1 /* $NetBSD: dm_target_linear.c,v 1.9 2010/01/04 00:14:41 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 /*
34 * This file implements initial version of device-mapper dklinear target.
35 */
36
37 #include <dev/disk/dm/dm.h>
38 #include <sys/malloc.h> /* for malloc macros, dm.h includes sys/param.h */
39
40 MALLOC_DEFINE(M_DMLINEAR, "dm_linear", "Device Mapper Target Linear");
41
42 typedef struct target_linear_config {
43 dm_pdev_t *pdev;
44 uint64_t offset;
45 } dm_target_linear_config_t;
46
47 /*
48 * Allocate target specific config data, and link them to table.
49 * This function is called only when, flags is not READONLY and
50 * therefore we can add things to pdev list. This should not a
51 * problem because this routine is called only from dm_table_load_ioctl.
52 * @argv[0] is name,
53 * @argv[1] is physical data offset.
54 */
55 static int
dm_target_linear_init(dm_table_entry_t * table_en,int argc,char ** argv)56 dm_target_linear_init(dm_table_entry_t *table_en, int argc, char **argv)
57 {
58 dm_target_linear_config_t *tlc;
59 dm_pdev_t *dmp;
60
61 if (argc != 2) {
62 kprintf("Linear target takes 2 args\n");
63 return EINVAL;
64 }
65
66 /* Insert dmp to global pdev list */
67 if ((dmp = dm_pdev_insert(argv[0])) == NULL)
68 return ENOENT;
69
70 if ((tlc = kmalloc(sizeof(dm_target_linear_config_t), M_DMLINEAR, M_WAITOK))
71 == NULL)
72 return ENOMEM;
73
74 tlc->pdev = dmp;
75 tlc->offset = atoi64(argv[1]);
76
77 dm_table_add_deps(table_en, dmp);
78
79 dm_table_init_target(table_en, tlc);
80
81 return 0;
82 }
83
84 /*
85 * Table routine is called to get params string, which is target
86 * specific. When dm_table_status_ioctl is called with flag
87 * DM_STATUS_TABLE_FLAG I have to sent params string back.
88 */
89 static char *
dm_target_linear_table(void * target_config)90 dm_target_linear_table(void *target_config)
91 {
92 dm_target_linear_config_t *tlc;
93 char *params;
94 tlc = target_config;
95
96 params = dm_alloc_string(DM_MAX_PARAMS_SIZE);
97
98 ksnprintf(params, DM_MAX_PARAMS_SIZE, "%s %" PRIu64,
99 tlc->pdev->udev_name, tlc->offset);
100
101 return params;
102 }
103
104 /*
105 * Do IO operation, called from dmstrategy routine.
106 */
107 static int
dm_target_linear_strategy(dm_table_entry_t * table_en,struct buf * bp)108 dm_target_linear_strategy(dm_table_entry_t *table_en, struct buf *bp)
109 {
110 dm_target_linear_config_t *tlc;
111
112 tlc = table_en->target_config;
113
114 bp->b_bio1.bio_offset += tlc->offset * DEV_BSIZE;
115
116 vn_strategy(tlc->pdev->pdev_vnode, &bp->b_bio1);
117
118 return 0;
119
120 }
121
122 static int
dm_target_linear_dump(dm_table_entry_t * table_en,void * data,size_t length,off_t offset)123 dm_target_linear_dump(dm_table_entry_t *table_en, void *data, size_t length, off_t offset)
124 {
125 dm_target_linear_config_t *tlc;
126
127 tlc = table_en->target_config;
128
129 offset += tlc->offset * DEV_BSIZE;
130 offset = dm_pdev_correct_dump_offset(tlc->pdev, offset);
131
132 if (tlc->pdev->pdev_vnode->v_rdev == NULL)
133 return ENXIO;
134
135 return dev_ddump(tlc->pdev->pdev_vnode->v_rdev, data, 0, offset, length);
136 }
137
138 /*
139 * Destroy target specific data. Decrement table pdevs.
140 */
141 static int
dm_target_linear_destroy(dm_table_entry_t * table_en)142 dm_target_linear_destroy(dm_table_entry_t *table_en)
143 {
144 dm_target_linear_config_t *tlc;
145
146 /*
147 * Destroy function is called for every target even if it
148 * doesn't have target_config.
149 */
150
151 if (table_en->target_config == NULL)
152 return 0;
153
154 tlc = table_en->target_config;
155
156 /* Decrement pdev ref counter if 0 remove it */
157 dm_pdev_decr(tlc->pdev);
158
159 kfree(table_en->target_config, M_DMLINEAR);
160
161 return 0;
162 }
163
164 static int
dmtl_mod_handler(module_t mod,int type,void * unused)165 dmtl_mod_handler(module_t mod, int type, void *unused)
166 {
167 dm_target_t *dmt = NULL;
168 int err = 0;
169
170 switch(type) {
171 case MOD_LOAD:
172 if ((dmt = dm_target_lookup("linear")) != NULL) {
173 dm_target_unbusy(dmt);
174 return EEXIST;
175 }
176 dmt = dm_target_alloc("linear");
177 dmt->version[0] = 1;
178 dmt->version[1] = 0;
179 dmt->version[2] = 2;
180 dmt->init = &dm_target_linear_init;
181 dmt->destroy = &dm_target_linear_destroy;
182 dmt->strategy = &dm_target_linear_strategy;
183 dmt->table = &dm_target_linear_table;
184 dmt->dump = &dm_target_linear_dump;
185
186 err = dm_target_insert(dmt);
187 if (err == 0)
188 kprintf("dm_target_linear: Successfully initialized\n");
189 break;
190
191 case MOD_UNLOAD:
192 err = dm_target_remove("linear");
193 if (err == 0)
194 kprintf("dm_target_linear: unloaded\n");
195 break;
196 }
197
198 return err;
199 }
200
201 DM_TARGET_MODULE(dm_target_linear, dmtl_mod_handler);
202