xref: /dflybsd-src/sys/dev/disk/dm/dm_target_error.c (revision 19b2b39ddcb96e9acb2bfa544c4b368edfe81166)
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 <dev/disk/dm/dm.h>
36 
37 /* Init function called from dm_table_load_ioctl. */
38 static int
39 dm_target_error_init(dm_table_entry_t *table_en, int argc, char **argv)
40 {
41 	dm_table_init_target(table_en, NULL);
42 
43 	return 0;
44 }
45 
46 /* Strategy routine called from dm_strategy. */
47 static int
48 dm_target_error_strategy(dm_table_entry_t *table_en, struct buf *bp)
49 {
50 	bp->b_error = EIO;
51 	bp->b_resid = 0;
52 
53 	biodone(&bp->b_bio1);
54 
55 	return 0;
56 }
57 
58 /* Doesn't do anything here. */
59 static int
60 dm_target_error_destroy(dm_table_entry_t *table_en)
61 {
62 	return 0;
63 }
64 
65 static int
66 dmte_mod_handler(module_t mod, int type, void *unused)
67 {
68 	dm_target_t *dmt = NULL;
69 	int err = 0;
70 
71 	switch(type) {
72 	case MOD_LOAD:
73 		if ((dmt = dm_target_lookup("error")) != NULL) {
74 			dm_target_unbusy(dmt);
75 			return EEXIST;
76 		}
77 		dmt = dm_target_alloc("error");
78 		dmt->version[0] = 1;
79 		dmt->version[1] = 0;
80 		dmt->version[2] = 0;
81 		dmt->init = &dm_target_error_init;
82 		dmt->destroy = &dm_target_error_destroy;
83 		dmt->strategy = &dm_target_error_strategy;
84 
85 		err = dm_target_insert(dmt);
86 		if (err == 0)
87 			kprintf("dm_target_error: Successfully initialized\n");
88 		break;
89 
90 	case MOD_UNLOAD:
91 		err = dm_target_remove("error");
92 		if (err == 0)
93 			kprintf("dm_target_error: unloaded\n");
94 		break;
95 	}
96 
97 	return err;
98 }
99 
100 DM_TARGET_BUILTIN(dm_target_error, dmte_mod_handler);
101