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 * GPL HEADER END
20 */
21 /*
22 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Use is subject to license terms.
24 *
25 * Copyright (c) 2011, 2015, Intel Corporation.
26 */
27 /*
28 * This file is part of Lustre, http://www.lustre.org/
29 * Lustre is a trademark of Oracle Corporation, Inc.
30 */
31
32 #include "../../include/linux/libcfs/libcfs.h"
33
34 unsigned long cfs_fail_loc;
35 EXPORT_SYMBOL(cfs_fail_loc);
36
37 unsigned int cfs_fail_val;
38 EXPORT_SYMBOL(cfs_fail_val);
39
40 int cfs_fail_err;
41 EXPORT_SYMBOL(cfs_fail_err);
42
43 DECLARE_WAIT_QUEUE_HEAD(cfs_race_waitq);
44 EXPORT_SYMBOL(cfs_race_waitq);
45
46 int cfs_race_state;
47 EXPORT_SYMBOL(cfs_race_state);
48
__cfs_fail_check_set(__u32 id,__u32 value,int set)49 int __cfs_fail_check_set(__u32 id, __u32 value, int set)
50 {
51 static atomic_t cfs_fail_count = ATOMIC_INIT(0);
52
53 LASSERT(!(id & CFS_FAIL_ONCE));
54
55 if ((cfs_fail_loc & (CFS_FAILED | CFS_FAIL_ONCE)) ==
56 (CFS_FAILED | CFS_FAIL_ONCE)) {
57 atomic_set(&cfs_fail_count, 0); /* paranoia */
58 return 0;
59 }
60
61 /* Fail 1/cfs_fail_val times */
62 if (cfs_fail_loc & CFS_FAIL_RAND) {
63 if (cfs_fail_val < 2 || cfs_rand() % cfs_fail_val > 0)
64 return 0;
65 }
66
67 /* Skip the first cfs_fail_val, then fail */
68 if (cfs_fail_loc & CFS_FAIL_SKIP) {
69 if (atomic_inc_return(&cfs_fail_count) <= cfs_fail_val)
70 return 0;
71 }
72
73 /* check cfs_fail_val... */
74 if (set == CFS_FAIL_LOC_VALUE) {
75 if (cfs_fail_val != -1 && cfs_fail_val != value)
76 return 0;
77 }
78
79 /* Fail cfs_fail_val times, overridden by FAIL_ONCE */
80 if (cfs_fail_loc & CFS_FAIL_SOME &&
81 (!(cfs_fail_loc & CFS_FAIL_ONCE) || cfs_fail_val <= 1)) {
82 int count = atomic_inc_return(&cfs_fail_count);
83
84 if (count >= cfs_fail_val) {
85 set_bit(CFS_FAIL_ONCE_BIT, &cfs_fail_loc);
86 atomic_set(&cfs_fail_count, 0);
87 /* we are lost race to increase */
88 if (count > cfs_fail_val)
89 return 0;
90 }
91 }
92
93 /* Take into account the current call for FAIL_ONCE for ORSET only,
94 * as RESET is a new fail_loc, it does not change the current call
95 */
96 if ((set == CFS_FAIL_LOC_ORSET) && (value & CFS_FAIL_ONCE))
97 set_bit(CFS_FAIL_ONCE_BIT, &cfs_fail_loc);
98 /* Lost race to set CFS_FAILED_BIT. */
99 if (test_and_set_bit(CFS_FAILED_BIT, &cfs_fail_loc)) {
100 /* If CFS_FAIL_ONCE is valid, only one process can fail,
101 * otherwise multi-process can fail at the same time.
102 */
103 if (cfs_fail_loc & CFS_FAIL_ONCE)
104 return 0;
105 }
106
107 switch (set) {
108 case CFS_FAIL_LOC_NOSET:
109 case CFS_FAIL_LOC_VALUE:
110 break;
111 case CFS_FAIL_LOC_ORSET:
112 cfs_fail_loc |= value & ~(CFS_FAILED | CFS_FAIL_ONCE);
113 break;
114 case CFS_FAIL_LOC_RESET:
115 cfs_fail_loc = value;
116 break;
117 default:
118 LASSERTF(0, "called with bad set %u\n", set);
119 break;
120 }
121
122 return 1;
123 }
124 EXPORT_SYMBOL(__cfs_fail_check_set);
125
__cfs_fail_timeout_set(__u32 id,__u32 value,int ms,int set)126 int __cfs_fail_timeout_set(__u32 id, __u32 value, int ms, int set)
127 {
128 int ret;
129
130 ret = __cfs_fail_check_set(id, value, set);
131 if (ret && likely(ms > 0)) {
132 CERROR("cfs_fail_timeout id %x sleeping for %dms\n",
133 id, ms);
134 set_current_state(TASK_UNINTERRUPTIBLE);
135 schedule_timeout(cfs_time_seconds(ms) / 1000);
136 CERROR("cfs_fail_timeout id %x awake\n", id);
137 }
138 return ret;
139 }
140 EXPORT_SYMBOL(__cfs_fail_timeout_set);
141