sys/dev/disk/dm/dm_dev.c

   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
  40 #include "netbsd-dm.h"
  41 #include "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 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         int dlen;
 124         int slen;
 125
 126         slen = strlen(dm_dev_name);
 127
 128         if (slen == 0)
 129                 return NULL;
 130
 131         TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
 132
 133                 dlen = strlen(dmv->name);
 134
 135                 if (slen != dlen)
 136                         continue;
 137
 138                 if (strncmp(dm_dev_name, dmv->name, slen) == 0)
 139                         return dmv;
 140         }
 141
 142         return NULL;
 143 }
 144 /*
 145  * Lookup device with it's device uuid. Used mostly by LVM2tools.
 146  */
 147 static dm_dev_t *
 148 dm_dev_lookup_uuid(const char *dm_dev_uuid)
 149 {
 150         dm_dev_t *dmv;
 151         size_t len;
 152
 153         len = 0;
 154         len = strlen(dm_dev_uuid);
 155
 156         if (len == 0)
 157                 return NULL;
 158
 159         TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
 160
 161                 if (strlen(dmv->uuid) != len)
 162                         continue;
 163
 164                 if (strncmp(dm_dev_uuid, dmv->uuid, strlen(dmv->uuid)) == 0)
 165                         return dmv;
 166         }
 167
 168         return NULL;
 169 }
 170 /*
 171  * Insert new device to the global list of devices.
 172  */
 173 int
 174 dm_dev_insert(dm_dev_t * dev)
 175 {
 176         dm_dev_t *dmv;
 177         int r;
 178
 179         dmv = NULL;
 180         r = 0;
 181
 182         KKASSERT(dev != NULL);
 183         lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
 184         if (((dmv = dm_dev_lookup_uuid(dev->uuid)) == NULL) &&
 185             ((dmv = dm_dev_lookup_name(dev->name)) == NULL) &&
 186             ((dmv = dm_dev_lookup_minor(dev->minor)) == NULL)) {
 187
 188                 TAILQ_INSERT_TAIL(&dm_dev_list, dev, next_devlist);
 189
 190         } else
 191                 r = EEXIST;
 192
 193         lockmgr(&dm_dev_mutex, LK_RELEASE);
 194         return r;
 195 }
 196 #ifdef notyet
 197 /*
 198  * Lookup device with its minor number.
 199  */
 200 int
 201 dm_dev_test_minor(int dm_dev_minor)
 202 {
 203         dm_dev_t *dmv;
 204
 205         lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
 206         TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
 207                 if (dm_dev_minor == dmv->minor) {
 208                         lockmgr(&dm_dev_mutex, LK_RELEASE);
 209                         return 1;
 210                 }
 211         }
 212         lockmgr(&dm_dev_mutex, LK_RELEASE);
 213
 214         return 0;
 215 }
 216 #endif
 217
 218 #if 0
 219 /*
 220  * dm_dev_lookup_devt look for selected device_t. We keep this routine
 221  * outside of dm_dev_lookup because it is a temporally solution.
 222  *
 223  * TODO: This is a hack autoconf should be more flexible.
 224  */
 225 dm_dev_t *
 226 dm_dev_detach(device_t devt)
 227 {
 228        dm_dev_t *dmv;
 229
 230        lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
 231        TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
 232                if (devt == dmv->devt) {
 233                        disable_dev(dmv);
 234                        lockmgr(&dm_dev_mutex, LK_RELEASE);
 235                        return dmv;
 236                }
 237        }
 238        lockmgr(&dm_dev_mutex, LK_RELEASE);
 239
 240        return NULL;
 241 }
 242 #endif
 243
 244 /*
 245  * Remove device selected with dm_dev from global list of devices.
 246  */
 247 dm_dev_t *
 248 dm_dev_rem(const char *dm_dev_name, const char *dm_dev_uuid,
 249     int dm_dev_minor)
 250 {
 251         dm_dev_t *dmv;
 252         dmv = NULL;
 253
 254         lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
 255
 256         if (dm_dev_minor > 0)
 257                 if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) {
 258                         disable_dev(dmv);
 259                         return dmv;
 260                 }
 261         if (dm_dev_name != NULL)
 262                 if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) {
 263                         disable_dev(dmv);
 264                         return dmv;
 265                 }
 266         if (dm_dev_uuid != NULL)
 267                 if ((dmv = dm_dev_lookup_name(dm_dev_uuid)) != NULL) {
 268                         disable_dev(dmv);
 269                         return dmv;
 270                 }
 271         lockmgr(&dm_dev_mutex, LK_RELEASE);
 272
 273         return NULL;
 274 }
 275 /*
 276  * Destroy all devices created in device-mapper. Remove all tables
 277  * free all allocated memmory.
 278  */
 279 int
 280 dm_dev_destroy(void)
 281 {
 282         dm_dev_t *dmv;
 283         lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
 284
 285         while (TAILQ_FIRST(&dm_dev_list) != NULL) {
 286
 287                 dmv = TAILQ_FIRST(&dm_dev_list);
 288
 289                 TAILQ_REMOVE(&dm_dev_list, TAILQ_FIRST(&dm_dev_list),
 290                     next_devlist);
 291
 292                 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE);
 293
 294                 while (dmv->ref_cnt != 0)
 295                         cv_wait(&dmv->dev_cv, &dmv->dev_mtx);
 296
 297                 /* Destroy active table first.  */
 298                 dm_table_destroy(&dmv->table_head, DM_TABLE_ACTIVE);
 299
 300                 /* Destroy inactive table if exits, too. */
 301                 dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE);
 302
 303                 dm_table_head_destroy(&dmv->table_head);
 304
 305                 lockmgr(&dmv->dev_mtx, LK_RELEASE);
 306                 lockuninit(&dmv->dev_mtx);
 307                 cv_destroy(&dmv->dev_cv);
 308
 309                 (void) kfree(dmv, M_DM);
 310         }
 311         lockmgr(&dm_dev_mutex, LK_RELEASE);
 312
 313         lockuninit(&dm_dev_mutex);
 314         return 0;
 315 }
 316 /*
 317  * Allocate new device entry.
 318  */
 319 dm_dev_t *
 320 dm_dev_alloc(void)
 321 {
 322         dm_dev_t *dmv;
 323
 324         dmv = kmalloc(sizeof(dm_dev_t), M_DM, M_WAITOK | M_ZERO);
 325
 326         if (dmv != NULL)
 327                 dmv->diskp = kmalloc(sizeof(struct disk), M_DM, M_WAITOK | M_ZERO);
 328
 329         return dmv;
 330 }
 331 /*
 332  * Freed device entry.
 333  */
 334 int
 335 dm_dev_free(dm_dev_t * dmv)
 336 {
 337         KKASSERT(dmv != NULL);
 338
 339         lockuninit(&dmv->dev_mtx);
 340         lockuninit(&dmv->diskp_mtx);
 341         cv_destroy(&dmv->dev_cv);
 342
 343         if (dmv->diskp != NULL)
 344                 (void) kfree(dmv->diskp, M_DM);
 345
 346         (void) kfree(dmv, M_DM);
 347
 348         return 0;
 349 }
 350
 351 void
 352 dm_dev_busy(dm_dev_t * dmv)
 353 {
 354         lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE);
 355         dmv->ref_cnt++;
 356         lockmgr(&dmv->dev_mtx, LK_RELEASE);
 357 }
 358
 359 void
 360 dm_dev_unbusy(dm_dev_t * dmv)
 361 {
 362         KKASSERT(dmv->ref_cnt != 0);
 363
 364         lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE);
 365         if (--dmv->ref_cnt == 0)
 366                 cv_broadcast(&dmv->dev_cv);
 367         lockmgr(&dmv->dev_mtx, LK_RELEASE);
 368 }
 369 /*
 370  * Return prop_array of dm_targer_list dictionaries.
 371  */
 372 prop_array_t
 373 dm_dev_prop_list(void)
 374 {
 375         dm_dev_t *dmv;
 376         prop_array_t dev_array;
 377         prop_dictionary_t dev_dict;
 378
 379         dev_array = prop_array_create();
 380
 381         lockmgr(&dm_dev_mutex, LK_EXCLUSIVE);
 382
 383         TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
 384                 dev_dict = prop_dictionary_create();
 385
 386                 prop_dictionary_set_cstring(dev_dict, DM_DEV_NAME, dmv->name);
 387                 prop_dictionary_set_uint32(dev_dict, DM_DEV_DEV, dmv->minor);
 388
 389                 prop_array_add(dev_array, dev_dict);
 390                 prop_object_release(dev_dict);
 391         }
 392
 393         lockmgr(&dm_dev_mutex, LK_RELEASE);
 394         return dev_array;
 395 }
 396 /*
 397  * Initialize global device mutex.
 398  */
 399 int
 400 dm_dev_init(void)
 401 {
 402         TAILQ_INIT(&dm_dev_list);       /* initialize global dev list */
 403         lockinit(&dm_dev_mutex, "dmdevlist", 0, LK_CANRECURSE);
 404         return 0;
 405 }