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/types.h> 34 #include <sys/param.h> 35 #include <machine/thread.h> 36 #include <sys/thread2.h> 37 38 #include <sys/disk.h> 39 #include <sys/disklabel.h> 40 #include <sys/devicestat.h> 41 #include <sys/device.h> 42 #include <sys/udev.h> 43 #include <sys/devfs.h> 44 #include <sys/malloc.h> 45 #include <dev/disk/dm/dm.h> 46 47 #include "netbsd-dm.h" 48 49 extern struct dev_ops dm_ops; 50 51 struct devfs_bitmap dm_minor_bitmap; 52 uint64_t dm_dev_counter; 53 54 static dm_dev_t *dm_dev_lookup_name(const char *); 55 static dm_dev_t *dm_dev_lookup_uuid(const char *); 56 static dm_dev_t *dm_dev_lookup_minor(int); 57 58 static struct dm_dev_head dm_dev_list = 59 TAILQ_HEAD_INITIALIZER(dm_dev_list); 60 61 struct lock dm_dev_mutex; 62 63 /* dm_dev_mutex must be held by caller before using disable_dev. */ 64 static void 65 disable_dev(dm_dev_t * dmv) 66 { 67 KKASSERT(lockstatus(&dm_dev_mutex, curthread) == LK_EXCLUSIVE); 68 69 TAILQ_REMOVE(&dm_dev_list, dmv, next_devlist); 70 71 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE); 72 while (dmv->ref_cnt != 0) 73 cv_wait(&dmv->dev_cv, &dmv->dev_mtx); 74 lockmgr(&dmv->dev_mtx, LK_RELEASE); 75 } 76 /* 77 * Generic function used to lookup dm_dev_t. Calling with dm_dev_name 78 * and dm_dev_uuid NULL is allowed. 79 */ 80 dm_dev_t * 81 dm_dev_lookup(const char *dm_dev_name, const char *dm_dev_uuid, 82 int dm_dev_minor) 83 { 84 dm_dev_t *dmv; 85 86 dmv = NULL; 87 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 88 89 /* KKASSERT(dm_dev_name != NULL && dm_dev_uuid != NULL && dm_dev_minor 90 * > 0); */ 91 if (dm_dev_minor > 0) 92 if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) { 93 dm_dev_busy(dmv); 94 lockmgr(&dm_dev_mutex, LK_RELEASE); 95 return dmv; 96 } 97 if (dm_dev_name != NULL) 98 if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) { 99 dm_dev_busy(dmv); 100 lockmgr(&dm_dev_mutex, LK_RELEASE); 101 return dmv; 102 } 103 if (dm_dev_uuid != NULL) 104 if ((dmv = dm_dev_lookup_uuid(dm_dev_uuid)) != NULL) { 105 dm_dev_busy(dmv); 106 lockmgr(&dm_dev_mutex, LK_RELEASE); 107 return dmv; 108 } 109 lockmgr(&dm_dev_mutex, LK_RELEASE); 110 return NULL; 111 } 112 113 114 /* 115 * Lookup device with its minor number. 116 */ 117 static dm_dev_t * 118 dm_dev_lookup_minor(int dm_dev_minor) 119 { 120 dm_dev_t *dmv; 121 122 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) { 123 if (dm_dev_minor == dmv->minor) 124 return dmv; 125 } 126 127 return NULL; 128 } 129 /* 130 * Lookup device with it's device name. 131 */ 132 static dm_dev_t * 133 dm_dev_lookup_name(const char *dm_dev_name) 134 { 135 dm_dev_t *dmv; 136 137 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) { 138 if (strcmp(dm_dev_name, dmv->name) == 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; 151 152 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) { 153 if (strcmp(dm_dev_uuid, dmv->uuid) == 0) 154 return dmv; 155 } 156 157 return NULL; 158 } 159 /* 160 * Insert new device to the global list of devices. 161 */ 162 int 163 dm_dev_insert(dm_dev_t * dev) 164 { 165 dm_dev_t *dmv; 166 int r; 167 168 dmv = NULL; 169 r = 0; 170 171 KKASSERT(dev != NULL); 172 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 173 if (((dmv = dm_dev_lookup_uuid(dev->uuid)) == NULL) && 174 ((dmv = dm_dev_lookup_name(dev->name)) == NULL) && 175 ((dmv = dm_dev_lookup_minor(dev->minor)) == NULL)) { 176 177 TAILQ_INSERT_TAIL(&dm_dev_list, dev, next_devlist); 178 179 } else 180 r = EEXIST; 181 182 lockmgr(&dm_dev_mutex, LK_RELEASE); 183 return r; 184 } 185 186 /* 187 * Remove device selected with dm_dev from global list of devices. 188 */ 189 dm_dev_t * 190 dm_dev_rem(dm_dev_t *dmv, const char *dm_dev_name, const char *dm_dev_uuid, 191 int dm_dev_minor) 192 { 193 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 194 195 if (dmv != NULL) { 196 disable_dev(dmv); 197 } else if (dm_dev_minor > 0) { 198 if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) 199 disable_dev(dmv); 200 } else if (dm_dev_name != NULL) { 201 if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) 202 disable_dev(dmv); 203 } else if (dm_dev_uuid != NULL) { 204 if ((dmv = dm_dev_lookup_name(dm_dev_uuid)) != NULL) 205 disable_dev(dmv); 206 } 207 208 lockmgr(&dm_dev_mutex, LK_RELEASE); 209 210 return dmv; 211 } 212 213 int 214 dm_dev_create(dm_dev_t **dmvp, const char *name, const char *uuid, int flags) 215 { 216 dm_dev_t *dmv; 217 char name_buf[MAXPATHLEN]; 218 int r, dm_minor; 219 220 if ((dmv = dm_dev_alloc()) == NULL) 221 return ENOMEM; 222 223 if (uuid) 224 strncpy(dmv->uuid, uuid, DM_UUID_LEN); 225 else 226 dmv->uuid[0] = '\0'; 227 228 if (name) 229 strlcpy(dmv->name, name, DM_NAME_LEN); 230 231 dm_minor = devfs_clone_bitmap_get(&dm_minor_bitmap, 0); 232 233 dm_table_head_init(&dmv->table_head); 234 235 lockinit(&dmv->dev_mtx, "dmdev", 0, LK_CANRECURSE); 236 cv_init(&dmv->dev_cv, "dm_dev"); 237 238 if (flags & DM_READONLY_FLAG) 239 dmv->flags |= DM_READONLY_FLAG; 240 241 aprint_debug("Creating device dm/%s\n", name); 242 ksnprintf(name_buf, sizeof(name_buf), "mapper/%s", dmv->name); 243 244 devstat_add_entry(&dmv->stats, name, 0, DEV_BSIZE, 245 DEVSTAT_NO_ORDERED_TAGS, 246 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER, 247 DEVSTAT_PRIORITY_DISK); 248 249 dmv->devt = disk_create_named(name_buf, dm_minor, dmv->diskp, &dm_ops); 250 reference_dev(dmv->devt); 251 252 /* Make sure the device are immediately available */ 253 sync_devs(); 254 255 dmv->devt->si_drv1 = dmv; 256 dmv->devt->si_drv2 = dmv->diskp; 257 258 dmv->minor = minor(dmv->devt); 259 udev_dict_set_cstr(dmv->devt, "subsystem", "disk"); 260 261 if ((r = dm_dev_insert(dmv)) != 0) 262 dm_dev_destroy(dmv); 263 264 /* Increment device counter After creating device */ 265 ++dm_dev_counter; /* XXX: was atomic 64 */ 266 *dmvp = dmv; 267 268 return r; 269 } 270 271 int 272 dm_dev_destroy(dm_dev_t *dmv) 273 { 274 int minor; 275 276 /* Destroy active table first. */ 277 dm_table_destroy(&dmv->table_head, DM_TABLE_ACTIVE); 278 279 /* Destroy inactive table if exits, too. */ 280 dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE); 281 282 dm_table_head_destroy(&dmv->table_head); 283 284 minor = dkunit(dmv->devt); 285 disk_destroy(dmv->diskp); 286 devstat_remove_entry(&dmv->stats); 287 288 release_dev(dmv->devt); 289 devfs_clone_bitmap_put(&dm_minor_bitmap, minor); 290 291 lockuninit(&dmv->dev_mtx); 292 cv_destroy(&dmv->dev_cv); 293 294 /* Destroy device */ 295 (void)dm_dev_free(dmv); 296 297 /* Decrement device counter After removing device */ 298 --dm_dev_counter; /* XXX: was atomic 64 */ 299 300 return 0; 301 } 302 303 /* 304 * dm_detach is called to completely destroy & remove a dm disk device. 305 */ 306 int 307 dm_dev_remove(dm_dev_t *dmv) 308 { 309 /* Remove device from list and wait for refcnt to drop to zero */ 310 dm_dev_rem(dmv, NULL, NULL, -1); 311 312 /* Destroy and free the device */ 313 dm_dev_destroy(dmv); 314 315 return 0; 316 } 317 318 int 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 dm_dev_t * 351 dm_dev_alloc(void) 352 { 353 dm_dev_t *dmv; 354 355 dmv = kmalloc(sizeof(dm_dev_t), M_DM, M_WAITOK | M_ZERO); 356 357 if (dmv != NULL) 358 dmv->diskp = kmalloc(sizeof(struct disk), M_DM, M_WAITOK | M_ZERO); 359 360 return dmv; 361 } 362 /* 363 * Freed device entry. 364 */ 365 int 366 dm_dev_free(dm_dev_t * dmv) 367 { 368 KKASSERT(dmv != NULL); 369 370 if (dmv->diskp != NULL) 371 (void) kfree(dmv->diskp, M_DM); 372 373 (void) kfree(dmv, M_DM); 374 375 return 0; 376 } 377 378 void 379 dm_dev_busy(dm_dev_t * dmv) 380 { 381 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE); 382 dmv->ref_cnt++; 383 lockmgr(&dmv->dev_mtx, LK_RELEASE); 384 } 385 386 void 387 dm_dev_unbusy(dm_dev_t * dmv) 388 { 389 KKASSERT(dmv->ref_cnt != 0); 390 391 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE); 392 if (--dmv->ref_cnt == 0) 393 cv_broadcast(&dmv->dev_cv); 394 lockmgr(&dmv->dev_mtx, LK_RELEASE); 395 } 396 /* 397 * Return prop_array of dm_targer_list dictionaries. 398 */ 399 prop_array_t 400 dm_dev_prop_list(void) 401 { 402 dm_dev_t *dmv; 403 prop_array_t dev_array; 404 prop_dictionary_t dev_dict; 405 406 dev_array = prop_array_create(); 407 408 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 409 410 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) { 411 dev_dict = prop_dictionary_create(); 412 413 prop_dictionary_set_cstring(dev_dict, DM_DEV_NAME, dmv->name); 414 prop_dictionary_set_uint32(dev_dict, DM_DEV_DEV, dmv->minor); 415 416 prop_array_add(dev_array, dev_dict); 417 prop_object_release(dev_dict); 418 } 419 420 lockmgr(&dm_dev_mutex, LK_RELEASE); 421 return dev_array; 422 } 423 /* 424 * Initialize global device mutex. 425 */ 426 int 427 dm_dev_init(void) 428 { 429 TAILQ_INIT(&dm_dev_list); /* initialize global dev list */ 430 lockinit(&dm_dev_mutex, "dmdevlist", 0, LK_CANRECURSE); 431 devfs_clone_bitmap_init(&dm_minor_bitmap); 432 return 0; 433 } 434 435 /* 436 * Destroy all devices created in device-mapper. Remove all tables 437 * free all allocated memmory. 438 */ 439 int 440 dm_dev_uninit(void) 441 { 442 /* Force removal of all devices */ 443 dm_dev_remove_all(0); 444 445 lockuninit(&dm_dev_mutex); 446 return 0; 447 } 448