1/*        $NetBSD: dm_target_linear.c,v 1.37 2020/01/21 16:27:53 tkusumi 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#include <sys/cdefs.h>
32__KERNEL_RCSID(0, "$NetBSD: dm_target_linear.c,v 1.37 2020/01/21 16:27:53 tkusumi Exp $");
33
34/*
35 * This file implements initial version of device-mapper linear target.
36 */
37
38#include <sys/types.h>
39#include <sys/param.h>
40#include <sys/buf.h>
41#include <sys/kmem.h>
42#include <sys/lwp.h>
43
44#include <machine/int_fmtio.h>
45
46#include "dm.h"
47
48/*
49 * Allocate target specific config data, and link them to table.
50 * This function is called only when, flags is not READONLY and
51 * therefore we can add things to pdev list. This should not a
52 * problem because this routine is called only from dm_table_load_ioctl.
53 * @argv[0] is name,
54 * @argv[1] is physical data offset.
55 */
56int
57dm_target_linear_init(dm_table_entry_t *table_en, int argc, char **argv)
58{
59	dm_target_linear_config_t *tlc;
60	dm_pdev_t *dmp;
61
62	if (argc != 2) {
63		printf("Linear target takes 2 args, %d given\n", argc);
64		return EINVAL;
65	}
66
67	aprint_debug("Linear target init function called %s--%s!!\n",
68	    argv[0], argv[1]);
69
70	/* Insert dmp to global pdev list */
71	if ((dmp = dm_pdev_insert(argv[0])) == NULL)
72		return ENOENT;
73
74	tlc = kmem_alloc(sizeof(dm_target_linear_config_t), KM_SLEEP);
75	tlc->pdev = dmp;
76	tlc->offset = atoi64(argv[1]);
77
78	dm_table_add_deps(table_en, dmp);
79	table_en->target_config = 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 */
89char *
90dm_target_linear_table(void *target_config)
91{
92	dm_target_linear_config_t *tlc;
93	char *params;
94	tlc = target_config;
95
96	aprint_debug("Linear target table function called\n");
97
98	params = kmem_alloc(DM_MAX_PARAMS_SIZE, KM_SLEEP);
99	snprintf(params, DM_MAX_PARAMS_SIZE, "%s %" PRIu64,
100	    tlc->pdev->udev_name, tlc->offset);
101
102	return params;
103}
104
105/*
106 * Do IO operation, called from dmstrategy routine.
107 */
108int
109dm_target_linear_strategy(dm_table_entry_t *table_en, struct buf *bp)
110{
111	dm_target_linear_config_t *tlc;
112
113	tlc = table_en->target_config;
114
115	bp->b_blkno += tlc->offset;
116
117	VOP_STRATEGY(tlc->pdev->pdev_vnode, bp);
118
119	return 0;
120}
121
122/*
123 * Sync underlying disk caches.
124 */
125int
126dm_target_linear_sync(dm_table_entry_t *table_en)
127{
128	int cmd;
129	dm_target_linear_config_t *tlc;
130
131	tlc = table_en->target_config;
132
133	cmd = 1;
134
135	return VOP_IOCTL(tlc->pdev->pdev_vnode,  DIOCCACHESYNC, &cmd,
136	    FREAD|FWRITE, kauth_cred_get());
137}
138
139/*
140 * Destroy target specific data. Decrement table pdevs.
141 */
142int
143dm_target_linear_destroy(dm_table_entry_t *table_en)
144{
145
146	/*
147	 * Destroy function is called for every target even if it
148	 * doesn't have target_config.
149	 */
150	if (table_en->target_config == NULL)
151		goto out;
152
153	dm_target_linear_config_t *tlc = table_en->target_config;
154
155	/* Decrement pdev ref counter if 0 remove it */
156	dm_pdev_decr(tlc->pdev);
157
158	kmem_free(tlc, sizeof(*tlc));
159
160out:
161	/* Unbusy target so we can unload it */
162	dm_target_unbusy(table_en->target);
163	return 0;
164}
165
166#if 0
167/*
168 * Register upcall device.
169 * Linear target doesn't need any upcall devices but other targets like
170 * mirror, snapshot, multipath, stripe will use this functionality.
171 */
172int
173dm_target_linear_upcall(dm_table_entry_t *table_en, struct buf *bp)
174{
175
176	return 0;
177}
178#endif
179
180/*
181 * Query physical block size of this target
182 * For a linear target this is just the sector size of the underlying device
183 */
184int
185dm_target_linear_secsize(dm_table_entry_t *table_en, unsigned int *secsizep)
186{
187	dm_target_linear_config_t *tlc;
188	unsigned int secsize;
189
190	secsize = 0;
191
192	tlc = table_en->target_config;
193	if (tlc != NULL)
194		secsize = tlc->pdev->pdev_secsize;
195
196	*secsizep = secsize;
197
198	return 0;
199}
200