xref: /dragonfly/sys/dev/disk/dm/dm_target_error.c (revision 73610d44)
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 
37 #include <sys/buf.h>
38 
39 #include <dev/disk/dm/dm.h>
40 
41 /* Init function called from dm_table_load_ioctl. */
42 static int
43 dm_target_error_init(dm_table_entry_t *table_en, char *params)
44 {
45 
46 	kprintf("Error target init function called!!\n");
47 
48 	dm_table_init_target(table_en, DM_ERROR_DEV, NULL);
49 
50 	return 0;
51 }
52 
53 /* Table routine called to get params string. */
54 static char *
55 dm_target_error_table(void *target_config)
56 {
57 	return NULL;
58 }
59 
60 /* Strategy routine called from dm_strategy. */
61 static int
62 dm_target_error_strategy(dm_table_entry_t *table_en, struct buf *bp)
63 {
64 
65 	/* kprintf("Error target read function called!!\n"); */
66 
67 	bp->b_error = EIO;
68 	bp->b_resid = 0;
69 
70 	biodone(&bp->b_bio1);
71 
72 	return 0;
73 }
74 
75 /* Doesn't do anything here. */
76 static int
77 dm_target_error_destroy(dm_table_entry_t *table_en)
78 {
79 	table_en->target_config = NULL;
80 
81 	return 0;
82 }
83 
84 /* Unsupported for this target. */
85 static int
86 dm_target_error_upcall(dm_table_entry_t *table_en, struct buf *bp)
87 {
88 	return 0;
89 }
90 
91 static int
92 dmte_mod_handler(module_t mod, int type, void *unused)
93 {
94 	dm_target_t *dmt = NULL;
95 	int err = 0;
96 
97 	switch(type) {
98 	case MOD_LOAD:
99 		if ((dmt = dm_target_lookup("error")) != NULL) {
100 			dm_target_unbusy(dmt);
101 			return EEXIST;
102 		}
103 		dmt = dm_target_alloc("error");
104 		dmt->version[0] = 1;
105 		dmt->version[1] = 0;
106 		dmt->version[2] = 0;
107 		strlcpy(dmt->name, "error", DM_MAX_TYPE_NAME);
108 		dmt->init = &dm_target_error_init;
109 		dmt->table = &dm_target_error_table;
110 		dmt->strategy = &dm_target_error_strategy;
111 		dmt->destroy = &dm_target_error_destroy;
112 		dmt->upcall = &dm_target_error_upcall;
113 		dmt->dump = NULL;
114 
115 		err = dm_target_insert(dmt);
116 		if (err == 0)
117 			kprintf("dm_target_error: Successfully initialized\n");
118 		break;
119 
120 	case MOD_UNLOAD:
121 		err = dm_target_rem("error");
122 		if (err == 0)
123 			kprintf("dm_target_error: unloaded\n");
124 		break;
125 
126 	default:
127 		break;
128 	}
129 
130 	return err;
131 }
132 
133 DM_TARGET_BUILTIN(dm_target_error, dmte_mod_handler);
134