Revert "LU-4801 ldlm: discard l_lock from struct ldlm_lock."

[fs/lustre-release.git] / lustre / ldlm / l_lock.c

diff --git a/lustre/ldlm/l_lock.c b/lustre/ldlm/l_lock.c
index 6d37af1..a4f7c85 100644 (file)
--- a/lustre/ldlm/l_lock.c
+++ b/lustre/ldlm/l_lock.c
@@ -41,24 +41,19 @@
  *
  * LDLM locking uses resource to serialize access to locks
  * but there is a case when we change resource of lock upon
- * enqueue reply. We rely on rcu_assign_pointer(lock->l_resource, new_res)
+ * enqueue reply. We rely on lock->l_resource = new_res
  * being an atomic operation.
  */
 struct ldlm_resource *lock_res_and_lock(struct ldlm_lock *lock)
 {
-       struct ldlm_resource *res;
+       /* on server-side resource of lock doesn't change */
+       if (!ldlm_is_ns_srv(lock))
+               spin_lock(&lock->l_lock);
 
-       rcu_read_lock();
-       while (1) {
-               res = rcu_dereference(lock->l_resource);
-               lock_res(res);
-               if (res == lock->l_resource) {
-                       ldlm_set_res_locked(lock);
-                       rcu_read_unlock();
-                       return res;
-               }
-               unlock_res(res);
-       }
+       lock_res(lock->l_resource);
+
+       ldlm_set_res_locked(lock);
+       return lock->l_resource;
 }
 EXPORT_SYMBOL(lock_res_and_lock);
 
@@ -67,8 +62,11 @@ EXPORT_SYMBOL(lock_res_and_lock);
  */
 void unlock_res_and_lock(struct ldlm_lock *lock)
 {
+       /* on server-side resource of lock doesn't change */
        ldlm_clear_res_locked(lock);
 
        unlock_res(lock->l_resource);
+       if (!ldlm_is_ns_srv(lock))
+               spin_unlock(&lock->l_lock);
 }
 EXPORT_SYMBOL(unlock_res_and_lock);