drivers/staging/lustre/include/linux/libcfs/libcfs_fail.h

   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 #ifndef _LIBCFS_FAIL_H
  37 #define _LIBCFS_FAIL_H
  38
  39 extern unsigned long cfs_fail_loc;
  40 extern unsigned int cfs_fail_val;
  41
  42 extern wait_queue_head_t cfs_race_waitq;
  43 extern int cfs_race_state;
  44
  45 int __cfs_fail_check_set(__u32 id, __u32 value, int set);
  46 int __cfs_fail_timeout_set(__u32 id, __u32 value, int ms, int set);
  47
  48 enum {
  49         CFS_FAIL_LOC_NOSET      = 0,
  50         CFS_FAIL_LOC_ORSET      = 1,
  51         CFS_FAIL_LOC_RESET      = 2,
  52         CFS_FAIL_LOC_VALUE      = 3
  53 };
  54
  55 /* Failure injection control */
  56 #define CFS_FAIL_MASK_SYS    0x0000FF00
  57 #define CFS_FAIL_MASK_LOC   (0x000000FF | CFS_FAIL_MASK_SYS)
  58
  59 #define CFS_FAILED_BIT       30
  60 /* CFS_FAILED is 0x40000000 */
  61 #define CFS_FAILED        (1 << CFS_FAILED_BIT)
  62
  63 #define CFS_FAIL_ONCE_BIT    31
  64 /* CFS_FAIL_ONCE is 0x80000000 */
  65 #define CFS_FAIL_ONCE       (1 << CFS_FAIL_ONCE_BIT)
  66
  67 /* The following flags aren't made to be combined */
  68 #define CFS_FAIL_SKIP   0x20000000 /* skip N times then fail */
  69 #define CFS_FAIL_SOME   0x10000000 /* only fail N times */
  70 #define CFS_FAIL_RAND   0x08000000 /* fail 1/N of the times */
  71 #define CFS_FAIL_USR1   0x04000000 /* user flag */
  72
  73 #define CFS_FAIL_PRECHECK(id) (cfs_fail_loc &&                          \
  74                               (cfs_fail_loc & CFS_FAIL_MASK_LOC) ==        \
  75                               ((id) & CFS_FAIL_MASK_LOC))
  76
  77 static inline int cfs_fail_check_set(__u32 id, __u32 value,
  78                                      int set, int quiet)
  79 {
  80         int ret = 0;
  81
  82         if (unlikely(CFS_FAIL_PRECHECK(id) &&
  83                      (ret = __cfs_fail_check_set(id, value, set)))) {
  84                 if (quiet) {
  85                         CDEBUG(D_INFO, "*** cfs_fail_loc=%x, val=%u***\n",
  86                                id, value);
  87                 } else {
  88                         LCONSOLE_INFO("*** cfs_fail_loc=%x, val=%u***\n",
  89                                       id, value);
  90                 }
  91         }
  92
  93         return ret;
  94 }
  95
  96 /* If id hit cfs_fail_loc, return 1, otherwise return 0 */
  97 #define CFS_FAIL_CHECK(id) \
  98         cfs_fail_check_set(id, 0, CFS_FAIL_LOC_NOSET, 0)
  99 #define CFS_FAIL_CHECK_QUIET(id) \
 100         cfs_fail_check_set(id, 0, CFS_FAIL_LOC_NOSET, 1)
 101
 102 /* If id hit cfs_fail_loc and cfs_fail_val == (-1 or value) return 1,
 103  * otherwise return 0 */
 104 #define CFS_FAIL_CHECK_VALUE(id, value) \
 105         cfs_fail_check_set(id, value, CFS_FAIL_LOC_VALUE, 0)
 106 #define CFS_FAIL_CHECK_VALUE_QUIET(id, value) \
 107         cfs_fail_check_set(id, value, CFS_FAIL_LOC_VALUE, 1)
 108
 109 /* If id hit cfs_fail_loc, cfs_fail_loc |= value and return 1,
 110  * otherwise return 0 */
 111 #define CFS_FAIL_CHECK_ORSET(id, value) \
 112         cfs_fail_check_set(id, value, CFS_FAIL_LOC_ORSET, 0)
 113 #define CFS_FAIL_CHECK_ORSET_QUIET(id, value) \
 114         cfs_fail_check_set(id, value, CFS_FAIL_LOC_ORSET, 1)
 115
 116 /* If id hit cfs_fail_loc, cfs_fail_loc = value and return 1,
 117  * otherwise return 0 */
 118 #define CFS_FAIL_CHECK_RESET(id, value) \
 119         cfs_fail_check_set(id, value, CFS_FAIL_LOC_RESET, 0)
 120 #define CFS_FAIL_CHECK_RESET_QUIET(id, value) \
 121         cfs_fail_check_set(id, value, CFS_FAIL_LOC_RESET, 1)
 122
 123 static inline int cfs_fail_timeout_set(__u32 id, __u32 value, int ms, int set)
 124 {
 125         if (unlikely(CFS_FAIL_PRECHECK(id)))
 126                 return __cfs_fail_timeout_set(id, value, ms, set);
 127         else
 128                 return 0;
 129 }
 130
 131 /* If id hit cfs_fail_loc, sleep for seconds or milliseconds */
 132 #define CFS_FAIL_TIMEOUT(id, secs) \
 133         cfs_fail_timeout_set(id, 0, secs * 1000, CFS_FAIL_LOC_NOSET)
 134
 135 #define CFS_FAIL_TIMEOUT_MS(id, ms) \
 136         cfs_fail_timeout_set(id, 0, ms, CFS_FAIL_LOC_NOSET)
 137
 138 /* If id hit cfs_fail_loc, cfs_fail_loc |= value and
 139  * sleep seconds or milliseconds */
 140 #define CFS_FAIL_TIMEOUT_ORSET(id, value, secs) \
 141         cfs_fail_timeout_set(id, value, secs * 1000, CFS_FAIL_LOC_ORSET)
 142
 143 #define CFS_FAIL_TIMEOUT_MS_ORSET(id, value, ms) \
 144         cfs_fail_timeout_set(id, value, ms, CFS_FAIL_LOC_ORSET)
 145
 146 /* The idea here is to synchronise two threads to force a race. The
 147  * first thread that calls this with a matching fail_loc is put to
 148  * sleep. The next thread that calls with the same fail_loc wakes up
 149  * the first and continues. */
 150 static inline void cfs_race(__u32 id)
 151 {
 152
 153         if (CFS_FAIL_PRECHECK(id)) {
 154                 if (unlikely(__cfs_fail_check_set(id, 0, CFS_FAIL_LOC_NOSET))) {
 155                         int rc;
 156
 157                         cfs_race_state = 0;
 158                         CERROR("cfs_race id %x sleeping\n", id);
 159                         cfs_wait_event_interruptible(cfs_race_waitq,
 160                                                      cfs_race_state != 0, rc);
 161                         CERROR("cfs_fail_race id %x awake, rc=%d\n", id, rc);
 162                 } else {
 163                         CERROR("cfs_fail_race id %x waking\n", id);
 164                         cfs_race_state = 1;
 165                         wake_up(&cfs_race_waitq);
 166                 }
 167         }
 168 }
 169
 170 #define CFS_RACE(id) cfs_race(id)
 171
 172 #endif /* _LIBCFS_FAIL_H */