1 /*$NetBSD: dm_target_mirror.c,v 1.24 2020/01/21 16:27:53 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 1.24 2020/01/21 16:27:53 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 #include <sys/buf.h>
40
41 #include "dm.h"
42
43 /* dm_target_mirror.c */
44 int dm_target_mirror_init(dm_table_entry_t *, int, char **);
45 char *dm_target_mirror_table(void *);
46 int dm_target_mirror_strategy(dm_table_entry_t *, struct buf *);
47 int dm_target_mirror_sync(dm_table_entry_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 typedef struct target_mirror_config {
52 #define MAX_MIRROR_COPIES 4
53 dm_pdev_t *orig;
54 dm_pdev_t *copies[MAX_MIRROR_COPIES];
55
56 /* copied blocks bitmaps administration etc*/
57 dm_pdev_t *log_pdev; /* for administration */
58 uint64_t log_regionsize; /* blocksize of mirror */
59
60 /* list of parts that still need copied etc.; run length encoded? */
61 } dm_target_mirror_config_t;
62
63 #ifdef DM_TARGET_MODULE
64 /*
65 * Every target can be compiled directly to dm driver or as a
66 * separate module this part of target is used for loading targets
67 * to dm driver.
68 * Target can be unloaded from kernel only if there are no users of
69 * it e.g. there are no devices which uses that target.
70 */
71 #include <sys/kernel.h>
72 #include <sys/module.h>
73
74 MODULE(MODULE_CLASS_MISC, dm_target_mirror, "dm");
75
76 static int
dm_target_mirror_modcmd(modcmd_t cmd,void * arg)77 dm_target_mirror_modcmd(modcmd_t cmd, void *arg)
78 {
79 dm_target_t *dmt;
80 int r;
81
82 switch (cmd) {
83 case MODULE_CMD_INIT:
84 if ((dmt = dm_target_lookup("mirror")) != NULL) {
85 dm_target_unbusy(dmt);
86 return EEXIST;
87 }
88 dmt = dm_target_alloc("mirror");
89
90 dmt->version[0] = 1;
91 dmt->version[1] = 0;
92 dmt->version[2] = 0;
93 dmt->init = &dm_target_mirror_init;
94 dmt->table = &dm_target_mirror_table;
95 dmt->strategy = &dm_target_mirror_strategy;
96 dmt->sync = &dm_target_mirror_sync;
97 dmt->destroy = &dm_target_mirror_destroy;
98 //dmt->upcall = &dm_target_mirror_upcall;
99
100 r = dm_target_insert(dmt);
101
102 break;
103
104 case MODULE_CMD_FINI:
105 r = dm_target_rem("mirror");
106 break;
107
108 case MODULE_CMD_STAT:
109 return ENOTTY;
110
111 default:
112 return ENOTTY;
113 }
114
115 return r;
116 }
117 #endif
118
119 /*
120 * Init function called from dm_table_load_ioctl.
121 * start length mirror log_type #logargs logarg1 ... logargN #devs device1 offset1 ... deviceN offsetN
122 * 0 52428800 mirror clustered_disk 4 253:2 1024 UUID block_on_error 3 253:3 0 253:4 0 253:5 0
123 */
124 int
dm_target_mirror_init(dm_table_entry_t * table_en,int argc,char ** argv)125 dm_target_mirror_init(dm_table_entry_t *table_en, int argc, char **argv)
126 {
127
128 printf("Mirror target init function called!!\n");
129
130 table_en->target_config = NULL;
131
132 return ENOSYS;
133 }
134
135 /* Table routine called to get params string. */
136 char *
dm_target_mirror_table(void * target_config)137 dm_target_mirror_table(void *target_config)
138 {
139
140 return NULL;
141 }
142
143 /* Strategy routine called from dm_strategy. */
144 int
dm_target_mirror_strategy(dm_table_entry_t * table_en,struct buf * bp)145 dm_target_mirror_strategy(dm_table_entry_t *table_en, struct buf *bp)
146 {
147
148 bp->b_error = EIO;
149 bp->b_resid = 0;
150
151 biodone(bp);
152
153 return 0;
154 }
155
156 /* Sync underlying disk caches. */
157 int
dm_target_mirror_sync(dm_table_entry_t * table_en)158 dm_target_mirror_sync(dm_table_entry_t *table_en)
159 {
160
161 return 0;
162 }
163
164 /* Doesn't do anything here. */
165 int
dm_target_mirror_destroy(dm_table_entry_t * table_en)166 dm_target_mirror_destroy(dm_table_entry_t *table_en)
167 {
168
169 /* Unbusy target so we can unload it */
170 dm_target_unbusy(table_en->target);
171
172 return 0;
173 }
174
175 #if 0
176 /* Unsupported for this target. */
177 int
178 dm_target_mirror_upcall(dm_table_entry_t *table_en, struct buf *bp)
179 {
180
181 return 0;
182 }
183 #endif
184