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 http://www.gnu.org/licenses
18 *
19 * Please contact Oracle Corporation, Inc., 500 Oracle Parkway, Redwood Shores,
20 * CA 94065 USA or visit www.oracle.com if you need additional information or
21 * have any questions.
22 *
23 * GPL HEADER END
24 */
25 /*
26 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
27 * Use is subject to license terms.
28 *
29 * Copyright (c) 2011, 2012, Intel Corporation.
30 */
31 /*
32 * This file is part of Lustre, http://www.lustre.org/
33 * Lustre is a trademark of Oracle Corporation, Inc.
34 */
35
36 #include "../../include/linux/libcfs/libcfs.h"
37
38 unsigned long cfs_fail_loc;
39 EXPORT_SYMBOL(cfs_fail_loc);
40
41 unsigned int cfs_fail_val;
42 EXPORT_SYMBOL(cfs_fail_val);
43
44 DECLARE_WAIT_QUEUE_HEAD(cfs_race_waitq);
45 EXPORT_SYMBOL(cfs_race_waitq);
46
47 int cfs_race_state;
48 EXPORT_SYMBOL(cfs_race_state);
49
__cfs_fail_check_set(__u32 id,__u32 value,int set)50 int __cfs_fail_check_set(__u32 id, __u32 value, int set)
51 {
52 static atomic_t cfs_fail_count = ATOMIC_INIT(0);
53
54 LASSERT(!(id & CFS_FAIL_ONCE));
55
56 if ((cfs_fail_loc & (CFS_FAILED | CFS_FAIL_ONCE)) ==
57 (CFS_FAILED | CFS_FAIL_ONCE)) {
58 atomic_set(&cfs_fail_count, 0); /* paranoia */
59 return 0;
60 }
61
62 /* Fail 1/cfs_fail_val times */
63 if (cfs_fail_loc & CFS_FAIL_RAND) {
64 if (cfs_fail_val < 2 || cfs_rand() % cfs_fail_val > 0)
65 return 0;
66 }
67
68 /* Skip the first cfs_fail_val, then fail */
69 if (cfs_fail_loc & CFS_FAIL_SKIP) {
70 if (atomic_inc_return(&cfs_fail_count) <= cfs_fail_val)
71 return 0;
72 }
73
74 /* check cfs_fail_val... */
75 if (set == CFS_FAIL_LOC_VALUE) {
76 if (cfs_fail_val != -1 && cfs_fail_val != value)
77 return 0;
78 }
79
80 /* Fail cfs_fail_val times, overridden by FAIL_ONCE */
81 if (cfs_fail_loc & CFS_FAIL_SOME &&
82 (!(cfs_fail_loc & CFS_FAIL_ONCE) || cfs_fail_val <= 1)) {
83 int count = atomic_inc_return(&cfs_fail_count);
84
85 if (count >= cfs_fail_val) {
86 set_bit(CFS_FAIL_ONCE_BIT, &cfs_fail_loc);
87 atomic_set(&cfs_fail_count, 0);
88 /* we are lost race to increase */
89 if (count > cfs_fail_val)
90 return 0;
91 }
92 }
93
94 if ((set == CFS_FAIL_LOC_ORSET || set == CFS_FAIL_LOC_RESET) &&
95 (value & CFS_FAIL_ONCE))
96 set_bit(CFS_FAIL_ONCE_BIT, &cfs_fail_loc);
97 /* Lost race to set CFS_FAILED_BIT. */
98 if (test_and_set_bit(CFS_FAILED_BIT, &cfs_fail_loc)) {
99 /* If CFS_FAIL_ONCE is valid, only one process can fail,
100 * otherwise multi-process can fail at the same time. */
101 if (cfs_fail_loc & CFS_FAIL_ONCE)
102 return 0;
103 }
104
105 switch (set) {
106 case CFS_FAIL_LOC_NOSET:
107 case CFS_FAIL_LOC_VALUE:
108 break;
109 case CFS_FAIL_LOC_ORSET:
110 cfs_fail_loc |= value & ~(CFS_FAILED | CFS_FAIL_ONCE);
111 break;
112 case CFS_FAIL_LOC_RESET:
113 cfs_fail_loc = value;
114 break;
115 default:
116 LASSERTF(0, "called with bad set %u\n", set);
117 break;
118 }
119
120 return 1;
121 }
122 EXPORT_SYMBOL(__cfs_fail_check_set);
123
__cfs_fail_timeout_set(__u32 id,__u32 value,int ms,int set)124 int __cfs_fail_timeout_set(__u32 id, __u32 value, int ms, int set)
125 {
126 int ret;
127
128 ret = __cfs_fail_check_set(id, value, set);
129 if (ret) {
130 CERROR("cfs_fail_timeout id %x sleeping for %dms\n",
131 id, ms);
132 set_current_state(TASK_UNINTERRUPTIBLE);
133 schedule_timeout(cfs_time_seconds(ms) / 1000);
134 CERROR("cfs_fail_timeout id %x awake\n", id);
135 }
136 return ret;
137 }
138 EXPORT_SYMBOL(__cfs_fail_timeout_set);
139