sys/dev/dm/dm_target_error.c

   1 /*        $NetBSD: dm_target_error.c,v 1.9 2009/12/01 23:12:10 haad Exp $      */
   2
   3 /*
   4  * Copyright (c) 2008 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Adam Hamsik.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * This file implements initial version of device-mapper error target.
  34  */
  35 #include <sys/types.h>
  36 #include <sys/param.h>
  37
  38 #include <sys/buf.h>
  39
  40 #include "dm.h"
  41
  42 #ifdef DM_TARGET_MODULE
  43 /*
  44  * Every target can be compiled directly to dm driver or as a
  45  * separate module this part of target is used for loading targets
  46  * to dm driver.
  47  * Target can be unloaded from kernel only if there are no users of
  48  * it e.g. there are no devices which uses that target.
  49  */
  50 #include <sys/kernel.h>
  51 #include <sys/module.h>
  52
  53 MODULE(MODULE_CLASS_MISC, dm_target_error, "dm");
  54
  55 static int
  56 dm_target_error_modcmd(modcmd_t cmd, void *arg)
  57 {
  58         dm_target_t *dmt;
  59         int r;
  60         dmt = NULL;
  61
  62         switch (cmd) {
  63         case MODULE_CMD_INIT:
  64                 if ((dmt = dm_target_lookup("error")) != NULL) {
  65                         dm_target_unbusy(dmt);
  66                         return EEXIST;
  67                 }
  68                 dmt = dm_target_alloc("error");
  69
  70                 dmt->version[0] = 1;
  71                 dmt->version[1] = 0;
  72                 dmt->version[2] = 0;
  73                 strlcpy(dmt->name, "error", DM_MAX_TYPE_NAME);
  74                 dmt->init = &dm_target_error_init;
  75                 dmt->status = &dm_target_error_status;
  76                 dmt->strategy = &dm_target_error_strategy;
  77                 dmt->deps = &dm_target_error_deps;
  78                 dmt->destroy = &dm_target_error_destroy;
  79                 dmt->upcall = &dm_target_error_upcall;
  80
  81                 r = dm_target_insert(dmt);
  82
  83                 break;
  84
  85         case MODULE_CMD_FINI:
  86                 r = dm_target_rem("error");
  87                 break;
  88
  89         case MODULE_CMD_STAT:
  90                 return ENOTTY;
  91
  92         default:
  93                 return ENOTTY;
  94         }
  95
  96         return r;
  97 }
  98 #endif
  99
 100 /* Init function called from dm_table_load_ioctl. */
 101 int
 102 dm_target_error_init(dm_dev_t * dmv, void **target_config, char *argv)
 103 {
 104
 105         printf("Error target init function called!!\n");
 106
 107         *target_config = NULL;
 108
 109         dmv->dev_type = DM_ERROR_DEV;
 110
 111         return 0;
 112 }
 113 /* Status routine called to get params string. */
 114 char *
 115 dm_target_error_status(void *target_config)
 116 {
 117         return NULL;
 118 }
 119 /* Strategy routine called from dm_strategy. */
 120 int
 121 dm_target_error_strategy(dm_table_entry_t * table_en, struct buf * bp)
 122 {
 123
 124         printf("Error target read function called!!\n");
 125
 126         bp->b_error = EIO;
 127         bp->b_resid = 0;
 128
 129         biodone(bp);
 130
 131         return 0;
 132 }
 133 /* Doesn't do anything here. */
 134 int
 135 dm_target_error_destroy(dm_table_entry_t * table_en)
 136 {
 137         table_en->target_config = NULL;
 138
 139         /* Unbusy target so we can unload it */
 140         dm_target_unbusy(table_en->target);
 141
 142         return 0;
 143 }
 144 /* Doesn't not need to do anything here. */
 145 int
 146 dm_target_error_deps(dm_table_entry_t * table_en, prop_array_t prop_array)
 147 {
 148         return 0;
 149 }
 150 /* Unsupported for this target. */
 151 int
 152 dm_target_error_upcall(dm_table_entry_t * table_en, struct buf * bp)
 153 {
 154         return 0;
 155 }