4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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/
30 * Lustre is a trademark of Sun Microsystems, Inc.
33 #define DEBUG_SUBSYSTEM S_LDLM
34 #include <libcfs/libcfs.h>
36 #include <lustre_dlm.h>
37 #include <lustre_lib.h>
40 * Lock a lock and its resource.
42 * LDLM locking uses resource to serialize access to locks
43 * but there is a case when we change resource of lock upon
44 * enqueue reply. We rely on lock->l_resource = new_res
45 * being an atomic operation.
47 struct ldlm_resource *lock_res_and_lock(struct ldlm_lock *lock)
49 /* on server-side resource of lock doesn't change */
50 if (!ldlm_is_ns_srv(lock))
51 spin_lock(&lock->l_lock);
53 lock_res(lock->l_resource);
55 ldlm_set_res_locked(lock);
56 return lock->l_resource;
58 EXPORT_SYMBOL(lock_res_and_lock);
61 * Unlock a lock and its resource previously locked with lock_res_and_lock
63 void unlock_res_and_lock(struct ldlm_lock *lock)
65 /* on server-side resource of lock doesn't change */
66 ldlm_clear_res_locked(lock);
68 unlock_res(lock->l_resource);
69 if (!ldlm_is_ns_srv(lock))
70 spin_unlock(&lock->l_lock);
72 EXPORT_SYMBOL(unlock_res_and_lock);