2b875ba4e5115bd77b1b8e151298cdb32086e9dc
[dragonfly.git] / sys / dev / disk / dm / dm_target_error.c
1 /*        $NetBSD: dm_target_error.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  * This file implements initial version of device-mapper error target.
34  */
35 #include <sys/types.h>
36 #include <sys/param.h>
37
38 #include <sys/buf.h>
39
40 #include <sys/dm.h>
41
42 /* Init function called from dm_table_load_ioctl. */
43 static int
44 dm_target_error_init(dm_dev_t * dmv, void **target_config, char *argv)
45 {
46
47         kprintf("Error target init function called!!\n");
48
49         *target_config = NULL;
50
51         dmv->dev_type = DM_ERROR_DEV;
52
53         return 0;
54 }
55
56 /* Status routine called to get params string. */
57 static char *
58 dm_target_error_status(void *target_config)
59 {
60         return NULL;
61 }
62
63 /* Strategy routine called from dm_strategy. */
64 static int
65 dm_target_error_strategy(dm_table_entry_t * table_en, struct buf * bp)
66 {
67
68         kprintf("Error target read function called!!\n");
69
70         bp->b_error = EIO;
71         bp->b_resid = 0;
72
73         biodone(&bp->b_bio1);
74
75         return 0;
76 }
77
78 /* Doesn't do anything here. */
79 static int
80 dm_target_error_destroy(dm_table_entry_t * table_en)
81 {
82         table_en->target_config = NULL;
83
84         /* Unbusy target so we can unload it */
85         dm_target_unbusy(table_en->target);
86
87         return 0;
88 }
89
90 /* Doesn't not need to do anything here. */
91 static int
92 dm_target_error_deps(dm_table_entry_t * table_en, prop_array_t prop_array)
93 {
94         return 0;
95 }
96
97 /* Unsupported for this target. */
98 static int
99 dm_target_error_upcall(dm_table_entry_t * table_en, struct buf * bp)
100 {
101         return 0;
102 }
103
104 static int
105 dmte_mod_handler(module_t mod, int type, void *unused)
106 {
107         dm_target_t *dmt = NULL;
108         int err = 0;
109
110         switch(type) {
111         case MOD_LOAD:
112                 if ((dmt = dm_target_lookup("error")) != NULL) {
113                         dm_target_unbusy(dmt);
114                         return EEXIST;
115                 }
116                 dmt = dm_target_alloc("error");
117                 dmt->version[0] = 1;
118                 dmt->version[1] = 0;
119                 dmt->version[2] = 0;
120                 strlcpy(dmt->name, "error", DM_MAX_TYPE_NAME);
121                 dmt->init = &dm_target_error_init;
122                 dmt->status = &dm_target_error_status;
123                 dmt->strategy = &dm_target_error_strategy;
124                 dmt->deps = &dm_target_error_deps;
125                 dmt->destroy = &dm_target_error_destroy;
126                 dmt->upcall = &dm_target_error_upcall;
127                 dmt->dump = NULL;
128
129                 err = dm_target_insert(dmt);
130                 if (err == 0)
131                         kprintf("dm_target_error: Successfully initialized\n");
132                 break;
133
134         case MOD_UNLOAD:
135                 err = dm_target_rem("error");
136                 if (err == 0)
137                         kprintf("dm_target_error: unloaded\n");
138                 break;
139
140         default:
141                 break;
142         }
143
144         return err;
145 }
146
147 DM_TARGET_BUILTIN(dm_target_error, dmte_mod_handler);