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 #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 }