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Commit | Line | Data |
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1da177e4 | 1 | /* |
a1452a37 | 2 | * Interface to Linux block layer for MTD 'translation layers'. |
1da177e4 | 3 | * |
a1452a37 DW |
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 | |
1da177e4 LT |
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> | |
8a6cfeb6 | 32 | #include <linux/smp_lock.h> |
1da177e4 LT |
33 | #include <linux/hdreg.h> |
34 | #include <linux/init.h> | |
48b19268 | 35 | #include <linux/mutex.h> |
99f9b243 | 36 | #include <linux/kthread.h> |
1da177e4 | 37 | #include <asm/uaccess.h> |
1da177e4 | 38 | |
356d70f1 | 39 | #include "mtdcore.h" |
1da177e4 | 40 | |
356d70f1 | 41 | static LIST_HEAD(blktrans_majors); |
048d8719 ML |
42 | static DEFINE_MUTEX(blktrans_ref_mutex); |
43 | ||
44 | void blktrans_dev_release(struct kref *kref) | |
45 | { | |
46 | struct mtd_blktrans_dev *dev = | |
47 | container_of(kref, struct mtd_blktrans_dev, ref); | |
48 | ||
49 | dev->disk->private_data = NULL; | |
e4d64cab | 50 | blk_cleanup_queue(dev->rq); |
048d8719 ML |
51 | put_disk(dev->disk); |
52 | list_del(&dev->list); | |
53 | kfree(dev); | |
54 | } | |
55 | ||
56 | static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk) | |
57 | { | |
58 | struct mtd_blktrans_dev *dev; | |
59 | ||
60 | mutex_lock(&blktrans_ref_mutex); | |
61 | dev = disk->private_data; | |
62 | ||
63 | if (!dev) | |
64 | goto unlock; | |
65 | kref_get(&dev->ref); | |
66 | unlock: | |
67 | mutex_unlock(&blktrans_ref_mutex); | |
68 | return dev; | |
69 | } | |
70 | ||
71 | void blktrans_dev_put(struct mtd_blktrans_dev *dev) | |
72 | { | |
73 | mutex_lock(&blktrans_ref_mutex); | |
74 | kref_put(&dev->ref, blktrans_dev_release); | |
75 | mutex_unlock(&blktrans_ref_mutex); | |
76 | } | |
1da177e4 | 77 | |
1da177e4 LT |
78 | |
79 | static int do_blktrans_request(struct mtd_blktrans_ops *tr, | |
80 | struct mtd_blktrans_dev *dev, | |
81 | struct request *req) | |
82 | { | |
83 | unsigned long block, nsect; | |
84 | char *buf; | |
85 | ||
83096ebf | 86 | block = blk_rq_pos(req) << 9 >> tr->blkshift; |
1011c1b9 | 87 | nsect = blk_rq_cur_bytes(req) >> tr->blkshift; |
19187672 | 88 | |
1da177e4 LT |
89 | buf = req->buffer; |
90 | ||
33659ebb | 91 | if (req->cmd_type != REQ_TYPE_FS) |
f06d9a2b | 92 | return -EIO; |
1da177e4 | 93 | |
83096ebf TH |
94 | if (blk_rq_pos(req) + blk_rq_cur_sectors(req) > |
95 | get_capacity(req->rq_disk)) | |
f06d9a2b | 96 | return -EIO; |
1da177e4 | 97 | |
33659ebb | 98 | if (req->cmd_flags & REQ_DISCARD) |
1122a26f CH |
99 | return tr->discard(dev, block, nsect); |
100 | ||
1da177e4 LT |
101 | switch(rq_data_dir(req)) { |
102 | case READ: | |
19187672 | 103 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 104 | if (tr->readsect(dev, block, buf)) |
f06d9a2b | 105 | return -EIO; |
2d4dc890 | 106 | rq_flush_dcache_pages(req); |
f06d9a2b | 107 | return 0; |
1da177e4 LT |
108 | case WRITE: |
109 | if (!tr->writesect) | |
f06d9a2b | 110 | return -EIO; |
1da177e4 | 111 | |
2d4dc890 | 112 | rq_flush_dcache_pages(req); |
19187672 | 113 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 114 | if (tr->writesect(dev, block, buf)) |
f06d9a2b TH |
115 | return -EIO; |
116 | return 0; | |
1da177e4 | 117 | default: |
9a292308 | 118 | printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req)); |
f06d9a2b | 119 | return -EIO; |
1da177e4 LT |
120 | } |
121 | } | |
122 | ||
123 | static int mtd_blktrans_thread(void *arg) | |
124 | { | |
a8638622 ML |
125 | struct mtd_blktrans_dev *dev = arg; |
126 | struct request_queue *rq = dev->rq; | |
1498ada7 | 127 | struct request *req = NULL; |
1da177e4 | 128 | |
1da177e4 | 129 | spin_lock_irq(rq->queue_lock); |
1498ada7 | 130 | |
3e67fe45 | 131 | while (!kthread_should_stop()) { |
f06d9a2b | 132 | int res; |
1da177e4 | 133 | |
9934c8c0 | 134 | if (!req && !(req = blk_fetch_request(rq))) { |
1da177e4 | 135 | set_current_state(TASK_INTERRUPTIBLE); |
12aebf3e ML |
136 | |
137 | if (kthread_should_stop()) | |
138 | set_current_state(TASK_RUNNING); | |
139 | ||
1da177e4 | 140 | spin_unlock_irq(rq->queue_lock); |
1da177e4 | 141 | schedule(); |
1da177e4 | 142 | spin_lock_irq(rq->queue_lock); |
1da177e4 LT |
143 | continue; |
144 | } | |
145 | ||
1da177e4 LT |
146 | spin_unlock_irq(rq->queue_lock); |
147 | ||
48b19268 | 148 | mutex_lock(&dev->lock); |
a8638622 | 149 | res = do_blktrans_request(dev->tr, dev, req); |
48b19268 | 150 | mutex_unlock(&dev->lock); |
1da177e4 LT |
151 | |
152 | spin_lock_irq(rq->queue_lock); | |
153 | ||
1498ada7 TH |
154 | if (!__blk_end_request_cur(req, res)) |
155 | req = NULL; | |
1da177e4 | 156 | } |
1498ada7 TH |
157 | |
158 | if (req) | |
159 | __blk_end_request_all(req, -EIO); | |
160 | ||
1da177e4 LT |
161 | spin_unlock_irq(rq->queue_lock); |
162 | ||
3e67fe45 | 163 | return 0; |
1da177e4 LT |
164 | } |
165 | ||
166 | static void mtd_blktrans_request(struct request_queue *rq) | |
167 | { | |
048d8719 ML |
168 | struct mtd_blktrans_dev *dev; |
169 | struct request *req = NULL; | |
170 | ||
171 | dev = rq->queuedata; | |
1da177e4 | 172 | |
048d8719 ML |
173 | if (!dev) |
174 | while ((req = blk_fetch_request(rq)) != NULL) | |
175 | __blk_end_request_all(req, -ENODEV); | |
176 | else | |
177 | wake_up_process(dev->thread); | |
178 | } | |
1da177e4 | 179 | |
af0e2a0a | 180 | static int blktrans_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 181 | { |
048d8719 | 182 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
008c751e | 183 | int ret = 0; |
048d8719 ML |
184 | |
185 | if (!dev) | |
6e9624b8 | 186 | return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/ |
048d8719 ML |
187 | |
188 | mutex_lock(&dev->lock); | |
189 | ||
008c751e | 190 | if (dev->open++) |
048d8719 | 191 | goto unlock; |
048d8719 | 192 | |
008c751e ML |
193 | kref_get(&dev->ref); |
194 | __module_get(dev->tr->owner); | |
195 | ||
196 | if (dev->mtd) { | |
197 | ret = dev->tr->open ? dev->tr->open(dev) : 0; | |
198 | __get_mtd_device(dev->mtd); | |
199 | } | |
048d8719 | 200 | |
048d8719 ML |
201 | unlock: |
202 | mutex_unlock(&dev->lock); | |
203 | blktrans_dev_put(dev); | |
1da177e4 LT |
204 | return ret; |
205 | } | |
206 | ||
af0e2a0a | 207 | static int blktrans_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 208 | { |
048d8719 | 209 | struct mtd_blktrans_dev *dev = blktrans_dev_get(disk); |
008c751e | 210 | int ret = 0; |
1da177e4 | 211 | |
048d8719 ML |
212 | if (!dev) |
213 | return ret; | |
1da177e4 | 214 | |
048d8719 ML |
215 | mutex_lock(&dev->lock); |
216 | ||
008c751e | 217 | if (--dev->open) |
048d8719 ML |
218 | goto unlock; |
219 | ||
008c751e ML |
220 | kref_put(&dev->ref, blktrans_dev_release); |
221 | module_put(dev->tr->owner); | |
222 | ||
223 | if (dev->mtd) { | |
224 | ret = dev->tr->release ? dev->tr->release(dev) : 0; | |
225 | __put_mtd_device(dev->mtd); | |
226 | } | |
048d8719 ML |
227 | unlock: |
228 | mutex_unlock(&dev->lock); | |
229 | blktrans_dev_put(dev); | |
1da177e4 LT |
230 | return ret; |
231 | } | |
232 | ||
a885c8c4 CH |
233 | static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
234 | { | |
048d8719 ML |
235 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
236 | int ret = -ENXIO; | |
237 | ||
238 | if (!dev) | |
239 | return ret; | |
240 | ||
241 | mutex_lock(&dev->lock); | |
a885c8c4 | 242 | |
048d8719 ML |
243 | if (!dev->mtd) |
244 | goto unlock; | |
245 | ||
246 | ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0; | |
247 | unlock: | |
248 | mutex_unlock(&dev->lock); | |
249 | blktrans_dev_put(dev); | |
250 | return ret; | |
a885c8c4 | 251 | } |
1da177e4 | 252 | |
af0e2a0a | 253 | static int blktrans_ioctl(struct block_device *bdev, fmode_t mode, |
1da177e4 LT |
254 | unsigned int cmd, unsigned long arg) |
255 | { | |
048d8719 ML |
256 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
257 | int ret = -ENXIO; | |
258 | ||
259 | if (!dev) | |
260 | return ret; | |
261 | ||
262 | mutex_lock(&dev->lock); | |
263 | ||
264 | if (!dev->mtd) | |
265 | goto unlock; | |
1da177e4 LT |
266 | |
267 | switch (cmd) { | |
268 | case BLKFLSBUF: | |
048d8719 | 269 | ret = dev->tr->flush ? dev->tr->flush(dev) : 0; |
007c2d87 | 270 | break; |
1da177e4 | 271 | default: |
048d8719 | 272 | ret = -ENOTTY; |
1da177e4 | 273 | } |
048d8719 ML |
274 | unlock: |
275 | mutex_unlock(&dev->lock); | |
276 | blktrans_dev_put(dev); | |
277 | return ret; | |
1da177e4 LT |
278 | } |
279 | ||
83d5cde4 | 280 | static const struct block_device_operations mtd_blktrans_ops = { |
1da177e4 | 281 | .owner = THIS_MODULE, |
af0e2a0a AV |
282 | .open = blktrans_open, |
283 | .release = blktrans_release, | |
8a6cfeb6 | 284 | .ioctl = blktrans_ioctl, |
a885c8c4 | 285 | .getgeo = blktrans_getgeo, |
1da177e4 LT |
286 | }; |
287 | ||
288 | int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) | |
289 | { | |
290 | struct mtd_blktrans_ops *tr = new->tr; | |
71a928c0 | 291 | struct mtd_blktrans_dev *d; |
1da177e4 LT |
292 | int last_devnum = -1; |
293 | struct gendisk *gd; | |
a8638622 | 294 | int ret; |
1da177e4 | 295 | |
b3561ea9 | 296 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 297 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
298 | BUG(); |
299 | } | |
300 | ||
048d8719 | 301 | mutex_lock(&blktrans_ref_mutex); |
71a928c0 | 302 | list_for_each_entry(d, &tr->devs, list) { |
1da177e4 LT |
303 | if (new->devnum == -1) { |
304 | /* Use first free number */ | |
305 | if (d->devnum != last_devnum+1) { | |
306 | /* Found a free devnum. Plug it in here */ | |
307 | new->devnum = last_devnum+1; | |
308 | list_add_tail(&new->list, &d->list); | |
309 | goto added; | |
310 | } | |
311 | } else if (d->devnum == new->devnum) { | |
312 | /* Required number taken */ | |
048d8719 | 313 | mutex_unlock(&blktrans_ref_mutex); |
1da177e4 LT |
314 | return -EBUSY; |
315 | } else if (d->devnum > new->devnum) { | |
316 | /* Required number was free */ | |
317 | list_add_tail(&new->list, &d->list); | |
318 | goto added; | |
97894cda | 319 | } |
1da177e4 LT |
320 | last_devnum = d->devnum; |
321 | } | |
a8638622 ML |
322 | |
323 | ret = -EBUSY; | |
1da177e4 LT |
324 | if (new->devnum == -1) |
325 | new->devnum = last_devnum+1; | |
326 | ||
4d3a8534 BH |
327 | /* Check that the device and any partitions will get valid |
328 | * minor numbers and that the disk naming code below can cope | |
329 | * with this number. */ | |
330 | if (new->devnum > (MINORMASK >> tr->part_bits) || | |
048d8719 ML |
331 | (tr->part_bits && new->devnum >= 27 * 26)) { |
332 | mutex_unlock(&blktrans_ref_mutex); | |
a8638622 | 333 | goto error1; |
048d8719 | 334 | } |
1da177e4 | 335 | |
1da177e4 LT |
336 | list_add_tail(&new->list, &tr->devs); |
337 | added: | |
048d8719 ML |
338 | mutex_unlock(&blktrans_ref_mutex); |
339 | ||
ce37ab42 | 340 | mutex_init(&new->lock); |
048d8719 | 341 | kref_init(&new->ref); |
1da177e4 LT |
342 | if (!tr->writesect) |
343 | new->readonly = 1; | |
344 | ||
a8638622 ML |
345 | /* Create gendisk */ |
346 | ret = -ENOMEM; | |
1da177e4 | 347 | gd = alloc_disk(1 << tr->part_bits); |
a8638622 ML |
348 | |
349 | if (!gd) | |
350 | goto error2; | |
351 | ||
352 | new->disk = gd; | |
353 | gd->private_data = new; | |
1da177e4 LT |
354 | gd->major = tr->major; |
355 | gd->first_minor = (new->devnum) << tr->part_bits; | |
356 | gd->fops = &mtd_blktrans_ops; | |
97894cda | 357 | |
65a8de36 TP |
358 | if (tr->part_bits) |
359 | if (new->devnum < 26) | |
360 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
361 | "%s%c", tr->name, 'a' + new->devnum); | |
362 | else | |
363 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
364 | "%s%c%c", tr->name, | |
365 | 'a' - 1 + new->devnum / 26, | |
366 | 'a' + new->devnum % 26); | |
367 | else | |
368 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
369 | "%s%d", tr->name, new->devnum); | |
1da177e4 | 370 | |
19187672 | 371 | set_capacity(gd, (new->size * tr->blksize) >> 9); |
1da177e4 | 372 | |
a8638622 ML |
373 | /* Create the request queue */ |
374 | spin_lock_init(&new->queue_lock); | |
375 | new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock); | |
376 | ||
377 | if (!new->rq) | |
378 | goto error3; | |
379 | ||
380 | new->rq->queuedata = new; | |
381 | blk_queue_logical_block_size(new->rq, tr->blksize); | |
382 | ||
383 | if (tr->discard) | |
384 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, | |
385 | new->rq); | |
386 | ||
387 | gd->queue = new->rq; | |
388 | ||
389 | /* Create processing thread */ | |
390 | /* TODO: workqueue ? */ | |
391 | new->thread = kthread_run(mtd_blktrans_thread, new, | |
392 | "%s%d", tr->name, new->mtd->index); | |
393 | if (IS_ERR(new->thread)) { | |
394 | ret = PTR_ERR(new->thread); | |
395 | goto error4; | |
396 | } | |
d694846b | 397 | gd->driverfs_dev = &new->mtd->dev; |
1da177e4 LT |
398 | |
399 | if (new->readonly) | |
400 | set_disk_ro(gd, 1); | |
401 | ||
402 | add_disk(gd); | |
026ec578 | 403 | |
133fa8c7 ML |
404 | if (new->disk_attributes) { |
405 | ret = sysfs_create_group(&disk_to_dev(gd)->kobj, | |
026ec578 | 406 | new->disk_attributes); |
133fa8c7 ML |
407 | WARN_ON(ret); |
408 | } | |
1da177e4 | 409 | return 0; |
a8638622 ML |
410 | error4: |
411 | blk_cleanup_queue(new->rq); | |
412 | error3: | |
413 | put_disk(new->disk); | |
414 | error2: | |
415 | list_del(&new->list); | |
416 | error1: | |
417 | kfree(new); | |
418 | return ret; | |
1da177e4 LT |
419 | } |
420 | ||
421 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) | |
422 | { | |
048d8719 ML |
423 | unsigned long flags; |
424 | ||
b3561ea9 | 425 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 426 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
427 | BUG(); |
428 | } | |
429 | ||
026ec578 ML |
430 | if (old->disk_attributes) |
431 | sysfs_remove_group(&disk_to_dev(old->disk)->kobj, | |
432 | old->disk_attributes); | |
433 | ||
dba76c03 ML |
434 | /* Stop new requests to arrive */ |
435 | del_gendisk(old->disk); | |
436 | ||
437 | ||
a8638622 ML |
438 | /* Stop the thread */ |
439 | kthread_stop(old->thread); | |
440 | ||
048d8719 ML |
441 | /* Kill current requests */ |
442 | spin_lock_irqsave(&old->queue_lock, flags); | |
443 | old->rq->queuedata = NULL; | |
444 | blk_start_queue(old->rq); | |
445 | spin_unlock_irqrestore(&old->queue_lock, flags); | |
048d8719 | 446 | |
008c751e ML |
447 | /* If the device is currently open, tell trans driver to close it, |
448 | then put mtd device, and don't touch it again */ | |
048d8719 | 449 | mutex_lock(&old->lock); |
008c751e ML |
450 | if (old->open) { |
451 | if (old->tr->release) | |
452 | old->tr->release(old); | |
453 | __put_mtd_device(old->mtd); | |
048d8719 ML |
454 | } |
455 | ||
048d8719 ML |
456 | old->mtd = NULL; |
457 | ||
458 | mutex_unlock(&old->lock); | |
459 | blktrans_dev_put(old); | |
1da177e4 LT |
460 | return 0; |
461 | } | |
462 | ||
463 | static void blktrans_notify_remove(struct mtd_info *mtd) | |
464 | { | |
71a928c0 CM |
465 | struct mtd_blktrans_ops *tr; |
466 | struct mtd_blktrans_dev *dev, *next; | |
1da177e4 | 467 | |
71a928c0 CM |
468 | list_for_each_entry(tr, &blktrans_majors, list) |
469 | list_for_each_entry_safe(dev, next, &tr->devs, list) | |
1da177e4 LT |
470 | if (dev->mtd == mtd) |
471 | tr->remove_dev(dev); | |
1da177e4 LT |
472 | } |
473 | ||
474 | static void blktrans_notify_add(struct mtd_info *mtd) | |
475 | { | |
71a928c0 | 476 | struct mtd_blktrans_ops *tr; |
1da177e4 LT |
477 | |
478 | if (mtd->type == MTD_ABSENT) | |
479 | return; | |
480 | ||
71a928c0 | 481 | list_for_each_entry(tr, &blktrans_majors, list) |
1da177e4 | 482 | tr->add_mtd(tr, mtd); |
1da177e4 LT |
483 | } |
484 | ||
485 | static struct mtd_notifier blktrans_notifier = { | |
486 | .add = blktrans_notify_add, | |
487 | .remove = blktrans_notify_remove, | |
488 | }; | |
97894cda | 489 | |
1da177e4 LT |
490 | int register_mtd_blktrans(struct mtd_blktrans_ops *tr) |
491 | { | |
f1332ba2 BH |
492 | struct mtd_info *mtd; |
493 | int ret; | |
1da177e4 | 494 | |
97894cda | 495 | /* Register the notifier if/when the first device type is |
1da177e4 LT |
496 | registered, to prevent the link/init ordering from fucking |
497 | us over. */ | |
498 | if (!blktrans_notifier.list.next) | |
499 | register_mtd_user(&blktrans_notifier); | |
500 | ||
1da177e4 | 501 | |
48b19268 | 502 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
503 | |
504 | ret = register_blkdev(tr->major, tr->name); | |
505 | if (ret) { | |
506 | printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", | |
507 | tr->name, tr->major, ret); | |
48b19268 | 508 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
509 | return ret; |
510 | } | |
eae9acd1 | 511 | |
19187672 | 512 | tr->blkshift = ffs(tr->blksize) - 1; |
1da177e4 | 513 | |
1da177e4 LT |
514 | INIT_LIST_HEAD(&tr->devs); |
515 | list_add(&tr->list, &blktrans_majors); | |
516 | ||
f1332ba2 BH |
517 | mtd_for_each_device(mtd) |
518 | if (mtd->type != MTD_ABSENT) | |
519 | tr->add_mtd(tr, mtd); | |
1da177e4 | 520 | |
48b19268 | 521 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
522 | return 0; |
523 | } | |
524 | ||
525 | int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) | |
526 | { | |
71a928c0 | 527 | struct mtd_blktrans_dev *dev, *next; |
1da177e4 | 528 | |
48b19268 | 529 | mutex_lock(&mtd_table_mutex); |
1da177e4 | 530 | |
1da177e4 LT |
531 | /* Remove it from the list of active majors */ |
532 | list_del(&tr->list); | |
533 | ||
71a928c0 | 534 | list_for_each_entry_safe(dev, next, &tr->devs, list) |
1da177e4 | 535 | tr->remove_dev(dev); |
1da177e4 | 536 | |
1da177e4 | 537 | unregister_blkdev(tr->major, tr->name); |
48b19268 | 538 | mutex_unlock(&mtd_table_mutex); |
1da177e4 | 539 | |
373ebfbf | 540 | BUG_ON(!list_empty(&tr->devs)); |
1da177e4 LT |
541 | return 0; |
542 | } | |
543 | ||
544 | static void __exit mtd_blktrans_exit(void) | |
545 | { | |
546 | /* No race here -- if someone's currently in register_mtd_blktrans | |
547 | we're screwed anyway. */ | |
548 | if (blktrans_notifier.list.next) | |
549 | unregister_mtd_user(&blktrans_notifier); | |
550 | } | |
551 | ||
552 | module_exit(mtd_blktrans_exit); | |
553 | ||
554 | EXPORT_SYMBOL_GPL(register_mtd_blktrans); | |
555 | EXPORT_SYMBOL_GPL(deregister_mtd_blktrans); | |
556 | EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev); | |
557 | EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev); | |
558 | ||
559 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
560 | MODULE_LICENSE("GPL"); | |
561 | MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'"); |