1 /* $NetBSD: dm_target_error.c,v 1.28 2019/12/23 16:17:35 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 1.28 2019/12/23 16:17:35 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->strategy = &dm_target_error_strategy; 75 dmt->destroy = &dm_target_error_destroy; 76 dmt->upcall = &dm_target_error_upcall; 77 78 r = dm_target_insert(dmt); 79 80 break; 81 82 case MODULE_CMD_FINI: 83 r = dm_target_rem("error"); 84 break; 85 86 case MODULE_CMD_STAT: 87 return ENOTTY; 88 89 default: 90 return ENOTTY; 91 } 92 93 return r; 94 } 95 #endif 96 97 /* Init function called from dm_table_load_ioctl. */ 98 int 99 dm_target_error_init(dm_table_entry_t *table_en, int argc, char **argv) 100 { 101 102 if (argc != 0) { 103 printf("Error target takes 0 args, %d given\n", argc); 104 return EINVAL; 105 } 106 107 printf("Error target init function called!!\n"); 108 109 table_en->target_config = NULL; 110 111 return 0; 112 } 113 114 /* Strategy routine called from dm_strategy. */ 115 int 116 dm_target_error_strategy(dm_table_entry_t *table_en, struct buf *bp) 117 { 118 119 bp->b_error = EIO; 120 bp->b_resid = 0; 121 122 biodone(bp); 123 124 return 0; 125 } 126 127 /* Doesn't do anything here. */ 128 int 129 dm_target_error_destroy(dm_table_entry_t *table_en) 130 { 131 132 /* Unbusy target so we can unload it */ 133 dm_target_unbusy(table_en->target); 134 135 return 0; 136 } 137 138 /* Unsupported for this target. */ 139 int 140 dm_target_error_upcall(dm_table_entry_t *table_en, struct buf *bp) 141 { 142 143 return 0; 144 } 145