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dm_target_error.c revision 1.4 
      1 /*        $NetBSD: dm_target_error.c,v 1.4 2008/12/21 00:59:39 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, NULL);
     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 			return EEXIST;
     66 
     67 		dmt = dm_target_alloc("error");
     68 
     69 		dmt->version[0] = 1;
     70 		dmt->version[1] = 0;
     71 		dmt->version[2] = 0;
     72 		strlcpy(dmt->name, "error", DM_MAX_TYPE_NAME);
     73 		dmt->init = &dm_target_error_init;
     74 		dmt->status = &dm_target_error_status;
     75 		dmt->strategy = &dm_target_error_strategy;
     76 		dmt->deps = &dm_target_error_deps;
     77 		dmt->destroy = &dm_target_error_destroy;
     78 		dmt->upcall = &dm_target_error_upcall;
     79 
     80 		r = dm_target_insert(dmt);
     81 
     82 		break;
     83 
     84 	case MODULE_CMD_FINI:
     85 		r = dm_target_rem("error");
     86 		break;
     87 
     88 	case MODULE_CMD_STAT:
     89 		return ENOTTY;
     90 
     91 	default:
     92 		return ENOTTY;
     93 	}
     94 
     95 	return r;
     96 }
     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 
    114 /* Status routine called to get params string. */
    115 char *
    116 dm_target_error_status(void *target_config)
    117 {
    118 	return NULL;
    119 }
    120 
    121 /* Strategy routine called from dm_strategy. */
    122 int
    123 dm_target_error_strategy(dm_table_entry_t *table_en, struct buf *bp)
    124 {
    125 
    126 	printf("Error target read function called!!\n");
    127 
    128 	bp->b_error = EIO;
    129 	bp->b_resid = 0;
    130 
    131 	biodone(bp);
    132 
    133 	return 0;
    134 }
    135 
    136 /* Doesn't do anything here. */
    137 int
    138 dm_target_error_destroy(dm_table_entry_t *table_en)
    139 {
    140 	table_en->target_config = NULL;
    141 
    142 	/* Unbusy target so we can unload it */
    143 	dm_target_unbusy(table_en->target);
    144 
    145 	return 0;
    146 }
    147 
    148 /* Doesn't not need to do anything here. */
    149 int
    150 dm_target_error_deps(dm_table_entry_t *table_en, prop_array_t prop_array)
    151 {
    152 	return 0;
    153 }
    154 
    155 /* Unsupported for this target. */
    156 int
    157 dm_target_error_upcall(dm_table_entry_t *table_en, struct buf *bp)
    158 {
    159 	return 0;
    160 }
    161