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/param.h> 34 #include <machine/thread.h> 35 #include <sys/thread2.h> 36 37 #include <sys/disk.h> 38 #include <sys/disklabel.h> 39 #include <sys/devicestat.h> 40 #include <sys/device.h> 41 #include <sys/udev.h> 42 #include <sys/devfs.h> 43 #include <sys/malloc.h> 44 #include <dev/disk/dm/dm.h> 45 46 #include "netbsd-dm.h" 47 48 extern struct dev_ops dm_ops; 49 50 static struct devfs_bitmap dm_minor_bitmap; 51 uint64_t dm_dev_counter; 52 53 static dm_dev_t *dm_dev_lookup_name(const char *); 54 static dm_dev_t *dm_dev_lookup_uuid(const char *); 55 static dm_dev_t *dm_dev_lookup_minor(int); 56 57 static TAILQ_HEAD(dm_dev_head, dm_dev) dm_dev_list; 58 59 static struct lock dm_dev_mutex; 60 61 static char dummy_uuid[DM_UUID_LEN]; 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); 173 174 /* 175 * Ignore uuid lookup if dev->uuid is zero-filled. 176 */ 177 if (memcmp(dev->uuid, dummy_uuid, DM_UUID_LEN)) 178 dmv = dm_dev_lookup_uuid(dev->uuid); 179 180 if ((dmv == NULL) && 181 ((dmv = dm_dev_lookup_name(dev->name)) == NULL) && 182 ((dmv = dm_dev_lookup_minor(dev->minor)) == NULL)) { 183 TAILQ_INSERT_TAIL(&dm_dev_list, dev, next_devlist); 184 } else { 185 KKASSERT(dmv != NULL); 186 r = EEXIST; 187 } 188 189 lockmgr(&dm_dev_mutex, LK_RELEASE); 190 return r; 191 } 192 193 dm_dev_t * 194 dm_dev_rem_dev(dm_dev_t *dmv) 195 { 196 if (dmv == NULL) 197 return NULL; 198 199 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 200 disable_dev(dmv); 201 lockmgr(&dm_dev_mutex, LK_RELEASE); 202 203 KKASSERT(dmv != NULL); 204 return dmv; 205 } 206 207 /* 208 * Remove device selected with dm_dev from global list of devices. 209 */ 210 dm_dev_t * 211 dm_dev_rem(const char *dm_dev_name, const char *dm_dev_uuid, int dm_dev_minor) 212 { 213 dm_dev_t *dmv = NULL; 214 215 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 216 217 if (dm_dev_minor > 0) { 218 if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) 219 disable_dev(dmv); 220 } else if (dm_dev_name != NULL) { 221 if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) 222 disable_dev(dmv); 223 } else if (dm_dev_uuid != NULL) { 224 if ((dmv = dm_dev_lookup_name(dm_dev_uuid)) != NULL) 225 disable_dev(dmv); 226 } 227 228 lockmgr(&dm_dev_mutex, LK_RELEASE); 229 230 return dmv; 231 } 232 233 int 234 dm_dev_create(dm_dev_t **dmvp, const char *name, const char *uuid, int flags) 235 { 236 dm_dev_t *dmv; 237 char name_buf[MAXPATHLEN]; 238 int r, dm_minor; 239 240 if ((dmv = dm_dev_alloc()) == NULL) 241 return ENOMEM; 242 243 if (uuid) 244 strncpy(dmv->uuid, uuid, DM_UUID_LEN); 245 else 246 dmv->uuid[0] = '\0'; 247 248 if (name) 249 strlcpy(dmv->name, name, DM_NAME_LEN); 250 251 dm_minor = devfs_clone_bitmap_get(&dm_minor_bitmap, 0); 252 253 dm_table_head_init(&dmv->table_head); 254 255 lockinit(&dmv->dev_mtx, "dmdev", 0, LK_CANRECURSE); 256 cv_init(&dmv->dev_cv, "dm_dev"); 257 258 if (flags & DM_READONLY_FLAG) 259 dmv->flags |= DM_READONLY_FLAG; 260 261 dmdebug("Creating device dm/%s\n", name); 262 ksnprintf(name_buf, sizeof(name_buf), "mapper/%s", dmv->name); 263 264 devstat_add_entry(&dmv->stats, name, 0, DEV_BSIZE, 265 DEVSTAT_NO_ORDERED_TAGS, 266 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER, 267 DEVSTAT_PRIORITY_DISK); 268 269 dmv->devt = disk_create_named(name_buf, dm_minor, dmv->diskp, &dm_ops); 270 reference_dev(dmv->devt); 271 272 /* Make sure the device are immediately available */ 273 sync_devs(); 274 275 dmv->devt->si_drv1 = dmv; 276 dmv->devt->si_drv2 = dmv->diskp; 277 278 dmv->minor = minor(dmv->devt); 279 udev_dict_set_cstr(dmv->devt, "subsystem", "disk"); 280 281 if ((r = dm_dev_insert(dmv)) != 0) 282 dm_dev_destroy(dmv); 283 284 /* Increment device counter After creating device */ 285 ++dm_dev_counter; /* XXX: was atomic 64 */ 286 *dmvp = dmv; 287 288 return r; 289 } 290 291 int 292 dm_dev_destroy(dm_dev_t *dmv) 293 { 294 int minor; 295 296 /* Destroy active table first. */ 297 dm_table_destroy(&dmv->table_head, DM_TABLE_ACTIVE); 298 299 /* Destroy inactive table if exits, too. */ 300 dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE); 301 302 dm_table_head_destroy(&dmv->table_head); 303 304 minor = dkunit(dmv->devt); 305 disk_destroy(dmv->diskp); 306 devstat_remove_entry(&dmv->stats); 307 308 release_dev(dmv->devt); 309 devfs_clone_bitmap_put(&dm_minor_bitmap, minor); 310 311 lockuninit(&dmv->dev_mtx); 312 cv_destroy(&dmv->dev_cv); 313 314 /* Destroy device */ 315 dm_dev_free(dmv); 316 317 /* Decrement device counter After removing device */ 318 --dm_dev_counter; /* XXX: was atomic 64 */ 319 320 return 0; 321 } 322 323 /* 324 * dm_dev_remove is called to completely destroy & remove a dm disk device. 325 */ 326 int 327 dm_dev_remove(dm_dev_t *dmv) 328 { 329 /* Remove device from list and wait for refcnt to drop to zero */ 330 dm_dev_rem_dev(dmv); 331 332 /* Destroy and free the device */ 333 dm_dev_destroy(dmv); 334 335 return 0; 336 } 337 338 int 339 dm_dev_remove_all(int gentle) 340 { 341 dm_dev_t *dmv, *dmv2; 342 int r; 343 344 r = 0; 345 346 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 347 348 /* 349 * Process in reverse order so that it can deal with inter-depentent 350 * devices. 351 */ 352 TAILQ_FOREACH_REVERSE_MUTABLE(dmv, &dm_dev_list, dm_dev_head, 353 next_devlist, dmv2) { 354 if (gentle && dmv->is_open) { 355 r = EBUSY; 356 continue; 357 } 358 359 disable_dev(dmv); 360 dm_dev_destroy(dmv); 361 } 362 lockmgr(&dm_dev_mutex, LK_RELEASE); 363 364 return r; 365 } 366 367 /* 368 * Allocate new device entry. 369 */ 370 dm_dev_t * 371 dm_dev_alloc(void) 372 { 373 dm_dev_t *dmv; 374 375 dmv = kmalloc(sizeof(dm_dev_t), M_DM, M_WAITOK | M_ZERO); 376 377 if (dmv != NULL) 378 dmv->diskp = kmalloc(sizeof(struct disk), M_DM, M_WAITOK | M_ZERO); 379 380 return dmv; 381 } 382 /* 383 * Freed device entry. 384 */ 385 int 386 dm_dev_free(dm_dev_t *dmv) 387 { 388 KKASSERT(dmv != NULL); 389 390 if (dmv->diskp != NULL) 391 kfree(dmv->diskp, M_DM); 392 393 kfree(dmv, M_DM); 394 395 return 0; 396 } 397 398 void 399 dm_dev_busy(dm_dev_t *dmv) 400 { 401 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE); 402 dmv->ref_cnt++; 403 lockmgr(&dmv->dev_mtx, LK_RELEASE); 404 } 405 406 void 407 dm_dev_unbusy(dm_dev_t *dmv) 408 { 409 KKASSERT(dmv->ref_cnt != 0); 410 411 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE); 412 if (--dmv->ref_cnt == 0) 413 cv_broadcast(&dmv->dev_cv); 414 lockmgr(&dmv->dev_mtx, LK_RELEASE); 415 } 416 /* 417 * Return prop_array of dm_targer_list dictionaries. 418 */ 419 prop_array_t 420 dm_dev_prop_list(void) 421 { 422 dm_dev_t *dmv; 423 prop_array_t dev_array; 424 prop_dictionary_t dev_dict; 425 426 dev_array = prop_array_create(); 427 428 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 429 430 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) { 431 dev_dict = prop_dictionary_create(); 432 433 prop_dictionary_set_cstring(dev_dict, DM_DEV_NAME, dmv->name); 434 prop_dictionary_set_uint32(dev_dict, DM_DEV_DEV, dmv->minor); 435 436 prop_array_add(dev_array, dev_dict); 437 prop_object_release(dev_dict); 438 } 439 440 lockmgr(&dm_dev_mutex, LK_RELEASE); 441 return dev_array; 442 } 443 /* 444 * Initialize global device mutex. 445 */ 446 int 447 dm_dev_init(void) 448 { 449 TAILQ_INIT(&dm_dev_list); /* initialize global dev list */ 450 lockinit(&dm_dev_mutex, "dmdevlist", 0, LK_CANRECURSE); 451 devfs_clone_bitmap_init(&dm_minor_bitmap); 452 453 memset(dummy_uuid, 0, sizeof(dummy_uuid)); 454 return 0; 455 } 456 457 /* 458 * Destroy all devices created in device-mapper. Remove all tables 459 * free all allocated memmory. 460 */ 461 int 462 dm_dev_uninit(void) 463 { 464 /* Force removal of all devices */ 465 dm_dev_remove_all(0); 466 467 lockuninit(&dm_dev_mutex); 468 return 0; 469 } 470