sys/dev/disk/dm/dm_target_error.c

   1 /*        $NetBSD: dm_target_error.c,v 1.10 2010/01/04 00:12:22 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 <dev/disk/dm/dm.h>
  41
  42 /* Init function called from dm_table_load_ioctl. */
  43 static int
  44 dm_target_error_init(dm_dev_t * dmv, void **target_config, char *argv)
  45 {
  46
  47         kprintf("Error target init function called!!\n");
  48
  49         *target_config = NULL;
  50
  51         dmv->dev_type = DM_ERROR_DEV;
  52
  53         return 0;
  54 }
  55
  56 /* Status routine called to get params string. */
  57 static char *
  58 dm_target_error_status(void *target_config)
  59 {
  60         return NULL;
  61 }
  62
  63 /* Strategy routine called from dm_strategy. */
  64 static int
  65 dm_target_error_strategy(dm_table_entry_t * table_en, struct buf * bp)
  66 {
  67
  68         kprintf("Error target read function called!!\n");
  69
  70         bp->b_error = EIO;
  71         bp->b_resid = 0;
  72
  73         biodone(&bp->b_bio1);
  74
  75         return 0;
  76 }
  77
  78 /* Doesn't do anything here. */
  79 static int
  80 dm_target_error_destroy(dm_table_entry_t * table_en)
  81 {
  82         table_en->target_config = NULL;
  83
  84         return 0;
  85 }
  86
  87 /* Doesn't not need to do anything here. */
  88 static int
  89 dm_target_error_deps(dm_table_entry_t * table_en, prop_array_t prop_array)
  90 {
  91         return 0;
  92 }
  93
  94 /* Unsupported for this target. */
  95 static int
  96 dm_target_error_upcall(dm_table_entry_t * table_en, struct buf * bp)
  97 {
  98         return 0;
  99 }
 100
 101 static int
 102 dmte_mod_handler(module_t mod, int type, void *unused)
 103 {
 104         dm_target_t *dmt = NULL;
 105         int err = 0;
 106
 107         switch(type) {
 108         case MOD_LOAD:
 109                 if ((dmt = dm_target_lookup("error")) != NULL) {
 110                         dm_target_unbusy(dmt);
 111                         return EEXIST;
 112                 }
 113                 dmt = dm_target_alloc("error");
 114                 dmt->version[0] = 1;
 115                 dmt->version[1] = 0;
 116                 dmt->version[2] = 0;
 117                 strlcpy(dmt->name, "error", DM_MAX_TYPE_NAME);
 118                 dmt->init = &dm_target_error_init;
 119                 dmt->status = &dm_target_error_status;
 120                 dmt->strategy = &dm_target_error_strategy;
 121                 dmt->deps = &dm_target_error_deps;
 122                 dmt->destroy = &dm_target_error_destroy;
 123                 dmt->upcall = &dm_target_error_upcall;
 124                 dmt->dump = NULL;
 125
 126                 err = dm_target_insert(dmt);
 127                 if (err == 0)
 128                         kprintf("dm_target_error: Successfully initialized\n");
 129                 break;
 130
 131         case MOD_UNLOAD:
 132                 err = dm_target_rem("error");
 133                 if (err == 0)
 134                         kprintf("dm_target_error: unloaded\n");
 135                 break;
 136
 137         default:
 138                 break;
 139         }
 140
 141         return err;
 142 }
 143
 144 DM_TARGET_BUILTIN(dm_target_error, dmte_mod_handler);