xref: /dflybsd-src/sys/dev/disk/dm/dm_dev.c (revision b5d16701e255c342d21e69a6c80b8711c028dc65)
1 /*        $NetBSD: dm_dev.c,v 1.8 2010/01/04 00:19:08 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 #include <sys/types.h>
33 #include <sys/param.h>
34 
35 #include <sys/disk.h>
36 #include <sys/disklabel.h>
37 #include <sys/ioccom.h>
38 #include <sys/malloc.h>
39 #include <dev/disk/dm/dm.h>
40 
41 #include "netbsd-dm.h"
42 
43 static dm_dev_t *dm_dev_lookup_name(const char *);
44 static dm_dev_t *dm_dev_lookup_uuid(const char *);
45 static dm_dev_t *dm_dev_lookup_minor(int);
46 
47 static struct dm_dev_head dm_dev_list =
48 TAILQ_HEAD_INITIALIZER(dm_dev_list);
49 
50 struct lock dm_dev_mutex;
51 
52 /* dm_dev_mutex must be holdby caller before using disable_dev. */
53 static void
54 disable_dev(dm_dev_t * dmv)
55 {
56 	TAILQ_REMOVE(&dm_dev_list, dmv, next_devlist);
57 	lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE);
58 	lockmgr(&dm_dev_mutex, LK_RELEASE);
59 	while (dmv->ref_cnt != 0)
60 		cv_wait(&dmv->dev_cv, &dmv->dev_mtx);
61 	lockmgr(&dmv->dev_mtx, LK_RELEASE);
62 }
63 /*
64  * Generic function used to lookup dm_dev_t. Calling with dm_dev_name
65  * and dm_dev_uuid NULL is allowed.
66  */
67 dm_dev_t *
68 dm_dev_lookup(const char *dm_dev_name, const char *dm_dev_uuid,
69     int dm_dev_minor)
70 {
71 	dm_dev_t *dmv;
72 
73 	dmv = NULL;
74 	lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
75 
76 	/* KKASSERT(dm_dev_name != NULL && dm_dev_uuid != NULL && dm_dev_minor
77 	 * > 0); */
78 	if (dm_dev_minor > 0)
79 		if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) {
80 			dm_dev_busy(dmv);
81 			lockmgr(&dm_dev_mutex, LK_RELEASE);
82 			return dmv;
83 		}
84 	if (dm_dev_name != NULL)
85 		if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) {
86 			dm_dev_busy(dmv);
87 			lockmgr(&dm_dev_mutex, LK_RELEASE);
88 			return dmv;
89 		}
90 	if (dm_dev_uuid != NULL)
91 		if ((dmv = dm_dev_lookup_uuid(dm_dev_uuid)) != NULL) {
92 			dm_dev_busy(dmv);
93 			lockmgr(&dm_dev_mutex, LK_RELEASE);
94 			return dmv;
95 		}
96 	lockmgr(&dm_dev_mutex, LK_RELEASE);
97 	return NULL;
98 }
99 
100 
101 /*
102  * Lookup device with its minor number.
103  */
104 static dm_dev_t *
105 dm_dev_lookup_minor(int dm_dev_minor)
106 {
107 	dm_dev_t *dmv;
108 
109 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
110 		if (dm_dev_minor == dmv->minor)
111 			return dmv;
112 	}
113 
114 	return NULL;
115 }
116 /*
117  * Lookup device with it's device name.
118  */
119 static dm_dev_t *
120 dm_dev_lookup_name(const char *dm_dev_name)
121 {
122 	dm_dev_t *dmv;
123 
124 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
125 		if (strcmp(dm_dev_name, dmv->name) == 0)
126 			return dmv;
127 	}
128 
129 	return NULL;
130 }
131 /*
132  * Lookup device with it's device uuid. Used mostly by LVM2tools.
133  */
134 static dm_dev_t *
135 dm_dev_lookup_uuid(const char *dm_dev_uuid)
136 {
137 	dm_dev_t *dmv;
138 
139 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
140 		if (strcmp(dm_dev_uuid, dmv->uuid) == 0)
141 			return dmv;
142 	}
143 
144 	return NULL;
145 }
146 /*
147  * Insert new device to the global list of devices.
148  */
149 int
150 dm_dev_insert(dm_dev_t * dev)
151 {
152 	dm_dev_t *dmv;
153 	int r;
154 
155 	dmv = NULL;
156 	r = 0;
157 
158 	KKASSERT(dev != NULL);
159 	lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
160 	if (((dmv = dm_dev_lookup_uuid(dev->uuid)) == NULL) &&
161 	    ((dmv = dm_dev_lookup_name(dev->name)) == NULL) &&
162 	    ((dmv = dm_dev_lookup_minor(dev->minor)) == NULL)) {
163 
164 		TAILQ_INSERT_TAIL(&dm_dev_list, dev, next_devlist);
165 
166 	} else
167 		r = EEXIST;
168 
169 	lockmgr(&dm_dev_mutex, LK_RELEASE);
170 	return r;
171 }
172 
173 /*
174  * Remove device selected with dm_dev from global list of devices.
175  */
176 dm_dev_t *
177 dm_dev_rem(dm_dev_t *dmv, const char *dm_dev_name, const char *dm_dev_uuid,
178     int dm_dev_minor)
179 {
180 	lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
181 
182 	if (dmv != NULL) {
183 		disable_dev(dmv);
184 		return dmv;
185 	}
186 
187 	if (dm_dev_minor > 0)
188 		if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) {
189 			disable_dev(dmv);
190 			return dmv;
191 		}
192 	if (dm_dev_name != NULL)
193 		if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) {
194 			disable_dev(dmv);
195 			return dmv;
196 		}
197 	if (dm_dev_uuid != NULL)
198 		if ((dmv = dm_dev_lookup_name(dm_dev_uuid)) != NULL) {
199 			disable_dev(dmv);
200 			return dmv;
201 		}
202 	lockmgr(&dm_dev_mutex, LK_RELEASE);
203 
204 	return NULL;
205 }
206 /*
207  * Destroy all devices created in device-mapper. Remove all tables
208  * free all allocated memmory.
209  */
210 int
211 dm_dev_destroy(void)
212 {
213 	dm_dev_t *dmv;
214 	lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
215 
216 	while (TAILQ_FIRST(&dm_dev_list) != NULL) {
217 
218 		dmv = TAILQ_FIRST(&dm_dev_list);
219 
220 		TAILQ_REMOVE(&dm_dev_list, TAILQ_FIRST(&dm_dev_list),
221 		    next_devlist);
222 
223 		lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE);
224 
225 		while (dmv->ref_cnt != 0)
226 			cv_wait(&dmv->dev_cv, &dmv->dev_mtx);
227 
228 		/* Destroy active table first.  */
229 		dm_table_destroy(&dmv->table_head, DM_TABLE_ACTIVE);
230 
231 		/* Destroy inactive table if exits, too. */
232 		dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE);
233 
234 		dm_table_head_destroy(&dmv->table_head);
235 
236 		lockmgr(&dmv->dev_mtx, LK_RELEASE);
237 		lockuninit(&dmv->dev_mtx);
238 		cv_destroy(&dmv->dev_cv);
239 
240 		(void) kfree(dmv, M_DM);
241 	}
242 	lockmgr(&dm_dev_mutex, LK_RELEASE);
243 
244 	lockuninit(&dm_dev_mutex);
245 	return 0;
246 }
247 /*
248  * Allocate new device entry.
249  */
250 dm_dev_t *
251 dm_dev_alloc(void)
252 {
253 	dm_dev_t *dmv;
254 
255 	dmv = kmalloc(sizeof(dm_dev_t), M_DM, M_WAITOK | M_ZERO);
256 
257 	if (dmv != NULL)
258 		dmv->diskp = kmalloc(sizeof(struct disk), M_DM, M_WAITOK | M_ZERO);
259 
260 	return dmv;
261 }
262 /*
263  * Freed device entry.
264  */
265 int
266 dm_dev_free(dm_dev_t * dmv)
267 {
268 	KKASSERT(dmv != NULL);
269 
270 	lockuninit(&dmv->dev_mtx);
271 	lockuninit(&dmv->diskp_mtx);
272 	cv_destroy(&dmv->dev_cv);
273 
274 	if (dmv->diskp != NULL)
275 		(void) kfree(dmv->diskp, M_DM);
276 
277 	(void) kfree(dmv, M_DM);
278 
279 	return 0;
280 }
281 
282 void
283 dm_dev_busy(dm_dev_t * dmv)
284 {
285 	lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE);
286 	dmv->ref_cnt++;
287 	lockmgr(&dmv->dev_mtx, LK_RELEASE);
288 }
289 
290 void
291 dm_dev_unbusy(dm_dev_t * dmv)
292 {
293 	KKASSERT(dmv->ref_cnt != 0);
294 
295 	lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE);
296 	if (--dmv->ref_cnt == 0)
297 		cv_broadcast(&dmv->dev_cv);
298 	lockmgr(&dmv->dev_mtx, LK_RELEASE);
299 }
300 /*
301  * Return prop_array of dm_targer_list dictionaries.
302  */
303 prop_array_t
304 dm_dev_prop_list(void)
305 {
306 	dm_dev_t *dmv;
307 	prop_array_t dev_array;
308 	prop_dictionary_t dev_dict;
309 
310 	dev_array = prop_array_create();
311 
312 	lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
313 
314 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
315 		dev_dict = prop_dictionary_create();
316 
317 		prop_dictionary_set_cstring(dev_dict, DM_DEV_NAME, dmv->name);
318 		prop_dictionary_set_uint32(dev_dict, DM_DEV_DEV, dmv->minor);
319 
320 		prop_array_add(dev_array, dev_dict);
321 		prop_object_release(dev_dict);
322 	}
323 
324 	lockmgr(&dm_dev_mutex, LK_RELEASE);
325 	return dev_array;
326 }
327 /*
328  * Initialize global device mutex.
329  */
330 int
331 dm_dev_init(void)
332 {
333 	TAILQ_INIT(&dm_dev_list);	/* initialize global dev list */
334 	lockinit(&dm_dev_mutex, "dmdevlist", 0, LK_CANRECURSE);
335 	return 0;
336 }
337