LU-3321 osc: add weight function for DLM 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 ac268ec..904ad30 100644 (file)
--- a/lustre/ldlm/l_lock.c
+++ b/lustre/ldlm/l_lock.c
@@ -1,6 +1,4 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * GPL HEADER START
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -26,8 +24,10 @@
  * GPL HEADER END
  */
 /*
- * Copyright  2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
+ *
+ * Copyright (c) 2012, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -37,45 +37,44 @@
 #define DEBUG_SUBSYSTEM S_LDLM
 #ifdef __KERNEL__
 #include <libcfs/libcfs.h>
-#else 
+#else
 #include <liblustre.h>
 #endif
 
 #include <lustre_dlm.h>
 #include <lustre_lib.h>
 
-/*
- * ldlm locking uses resource to serialize access to locks
+/**
+ * Lock a lock and its resource.
+ *
+ * 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 that lock->l_resource = new_res
- * is atomic
+ * 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 *lock_res_and_lock(struct ldlm_lock *lock)
 {
-        struct ldlm_resource *res = lock->l_resource;
+       /* on server-side resource of lock doesn't change */
+       if (!ldlm_is_ns_srv(lock))
+               spin_lock(&lock->l_lock);
 
-        if (ns_is_server(res->lr_namespace)) {
-                /* on server-side resource of lock doesn't change */
-                lock_res(res);
-                return res;
-        } 
+       lock_res(lock->l_resource);
 
-        spin_lock(&lock->l_lock);
-        res = lock->l_resource;
-        lock_res(res);
-        return res;
+       ldlm_set_res_locked(lock);
+       return lock->l_resource;
 }
+EXPORT_SYMBOL(lock_res_and_lock);
 
+/**
+ * Unlock a lock and its resource previously locked with lock_res_and_lock
+ */
 void unlock_res_and_lock(struct ldlm_lock *lock)
 {
-        struct ldlm_resource *res = lock->l_resource;
-
-        if (ns_is_server(res->lr_namespace)) {
-                /* on server-side resource of lock doesn't change */
-                unlock_res(res);
-                return;
-        }
+       /* on server-side resource of lock doesn't change */
+       ldlm_clear_res_locked(lock);
 
-        unlock_res(res);
-        spin_unlock(&lock->l_lock);
+       unlock_res(lock->l_resource);
+       if (!ldlm_is_ns_srv(lock))
+               spin_unlock(&lock->l_lock);
 }
+EXPORT_SYMBOL(unlock_res_and_lock);