1 /* $NetBSD: dm_dev.c,v 1.8 2010/01/04 00:19:08 haad Exp $ */
2
3 /*
4 * Copyright (c) 2010-2011 Alex Hornung <alex@alexhornung.com>
5 * Copyright (c) 2008 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Adam Hamsik.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #include <sys/disk.h>
34 #include <sys/disklabel.h>
35 #include <sys/devicestat.h>
36 #include <sys/device.h>
37 #include <sys/udev.h>
38 #include <sys/devfs.h>
39 #include <sys/malloc.h>
40 #include <machine/thread.h>
41 #include <dev/disk/dm/dm.h>
42 #include <dev/disk/dm/netbsd-dm.h>
43
44 extern struct dev_ops dm_ops;
45
46 static struct devfs_bitmap dm_minor_bitmap;
47 uint64_t dm_dev_counter;
48
49 static dm_dev_t *dm_dev_lookup_name(const char *);
50 static dm_dev_t *dm_dev_lookup_uuid(const char *);
51 static dm_dev_t *dm_dev_lookup_minor(int);
52 static int dm_dev_destroy(dm_dev_t *);
53 static dm_dev_t *dm_dev_alloc(const char *, const char *);
54 static int dm_dev_free(dm_dev_t *);
55
56 static TAILQ_HEAD(dm_dev_head, dm_dev) dm_dev_list;
57
58 static struct lock dm_dev_mutex;
59
60 static char dummy_uuid[DM_UUID_LEN];
61
62 /*
63 * dm_dev_mutex must be held by caller before using disable_dev.
64 */
65 static void
disable_dev(dm_dev_t * dmv)66 disable_dev(dm_dev_t *dmv)
67 {
68 KKASSERT(lockstatus(&dm_dev_mutex, curthread) == LK_EXCLUSIVE);
69
70 TAILQ_REMOVE(&dm_dev_list, dmv, next_devlist);
71 dm_dev_counter--;
72
73 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE);
74 while (dmv->ref_cnt != 0)
75 cv_wait(&dmv->dev_cv, &dmv->dev_mtx);
76 lockmgr(&dmv->dev_mtx, LK_RELEASE);
77 }
78
79 static dm_dev_t *
_dm_dev_lookup(const char * name,const char * uuid,int minor)80 _dm_dev_lookup(const char *name, const char *uuid, int minor)
81 {
82 dm_dev_t *dmv;
83
84 if (minor > 0) {
85 if ((dmv = dm_dev_lookup_minor(minor)))
86 return dmv;
87 }
88 if (name != NULL) {
89 if ((dmv = dm_dev_lookup_name(name)))
90 return dmv;
91 }
92 if (uuid != NULL) {
93 if ((dmv = dm_dev_lookup_uuid(uuid)))
94 return dmv;
95 }
96
97 return NULL;
98 }
99
100 /*
101 * Generic function used to lookup dm_dev_t. Calling with name NULL
102 * and uuid NULL is allowed.
103 */
104 dm_dev_t *
dm_dev_lookup(const char * name,const char * uuid,int minor)105 dm_dev_lookup(const char *name, const char *uuid, int minor)
106 {
107 dm_dev_t *dmv;
108
109 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
110
111 dmv = _dm_dev_lookup(name, uuid, minor);
112 if (dmv)
113 dm_dev_busy(dmv);
114
115 lockmgr(&dm_dev_mutex, LK_RELEASE);
116
117 return dmv;
118 }
119
120
121 /*
122 * Lookup device with its minor number.
123 */
124 static dm_dev_t *
dm_dev_lookup_minor(int dm_dev_minor)125 dm_dev_lookup_minor(int dm_dev_minor)
126 {
127 dm_dev_t *dmv;
128
129 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
130 if (dm_dev_minor == dmv->minor)
131 return dmv;
132 }
133
134 return NULL;
135 }
136
137 /*
138 * Lookup device with it's device name.
139 */
140 static dm_dev_t *
dm_dev_lookup_name(const char * dm_dev_name)141 dm_dev_lookup_name(const char *dm_dev_name)
142 {
143 dm_dev_t *dmv;
144
145 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
146 if (strcmp(dm_dev_name, dmv->name) == 0)
147 return dmv;
148 }
149
150 return NULL;
151 }
152
153 /*
154 * Lookup device with it's device uuid. Used mostly by LVM2tools.
155 */
156 static dm_dev_t *
dm_dev_lookup_uuid(const char * dm_dev_uuid)157 dm_dev_lookup_uuid(const char *dm_dev_uuid)
158 {
159 dm_dev_t *dmv;
160
161 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
162 if (strcmp(dm_dev_uuid, dmv->uuid) == 0)
163 return dmv;
164 }
165
166 return NULL;
167 }
168
169 /*
170 * Insert new device to the global list of devices.
171 */
172 int
dm_dev_insert(dm_dev_t * dev)173 dm_dev_insert(dm_dev_t *dev)
174 {
175 dm_dev_t *dmv;
176 int r;
177
178 dmv = NULL;
179 r = 0;
180
181 KKASSERT(dev != NULL);
182 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
183
184 /*
185 * Ignore uuid lookup if dev->uuid is zero-filled.
186 */
187 if (memcmp(dev->uuid, dummy_uuid, DM_UUID_LEN))
188 dmv = dm_dev_lookup_uuid(dev->uuid);
189
190 if ((dmv == NULL) &&
191 (_dm_dev_lookup(dev->name, NULL, dev->minor) == NULL)) {
192 TAILQ_INSERT_TAIL(&dm_dev_list, dev, next_devlist);
193 dm_dev_counter++;
194 } else {
195 KKASSERT(dmv != NULL);
196 r = EEXIST;
197 }
198
199 lockmgr(&dm_dev_mutex, LK_RELEASE);
200 return r;
201 }
202
203 #if 0
204 /*
205 * Remove device selected with dm_dev from global list of devices.
206 */
207 dm_dev_t *
208 dm_dev_lookup_evict(const char *name, const char *uuid, int minor)
209 {
210 dm_dev_t *dmv;
211
212 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
213
214 dmv = _dm_dev_lookup(name, uuid, minor);
215 if (dmv)
216 disable_dev(dmv);
217
218 lockmgr(&dm_dev_mutex, LK_RELEASE);
219
220 return dmv;
221 }
222 #endif
223
224 int
dm_dev_create(dm_dev_t ** dmvp,const char * name,const char * uuid,int flags)225 dm_dev_create(dm_dev_t **dmvp, const char *name, const char *uuid, int flags)
226 {
227 dm_dev_t *dmv;
228 char name_buf[MAXPATHLEN];
229 int r, dm_minor;
230
231 if ((dmv = dm_dev_alloc(name, uuid)) == NULL)
232 return ENOMEM;
233
234 dm_minor = devfs_clone_bitmap_get(&dm_minor_bitmap, 0);
235
236 dm_table_head_init(&dmv->table_head);
237
238 lockinit(&dmv->dev_mtx, "dmdev", 0, LK_CANRECURSE);
239 cv_init(&dmv->dev_cv, "dm_dev");
240
241 if (flags & DM_READONLY_FLAG)
242 dmv->flags |= DM_READONLY_FLAG;
243
244 dmdebug("Creating device dm/%s\n", name);
245 ksnprintf(name_buf, sizeof(name_buf), "mapper/%s", dmv->name);
246
247 devstat_add_entry(&dmv->stats, name, 0, DEV_BSIZE,
248 DEVSTAT_NO_ORDERED_TAGS,
249 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER,
250 DEVSTAT_PRIORITY_DISK);
251
252 dmv->devt = disk_create_named(name_buf, dm_minor, dmv->diskp, &dm_ops);
253 reference_dev(dmv->devt);
254
255 /* Make sure the device are immediately available */
256 sync_devs();
257
258 dmv->devt->si_drv1 = dmv;
259 dmv->devt->si_drv2 = dmv->diskp;
260
261 dmv->minor = minor(dmv->devt);
262 udev_dict_set_cstr(dmv->devt, "subsystem", "disk");
263
264 if ((r = dm_dev_insert(dmv)) != 0)
265 dm_dev_destroy(dmv);
266
267 *dmvp = dmv;
268
269 return r;
270 }
271
272 static int
dm_dev_destroy(dm_dev_t * dmv)273 dm_dev_destroy(dm_dev_t *dmv)
274 {
275 int minor;
276
277 /* Destroy active table first. */
278 dm_table_destroy(&dmv->table_head, DM_TABLE_ACTIVE);
279
280 /* Destroy inactive table if exits, too. */
281 dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE);
282
283 dm_table_head_destroy(&dmv->table_head);
284
285 minor = dkunit(dmv->devt);
286 disk_destroy(dmv->diskp);
287 devstat_remove_entry(&dmv->stats);
288
289 release_dev(dmv->devt);
290 devfs_clone_bitmap_put(&dm_minor_bitmap, minor);
291
292 lockuninit(&dmv->dev_mtx);
293 cv_destroy(&dmv->dev_cv);
294
295 /* Destroy device */
296 dm_dev_free(dmv);
297
298 return 0;
299 }
300
301 /*
302 * dm_dev_remove is called to completely destroy & remove a dm disk device.
303 */
304 int
dm_dev_remove(dm_dev_t * dmv)305 dm_dev_remove(dm_dev_t *dmv)
306 {
307 /* Remove device from list and wait for refcnt to drop to zero */
308 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
309 disable_dev(dmv);
310 lockmgr(&dm_dev_mutex, LK_RELEASE);
311
312 /* Destroy and free the device */
313 dm_dev_destroy(dmv);
314
315 return 0;
316 }
317
318 int
dm_dev_remove_all(int gentle)319 dm_dev_remove_all(int gentle)
320 {
321 dm_dev_t *dmv, *dmv2;
322 int r;
323
324 r = 0;
325
326 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
327
328 /*
329 * Process in reverse order so that it can deal with inter-depentent
330 * devices.
331 */
332 TAILQ_FOREACH_REVERSE_MUTABLE(dmv, &dm_dev_list, dm_dev_head,
333 next_devlist, dmv2) {
334 if (gentle && dmv->is_open) {
335 r = EBUSY;
336 continue;
337 }
338
339 disable_dev(dmv);
340 dm_dev_destroy(dmv);
341 }
342 lockmgr(&dm_dev_mutex, LK_RELEASE);
343
344 return r;
345 }
346
347 /*
348 * Allocate new device entry.
349 */
350 static dm_dev_t *
dm_dev_alloc(const char * name,const char * uuid)351 dm_dev_alloc(const char *name, const char*uuid)
352 {
353 dm_dev_t *dmv;
354
355 dmv = kmalloc(sizeof(*dmv), M_DM, M_WAITOK | M_ZERO);
356 if (dmv == NULL)
357 return NULL;
358
359 dmv->diskp = kmalloc(sizeof(*dmv->diskp), M_DM, M_WAITOK | M_ZERO);
360 if (dmv->diskp == NULL) {
361 kfree(dmv, M_DM);
362 return NULL;
363 }
364
365 if (name)
366 strlcpy(dmv->name, name, sizeof(dmv->name));
367 if (uuid)
368 strncpy(dmv->uuid, uuid, sizeof(dmv->uuid));
369
370 return dmv;
371 }
372
373 /*
374 * Freed device entry.
375 */
376 static int
dm_dev_free(dm_dev_t * dmv)377 dm_dev_free(dm_dev_t *dmv)
378 {
379 KKASSERT(dmv != NULL);
380
381 if (dmv->diskp != NULL)
382 kfree(dmv->diskp, M_DM);
383
384 kfree(dmv, M_DM);
385
386 return 0;
387 }
388
389 void
dm_dev_busy(dm_dev_t * dmv)390 dm_dev_busy(dm_dev_t *dmv)
391 {
392 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE);
393 dmv->ref_cnt++;
394 lockmgr(&dmv->dev_mtx, LK_RELEASE);
395 }
396
397 void
dm_dev_unbusy(dm_dev_t * dmv)398 dm_dev_unbusy(dm_dev_t *dmv)
399 {
400 KKASSERT(dmv->ref_cnt != 0);
401
402 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE);
403 if (--dmv->ref_cnt == 0)
404 cv_broadcast(&dmv->dev_cv);
405 lockmgr(&dmv->dev_mtx, LK_RELEASE);
406 }
407
408 /*
409 * Return prop_array of dm_targer_list dictionaries.
410 */
411 prop_array_t
dm_dev_prop_list(void)412 dm_dev_prop_list(void)
413 {
414 dm_dev_t *dmv;
415 prop_array_t dev_array;
416 prop_dictionary_t dev_dict;
417
418 dev_array = prop_array_create();
419
420 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
421
422 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
423 dev_dict = prop_dictionary_create();
424
425 prop_dictionary_set_cstring(dev_dict, DM_DEV_NAME, dmv->name);
426 prop_dictionary_set_uint32(dev_dict, DM_DEV_DEV, dmv->minor);
427
428 prop_array_add(dev_array, dev_dict);
429 prop_object_release(dev_dict);
430 }
431
432 lockmgr(&dm_dev_mutex, LK_RELEASE);
433 return dev_array;
434 }
435
436 /*
437 * Initialize global device mutex.
438 */
439 int
dm_dev_init(void)440 dm_dev_init(void)
441 {
442 TAILQ_INIT(&dm_dev_list); /* initialize global dev list */
443 lockinit(&dm_dev_mutex, "dmdevlist", 0, LK_CANRECURSE);
444 devfs_clone_bitmap_init(&dm_minor_bitmap);
445
446 memset(dummy_uuid, 0, sizeof(dummy_uuid));
447 return 0;
448 }
449
450 /*
451 * Destroy all devices created in device-mapper. Remove all tables
452 * free all allocated memmory.
453 */
454 int
dm_dev_uninit(void)455 dm_dev_uninit(void)
456 {
457 /* Force removal of all devices */
458 dm_dev_remove_all(0);
459
460 lockuninit(&dm_dev_mutex);
461 return 0;
462 }
463