| 1 | /* |
| 2 | * Interface to Linux block layer for MTD 'translation layers'. |
| 3 | * |
| 4 | * Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | * |
| 20 | */ |
| 21 | |
| 22 | #include <linux/kernel.h> |
| 23 | #include <linux/slab.h> |
| 24 | #include <linux/module.h> |
| 25 | #include <linux/list.h> |
| 26 | #include <linux/fs.h> |
| 27 | #include <linux/mtd/blktrans.h> |
| 28 | #include <linux/mtd/mtd.h> |
| 29 | #include <linux/blkdev.h> |
| 30 | #include <linux/blkpg.h> |
| 31 | #include <linux/spinlock.h> |
| 32 | #include <linux/hdreg.h> |
| 33 | #include <linux/init.h> |
| 34 | #include <linux/mutex.h> |
| 35 | #include <linux/kthread.h> |
| 36 | #include <asm/uaccess.h> |
| 37 | |
| 38 | #include "mtdcore.h" |
| 39 | |
| 40 | static LIST_HEAD(blktrans_majors); |
| 41 | static DEFINE_MUTEX(blktrans_ref_mutex); |
| 42 | |
| 43 | static void blktrans_dev_release(struct kref *kref) |
| 44 | { |
| 45 | struct mtd_blktrans_dev *dev = |
| 46 | container_of(kref, struct mtd_blktrans_dev, ref); |
| 47 | |
| 48 | dev->disk->private_data = NULL; |
| 49 | blk_cleanup_queue(dev->rq); |
| 50 | put_disk(dev->disk); |
| 51 | list_del(&dev->list); |
| 52 | kfree(dev); |
| 53 | } |
| 54 | |
| 55 | static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk) |
| 56 | { |
| 57 | struct mtd_blktrans_dev *dev; |
| 58 | |
| 59 | mutex_lock(&blktrans_ref_mutex); |
| 60 | dev = disk->private_data; |
| 61 | |
| 62 | if (!dev) |
| 63 | goto unlock; |
| 64 | kref_get(&dev->ref); |
| 65 | unlock: |
| 66 | mutex_unlock(&blktrans_ref_mutex); |
| 67 | return dev; |
| 68 | } |
| 69 | |
| 70 | static void blktrans_dev_put(struct mtd_blktrans_dev *dev) |
| 71 | { |
| 72 | mutex_lock(&blktrans_ref_mutex); |
| 73 | kref_put(&dev->ref, blktrans_dev_release); |
| 74 | mutex_unlock(&blktrans_ref_mutex); |
| 75 | } |
| 76 | |
| 77 | |
| 78 | static int do_blktrans_request(struct mtd_blktrans_ops *tr, |
| 79 | struct mtd_blktrans_dev *dev, |
| 80 | struct request *req) |
| 81 | { |
| 82 | unsigned long block, nsect; |
| 83 | char *buf; |
| 84 | |
| 85 | block = blk_rq_pos(req) << 9 >> tr->blkshift; |
| 86 | nsect = blk_rq_cur_bytes(req) >> tr->blkshift; |
| 87 | |
| 88 | buf = req->buffer; |
| 89 | |
| 90 | if (req->cmd_type != REQ_TYPE_FS) |
| 91 | return -EIO; |
| 92 | |
| 93 | if (blk_rq_pos(req) + blk_rq_cur_sectors(req) > |
| 94 | get_capacity(req->rq_disk)) |
| 95 | return -EIO; |
| 96 | |
| 97 | if (req->cmd_flags & REQ_DISCARD) |
| 98 | return tr->discard(dev, block, nsect); |
| 99 | |
| 100 | switch(rq_data_dir(req)) { |
| 101 | case READ: |
| 102 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
| 103 | if (tr->readsect(dev, block, buf)) |
| 104 | return -EIO; |
| 105 | rq_flush_dcache_pages(req); |
| 106 | return 0; |
| 107 | case WRITE: |
| 108 | if (!tr->writesect) |
| 109 | return -EIO; |
| 110 | |
| 111 | rq_flush_dcache_pages(req); |
| 112 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
| 113 | if (tr->writesect(dev, block, buf)) |
| 114 | return -EIO; |
| 115 | return 0; |
| 116 | default: |
| 117 | printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req)); |
| 118 | return -EIO; |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev) |
| 123 | { |
| 124 | if (kthread_should_stop()) |
| 125 | return 1; |
| 126 | |
| 127 | return dev->bg_stop; |
| 128 | } |
| 129 | EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background); |
| 130 | |
| 131 | static int mtd_blktrans_thread(void *arg) |
| 132 | { |
| 133 | struct mtd_blktrans_dev *dev = arg; |
| 134 | struct mtd_blktrans_ops *tr = dev->tr; |
| 135 | struct request_queue *rq = dev->rq; |
| 136 | struct request *req = NULL; |
| 137 | int background_done = 0; |
| 138 | |
| 139 | spin_lock_irq(rq->queue_lock); |
| 140 | |
| 141 | while (!kthread_should_stop()) { |
| 142 | int res; |
| 143 | |
| 144 | dev->bg_stop = false; |
| 145 | if (!req && !(req = blk_fetch_request(rq))) { |
| 146 | if (tr->background && !background_done) { |
| 147 | spin_unlock_irq(rq->queue_lock); |
| 148 | mutex_lock(&dev->lock); |
| 149 | tr->background(dev); |
| 150 | mutex_unlock(&dev->lock); |
| 151 | spin_lock_irq(rq->queue_lock); |
| 152 | /* |
| 153 | * Do background processing just once per idle |
| 154 | * period. |
| 155 | */ |
| 156 | background_done = !dev->bg_stop; |
| 157 | continue; |
| 158 | } |
| 159 | set_current_state(TASK_INTERRUPTIBLE); |
| 160 | |
| 161 | if (kthread_should_stop()) |
| 162 | set_current_state(TASK_RUNNING); |
| 163 | |
| 164 | spin_unlock_irq(rq->queue_lock); |
| 165 | schedule(); |
| 166 | spin_lock_irq(rq->queue_lock); |
| 167 | continue; |
| 168 | } |
| 169 | |
| 170 | spin_unlock_irq(rq->queue_lock); |
| 171 | |
| 172 | mutex_lock(&dev->lock); |
| 173 | res = do_blktrans_request(dev->tr, dev, req); |
| 174 | mutex_unlock(&dev->lock); |
| 175 | |
| 176 | spin_lock_irq(rq->queue_lock); |
| 177 | |
| 178 | if (!__blk_end_request_cur(req, res)) |
| 179 | req = NULL; |
| 180 | |
| 181 | background_done = 0; |
| 182 | } |
| 183 | |
| 184 | if (req) |
| 185 | __blk_end_request_all(req, -EIO); |
| 186 | |
| 187 | spin_unlock_irq(rq->queue_lock); |
| 188 | |
| 189 | return 0; |
| 190 | } |
| 191 | |
| 192 | static void mtd_blktrans_request(struct request_queue *rq) |
| 193 | { |
| 194 | struct mtd_blktrans_dev *dev; |
| 195 | struct request *req = NULL; |
| 196 | |
| 197 | dev = rq->queuedata; |
| 198 | |
| 199 | if (!dev) |
| 200 | while ((req = blk_fetch_request(rq)) != NULL) |
| 201 | __blk_end_request_all(req, -ENODEV); |
| 202 | else { |
| 203 | dev->bg_stop = true; |
| 204 | wake_up_process(dev->thread); |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | static int blktrans_open(struct block_device *bdev, fmode_t mode) |
| 209 | { |
| 210 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
| 211 | int ret = 0; |
| 212 | |
| 213 | if (!dev) |
| 214 | return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/ |
| 215 | |
| 216 | mutex_lock(&dev->lock); |
| 217 | |
| 218 | if (dev->open) |
| 219 | goto unlock; |
| 220 | |
| 221 | kref_get(&dev->ref); |
| 222 | __module_get(dev->tr->owner); |
| 223 | |
| 224 | if (!dev->mtd) |
| 225 | goto unlock; |
| 226 | |
| 227 | if (dev->tr->open) { |
| 228 | ret = dev->tr->open(dev); |
| 229 | if (ret) |
| 230 | goto error_put; |
| 231 | } |
| 232 | |
| 233 | ret = __get_mtd_device(dev->mtd); |
| 234 | if (ret) |
| 235 | goto error_release; |
| 236 | |
| 237 | unlock: |
| 238 | dev->open++; |
| 239 | mutex_unlock(&dev->lock); |
| 240 | blktrans_dev_put(dev); |
| 241 | return ret; |
| 242 | |
| 243 | error_release: |
| 244 | if (dev->tr->release) |
| 245 | dev->tr->release(dev); |
| 246 | error_put: |
| 247 | module_put(dev->tr->owner); |
| 248 | kref_put(&dev->ref, blktrans_dev_release); |
| 249 | mutex_unlock(&dev->lock); |
| 250 | blktrans_dev_put(dev); |
| 251 | return ret; |
| 252 | } |
| 253 | |
| 254 | static int blktrans_release(struct gendisk *disk, fmode_t mode) |
| 255 | { |
| 256 | struct mtd_blktrans_dev *dev = blktrans_dev_get(disk); |
| 257 | int ret = 0; |
| 258 | |
| 259 | if (!dev) |
| 260 | return ret; |
| 261 | |
| 262 | mutex_lock(&dev->lock); |
| 263 | |
| 264 | if (--dev->open) |
| 265 | goto unlock; |
| 266 | |
| 267 | kref_put(&dev->ref, blktrans_dev_release); |
| 268 | module_put(dev->tr->owner); |
| 269 | |
| 270 | if (dev->mtd) { |
| 271 | ret = dev->tr->release ? dev->tr->release(dev) : 0; |
| 272 | __put_mtd_device(dev->mtd); |
| 273 | } |
| 274 | unlock: |
| 275 | mutex_unlock(&dev->lock); |
| 276 | blktrans_dev_put(dev); |
| 277 | return ret; |
| 278 | } |
| 279 | |
| 280 | static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
| 281 | { |
| 282 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
| 283 | int ret = -ENXIO; |
| 284 | |
| 285 | if (!dev) |
| 286 | return ret; |
| 287 | |
| 288 | mutex_lock(&dev->lock); |
| 289 | |
| 290 | if (!dev->mtd) |
| 291 | goto unlock; |
| 292 | |
| 293 | ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0; |
| 294 | unlock: |
| 295 | mutex_unlock(&dev->lock); |
| 296 | blktrans_dev_put(dev); |
| 297 | return ret; |
| 298 | } |
| 299 | |
| 300 | static int blktrans_ioctl(struct block_device *bdev, fmode_t mode, |
| 301 | unsigned int cmd, unsigned long arg) |
| 302 | { |
| 303 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
| 304 | int ret = -ENXIO; |
| 305 | |
| 306 | if (!dev) |
| 307 | return ret; |
| 308 | |
| 309 | mutex_lock(&dev->lock); |
| 310 | |
| 311 | if (!dev->mtd) |
| 312 | goto unlock; |
| 313 | |
| 314 | switch (cmd) { |
| 315 | case BLKFLSBUF: |
| 316 | ret = dev->tr->flush ? dev->tr->flush(dev) : 0; |
| 317 | break; |
| 318 | default: |
| 319 | ret = -ENOTTY; |
| 320 | } |
| 321 | unlock: |
| 322 | mutex_unlock(&dev->lock); |
| 323 | blktrans_dev_put(dev); |
| 324 | return ret; |
| 325 | } |
| 326 | |
| 327 | static const struct block_device_operations mtd_blktrans_ops = { |
| 328 | .owner = THIS_MODULE, |
| 329 | .open = blktrans_open, |
| 330 | .release = blktrans_release, |
| 331 | .ioctl = blktrans_ioctl, |
| 332 | .getgeo = blktrans_getgeo, |
| 333 | }; |
| 334 | |
| 335 | int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) |
| 336 | { |
| 337 | struct mtd_blktrans_ops *tr = new->tr; |
| 338 | struct mtd_blktrans_dev *d; |
| 339 | int last_devnum = -1; |
| 340 | struct gendisk *gd; |
| 341 | int ret; |
| 342 | |
| 343 | if (mutex_trylock(&mtd_table_mutex)) { |
| 344 | mutex_unlock(&mtd_table_mutex); |
| 345 | BUG(); |
| 346 | } |
| 347 | |
| 348 | mutex_lock(&blktrans_ref_mutex); |
| 349 | list_for_each_entry(d, &tr->devs, list) { |
| 350 | if (new->devnum == -1) { |
| 351 | /* Use first free number */ |
| 352 | if (d->devnum != last_devnum+1) { |
| 353 | /* Found a free devnum. Plug it in here */ |
| 354 | new->devnum = last_devnum+1; |
| 355 | list_add_tail(&new->list, &d->list); |
| 356 | goto added; |
| 357 | } |
| 358 | } else if (d->devnum == new->devnum) { |
| 359 | /* Required number taken */ |
| 360 | mutex_unlock(&blktrans_ref_mutex); |
| 361 | return -EBUSY; |
| 362 | } else if (d->devnum > new->devnum) { |
| 363 | /* Required number was free */ |
| 364 | list_add_tail(&new->list, &d->list); |
| 365 | goto added; |
| 366 | } |
| 367 | last_devnum = d->devnum; |
| 368 | } |
| 369 | |
| 370 | ret = -EBUSY; |
| 371 | if (new->devnum == -1) |
| 372 | new->devnum = last_devnum+1; |
| 373 | |
| 374 | /* Check that the device and any partitions will get valid |
| 375 | * minor numbers and that the disk naming code below can cope |
| 376 | * with this number. */ |
| 377 | if (new->devnum > (MINORMASK >> tr->part_bits) || |
| 378 | (tr->part_bits && new->devnum >= 27 * 26)) { |
| 379 | mutex_unlock(&blktrans_ref_mutex); |
| 380 | goto error1; |
| 381 | } |
| 382 | |
| 383 | list_add_tail(&new->list, &tr->devs); |
| 384 | added: |
| 385 | mutex_unlock(&blktrans_ref_mutex); |
| 386 | |
| 387 | mutex_init(&new->lock); |
| 388 | kref_init(&new->ref); |
| 389 | if (!tr->writesect) |
| 390 | new->readonly = 1; |
| 391 | |
| 392 | /* Create gendisk */ |
| 393 | ret = -ENOMEM; |
| 394 | gd = alloc_disk(1 << tr->part_bits); |
| 395 | |
| 396 | if (!gd) |
| 397 | goto error2; |
| 398 | |
| 399 | new->disk = gd; |
| 400 | gd->private_data = new; |
| 401 | gd->major = tr->major; |
| 402 | gd->first_minor = (new->devnum) << tr->part_bits; |
| 403 | gd->fops = &mtd_blktrans_ops; |
| 404 | |
| 405 | if (tr->part_bits) |
| 406 | if (new->devnum < 26) |
| 407 | snprintf(gd->disk_name, sizeof(gd->disk_name), |
| 408 | "%s%c", tr->name, 'a' + new->devnum); |
| 409 | else |
| 410 | snprintf(gd->disk_name, sizeof(gd->disk_name), |
| 411 | "%s%c%c", tr->name, |
| 412 | 'a' - 1 + new->devnum / 26, |
| 413 | 'a' + new->devnum % 26); |
| 414 | else |
| 415 | snprintf(gd->disk_name, sizeof(gd->disk_name), |
| 416 | "%s%d", tr->name, new->devnum); |
| 417 | |
| 418 | set_capacity(gd, (new->size * tr->blksize) >> 9); |
| 419 | |
| 420 | /* Create the request queue */ |
| 421 | spin_lock_init(&new->queue_lock); |
| 422 | new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock); |
| 423 | |
| 424 | if (!new->rq) |
| 425 | goto error3; |
| 426 | |
| 427 | new->rq->queuedata = new; |
| 428 | blk_queue_logical_block_size(new->rq, tr->blksize); |
| 429 | |
| 430 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq); |
| 431 | |
| 432 | if (tr->discard) { |
| 433 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq); |
| 434 | new->rq->limits.max_discard_sectors = UINT_MAX; |
| 435 | } |
| 436 | |
| 437 | gd->queue = new->rq; |
| 438 | |
| 439 | /* Create processing thread */ |
| 440 | /* TODO: workqueue ? */ |
| 441 | new->thread = kthread_run(mtd_blktrans_thread, new, |
| 442 | "%s%d", tr->name, new->mtd->index); |
| 443 | if (IS_ERR(new->thread)) { |
| 444 | ret = PTR_ERR(new->thread); |
| 445 | goto error4; |
| 446 | } |
| 447 | gd->driverfs_dev = &new->mtd->dev; |
| 448 | |
| 449 | if (new->readonly) |
| 450 | set_disk_ro(gd, 1); |
| 451 | |
| 452 | add_disk(gd); |
| 453 | |
| 454 | if (new->disk_attributes) { |
| 455 | ret = sysfs_create_group(&disk_to_dev(gd)->kobj, |
| 456 | new->disk_attributes); |
| 457 | WARN_ON(ret); |
| 458 | } |
| 459 | return 0; |
| 460 | error4: |
| 461 | blk_cleanup_queue(new->rq); |
| 462 | error3: |
| 463 | put_disk(new->disk); |
| 464 | error2: |
| 465 | list_del(&new->list); |
| 466 | error1: |
| 467 | return ret; |
| 468 | } |
| 469 | |
| 470 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) |
| 471 | { |
| 472 | unsigned long flags; |
| 473 | |
| 474 | if (mutex_trylock(&mtd_table_mutex)) { |
| 475 | mutex_unlock(&mtd_table_mutex); |
| 476 | BUG(); |
| 477 | } |
| 478 | |
| 479 | if (old->disk_attributes) |
| 480 | sysfs_remove_group(&disk_to_dev(old->disk)->kobj, |
| 481 | old->disk_attributes); |
| 482 | |
| 483 | /* Stop new requests to arrive */ |
| 484 | del_gendisk(old->disk); |
| 485 | |
| 486 | |
| 487 | /* Stop the thread */ |
| 488 | kthread_stop(old->thread); |
| 489 | |
| 490 | /* Kill current requests */ |
| 491 | spin_lock_irqsave(&old->queue_lock, flags); |
| 492 | old->rq->queuedata = NULL; |
| 493 | blk_start_queue(old->rq); |
| 494 | spin_unlock_irqrestore(&old->queue_lock, flags); |
| 495 | |
| 496 | /* If the device is currently open, tell trans driver to close it, |
| 497 | then put mtd device, and don't touch it again */ |
| 498 | mutex_lock(&old->lock); |
| 499 | if (old->open) { |
| 500 | if (old->tr->release) |
| 501 | old->tr->release(old); |
| 502 | __put_mtd_device(old->mtd); |
| 503 | } |
| 504 | |
| 505 | old->mtd = NULL; |
| 506 | |
| 507 | mutex_unlock(&old->lock); |
| 508 | blktrans_dev_put(old); |
| 509 | return 0; |
| 510 | } |
| 511 | |
| 512 | static void blktrans_notify_remove(struct mtd_info *mtd) |
| 513 | { |
| 514 | struct mtd_blktrans_ops *tr; |
| 515 | struct mtd_blktrans_dev *dev, *next; |
| 516 | |
| 517 | list_for_each_entry(tr, &blktrans_majors, list) |
| 518 | list_for_each_entry_safe(dev, next, &tr->devs, list) |
| 519 | if (dev->mtd == mtd) |
| 520 | tr->remove_dev(dev); |
| 521 | } |
| 522 | |
| 523 | static void blktrans_notify_add(struct mtd_info *mtd) |
| 524 | { |
| 525 | struct mtd_blktrans_ops *tr; |
| 526 | |
| 527 | if (mtd->type == MTD_ABSENT) |
| 528 | return; |
| 529 | |
| 530 | list_for_each_entry(tr, &blktrans_majors, list) |
| 531 | tr->add_mtd(tr, mtd); |
| 532 | } |
| 533 | |
| 534 | static struct mtd_notifier blktrans_notifier = { |
| 535 | .add = blktrans_notify_add, |
| 536 | .remove = blktrans_notify_remove, |
| 537 | }; |
| 538 | |
| 539 | int register_mtd_blktrans(struct mtd_blktrans_ops *tr) |
| 540 | { |
| 541 | struct mtd_info *mtd; |
| 542 | int ret; |
| 543 | |
| 544 | /* Register the notifier if/when the first device type is |
| 545 | registered, to prevent the link/init ordering from fucking |
| 546 | us over. */ |
| 547 | if (!blktrans_notifier.list.next) |
| 548 | register_mtd_user(&blktrans_notifier); |
| 549 | |
| 550 | |
| 551 | mutex_lock(&mtd_table_mutex); |
| 552 | |
| 553 | ret = register_blkdev(tr->major, tr->name); |
| 554 | if (ret < 0) { |
| 555 | printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", |
| 556 | tr->name, tr->major, ret); |
| 557 | mutex_unlock(&mtd_table_mutex); |
| 558 | return ret; |
| 559 | } |
| 560 | |
| 561 | if (ret) |
| 562 | tr->major = ret; |
| 563 | |
| 564 | tr->blkshift = ffs(tr->blksize) - 1; |
| 565 | |
| 566 | INIT_LIST_HEAD(&tr->devs); |
| 567 | list_add(&tr->list, &blktrans_majors); |
| 568 | |
| 569 | mtd_for_each_device(mtd) |
| 570 | if (mtd->type != MTD_ABSENT) |
| 571 | tr->add_mtd(tr, mtd); |
| 572 | |
| 573 | mutex_unlock(&mtd_table_mutex); |
| 574 | return 0; |
| 575 | } |
| 576 | |
| 577 | int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) |
| 578 | { |
| 579 | struct mtd_blktrans_dev *dev, *next; |
| 580 | |
| 581 | mutex_lock(&mtd_table_mutex); |
| 582 | |
| 583 | /* Remove it from the list of active majors */ |
| 584 | list_del(&tr->list); |
| 585 | |
| 586 | list_for_each_entry_safe(dev, next, &tr->devs, list) |
| 587 | tr->remove_dev(dev); |
| 588 | |
| 589 | unregister_blkdev(tr->major, tr->name); |
| 590 | mutex_unlock(&mtd_table_mutex); |
| 591 | |
| 592 | BUG_ON(!list_empty(&tr->devs)); |
| 593 | return 0; |
| 594 | } |
| 595 | |
| 596 | static void __exit mtd_blktrans_exit(void) |
| 597 | { |
| 598 | /* No race here -- if someone's currently in register_mtd_blktrans |
| 599 | we're screwed anyway. */ |
| 600 | if (blktrans_notifier.list.next) |
| 601 | unregister_mtd_user(&blktrans_notifier); |
| 602 | } |
| 603 | |
| 604 | module_exit(mtd_blktrans_exit); |
| 605 | |
| 606 | EXPORT_SYMBOL_GPL(register_mtd_blktrans); |
| 607 | EXPORT_SYMBOL_GPL(deregister_mtd_blktrans); |
| 608 | EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev); |
| 609 | EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev); |
| 610 | |
| 611 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); |
| 612 | MODULE_LICENSE("GPL"); |
| 613 | MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'"); |