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dm_target_mirror.c revision 1.9 
      1 /*$NetBSD: dm_target_mirror.c,v 1.9 2010/05/18 15:10:38 haad 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 
     32 /*
     33  * This file implements initial version of device-mapper mirror 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 /* dm_target_mirror.c */
     43 int dm_target_mirror_init(dm_dev_t *, void**, char *);
     44 char * dm_target_mirror_status(void *);
     45 int dm_target_mirror_strategy(dm_table_entry_t *, struct buf *);
     46 int dm_target_mirror_sync(dm_table_entry_t *);
     47 int dm_target_mirror_deps(dm_table_entry_t *, prop_array_t);
     48 int dm_target_mirror_destroy(dm_table_entry_t *);
     49 int dm_target_mirror_upcall(dm_table_entry_t *, struct buf *);
     50 
     51 #ifdef DM_TARGET_MODULE
     52 /*
     53  * Every target can be compiled directly to dm driver or as a
     54  * separate module this part of target is used for loading targets
     55  * to dm driver.
     56  * Target can be unloaded from kernel only if there are no users of
     57  * it e.g. there are no devices which uses that target.
     58  */
     59 #include <sys/kernel.h>
     60 #include <sys/module.h>
     61 
     62 MODULE(MODULE_CLASS_MISC, dm_target_mirror, "dm");
     63 
     64 static int
     65 dm_target_mirror_modcmd(modcmd_t cmd, void *arg)
     66 {
     67 	dm_target_t *dmt;
     68 	int r;
     69 	dmt = NULL;
     70 
     71 	switch (cmd) {
     72 	case MODULE_CMD_INIT:
     73 		if ((dmt = dm_target_lookup("mirror")) != NULL) {
     74 			dm_target_unbusy(dmt);
     75 			return EEXIST;
     76 		}
     77 		dmt = dm_target_alloc("mirror");
     78 
     79 		dmt->version[0] = 1;
     80 		dmt->version[1] = 0;
     81 		dmt->version[2] = 0;
     82 		strlcpy(dmt->name, "mirror", DM_MAX_TYPE_NAME);
     83 		dmt->init = &dm_target_mirror_init;
     84 		dmt->status = &dm_target_mirror_status;
     85 		dmt->strategy = &dm_target_mirror_strategy;
     86 		dmt->sync = &dm_target_mirror_sync;
     87 		dmt->deps = &dm_target_mirror_deps;
     88 		dmt->destroy = &dm_target_mirror_destroy;
     89 		dmt->upcall = &dm_target_mirror_upcall;
     90 
     91 		r = dm_target_insert(dmt);
     92 
     93 		break;
     94 
     95 	case MODULE_CMD_FINI:
     96 		r = dm_target_rem("mirror");
     97 		break;
     98 
     99 	case MODULE_CMD_STAT:
    100 		return ENOTTY;
    101 
    102 	default:
    103 		return ENOTTY;
    104 	}
    105 
    106 	return r;
    107 }
    108 #endif
    109 
    110 /*
    111  * Init function called from dm_table_load_ioctl.
    112  * start length mirror log_type #logargs logarg1 ... logargN #devs device1 offset1 ... deviceN offsetN
    113  * 0 52428800 mirror clustered_disk 4 253:2 1024 UUID block_on_error 3 253:3 0 253:4 0 253:5 0
    114  */
    115 int
    116 dm_target_mirror_init(dm_dev_t * dmv, void **target_config, char *argv)
    117 {
    118 
    119 	printf("Mirror target init function called!!\n");
    120 
    121 	*target_config = NULL;
    122 
    123 	dmv->dev_type = DM_MIRROR_DEV;
    124 
    125 	return ENOSYS;
    126 }
    127 /* Status routine called to get params string. */
    128 char *
    129 dm_target_mirror_status(void *target_config)
    130 {
    131 	return NULL;
    132 }
    133 /* Strategy routine called from dm_strategy. */
    134 int
    135 dm_target_mirror_strategy(dm_table_entry_t * table_en, struct buf * bp)
    136 {
    137 
    138 	printf("Mirror target read function called!!\n");
    139 
    140 	bp->b_error = EIO;
    141 	bp->b_resid = 0;
    142 
    143 	biodone(bp);
    144 
    145 	return 0;
    146 }
    147 /* Sync underlying disk caches. */
    148 int
    149 dm_target_mirror_sync(dm_table_entry_t * table_en)
    150 {
    151 
    152 	return 0;
    153 }
    154 /* Doesn't do anything here. */
    155 int
    156 dm_target_mirror_destroy(dm_table_entry_t * table_en)
    157 {
    158 	table_en->target_config = NULL;
    159 
    160 	/* Unbusy target so we can unload it */
    161 	dm_target_unbusy(table_en->target);
    162 
    163 	return 0;
    164 }
    165 /* Doesn't not need to do anything here. */
    166 int
    167 dm_target_mirror_deps(dm_table_entry_t * table_en, prop_array_t prop_array)
    168 {
    169 	return 0;
    170 }
    171 /* Unsupported for this target. */
    172 int
    173 dm_target_mirror_upcall(dm_table_entry_t * table_en, struct buf * bp)
    174 {
    175 	return 0;
    176 }
    177