xref: /dragonfly/sys/dev/disk/dm/dm_target_error.c (revision 31524921)
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, int argc, char **argv)
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 /* Strategy routine called from dm_strategy. */
54 static int
55 dm_target_error_strategy(dm_table_entry_t *table_en, struct buf *bp)
56 {
57 
58 	/* kprintf("Error target read function called!!\n"); */
59 
60 	bp->b_error = EIO;
61 	bp->b_resid = 0;
62 
63 	biodone(&bp->b_bio1);
64 
65 	return 0;
66 }
67 
68 /* Doesn't do anything here. */
69 static int
70 dm_target_error_destroy(dm_table_entry_t *table_en)
71 {
72 	table_en->target_config = NULL;
73 
74 	return 0;
75 }
76 
77 static int
78 dmte_mod_handler(module_t mod, int type, void *unused)
79 {
80 	dm_target_t *dmt = NULL;
81 	int err = 0;
82 
83 	switch(type) {
84 	case MOD_LOAD:
85 		if ((dmt = dm_target_lookup("error")) != NULL) {
86 			dm_target_unbusy(dmt);
87 			return EEXIST;
88 		}
89 		dmt = dm_target_alloc("error");
90 		dmt->version[0] = 1;
91 		dmt->version[1] = 0;
92 		dmt->version[2] = 0;
93 		strlcpy(dmt->name, "error", DM_MAX_TYPE_NAME);
94 		dmt->init = &dm_target_error_init;
95 		dmt->destroy = &dm_target_error_destroy;
96 		dmt->strategy = &dm_target_error_strategy;
97 
98 		err = dm_target_insert(dmt);
99 		if (err == 0)
100 			kprintf("dm_target_error: Successfully initialized\n");
101 		break;
102 
103 	case MOD_UNLOAD:
104 		err = dm_target_rem("error");
105 		if (err == 0)
106 			kprintf("dm_target_error: unloaded\n");
107 		break;
108 
109 	default:
110 		break;
111 	}
112 
113 	return err;
114 }
115 
116 DM_TARGET_BUILTIN(dm_target_error, dmte_mod_handler);
117