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dm_target_error.c revision 1.7 
      1 /*        $NetBSD: dm_target_error.c,v 1.7 2009/02/19 23:07:33 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 
     99 #endif
    100 
    101 /* Init function called from dm_table_load_ioctl. */
    102 int
    103 dm_target_error_init(dm_dev_t *dmv, void **target_config, char *argv)
    104 {
    105 
    106 	printf("Error target init function called!!\n");
    107 
    108 	*target_config = NULL;
    109 
    110 	dmv->dev_type = DM_ERROR_DEV;
    111 
    112 	return 0;
    113 }
    114 
    115 /* Status routine called to get params string. */
    116 char *
    117 dm_target_error_status(void *target_config)
    118 {
    119 	return NULL;
    120 }
    121 
    122 /* Strategy routine called from dm_strategy. */
    123 int
    124 dm_target_error_strategy(dm_table_entry_t *table_en, struct buf *bp)
    125 {
    126 
    127 	printf("Error target read function called!!\n");
    128 
    129 	bp->b_error = EIO;
    130 	bp->b_resid = 0;
    131 
    132 	biodone(bp);
    133 
    134 	return 0;
    135 }
    136 
    137 /* Doesn't do anything here. */
    138 int
    139 dm_target_error_destroy(dm_table_entry_t *table_en)
    140 {
    141 	table_en->target_config = NULL;
    142 
    143 	/* Unbusy target so we can unload it */
    144 	dm_target_unbusy(table_en->target);
    145 
    146 	return 0;
    147 }
    148 
    149 /* Doesn't not need to do anything here. */
    150 int
    151 dm_target_error_deps(dm_table_entry_t *table_en, prop_array_t prop_array)
    152 {
    153 	return 0;
    154 }
    155 
    156 /* Unsupported for this target. */
    157 int
    158 dm_target_error_upcall(dm_table_entry_t *table_en, struct buf *bp)
    159 {
    160 	return 0;
    161 }
    162