tipc: convert bearer_list to RCU list

Convert bearer_list to RCU list. It's protected by RTNL lock on
update side, and RCU read lock is applied to read side.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Tested-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 3 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 95ab5ef92920..223a19929024 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -659,6 +659,7 @@ void tipc_bcbearer_sort(void)
 {
         struct tipc_bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
         struct tipc_bcbearer_pair *bp_curr;
+        struct tipc_bearer *b;
         int b_index;
         int pri;
 
@@ -667,8 +668,9 @@ void tipc_bcbearer_sort(void)
         /* Group bearers by priority (can assume max of two per priority) */
         memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
 
+        rcu_read_lock();
         for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
-                struct tipc_bearer *b = bearer_list[b_index];
+                b = rcu_dereference_rtnl(bearer_list[b_index]);
                 if (!b || !b->nodes.count)
                         continue;
 
@@ -677,6 +679,7 @@ void tipc_bcbearer_sort(void)
                 else
                         bp_temp[b->priority].secondary = b;
         }
+        rcu_read_unlock();
 
         /* Create array of bearer pairs for broadcasting */
         bp_curr = bcbearer->bpairs;
@@ -784,7 +787,7 @@ void tipc_bclink_init(void)
         bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
         tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
         bcl->b_ptr = &bcbearer->bearer;
-        bearer_list[BCBEARER] = &bcbearer->bearer;
+        rcu_assign_pointer(bearer_list[MAX_BEARERS], &bcbearer->bearer);
         bcl->state = WORKING_WORKING;
         strlcpy(bcl->name, tipc_bclink_name, TIPC_MAX_LINK_NAME);
 }
@@ -795,7 +798,7 @@ void tipc_bclink_stop(void)
         tipc_link_purge_queues(bcl);
         spin_unlock_bh(&bc_lock);
 
-        bearer_list[BCBEARER] = NULL;
+        RCU_INIT_POINTER(bearer_list[BCBEARER], NULL);
         memset(bclink, 0, sizeof(*bclink));
         memset(bcbearer, 0, sizeof(*bcbearer));
 }