xref: /netbsd-src/sys/dev/dm/dm_dev.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*        $NetBSD: dm_dev.c,v 1.11 2018/01/05 14:22:26 christos 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_dev.c,v 1.11 2018/01/05 14:22:26 christos Exp $");
33 
34 #include <sys/types.h>
35 #include <sys/param.h>
36 
37 #include <sys/disk.h>
38 #include <sys/disklabel.h>
39 #include <sys/ioctl.h>
40 #include <sys/ioccom.h>
41 #include <sys/kmem.h>
42 
43 #include "netbsd-dm.h"
44 #include "dm.h"
45 
46 static dm_dev_t *dm_dev_lookup_name(const char *);
47 static dm_dev_t *dm_dev_lookup_uuid(const char *);
48 static dm_dev_t *dm_dev_lookup_minor(int);
49 
50 static struct dm_dev_head dm_dev_list =
51 TAILQ_HEAD_INITIALIZER(dm_dev_list);
52 
53 kmutex_t dm_dev_mutex;
54 
55 /* dm_dev_mutex must be holdby caller before using disable_dev. */
56 __inline static void
57 disable_dev(dm_dev_t * dmv)
58 {
59 	TAILQ_REMOVE(&dm_dev_list, dmv, next_devlist);
60 	mutex_enter(&dmv->dev_mtx);
61 	mutex_exit(&dm_dev_mutex);
62 	while (dmv->ref_cnt != 0)
63 		cv_wait(&dmv->dev_cv, &dmv->dev_mtx);
64 	mutex_exit(&dmv->dev_mtx);
65 }
66 
67 /*
68  * Generic function used to lookup dm_dev_t. Calling with dm_dev_name
69  * and dm_dev_uuid NULL is allowed.
70  */
71 dm_dev_t *
72 dm_dev_lookup(const char *dm_dev_name, const char *dm_dev_uuid,
73     int dm_dev_minor)
74 {
75 	dm_dev_t *dmv;
76 
77 	dmv = NULL;
78 	mutex_enter(&dm_dev_mutex);
79 
80 	/* KASSERT(dm_dev_name != NULL && dm_dev_uuid != NULL && dm_dev_minor
81 	 * > 0); */
82 	if (dm_dev_minor > 0)
83 		if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) {
84 			dm_dev_busy(dmv);
85 			mutex_exit(&dm_dev_mutex);
86 			return dmv;
87 		}
88 	if (dm_dev_name != NULL)
89 		if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) {
90 			dm_dev_busy(dmv);
91 			mutex_exit(&dm_dev_mutex);
92 			return dmv;
93 		}
94 	if (dm_dev_uuid != NULL)
95 		if ((dmv = dm_dev_lookup_uuid(dm_dev_uuid)) != NULL) {
96 			dm_dev_busy(dmv);
97 			mutex_exit(&dm_dev_mutex);
98 			return dmv;
99 		}
100 	mutex_exit(&dm_dev_mutex);
101 	return NULL;
102 }
103 
104 /*
105  * Lookup device with its minor number.
106  */
107 static dm_dev_t *
108 dm_dev_lookup_minor(int dm_dev_minor)
109 {
110 	dm_dev_t *dmv;
111 
112 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
113 		if (dm_dev_minor == dmv->minor)
114 			return dmv;
115 	}
116 
117 	return NULL;
118 }
119 
120 /*
121  * Lookup device with its device name.
122  */
123 static dm_dev_t *
124 dm_dev_lookup_name(const char *dm_dev_name)
125 {
126 	dm_dev_t *dmv;
127 	size_t dlen;
128 	size_t slen;
129 
130 	slen = strlen(dm_dev_name);
131 
132 	if (slen == 0)
133 		return NULL;
134 
135 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
136 
137 		dlen = strlen(dmv->name);
138 
139 		if (slen != dlen)
140 			continue;
141 
142 		if (strncmp(dm_dev_name, dmv->name, slen) == 0)
143 			return dmv;
144 	}
145 
146 	return NULL;
147 }
148 
149 /*
150  * Lookup device with its device uuid. Used mostly by LVM2tools.
151  */
152 static dm_dev_t *
153 dm_dev_lookup_uuid(const char *dm_dev_uuid)
154 {
155 	dm_dev_t *dmv;
156 	size_t len;
157 
158 	len = 0;
159 	len = strlen(dm_dev_uuid);
160 
161 	if (len == 0)
162 		return NULL;
163 
164 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
165 
166 		if (strlen(dmv->uuid) != len)
167 			continue;
168 
169 		if (strncmp(dm_dev_uuid, dmv->uuid, strlen(dmv->uuid)) == 0)
170 			return dmv;
171 	}
172 
173 	return NULL;
174 }
175 
176 /*
177  * Insert new device to the global list of devices.
178  */
179 int
180 dm_dev_insert(dm_dev_t * dev)
181 {
182 	dm_dev_t *dmv;
183 	int r;
184 
185 	dmv = NULL;
186 	r = 0;
187 
188 	KASSERT(dev != NULL);
189 	mutex_enter(&dm_dev_mutex);
190 	if (((dmv = dm_dev_lookup_uuid(dev->uuid)) == NULL) &&
191 	    ((dmv = dm_dev_lookup_name(dev->name)) == NULL) &&
192 	    ((dmv = dm_dev_lookup_minor(dev->minor)) == NULL)) {
193 
194 		TAILQ_INSERT_TAIL(&dm_dev_list, dev, next_devlist);
195 
196 	} else
197 		r = EEXIST;
198 
199 	mutex_exit(&dm_dev_mutex);
200 	return r;
201 }
202 
203 #ifdef notyet
204 /*
205  * Lookup device with its minor number.
206  */
207 int
208 dm_dev_test_minor(int dm_dev_minor)
209 {
210 	dm_dev_t *dmv;
211 
212 	mutex_enter(&dm_dev_mutex);
213 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
214 		if (dm_dev_minor == dmv->minor) {
215 			mutex_exit(&dm_dev_mutex);
216 			return 1;
217 		}
218 	}
219 	mutex_exit(&dm_dev_mutex);
220 
221 	return 0;
222 }
223 #endif
224 
225 /*
226  * dm_dev_lookup_devt look for selected device_t. We keep this routine
227  * outside of dm_dev_lookup because it is a temporally solution.
228  *
229  * TODO: This is a hack autoconf should be more flexible.
230  */
231 dm_dev_t *
232 dm_dev_detach(device_t devt)
233 {
234 	dm_dev_t *dmv;
235 
236 	mutex_enter(&dm_dev_mutex);
237 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
238 		if (devt == dmv->devt) {
239 			disable_dev(dmv);
240 			return dmv;
241 		}
242 	}
243 	mutex_exit(&dm_dev_mutex);
244 
245 	return NULL;
246 }
247 
248 /*
249  * Remove device selected with dm_dev from global list of devices.
250  */
251 dm_dev_t *
252 dm_dev_rem(const char *dm_dev_name, const char *dm_dev_uuid,
253     int dm_dev_minor)
254 {
255 	dm_dev_t *dmv;
256 	dmv = NULL;
257 
258 	mutex_enter(&dm_dev_mutex);
259 
260 	if (dm_dev_minor > 0)
261 		if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) {
262 			disable_dev(dmv);
263 			return dmv;
264 		}
265 	if (dm_dev_name != NULL)
266 		if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) {
267 			disable_dev(dmv);
268 			return dmv;
269 		}
270 	if (dm_dev_uuid != NULL)
271 		if ((dmv = dm_dev_lookup_name(dm_dev_uuid)) != NULL) {
272 			disable_dev(dmv);
273 			return dmv;
274 		}
275 	mutex_exit(&dm_dev_mutex);
276 
277 	return NULL;
278 }
279 
280 /*
281  * Destroy all devices created in device-mapper. Remove all tables
282  * free all allocated memmory.
283  */
284 int
285 dm_dev_destroy(void)
286 {
287 	dm_dev_t *dmv;
288 	mutex_enter(&dm_dev_mutex);
289 
290 	while (TAILQ_FIRST(&dm_dev_list) != NULL) {
291 
292 		dmv = TAILQ_FIRST(&dm_dev_list);
293 
294 		TAILQ_REMOVE(&dm_dev_list, TAILQ_FIRST(&dm_dev_list),
295 		    next_devlist);
296 
297 		mutex_enter(&dmv->dev_mtx);
298 
299 		while (dmv->ref_cnt != 0)
300 			cv_wait(&dmv->dev_cv, &dmv->dev_mtx);
301 
302 		/* Destroy active table first.  */
303 		dm_table_destroy(&dmv->table_head, DM_TABLE_ACTIVE);
304 
305 		/* Destroy inactive table if exits, too. */
306 		dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE);
307 
308 		dm_table_head_destroy(&dmv->table_head);
309 
310 		mutex_exit(&dmv->dev_mtx);
311 		mutex_destroy(&dmv->dev_mtx);
312 		cv_destroy(&dmv->dev_cv);
313 
314 		(void) kmem_free(dmv, sizeof(dm_dev_t));
315 	}
316 	mutex_exit(&dm_dev_mutex);
317 
318 	mutex_destroy(&dm_dev_mutex);
319 	return 0;
320 }
321 
322 /*
323  * Allocate new device entry.
324  */
325 dm_dev_t *
326 dm_dev_alloc(void)
327 {
328 	dm_dev_t *dmv;
329 
330 	dmv = kmem_zalloc(sizeof(dm_dev_t), KM_SLEEP);
331 	dmv->diskp = kmem_zalloc(sizeof(struct disk), KM_SLEEP);
332 	return dmv;
333 }
334 
335 /*
336  * Freed device entry.
337  */
338 int
339 dm_dev_free(dm_dev_t * dmv)
340 {
341 	KASSERT(dmv != NULL);
342 
343 	mutex_destroy(&dmv->dev_mtx);
344 	mutex_destroy(&dmv->diskp_mtx);
345 	cv_destroy(&dmv->dev_cv);
346 
347 	if (dmv->diskp != NULL)
348 		(void) kmem_free(dmv->diskp, sizeof(struct disk));
349 
350 	(void) kmem_free(dmv, sizeof(dm_dev_t));
351 
352 	return 0;
353 }
354 
355 void
356 dm_dev_busy(dm_dev_t * dmv)
357 {
358 	mutex_enter(&dmv->dev_mtx);
359 	dmv->ref_cnt++;
360 	mutex_exit(&dmv->dev_mtx);
361 }
362 
363 void
364 dm_dev_unbusy(dm_dev_t * dmv)
365 {
366 	KASSERT(dmv->ref_cnt != 0);
367 
368 	mutex_enter(&dmv->dev_mtx);
369 	if (--dmv->ref_cnt == 0)
370 		cv_broadcast(&dmv->dev_cv);
371 	mutex_exit(&dmv->dev_mtx);
372 }
373 
374 /*
375  * Return prop_array of dm_targer_list dictionaries.
376  */
377 prop_array_t
378 dm_dev_prop_list(void)
379 {
380 	dm_dev_t *dmv;
381 	prop_array_t dev_array;
382 	prop_dictionary_t dev_dict;
383 
384 	dev_array = prop_array_create();
385 
386 	mutex_enter(&dm_dev_mutex);
387 
388 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
389 		dev_dict = prop_dictionary_create();
390 
391 		prop_dictionary_set_cstring(dev_dict, DM_DEV_NAME, dmv->name);
392 		prop_dictionary_set_uint32(dev_dict, DM_DEV_DEV, dmv->minor);
393 
394 		prop_array_add(dev_array, dev_dict);
395 		prop_object_release(dev_dict);
396 	}
397 
398 	mutex_exit(&dm_dev_mutex);
399 	return dev_array;
400 }
401 
402 /*
403  * Initialize global device mutex.
404  */
405 int
406 dm_dev_init(void)
407 {
408 	TAILQ_INIT(&dm_dev_list);	/* initialize global dev list */
409 	mutex_init(&dm_dev_mutex, MUTEX_DEFAULT, IPL_NONE);
410 	return 0;
411 }
412