drbd: Use RCU for the drbd_tconns list

Preparing removal of drbd_cfg_rwsem

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 8da0e99ee7e6..771b53ece970 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2341,7 +2341,7 @@ static void drbd_cleanup(void)
         }
 
         list_for_each_entry_safe(tconn, tmp, &drbd_tconns, all_tconn) {
-                list_del(&tconn->all_tconn);
+                list_del_rcu(&tconn->all_tconn);
                 synchronize_rcu();
                 kref_put(&tconn->kref, &conn_destroy);
         }
@@ -2409,7 +2409,7 @@ struct drbd_tconn *conn_get_by_name(const char *name)
                 return NULL;
 
         down_read(&drbd_cfg_rwsem);
-        list_for_each_entry(tconn, &drbd_tconns, all_tconn) {
+        list_for_each_entry_rcu(tconn, &drbd_tconns, all_tconn) {
                 if (!strcmp(tconn->name, name)) {
                         kref_get(&tconn->kref);
                         goto found;
@@ -2459,6 +2459,7 @@ void conn_free_crypto(struct drbd_tconn *tconn)
         tconn->int_dig_vv = NULL;
 }
 
+/* caller must be under genl_lock() */
 struct drbd_tconn *conn_create(const char *name)
 {
         struct drbd_tconn *tconn;
@@ -2503,7 +2504,7 @@ struct drbd_tconn *conn_create(const char *name)
 
         down_write(&drbd_cfg_rwsem);
         kref_init(&tconn->kref);
-        list_add_tail(&tconn->all_tconn, &drbd_tconns);
+        list_add_tail_rcu(&tconn->all_tconn, &drbd_tconns);
         up_write(&drbd_cfg_rwsem);
 
         return tconn;