libcfs/include/libcfs/libcfs_fail.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 /*
   4  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
   5  * Use is subject to license terms.
   6  *
   7  * Copyright (c) 2011, 2014, Intel Corporation.
   8  */
   9
  10 /*
  11  * This file is part of Lustre, http://www.lustre.org/
  12  */
  13
  14 #ifndef _LIBCFS_FAIL_H
  15 #define _LIBCFS_FAIL_H
  16
  17 extern unsigned long cfs_fail_loc;
  18 extern unsigned int cfs_fail_val;
  19 extern int cfs_fail_err;
  20
  21 extern wait_queue_head_t cfs_race_waitq;
  22 extern int cfs_race_state;
  23
  24 int __cfs_fail_check_set(__u32 id, __u32 value, int set);
  25 int __cfs_fail_timeout_set(const char *file, const char *func, int line,
  26                            __u32 id, __u32 value, int ms, int set);
  27
  28 enum {
  29         CFS_FAIL_LOC_NOSET = 0,
  30         CFS_FAIL_LOC_ORSET = 1,
  31         CFS_FAIL_LOC_RESET = 2,
  32         CFS_FAIL_LOC_VALUE = 3
  33 };
  34
  35 /*
  36  * Failure ranges:
  37  *      "0x0100 - 0x3fff" for Lustre
  38  *      "0xe000 - 0xefff" for LNet
  39  *      "0xf000 - 0xffff" for LNDs
  40  */
  41
  42 /* Failure injection control */
  43 #define CFS_FAIL_MASK_SYS    0x0000FF00
  44 #define CFS_FAIL_MASK_LOC   (0x000000FF | CFS_FAIL_MASK_SYS)
  45
  46 #define CFS_FAILED_BIT       30
  47 /* CFS_FAILED is 0x40000000 */
  48 #define CFS_FAILED          BIT(CFS_FAILED_BIT)
  49
  50 #define CFS_FAIL_ONCE_BIT    31
  51 /* CFS_FAIL_ONCE is 0x80000000 */
  52 #define CFS_FAIL_ONCE       BIT(CFS_FAIL_ONCE_BIT)
  53
  54 /* The following flags aren't made to be combined */
  55 #define CFS_FAIL_SKIP        0x20000000 /* skip N times then fail */
  56 #define CFS_FAIL_SOME        0x10000000 /* only fail N times */
  57 #define CFS_FAIL_RAND        0x08000000 /* fail 1/N of the times */
  58 #define CFS_FAIL_USR1        0x04000000 /* user flag */
  59
  60 /* CFS_FAULT may be combined with any one of the above flags. */
  61 #define CFS_FAULT            0x02000000 /* match any CFS_FAULT_CHECK */
  62
  63 static inline bool CFS_FAIL_PRECHECK(__u32 id)
  64 {
  65         return unlikely(cfs_fail_loc != 0 &&
  66               ((cfs_fail_loc & CFS_FAIL_MASK_LOC) == (id & CFS_FAIL_MASK_LOC) ||
  67                (cfs_fail_loc & id & CFS_FAULT)));
  68 }
  69
  70 #define UNLIKELY_CHECK_SET(id, value, set, quiet)                       \
  71         (unlikely(cfs_fail_check_set_loc(__FILE__, __func__, __LINE__,  \
  72                                          id, value, set, quiet)))
  73
  74 static inline int cfs_fail_check_set_loc(const char *file, const char *func,
  75                                          int line, __u32 id, __u32 value,
  76                                          int set, int quiet)
  77 {
  78         int ret = 0;
  79
  80         if (CFS_FAIL_PRECHECK(id)) {
  81                 /* set failed_once before the CFS_FAILED flag is set below */
  82                 unsigned long failed_once = cfs_fail_loc & CFS_FAILED;
  83
  84                 ret = __cfs_fail_check_set(id, value, set);
  85                 if (ret)
  86                         CDEBUG_LIMIT_LOC(file, func, line,
  87                                          (quiet && failed_once) ?
  88                                                 D_INFO : D_CONSOLE,
  89                                          "*** cfs_fail_loc=%x, val=%u***\n",
  90                                          id, value);
  91         }
  92
  93         return ret;
  94 }
  95
  96 /*
  97  * If id hit cfs_fail_loc, return 1, otherwise return 0
  98  */
  99 #define CFS_FAIL_CHECK(id) \
 100         UNLIKELY_CHECK_SET(id, cfs_fail_val, CFS_FAIL_LOC_NOSET, 0)
 101 #define CFS_FAIL_CHECK_QUIET(id) \
 102         UNLIKELY_CHECK_SET(id, cfs_fail_val, CFS_FAIL_LOC_NOSET, 1)
 103
 104 /*
 105  * If id hit cfs_fail_loc and cfs_fail_val == (-1 or value) return 1,
 106  * otherwise return 0
 107  */
 108 #define CFS_FAIL_CHECK_VALUE(id, value) \
 109         UNLIKELY_CHECK_SET(id, value, CFS_FAIL_LOC_VALUE, 0)
 110 #define CFS_FAIL_CHECK_VALUE_QUIET(id, value) \
 111         UNLIKELY_CHECK_SET(id, value, CFS_FAIL_LOC_VALUE, 1)
 112
 113 /*
 114  * If id hit cfs_fail_loc, cfs_fail_loc |= value and return 1,
 115  * otherwise return 0
 116  */
 117 #define CFS_FAIL_CHECK_ORSET(id, value) \
 118         UNLIKELY_CHECK_SET(id, value, CFS_FAIL_LOC_ORSET, 0)
 119 #define CFS_FAIL_CHECK_ORSET_QUIET(id, value) \
 120         UNLIKELY_CHECK_SET(id, value, CFS_FAIL_LOC_ORSET, 1)
 121
 122 /*
 123  * If id hit cfs_fail_loc, cfs_fail_loc = value and return 1,
 124  * otherwise return 0
 125  */
 126 #define CFS_FAIL_CHECK_RESET(id, value) \
 127         UNLIKELY_CHECK_SET(id, value, CFS_FAIL_LOC_RESET, 0)
 128 #define CFS_FAIL_CHECK_RESET_QUIET(id, value) \
 129         UNLIKELY_CHECK_SET(id, value, CFS_FAIL_LOC_RESET, 1)
 130
 131 #define UNLIKELY_TIMEOUT_SET(id, value, ms, set) \
 132         (unlikely(cfs_fail_timeout_set_loc(__FILE__, __func__, __LINE__, \
 133                                            id, value, ms, set)))
 134
 135 static inline int cfs_fail_timeout_set_loc(const char *file, const char *func,
 136                                            int line, __u32 id, __u32 value,
 137                                            int ms, int set)
 138 {
 139         if (CFS_FAIL_PRECHECK(id))
 140                 return __cfs_fail_timeout_set(file, func, line, id, value, ms,
 141                                               set);
 142         return 0;
 143 }
 144
 145 /* If id hit cfs_fail_loc, sleep for seconds or milliseconds */
 146 #define CFS_FAIL_TIMEOUT(id, secs) \
 147         UNLIKELY_TIMEOUT_SET(id, cfs_fail_val, (secs)*1000, CFS_FAIL_LOC_NOSET)
 148 #define CFS_FAIL_TIMEOUT_MS(id, ms) \
 149         UNLIKELY_TIMEOUT_SET(id, cfs_fail_val, ms, CFS_FAIL_LOC_NOSET)
 150
 151 /*
 152  * If id hit cfs_fail_loc, cfs_fail_loc |= value and
 153  * sleep seconds or milliseconds
 154  */
 155 #define CFS_FAIL_TIMEOUT_ORSET(id, value, secs) \
 156         UNLIKELY_TIMEOUT_SET(id, value, (secs) * 1000, CFS_FAIL_LOC_ORSET)
 157
 158 #define CFS_FAIL_TIMEOUT_RESET(id, value, secs) \
 159         UNLIKELY_TIMEOUT_SET(id, value, (secs) * 1000, CFS_FAIL_LOC_RESET)
 160
 161 #define CFS_FAIL_TIMEOUT_MS_ORSET(id, value, ms) \
 162         UNLIKELY_TIMEOUT_SET(id, value, ms, CFS_FAIL_LOC_ORSET)
 163 #define CFS_FAULT_CHECK(id)                     \
 164         CFS_FAIL_CHECK(CFS_FAULT | (id))
 165
 166 /*
 167  * The idea here is to synchronise two threads to force a race. The
 168  * first thread that calls this with a matching fail_loc is put to
 169  * sleep. The next thread that calls with the same fail_loc wakes up
 170  * the first and continues.
 171  */
 172 static inline void cfs_race_loc(const char *file, const char *func, int line,
 173                                 __u32 id)
 174 {
 175         if (CFS_FAIL_PRECHECK(id)) {
 176                 if (unlikely(__cfs_fail_check_set(id, 0, CFS_FAIL_LOC_NOSET))) {
 177                         int rc;
 178                         cfs_race_state = 0;
 179                         CDEBUG_LIMIT_LOC(file, func, line, D_ERROR,
 180                                          "cfs_race id %x sleeping\n", id);
 181                         /*
 182                          * XXX: don't wait forever as there is no guarantee
 183                          * that this branch is executed first. for testing
 184                          * purposes this construction works good enough
 185                          */
 186                         rc = wait_event_interruptible_timeout(cfs_race_waitq,
 187                                                       cfs_race_state != 0,
 188                                                       cfs_time_seconds(5));
 189                         CDEBUG_LIMIT_LOC(file, func, line, D_ERROR,
 190                                          "cfs_fail_race id %x awake: rc=%d\n",
 191                                          id, rc);
 192                 } else {
 193                         CDEBUG_LIMIT_LOC(file, func, line, D_ERROR,
 194                                          "cfs_fail_race id %x waking\n", id);
 195                         cfs_race_state = 1;
 196                         wake_up(&cfs_race_waitq);
 197                 }
 198         }
 199 }
 200 #define CFS_RACE(id) cfs_race_loc(__FILE__, __func__, __LINE__, id)
 201
 202 /**
 203  * Wait on race.
 204  *
 205  * The first thread that calls this with a matching fail_loc is put to sleep,
 206  * but subseqent callers of this won't sleep. Until another thread that calls
 207  * cfs_race_wakeup(), the first thread will be woken up and continue.
 208  */
 209 static inline void cfs_race_wait_loc(const char *file, const char *func,
 210                                      int line, __u32 id)
 211 {
 212         if (CFS_FAIL_PRECHECK(id)) {
 213                 if (unlikely(__cfs_fail_check_set(id, 0, CFS_FAIL_LOC_NOSET))) {
 214                         int rc;
 215
 216                         cfs_race_state = 0;
 217                         CDEBUG_LIMIT_LOC(file, func, line, D_ERROR,
 218                                          "cfs_race id %x sleeping\n", id);
 219                         rc = wait_event_interruptible(cfs_race_waitq,
 220                                                       cfs_race_state != 0);
 221                         CDEBUG_LIMIT_LOC(file, func, line, D_ERROR,
 222                                          "cfs_fail_race id %x awake: rc=%d\n",
 223                                          id, rc);
 224                 }
 225         }
 226 }
 227 #define CFS_RACE_WAIT(id) cfs_race_wait_loc(__FILE__, __func__, __LINE__, id)
 228
 229 /**
 230  * Wake up the thread that is waiting on the matching fail_loc.
 231  */
 232 static inline void cfs_race_wakeup_loc(const char *file, const char *func,
 233                                        int line, __u32 id)
 234 {
 235         if (CFS_FAIL_PRECHECK(id)) {
 236                 if (likely(!__cfs_fail_check_set(id, 0, CFS_FAIL_LOC_NOSET))) {
 237                         CDEBUG_LIMIT_LOC(file, func, line, D_ERROR,
 238                                          "cfs_fail_race id %x waking\n", id);
 239                         cfs_race_state = 1;
 240                         wake_up(&cfs_race_waitq);
 241                 }
 242         }
 243 }
 244 #define CFS_RACE_WAKEUP(id) cfs_race_wakeup_loc(__FILE__, __func__, __LINE__,id)
 245
 246 #endif /* _LIBCFS_FAIL_H */