically since it's invoked
from a single function only) since it obtains the
new size of the table without any locking, so two
invocations of the function could attempt the same
resize.
Additionally, it uses synchronize_rcu() which is
rather expensive and can be avoided trivially here.
Modify the functions to only use the table lock
and use call_rcu() instead of synchronize_rcu().
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index e7c5fdd..eb733c0 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -120,6 +120,7 @@
* buckets
* @mean_chain_len: maximum average length for the hash buckets' list, if it is
* reached, the table will grow
+ * rcu_head: RCU head to free the table
*/
struct mesh_table {
/* Number of buckets will be 2^N */
@@ -132,6 +133,8 @@
int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
int size_order;
int mean_chain_len;
+
+ struct rcu_head rcu_head;
};
/* Recent multicast cache */