dm - undo my pointless moving of dm.h
[dragonfly.git] / sys / dev / disk / dm / dm_target_zero.c
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1/* $NetBSD: dm_target_zero.c,v 1.10 2010/01/04 00:12:22 haad Exp $ */
2
3/*
4 * Copyright (c) 2008 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/*
34 * This file implements initial version of device-mapper zero target.
35 */
36#include <sys/types.h>
37#include <sys/param.h>
38
39#include <sys/buf.h>
40
a84e173e 41#include <dev/disk/dm/dm.h>
ff56536e 42
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43/*
44 * Zero target init function. This target doesn't need
45 * target specific config area.
46 */
5c411e8e 47static int
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48dm_target_zero_init(dm_dev_t * dmv, void **target_config, char *argv)
49{
50
5b279a20 51 kprintf("Zero target init function called!!\n");
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52
53 dmv->dev_type = DM_ZERO_DEV;
54
55 *target_config = NULL;
56
57 return 0;
58}
5c411e8e 59
ff56536e 60/* Status routine called to get params string. */
5c411e8e 61static char *
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62dm_target_zero_status(void *target_config)
63{
64 return NULL;
65}
66
67
68/*
69 * This routine does IO operations.
70 */
5c411e8e 71static int
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72dm_target_zero_strategy(dm_table_entry_t * table_en, struct buf * bp)
73{
74
75 /* printf("Zero target read function called %d!!\n", bp->b_bcount); */
76
77 memset(bp->b_data, 0, bp->b_bcount);
3adc52bc 78 bp->b_resid = 0;
5b279a20 79 biodone(&bp->b_bio1);
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80
81 return 0;
82}
5c411e8e 83
ff56536e 84/* Doesn't not need to do anything here. */
5c411e8e 85static int
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86dm_target_zero_destroy(dm_table_entry_t * table_en)
87{
88 table_en->target_config = NULL;
89
90 /* Unbusy target so we can unload it */
91 dm_target_unbusy(table_en->target);
92
93 return 0;
94}
5c411e8e 95
ff56536e 96/* Doesn't not need to do anything here. */
5c411e8e 97static int
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98dm_target_zero_deps(dm_table_entry_t * table_en, prop_array_t prop_array)
99{
100 return 0;
101}
102/* Unsuported for this target. */
5c411e8e 103static int
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104dm_target_zero_upcall(dm_table_entry_t * table_en, struct buf * bp)
105{
106 return 0;
107}
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108
109static int
110dmtz_mod_handler(module_t mod, int type, void *unused)
111{
112 dm_target_t *dmt = NULL;
113 int err = 0;
114
115 switch(type) {
116 case MOD_LOAD:
117 if ((dmt = dm_target_lookup("zero")) != NULL) {
118 dm_target_unbusy(dmt);
119 return EEXIST;
120 }
121 dmt = dm_target_alloc("zero");
122 dmt->version[0] = 1;
123 dmt->version[1] = 0;
124 dmt->version[2] = 0;
125 strlcpy(dmt->name, "zero", DM_MAX_TYPE_NAME);
126 dmt->init = &dm_target_zero_init;
127 dmt->status = &dm_target_zero_status;
128 dmt->strategy = &dm_target_zero_strategy;
129 dmt->deps = &dm_target_zero_deps;
130 dmt->destroy = &dm_target_zero_destroy;
131 dmt->upcall = &dm_target_zero_upcall;
132 dmt->dump = NULL;
133
134 err = dm_target_insert(dmt);
135 if (err == 0)
136 kprintf("dm_target_zero: Successfully initialized\n");
137 break;
138
139 case MOD_UNLOAD:
140 err = dm_target_rem("zero");
141 if (err == 0)
142 kprintf("dm_target_zero: unloaded\n");
143 break;
144
145 default:
146 break;
147 }
148
149 return err;
150}
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151
152DM_TARGET_BUILTIN(dm_target_zero, dmtz_mod_handler);