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7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2012, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
32 #define DEBUG_SUBSYSTEM S_LDLM
33 #include <libcfs/libcfs.h>
35 #include <lustre_dlm.h>
36 #include <lustre_lib.h>
39 * Lock a lock and its resource.
41 * LDLM locking uses resource to serialize access to locks
42 * but there is a case when we change resource of lock upon
43 * enqueue reply. We rely on rcu_assign_pointer(lock->l_resource, new_res)
44 * being an atomic operation.
46 struct ldlm_resource *lock_res_and_lock(struct ldlm_lock *lock)
48 struct ldlm_resource *res;
52 res = rcu_dereference(lock->l_resource);
54 if (res == lock->l_resource) {
55 ldlm_set_res_locked(lock);
62 EXPORT_SYMBOL(lock_res_and_lock);
65 * Unlock a lock and its resource previously locked with lock_res_and_lock
67 void unlock_res_and_lock(struct ldlm_lock *lock)
69 ldlm_clear_res_locked(lock);
71 unlock_res(lock->l_resource);
73 EXPORT_SYMBOL(unlock_res_and_lock);