lustre/lvfs/lvfs_lib.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  lustre/lvfs/lvfs_lib.c
   5  *  Lustre filesystem abstraction routines
   6  *
   7  *  Copyright (C) 2007 Cluster File Systems, Inc.
   8  *   Author: Andreas Dilger <adilger@clusterfs.com>
   9  *
  10  *   This file is part of Lustre, http://www.lustre.org.
  11  *
  12  *   Lustre is free software; you can redistribute it and/or
  13  *   modify it under the terms of version 2 of the GNU General Public
  14  *   License as published by the Free Software Foundation.
  15  *
  16  *   Lustre is distributed in the hope that it will be useful,
  17  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *   GNU General Public License for more details.
  20  *
  21  *   You should have received a copy of the GNU General Public License
  22  *   along with Lustre; if not, write to the Free Software
  23  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25 #ifdef __KERNEL__
  26 #include <linux/module.h>
  27 #include <linux/random.h>
  28 #else
  29 #include <liblustre.h>
  30 #endif
  31 #include <lustre_lib.h>
  32
  33 unsigned int obd_fail_val = 0;
  34 unsigned long obd_fail_loc = 0;
  35 unsigned int obd_alloc_fail_rate = 0;
  36
  37 int obd_alloc_fail(const void *ptr, const char *name, const char *type,
  38                    size_t size, const char *file, int line)
  39 {
  40         if (ptr == NULL ||
  41             (ll_rand() & OBD_ALLOC_FAIL_MASK) < obd_alloc_fail_rate) {
  42                 CERROR("%s%salloc of %s ("LPU64" bytes) failed at %s:%d\n",
  43                        ptr ? "force " :"", type, name, (__u64)size, file,
  44                        line);
  45                 CERROR(LPU64" total bytes and "LPU64" total pages "
  46                        "("LPU64" bytes) allocated by Lustre, "
  47                        "%d total bytes by LNET\n",
  48                        obd_memory_sum(),
  49                        obd_pages_sum() << CFS_PAGE_SHIFT,
  50                        obd_pages_sum(),
  51                        atomic_read(&libcfs_kmemory));
  52                 return 1;
  53         }
  54         return 0;
  55 }
  56 EXPORT_SYMBOL(obd_alloc_fail);
  57
  58 int __obd_fail_check_set(__u32 id, __u32 value, int set)
  59 {
  60         static atomic_t obd_fail_count = ATOMIC_INIT(0);
  61
  62         LASSERT(!(id & OBD_FAIL_ONCE));
  63
  64         if ((obd_fail_loc & (OBD_FAILED | OBD_FAIL_ONCE)) ==
  65             (OBD_FAILED | OBD_FAIL_ONCE)) {
  66                 atomic_set(&obd_fail_count, 0); /* paranoia */
  67                 return 0;
  68         }
  69
  70         /* Fail 1/obd_fail_val times */
  71         if (obd_fail_loc & OBD_FAIL_RAND) {
  72                 if (obd_fail_val < 2 || ll_rand() % obd_fail_val > 0)
  73                         return 0;
  74         }
  75
  76         /* Skip the first obd_fail_val, then fail */
  77         if (obd_fail_loc & OBD_FAIL_SKIP) {
  78                 if (atomic_inc_return(&obd_fail_count) <= obd_fail_val)
  79                         return 0;
  80         }
  81
  82         /* Fail obd_fail_val times, overridden by FAIL_ONCE */
  83         if (obd_fail_loc & OBD_FAIL_SOME &&
  84             (!(obd_fail_loc & OBD_FAIL_ONCE) || obd_fail_val <= 1)) {
  85                 int count = atomic_inc_return(&obd_fail_count);
  86
  87                 if (count >= obd_fail_val) {
  88                         set_bit(OBD_FAIL_ONCE_BIT, &obd_fail_loc);
  89                         atomic_set(&obd_fail_count, 0);
  90                         /* we are lost race to increase obd_fail_count */
  91                         if (count > obd_fail_val)
  92                                 return 0;
  93                 }
  94         }
  95
  96         if ((set == OBD_FAIL_LOC_ORSET || set == OBD_FAIL_LOC_RESET) &&
  97             (value & OBD_FAIL_ONCE))
  98                 set_bit(OBD_FAIL_ONCE_BIT, &obd_fail_loc);
  99
 100         /* Lost race to set OBD_FAILED_BIT. */
 101         if (test_and_set_bit(OBD_FAILED_BIT, &obd_fail_loc)) {
 102                 /* If OBD_FAIL_ONCE is valid, only one process can fail,
 103                  * otherwise multi-process can fail at the same time. */
 104                 if (obd_fail_loc & OBD_FAIL_ONCE)
 105                         return 0;
 106         }
 107
 108         switch (set) {
 109                 case OBD_FAIL_LOC_NOSET:
 110                         break;
 111                 case OBD_FAIL_LOC_ORSET:
 112                         obd_fail_loc |= value & ~(OBD_FAILED | OBD_FAIL_ONCE);
 113                         break;
 114                 case OBD_FAIL_LOC_RESET:
 115                         obd_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(__obd_fail_check_set);
 125
 126 EXPORT_SYMBOL(obd_fail_loc);
 127 EXPORT_SYMBOL(obd_alloc_fail_rate);
 128 EXPORT_SYMBOL(obd_fail_val);