xref: /netbsd-src/sys/dev/dm/dm_target_mirror.c (revision b794fcf3ad6f6269c25a753348b490c50595f79a)
1 /*$NetBSD: dm_target_mirror.c,v 1.14 2019/12/07 15:28:39 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 1.14 2019/12/07 15:28:39 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_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 		dmt->init = &dm_target_mirror_init;
85 		dmt->status = &dm_target_mirror_status;
86 		dmt->strategy = &dm_target_mirror_strategy;
87 		dmt->sync = &dm_target_mirror_sync;
88 		dmt->deps = &dm_target_mirror_deps;
89 		dmt->destroy = &dm_target_mirror_destroy;
90 		dmt->upcall = &dm_target_mirror_upcall;
91 
92 		r = dm_target_insert(dmt);
93 
94 		break;
95 
96 	case MODULE_CMD_FINI:
97 		r = dm_target_rem("mirror");
98 		break;
99 
100 	case MODULE_CMD_STAT:
101 		return ENOTTY;
102 
103 	default:
104 		return ENOTTY;
105 	}
106 
107 	return r;
108 }
109 #endif
110 
111 /*
112  * Init function called from dm_table_load_ioctl.
113  * start length mirror log_type #logargs logarg1 ... logargN #devs device1 offset1 ... deviceN offsetN
114  * 0 52428800 mirror clustered_disk 4 253:2 1024 UUID block_on_error 3 253:3 0 253:4 0 253:5 0
115  */
116 int
117 dm_target_mirror_init(dm_dev_t *dmv, void **target_config, char *argv)
118 {
119 
120 	printf("Mirror target init function called!!\n");
121 
122 	*target_config = NULL;
123 
124 	return ENOSYS;
125 }
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 
134 /* Strategy routine called from dm_strategy. */
135 int
136 dm_target_mirror_strategy(dm_table_entry_t *table_en, struct buf *bp)
137 {
138 
139 	printf("Mirror target read function called!!\n");
140 
141 	bp->b_error = EIO;
142 	bp->b_resid = 0;
143 
144 	biodone(bp);
145 
146 	return 0;
147 }
148 
149 /* Sync underlying disk caches. */
150 int
151 dm_target_mirror_sync(dm_table_entry_t *table_en)
152 {
153 
154 	return 0;
155 }
156 
157 /* Doesn't do anything here. */
158 int
159 dm_target_mirror_destroy(dm_table_entry_t *table_en)
160 {
161 	/* Unbusy target so we can unload it */
162 	dm_target_unbusy(table_en->target);
163 
164 	return 0;
165 }
166 
167 /* Doesn't not need to do anything here. */
168 int
169 dm_target_mirror_deps(dm_table_entry_t *table_en, prop_array_t prop_array)
170 {
171 	return 0;
172 }
173 
174 /* Unsupported for this target. */
175 int
176 dm_target_mirror_upcall(dm_table_entry_t *table_en, struct buf *bp)
177 {
178 	return 0;
179 }
180