1/* $NetBSD: dm_pdev.c,v 1.8 2010/12/23 14:58:13 mlelstv 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#include <sys/types.h>
33#include <sys/param.h>
34
35#include <sys/disk.h>
36#include <sys/fcntl.h>
37#include <sys/kmem.h>
38#include <sys/namei.h>
39#include <sys/vnode.h>
40
41#include <dev/dkvar.h>
42
43#include "dm.h"
44
45SLIST_HEAD(dm_pdevs, dm_pdev) dm_pdev_list;
46
47 kmutex_t dm_pdev_mutex;
48
49 static dm_pdev_t *dm_pdev_alloc(const char *);
50 static int dm_pdev_rem(dm_pdev_t *);
51 static dm_pdev_t *dm_pdev_lookup_name(const char *);
52
53/*
54 * Find used pdev with name == dm_pdev_name.
55 */
56 dm_pdev_t *
57 dm_pdev_lookup_name(const char *dm_pdev_name)
58{
59 dm_pdev_t *dm_pdev;
60 int dlen;
61 int slen;
62
63 KASSERT(dm_pdev_name != NULL);
64
65 slen = strlen(dm_pdev_name);
66
67 SLIST_FOREACH(dm_pdev, &dm_pdev_list, next_pdev) {
68 dlen = strlen(dm_pdev->name);
69
70 if (slen != dlen)
71 continue;
72
73 if (strncmp(dm_pdev_name, dm_pdev->name, slen) == 0)
74 return dm_pdev;
75 }
76
77 return NULL;
78}
79/*
80 * Create entry for device with name dev_name and open vnode for it.
81 * If entry already exists in global SLIST I will only increment
82 * reference counter.
83 */
84dm_pdev_t *
85dm_pdev_insert(const char *dev_name)
86{
87 struct pathbuf *dev_pb;
88 dm_pdev_t *dmp;
89 int error;
90
91 KASSERT(dev_name != NULL);
92
93 mutex_enter(&dm_pdev_mutex);
94 dmp = dm_pdev_lookup_name(dev_name);
95
96 if (dmp != NULL) {
97 dmp->ref_cnt++;
98 aprint_debug("dmp_pdev_insert pdev %s already in tree\n", dev_name);
99 mutex_exit(&dm_pdev_mutex);
100 return dmp;
101 }
102 mutex_exit(&dm_pdev_mutex);
103
104 if ((dmp = dm_pdev_alloc(dev_name)) == NULL)
105 return NULL;
106
107 dev_pb = pathbuf_create(dev_name);
108 if (dev_pb == NULL) {
109 aprint_debug("pathbuf_create on device: %s failed!\n",
110 dev_name);
111 kmem_free(dmp, sizeof(dm_pdev_t));
112 return NULL;
113 }
114 error = dk_lookup(dev_pb, curlwp, &dmp->pdev_vnode);
115 pathbuf_destroy(dev_pb);
116 if (error) {
117 aprint_debug("dk_lookup on device: %s failed with error %d!\n",
118 dev_name, error);
119 kmem_free(dmp, sizeof(dm_pdev_t));
120 return NULL;
121 }
122 getdisksize(dmp->pdev_vnode, &dmp->pdev_numsec, &dmp->pdev_secsize);
123 dmp->ref_cnt = 1;
124
125 mutex_enter(&dm_pdev_mutex);
126 SLIST_INSERT_HEAD(&dm_pdev_list, dmp, next_pdev);
127 mutex_exit(&dm_pdev_mutex);
128
129 return dmp;
130}
131/*
132 * Initialize pdev subsystem.
133 */
134int
135dm_pdev_init(void)
136{
137 SLIST_INIT(&dm_pdev_list); /* initialize global pdev list */
138 mutex_init(&dm_pdev_mutex, MUTEX_DEFAULT, IPL_NONE);
139
140 return 0;
141}
142/*
143 * Allocat new pdev structure if is not already present and
144 * set name.
145 */
146static dm_pdev_t *
147dm_pdev_alloc(const char *name)
148{
149 dm_pdev_t *dmp;
150
151 if ((dmp = kmem_zalloc(sizeof(dm_pdev_t), KM_SLEEP)) == NULL)
152 return NULL;
153
154 strlcpy(dmp->name, name, MAX_DEV_NAME);
155
156 dmp->ref_cnt = 0;
157 dmp->pdev_vnode = NULL;
158
159 return dmp;
160}
161/*
162 * Destroy allocated dm_pdev.
163 */
164static int
165dm_pdev_rem(dm_pdev_t * dmp)
166{
167 int err;
168
169 KASSERT(dmp != NULL);
170
171 if (dmp->pdev_vnode != NULL) {
172 err = vn_close(dmp->pdev_vnode, FREAD | FWRITE, FSCRED);
173 if (err != 0)
174 return err;
175 }
176 kmem_free(dmp, sizeof(*dmp));
177 dmp = NULL;
178
179 return 0;
180}
181/*
182 * Destroy all existing pdev's in device-mapper.
183 */
184int
185dm_pdev_destroy(void)
186{
187 dm_pdev_t *dm_pdev;
188
189 mutex_enter(&dm_pdev_mutex);
190 while (!SLIST_EMPTY(&dm_pdev_list)) { /* List Deletion. */
191
192 dm_pdev = SLIST_FIRST(&dm_pdev_list);
193
194 SLIST_REMOVE_HEAD(&dm_pdev_list, next_pdev);
195
196 dm_pdev_rem(dm_pdev);
197 }
198 mutex_exit(&dm_pdev_mutex);
199
200 mutex_destroy(&dm_pdev_mutex);
201 return 0;
202}
203/*
204 * This funcion is called from dm_dev_remove_ioctl.
205 * When I'm removing device from list, I have to decrement
206 * reference counter. If reference counter is 0 I will remove
207 * dmp from global list and from device list to. And I will CLOSE
208 * dmp vnode too.
209 */
210
211/*
212 * Decrement pdev reference counter if 0 remove it.
213 */
214int
215dm_pdev_decr(dm_pdev_t * dmp)
216{
217 KASSERT(dmp != NULL);
218 /*
219 * If this was last reference remove dmp from
220 * global list also.
221 */
222 mutex_enter(&dm_pdev_mutex);
223
224 if (--dmp->ref_cnt == 0) {
225 SLIST_REMOVE(&dm_pdev_list, dmp, dm_pdev, next_pdev);
226 mutex_exit(&dm_pdev_mutex);
227 dm_pdev_rem(dmp);
228 return 0;
229 }
230 mutex_exit(&dm_pdev_mutex);
231 return 0;
232}
233/*static int
234 dm_pdev_dump_list(void)
235 {
236 dm_pdev_t *dmp;
237
238 aprint_verbose("Dumping dm_pdev_list \n");
239
240 SLIST_FOREACH(dmp, &dm_pdev_list, next_pdev) {
241 aprint_verbose("dm_pdev_name %s ref_cnt %d list_rf_cnt %d\n",
242 dmp->name, dmp->ref_cnt, dmp->list_ref_cnt);
243 }
244
245 return 0;
246
247 }*/
248