xref: /netbsd-src/sys/dev/dm/dm_target_error.c (revision 62e994ce9603e863ae6d9a2bbbe8aa35680d2e7c)
1 /*        $NetBSD: dm_target_error.c,v 1.8 2009/06/05 19:56:40 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 "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_error, "dm");
54 
55 static int
56 dm_target_error_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 ((dmt = dm_target_lookup("error")) != NULL){
65 			dm_target_unbusy(dmt);
66 			return EEXIST;
67 		}
68 		dmt = dm_target_alloc("error");
69 
70 		dmt->version[0] = 1;
71 		dmt->version[1] = 0;
72 		dmt->version[2] = 0;
73 		strlcpy(dmt->name, "error", DM_MAX_TYPE_NAME);
74 		dmt->init = &dm_target_error_init;
75 		dmt->status = &dm_target_error_status;
76 		dmt->strategy = &dm_target_error_strategy;
77 		dmt->deps = &dm_target_error_deps;
78 		dmt->destroy = &dm_target_error_destroy;
79 		dmt->upcall = &dm_target_error_upcall;
80 
81 		r = dm_target_insert(dmt);
82 
83 		break;
84 
85 	case MODULE_CMD_FINI:
86 		r = dm_target_rem("error");
87 		break;
88 
89 	case MODULE_CMD_STAT:
90 		return ENOTTY;
91 
92 	default:
93 		return ENOTTY;
94 	}
95 
96 	return r;
97 }
98 
99 #endif
100 
101 /* Init function called from dm_table_load_ioctl. */
102 int
103 dm_target_error_init(dm_dev_t *dmv, void **target_config, prop_dictionary_t dict)
104 {
105 
106 	printf("Error target init function called!!\n");
107 
108 	*target_config = NULL;
109 
110 	dmv->dev_type = DM_ERROR_DEV;
111 
112 	return 0;
113 }
114 
115 /* Status routine called to get params string. */
116 char *
117 dm_target_error_status(void *target_config)
118 {
119 	return NULL;
120 }
121 
122 /* Strategy routine called from dm_strategy. */
123 int
124 dm_target_error_strategy(dm_table_entry_t *table_en, struct buf *bp)
125 {
126 
127 	printf("Error target read function called!!\n");
128 
129 	bp->b_error = EIO;
130 	bp->b_resid = 0;
131 
132 	biodone(bp);
133 
134 	return 0;
135 }
136 
137 /* Doesn't do anything here. */
138 int
139 dm_target_error_destroy(dm_table_entry_t *table_en)
140 {
141 	table_en->target_config = NULL;
142 
143 	/* Unbusy target so we can unload it */
144 	dm_target_unbusy(table_en->target);
145 
146 	return 0;
147 }
148 
149 /* Doesn't not need to do anything here. */
150 int
151 dm_target_error_deps(dm_table_entry_t *table_en, prop_array_t prop_array)
152 {
153 	return 0;
154 }
155 
156 /* Unsupported for this target. */
157 int
158 dm_target_error_upcall(dm_table_entry_t *table_en, struct buf *bp)
159 {
160 	return 0;
161 }
162