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.
34 * This file implements initial version of device-mapper zero target.
36 #include <sys/types.h>
37 #include <sys/param.h>
43 #ifdef DM_TARGET_MODULE
45 * Every target can be compiled directly to dm driver or as a
46 * separate module this part of target is used for loading targets
48 * Target can be unloaded from kernel only if there are no users of
49 * it e.g. there are no devices which uses that target.
51 #include <sys/kernel.h>
52 #include <sys/module.h>
54 MODULE(MODULE_CLASS_MISC, dm_target_zero, "dm");
57 dm_target_zero_modcmd(modcmd_t cmd, void *arg)
65 if ((dmt = dm_target_lookup("zero")) != NULL) {
66 dm_target_unbusy(dmt);
69 dmt = dm_target_alloc("zero");
74 strlcpy(dmt->name, "zero", DM_MAX_TYPE_NAME);
75 dmt->init = &dm_target_zero_init;
76 dmt->status = &dm_target_zero_status;
77 dmt->strategy = &dm_target_zero_strategy;
78 dmt->deps = &dm_target_zero_deps;
79 dmt->destroy = &dm_target_zero_destroy;
80 dmt->upcall = &dm_target_zero_upcall;
82 r = dm_target_insert(dmt);
86 r = dm_target_rem("zero");
102 * Zero target init function. This target doesn't need
103 * target specific config area.
106 dm_target_zero_init(dm_dev_t * dmv, void **target_config, char *argv)
109 kprintf("Zero target init function called!!\n");
111 dmv->dev_type = DM_ZERO_DEV;
113 *target_config = NULL;
117 /* Status routine called to get params string. */
119 dm_target_zero_status(void *target_config)
126 * This routine does IO operations.
129 dm_target_zero_strategy(dm_table_entry_t * table_en, struct buf * bp)
132 /* printf("Zero target read function called %d!!\n", bp->b_bcount); */
134 memset(bp->b_data, 0, bp->b_bcount);
136 biodone(&bp->b_bio1);
140 /* Doesn't not need to do anything here. */
142 dm_target_zero_destroy(dm_table_entry_t * table_en)
144 table_en->target_config = NULL;
146 /* Unbusy target so we can unload it */
147 dm_target_unbusy(table_en->target);
151 /* Doesn't not need to do anything here. */
153 dm_target_zero_deps(dm_table_entry_t * table_en, prop_array_t prop_array)
157 /* Unsuported for this target. */
159 dm_target_zero_upcall(dm_table_entry_t * table_en, struct buf * bp)