1 /*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
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).
15 *
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.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26 /*
27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 */
30 /*
31 * This file is part of Lustre, http://www.lustre.org/
32 * Lustre is a trademark of Sun Microsystems, Inc.
33 *
34 * Implementation of cl_lock for VVP layer.
35 *
36 * Author: Nikita Danilov <nikita.danilov@sun.com>
37 */
38
39 #define DEBUG_SUBSYSTEM S_LLITE
40
41 #include "../include/obd.h"
42 #include "../include/lustre_lite.h"
43
44 #include "vvp_internal.h"
45
46 /*****************************************************************************
47 *
48 * Vvp lock functions.
49 *
50 */
51
52 /**
53 * Estimates lock value for the purpose of managing the lock cache during
54 * memory shortages.
55 *
56 * Locks for memory mapped files are almost infinitely precious, others are
57 * junk. "Mapped locks" are heavy, but not infinitely heavy, so that they are
58 * ordered within themselves by weights assigned from other layers.
59 */
vvp_lock_weigh(const struct lu_env * env,const struct cl_lock_slice * slice)60 static unsigned long vvp_lock_weigh(const struct lu_env *env,
61 const struct cl_lock_slice *slice)
62 {
63 struct ccc_object *cob = cl2ccc(slice->cls_obj);
64
65 return atomic_read(&cob->cob_mmap_cnt) > 0 ? ~0UL >> 2 : 0;
66 }
67
68 static const struct cl_lock_operations vvp_lock_ops = {
69 .clo_delete = ccc_lock_delete,
70 .clo_fini = ccc_lock_fini,
71 .clo_enqueue = ccc_lock_enqueue,
72 .clo_wait = ccc_lock_wait,
73 .clo_use = ccc_lock_use,
74 .clo_unuse = ccc_lock_unuse,
75 .clo_fits_into = ccc_lock_fits_into,
76 .clo_state = ccc_lock_state,
77 .clo_weigh = vvp_lock_weigh
78 };
79
vvp_lock_init(const struct lu_env * env,struct cl_object * obj,struct cl_lock * lock,const struct cl_io * io)80 int vvp_lock_init(const struct lu_env *env, struct cl_object *obj,
81 struct cl_lock *lock, const struct cl_io *io)
82 {
83 return ccc_lock_init(env, obj, lock, io, &vvp_lock_ops);
84 }
85