1 /*$NetBSD: dm_target_mirror.c,v 1.18 2019/12/12 16:28:24 tkusumi Exp $*/ 2 3 /* 4 * Copyright (c) 2009 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Adam Hamsik. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 #include <sys/cdefs.h> 32 __KERNEL_RCSID(0, "$NetBSD: dm_target_mirror.c,v 1.18 2019/12/12 16:28:24 tkusumi Exp $"); 33 34 /* 35 * This file implements initial version of device-mapper mirror target. 36 */ 37 #include <sys/types.h> 38 #include <sys/param.h> 39 40 #include <sys/buf.h> 41 42 #include "dm.h" 43 44 /* dm_target_mirror.c */ 45 int dm_target_mirror_init(dm_table_entry_t *, int, char **); 46 char *dm_target_mirror_status(void *); 47 int dm_target_mirror_strategy(dm_table_entry_t *, struct buf *); 48 int dm_target_mirror_sync(dm_table_entry_t *); 49 int dm_target_mirror_deps(dm_table_entry_t *, prop_array_t); 50 int dm_target_mirror_destroy(dm_table_entry_t *); 51 int dm_target_mirror_upcall(dm_table_entry_t *, struct buf *); 52 53 typedef struct target_mirror_config { 54 #define MAX_MIRROR_COPIES 4 55 dm_pdev_t *orig; 56 dm_pdev_t *copies[MAX_MIRROR_COPIES]; 57 58 /* copied blocks bitmaps administration etc*/ 59 dm_pdev_t *log_pdev; /* for administration */ 60 uint64_t log_regionsize; /* blocksize of mirror */ 61 62 /* list of parts that still need copied etc.; run length encoded? */ 63 } dm_target_mirror_config_t; 64 65 #ifdef DM_TARGET_MODULE 66 /* 67 * Every target can be compiled directly to dm driver or as a 68 * separate module this part of target is used for loading targets 69 * to dm driver. 70 * Target can be unloaded from kernel only if there are no users of 71 * it e.g. there are no devices which uses that target. 72 */ 73 #include <sys/kernel.h> 74 #include <sys/module.h> 75 76 MODULE(MODULE_CLASS_MISC, dm_target_mirror, "dm"); 77 78 static int 79 dm_target_mirror_modcmd(modcmd_t cmd, void *arg) 80 { 81 dm_target_t *dmt; 82 int r; 83 dmt = NULL; 84 85 switch (cmd) { 86 case MODULE_CMD_INIT: 87 if ((dmt = dm_target_lookup("mirror")) != NULL) { 88 dm_target_unbusy(dmt); 89 return EEXIST; 90 } 91 dmt = dm_target_alloc("mirror"); 92 93 dmt->version[0] = 1; 94 dmt->version[1] = 0; 95 dmt->version[2] = 0; 96 dmt->init = &dm_target_mirror_init; 97 dmt->status = &dm_target_mirror_status; 98 dmt->strategy = &dm_target_mirror_strategy; 99 dmt->sync = &dm_target_mirror_sync; 100 dmt->deps = &dm_target_mirror_deps; 101 dmt->destroy = &dm_target_mirror_destroy; 102 dmt->upcall = &dm_target_mirror_upcall; 103 dmt->secsize = dm_target_dummy_secsize; 104 105 r = dm_target_insert(dmt); 106 107 break; 108 109 case MODULE_CMD_FINI: 110 r = dm_target_rem("mirror"); 111 break; 112 113 case MODULE_CMD_STAT: 114 return ENOTTY; 115 116 default: 117 return ENOTTY; 118 } 119 120 return r; 121 } 122 #endif 123 124 /* 125 * Init function called from dm_table_load_ioctl. 126 * start length mirror log_type #logargs logarg1 ... logargN #devs device1 offset1 ... deviceN offsetN 127 * 0 52428800 mirror clustered_disk 4 253:2 1024 UUID block_on_error 3 253:3 0 253:4 0 253:5 0 128 */ 129 int 130 dm_target_mirror_init(dm_table_entry_t *table_en, int argc, char **argv) 131 { 132 133 printf("Mirror target init function called!!\n"); 134 135 table_en->target_config = NULL; 136 137 return ENOSYS; 138 } 139 140 /* Status routine called to get params string. */ 141 char * 142 dm_target_mirror_status(void *target_config) 143 { 144 return NULL; 145 } 146 147 /* Strategy routine called from dm_strategy. */ 148 int 149 dm_target_mirror_strategy(dm_table_entry_t *table_en, struct buf *bp) 150 { 151 152 printf("Mirror target read function called!!\n"); 153 154 bp->b_error = EIO; 155 bp->b_resid = 0; 156 157 biodone(bp); 158 159 return 0; 160 } 161 162 /* Sync underlying disk caches. */ 163 int 164 dm_target_mirror_sync(dm_table_entry_t *table_en) 165 { 166 167 return 0; 168 } 169 170 /* Doesn't do anything here. */ 171 int 172 dm_target_mirror_destroy(dm_table_entry_t *table_en) 173 { 174 /* Unbusy target so we can unload it */ 175 dm_target_unbusy(table_en->target); 176 177 return 0; 178 } 179 180 /* Doesn't not need to do anything here. */ 181 int 182 dm_target_mirror_deps(dm_table_entry_t *table_en, prop_array_t prop_array) 183 { 184 return 0; 185 } 186 187 /* Unsupported for this target. */ 188 int 189 dm_target_mirror_upcall(dm_table_entry_t *table_en, struct buf *bp) 190 { 191 return 0; 192 } 193