LU-15167 quota: fallocate send UID/GID for quota

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

diff --git a/lustre/ldlm/l_lock.c b/lustre/ldlm/l_lock.c
index e23a755..0c10b30 100644 (file)
--- a/lustre/ldlm/l_lock.c
+++ b/lustre/ldlm/l_lock.c
@@ -1,71 +1,73 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
+/*
+ * GPL HEADER START
  *
- * Copyright (C) 2001, 2002 Cluster File Systems, Inc.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
- *   This file is part of the Lustre file system, http://www.lustre.org
- *   Lustre is a trademark of Cluster File Systems, Inc.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
  *
- *   You may have signed or agreed to another license before downloading
- *   this software.  If so, you are bound by the terms and conditions
- *   of that agreement, and the following does not apply to you.  See the
- *   LICENSE file included with this distribution for more information.
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
  *
- *   If you did not agree to a different license, then this copy of Lustre
- *   is open source software; you can redistribute it and/or modify it
- *   under the terms of version 2 of the GNU General Public License as
- *   published by the Free Software Foundation.
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.gnu.org/licenses/gpl-2.0.html
  *
- *   In either case, Lustre is distributed in the hope that it will be
- *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
- *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *   license text for more details.
+ * GPL HEADER END
+ */
+/*
+ * 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/
  */
 
 #define DEBUG_SUBSYSTEM S_LDLM
-#ifdef __KERNEL__
 #include <libcfs/libcfs.h>
-#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 rcu_assign_pointer(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;
-
-        if (ns_is_server(res->lr_namespace)) {
-                /* on server-side resource of lock doesn't change */
-                lock_res(res);
-                return res;
-        } 
+       struct ldlm_resource *res;
 
-        spin_lock(&lock->l_lock);
-        res = lock->l_resource;
-        lock_res(res);
-        return res;
+       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);
+       }
 }
+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;
+       ldlm_clear_res_locked(lock);
 
-        if (ns_is_server(res->lr_namespace)) {
-                /* on server-side resource of lock doesn't change */
-                unlock_res(res);
-                return;
-        }
-
-        unlock_res(res);
-        spin_unlock(&lock->l_lock);
+       unlock_res(lock->l_resource);
 }
-
+EXPORT_SYMBOL(unlock_res_and_lock);