1 /* $NetBSD: dm_target_error.c,v 1.27 2019/12/21 11:59:03 tkusumi 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 #include <sys/cdefs.h> 32 __KERNEL_RCSID(0, "$NetBSD: dm_target_error.c,v 1.27 2019/12/21 11:59:03 tkusumi Exp $"); 33 34 /* 35 * This file implements initial version of device-mapper error target. 36 */ 37 #include <sys/types.h> 38 #include <sys/param.h> 39 #include <sys/buf.h> 40 41 #include "dm.h" 42 43 #ifdef DM_TARGET_MODULE 44 /* 45 * Every target can be compiled directly to dm driver or as a 46 * separate module this part of target is used for loading targets 47 * to dm driver. 48 * Target can be unloaded from kernel only if there are no users of 49 * it e.g. there are no devices which uses that target. 50 */ 51 #include <sys/kernel.h> 52 #include <sys/module.h> 53 54 MODULE(MODULE_CLASS_MISC, dm_target_error, "dm"); 55 56 static int 57 dm_target_error_modcmd(modcmd_t cmd, void *arg) 58 { 59 dm_target_t *dmt; 60 int r; 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 dmt->init = &dm_target_error_init; 74 dmt->table = &dm_target_error_table; 75 dmt->strategy = &dm_target_error_strategy; 76 dmt->destroy = &dm_target_error_destroy; 77 dmt->upcall = &dm_target_error_upcall; 78 79 r = dm_target_insert(dmt); 80 81 break; 82 83 case MODULE_CMD_FINI: 84 r = dm_target_rem("error"); 85 break; 86 87 case MODULE_CMD_STAT: 88 return ENOTTY; 89 90 default: 91 return ENOTTY; 92 } 93 94 return r; 95 } 96 #endif 97 98 /* Init function called from dm_table_load_ioctl. */ 99 int 100 dm_target_error_init(dm_table_entry_t *table_en, int argc, char **argv) 101 { 102 103 if (argc != 0) { 104 printf("Error target takes 0 args, %d given\n", argc); 105 return EINVAL; 106 } 107 108 printf("Error target init function called!!\n"); 109 110 table_en->target_config = NULL; 111 112 return 0; 113 } 114 115 /* Table routine called to get params string. */ 116 char * 117 dm_target_error_table(void *target_config) 118 { 119 120 return NULL; 121 } 122 123 /* Strategy routine called from dm_strategy. */ 124 int 125 dm_target_error_strategy(dm_table_entry_t *table_en, struct buf *bp) 126 { 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 { 140 141 /* Unbusy target so we can unload it */ 142 dm_target_unbusy(table_en->target); 143 144 return 0; 145 } 146 147 /* Unsupported for this target. */ 148 int 149 dm_target_error_upcall(dm_table_entry_t *table_en, struct buf *bp) 150 { 151 152 return 0; 153 } 154