xref: /netbsd-src/sys/dev/dm/dm_target_mirror.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*$NetBSD: dm_target_mirror.c,v 1.2 2009/01/02 22:33:51 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 #ifdef DM_TARGET_MODULE
43 /*
44  * Every target can be compiled directly to dm driver or as a
45  * separate module this part of target is used for loading targets
46  * to dm driver.
47  * Target can be unloaded from kernel only if there are no users of
48  * it e.g. there are no devices which uses that target.
49  */
50 #include <sys/kernel.h>
51 #include <sys/module.h>
52 
53 MODULE(MODULE_CLASS_MISC, dm_target_mirror, NULL);
54 
55 static int
56 dm_target_mirror_modcmd(modcmd_t cmd, void *arg)
57 {
58 	dm_target_t *dmt;
59 	int r;
60 	dmt = NULL;
61 
62 	switch (cmd) {
63 	case MODULE_CMD_INIT:
64 		if ((r = module_hold("dm")) != 0)
65 			return r;
66 
67 		if ((dmt = dm_target_lookup("mirror")) != NULL)
68 			return EEXIST;
69 
70 		dmt = dm_target_alloc("mirror");
71 
72 		dmt->version[0] = 1;
73 		dmt->version[1] = 0;
74 		dmt->version[2] = 0;
75 		strlcpy(dmt->name, "mirror", DM_MAX_TYPE_NAME);
76 		dmt->init = &dm_target_mirror_init;
77 		dmt->status = &dm_target_mirror_status;
78 		dmt->strategy = &dm_target_mirror_strategy;
79 		dmt->deps = &dm_target_mirror_deps;
80 		dmt->destroy = &dm_target_mirror_destroy;
81 		dmt->upcall = &dm_target_mirror_upcall;
82 
83 		r = dm_target_insert(dmt);
84 
85 		break;
86 
87 	case MODULE_CMD_FINI:
88 		r = dm_target_rem("mirror");
89 		module_rele("dm"); /* release usage counter on dm module */
90 		break;
91 
92 	case MODULE_CMD_STAT:
93 		return ENOTTY;
94 
95 	default:
96 		return ENOTTY;
97 	}
98 
99 	return r;
100 }
101 
102 #endif
103 
104 /* Init function called from dm_table_load_ioctl. */
105 int
106 dm_target_mirror_init(dm_dev_t *dmv, void **target_config, char *argv)
107 {
108 
109 	printf("Mirror target init function called!!\n");
110 
111 	*target_config = NULL;
112 
113 	dmv->dev_type = DM_MIRROR_DEV;
114 
115 	return ENOSYS;
116 }
117 
118 /* Status routine called to get params string. */
119 char *
120 dm_target_mirror_status(void *target_config)
121 {
122 	return NULL;
123 }
124 
125 /* Strategy routine called from dm_strategy. */
126 int
127 dm_target_mirror_strategy(dm_table_entry_t *table_en, struct buf *bp)
128 {
129 
130 	printf("Mirror target read function called!!\n");
131 
132 	bp->b_error = EIO;
133 	bp->b_resid = 0;
134 
135 	biodone(bp);
136 
137 	return 0;
138 }
139 
140 /* Doesn't do anything here. */
141 int
142 dm_target_mirror_destroy(dm_table_entry_t *table_en)
143 {
144 	table_en->target_config = NULL;
145 
146 	/* Unbusy target so we can unload it */
147 	dm_target_unbusy(table_en->target);
148 
149 	return 0;
150 }
151 
152 /* Doesn't not need to do anything here. */
153 int
154 dm_target_mirror_deps(dm_table_entry_t *table_en, prop_array_t prop_array)
155 {
156 	return 0;
157 }
158 
159 /* Unsupported for this target. */
160 int
161 dm_target_mirror_upcall(dm_table_entry_t *table_en, struct buf *bp)
162 {
163 	return 0;
164 }
165