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dm_target_mirror.c revision 1.10 
      1 /*$NetBSD: dm_target_mirror.c,v 1.10 2018/01/05 14:22:26 christos 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 1.10 2018/01/05 14:22:26 christos 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_dev_t *, void**, 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 #ifdef DM_TARGET_MODULE
     54 /*
     55  * Every target can be compiled directly to dm driver or as a
     56  * separate module this part of target is used for loading targets
     57  * to dm driver.
     58  * Target can be unloaded from kernel only if there are no users of
     59  * it e.g. there are no devices which uses that target.
     60  */
     61 #include <sys/kernel.h>
     62 #include <sys/module.h>
     63 
     64 MODULE(MODULE_CLASS_MISC, dm_target_mirror, "dm");
     65 
     66 static int
     67 dm_target_mirror_modcmd(modcmd_t cmd, void *arg)
     68 {
     69 	dm_target_t *dmt;
     70 	int r;
     71 	dmt = NULL;
     72 
     73 	switch (cmd) {
     74 	case MODULE_CMD_INIT:
     75 		if ((dmt = dm_target_lookup("mirror")) != NULL) {
     76 			dm_target_unbusy(dmt);
     77 			return EEXIST;
     78 		}
     79 		dmt = dm_target_alloc("mirror");
     80 
     81 		dmt->version[0] = 1;
     82 		dmt->version[1] = 0;
     83 		dmt->version[2] = 0;
     84 		strlcpy(dmt->name, "mirror", DM_MAX_TYPE_NAME);
     85 		dmt->init = &dm_target_mirror_init;
     86 		dmt->status = &dm_target_mirror_status;
     87 		dmt->strategy = &dm_target_mirror_strategy;
     88 		dmt->sync = &dm_target_mirror_sync;
     89 		dmt->deps = &dm_target_mirror_deps;
     90 		dmt->destroy = &dm_target_mirror_destroy;
     91 		dmt->upcall = &dm_target_mirror_upcall;
     92 
     93 		r = dm_target_insert(dmt);
     94 
     95 		break;
     96 
     97 	case MODULE_CMD_FINI:
     98 		r = dm_target_rem("mirror");
     99 		break;
    100 
    101 	case MODULE_CMD_STAT:
    102 		return ENOTTY;
    103 
    104 	default:
    105 		return ENOTTY;
    106 	}
    107 
    108 	return r;
    109 }
    110 #endif
    111 
    112 /*
    113  * Init function called from dm_table_load_ioctl.
    114  * start length mirror log_type #logargs logarg1 ... logargN #devs device1 offset1 ... deviceN offsetN
    115  * 0 52428800 mirror clustered_disk 4 253:2 1024 UUID block_on_error 3 253:3 0 253:4 0 253:5 0
    116  */
    117 int
    118 dm_target_mirror_init(dm_dev_t * dmv, void **target_config, char *argv)
    119 {
    120 
    121 	printf("Mirror target init function called!!\n");
    122 
    123 	*target_config = NULL;
    124 
    125 	dmv->dev_type = DM_MIRROR_DEV;
    126 
    127 	return ENOSYS;
    128 }
    129 
    130 /* Status routine called to get params string. */
    131 char *
    132 dm_target_mirror_status(void *target_config)
    133 {
    134 	return NULL;
    135 }
    136 
    137 /* Strategy routine called from dm_strategy. */
    138 int
    139 dm_target_mirror_strategy(dm_table_entry_t * table_en, struct buf * bp)
    140 {
    141 
    142 	printf("Mirror target read function called!!\n");
    143 
    144 	bp->b_error = EIO;
    145 	bp->b_resid = 0;
    146 
    147 	biodone(bp);
    148 
    149 	return 0;
    150 }
    151 
    152 /* Sync underlying disk caches. */
    153 int
    154 dm_target_mirror_sync(dm_table_entry_t * table_en)
    155 {
    156 
    157 	return 0;
    158 }
    159 
    160 /* Doesn't do anything here. */
    161 int
    162 dm_target_mirror_destroy(dm_table_entry_t * table_en)
    163 {
    164 	table_en->target_config = NULL;
    165 
    166 	/* Unbusy target so we can unload it */
    167 	dm_target_unbusy(table_en->target);
    168 
    169 	return 0;
    170 }
    171 
    172 /* Doesn't not need to do anything here. */
    173 int
    174 dm_target_mirror_deps(dm_table_entry_t * table_en, prop_array_t prop_array)
    175 {
    176 	return 0;
    177 }
    178 
    179 /* Unsupported for this target. */
    180 int
    181 dm_target_mirror_upcall(dm_table_entry_t * table_en, struct buf * bp)
    182 {
    183 	return 0;
    184 }
    185