4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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.
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).
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17 * version 2 along with this program; If not, see http://www.gnu.org/licenses
22 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Use is subject to license terms.
25 * Copyright (c) 2012, 2015, Intel Corporation.
28 * This file is part of Lustre, http://www.lustre.org/
29 * Lustre is a trademark of Oracle Corporation, Inc.
32 #include <linux/random.h>
33 #include <libcfs/libcfs.h>
35 unsigned long cfs_fail_loc = 0;
36 unsigned int cfs_fail_val = 0;
38 DECLARE_WAIT_QUEUE_HEAD(cfs_race_waitq);
41 EXPORT_SYMBOL(cfs_fail_loc);
42 EXPORT_SYMBOL(cfs_fail_val);
43 EXPORT_SYMBOL(cfs_fail_err);
44 EXPORT_SYMBOL(cfs_race_waitq);
45 EXPORT_SYMBOL(cfs_race_state);
47 int __cfs_fail_check_set(__u32 id, __u32 value, int set)
49 static atomic_t cfs_fail_count = ATOMIC_INIT(0);
51 LASSERT(!(id & CFS_FAIL_ONCE));
53 if ((cfs_fail_loc & (CFS_FAILED | CFS_FAIL_ONCE)) ==
54 (CFS_FAILED | CFS_FAIL_ONCE)) {
55 atomic_set(&cfs_fail_count, 0); /* paranoia */
59 /* Fail 1/cfs_fail_val times */
60 if (cfs_fail_loc & CFS_FAIL_RAND) {
61 if (cfs_fail_val < 2 || prandom_u32_max(cfs_fail_val) > 0)
65 /* Skip the first cfs_fail_val, then fail */
66 if (cfs_fail_loc & CFS_FAIL_SKIP) {
67 if (atomic_inc_return(&cfs_fail_count) <= cfs_fail_val)
71 /* check cfs_fail_val... */
72 if (set == CFS_FAIL_LOC_VALUE) {
73 if (cfs_fail_val != -1 && cfs_fail_val != value)
77 /* Fail cfs_fail_val times, overridden by FAIL_ONCE */
78 if (cfs_fail_loc & CFS_FAIL_SOME &&
79 (!(cfs_fail_loc & CFS_FAIL_ONCE) || cfs_fail_val <= 1)) {
80 int count = atomic_inc_return(&cfs_fail_count);
82 if (count >= cfs_fail_val) {
83 set_bit(CFS_FAIL_ONCE_BIT, &cfs_fail_loc);
84 atomic_set(&cfs_fail_count, 0);
85 /* we are lost race to increase */
86 if (count > cfs_fail_val)
91 /* Take into account the current call for FAIL_ONCE for ORSET only,
92 * as RESET is a new fail_loc, it does not change the current call */
93 if ((set == CFS_FAIL_LOC_ORSET) && (value & CFS_FAIL_ONCE))
94 set_bit(CFS_FAIL_ONCE_BIT, &cfs_fail_loc);
95 /* Lost race to set CFS_FAILED_BIT. */
96 if (test_and_set_bit(CFS_FAILED_BIT, &cfs_fail_loc)) {
97 /* If CFS_FAIL_ONCE is valid, only one process can fail,
98 * otherwise multi-process can fail at the same time. */
99 if (cfs_fail_loc & CFS_FAIL_ONCE)
104 case CFS_FAIL_LOC_NOSET:
105 case CFS_FAIL_LOC_VALUE:
107 case CFS_FAIL_LOC_ORSET:
108 cfs_fail_loc |= value & ~(CFS_FAILED | CFS_FAIL_ONCE);
110 case CFS_FAIL_LOC_RESET:
111 cfs_fail_loc = value;
112 atomic_set(&cfs_fail_count, 0);
115 LASSERTF(0, "called with bad set %u\n", set);
121 EXPORT_SYMBOL(__cfs_fail_check_set);
123 int __cfs_fail_timeout_set(__u32 id, __u32 value, int ms, int set)
125 ktime_t till = ktime_add_ms(ktime_get(), ms);
128 ret = __cfs_fail_check_set(id, value, set);
129 if (ret && likely(ms > 0)) {
130 CERROR("cfs_fail_timeout id %x sleeping for %dms\n", id, ms);
131 while (ktime_before(ktime_get(), till)) {
132 set_current_state(TASK_UNINTERRUPTIBLE);
133 schedule_timeout(msecs_to_jiffies(1000) / 10);
134 set_current_state(TASK_RUNNING);
136 CERROR("cfs_fail_timeout interrupted\n");
141 CERROR("cfs_fail_timeout id %x awake\n", id);
145 EXPORT_SYMBOL(__cfs_fail_timeout_set);