1 /* $NetBSD: dm_target_zero.c,v 1.10 2010/01/04 00:12:22 haad Exp $ */
4 * Copyright (c) 2008 The NetBSD Foundation, Inc.
7 * This code is derived from software contributed to The NetBSD Foundation
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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.
33 * This file implements initial version of device-mapper zero target.
35 #include <dev/disk/dm/dm.h>
38 * Zero target init function. This target doesn't need
39 * target specific config area.
42 dm_target_zero_init(dm_table_entry_t *table_en, int argc, char **argv)
45 kprintf("Zero target init function called!!\n");
47 dm_table_init_target(table_en, DM_ZERO_DEV, NULL);
53 * This routine does IO operations.
56 dm_target_zero_strategy(dm_table_entry_t *table_en, struct buf *bp)
59 /* kprintf("Zero target read function called %d!!\n", bp->b_bcount); */
61 memset(bp->b_data, 0, bp->b_bcount);
68 /* Doesn't not need to do anything here. */
70 dm_target_zero_destroy(dm_table_entry_t *table_en)
76 dmtz_mod_handler(module_t mod, int type, void *unused)
78 dm_target_t *dmt = NULL;
83 if ((dmt = dm_target_lookup("zero")) != NULL) {
84 dm_target_unbusy(dmt);
87 dmt = dm_target_alloc("zero");
91 dmt->init = &dm_target_zero_init;
92 dmt->destroy = &dm_target_zero_destroy;
93 dmt->strategy = &dm_target_zero_strategy;
95 err = dm_target_insert(dmt);
97 kprintf("dm_target_zero: Successfully initialized\n");
101 err = dm_target_remove("zero");
103 kprintf("dm_target_zero: unloaded\n");
110 DM_TARGET_BUILTIN(dm_target_zero, dmtz_mod_handler);