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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> | |
32 | #include <linux/hdreg.h> | |
48b19268 | 33 | #include <linux/mutex.h> |
7c0f6ba6 | 34 | #include <linux/uaccess.h> |
1da177e4 | 35 | |
356d70f1 | 36 | #include "mtdcore.h" |
1da177e4 | 37 | |
356d70f1 | 38 | static LIST_HEAD(blktrans_majors); |
048d8719 ML |
39 | static DEFINE_MUTEX(blktrans_ref_mutex); |
40 | ||
7f53f12f | 41 | static void blktrans_dev_release(struct kref *kref) |
048d8719 ML |
42 | { |
43 | struct mtd_blktrans_dev *dev = | |
44 | container_of(kref, struct mtd_blktrans_dev, ref); | |
45 | ||
46 | dev->disk->private_data = NULL; | |
e4d64cab | 47 | blk_cleanup_queue(dev->rq); |
048d8719 ML |
48 | put_disk(dev->disk); |
49 | list_del(&dev->list); | |
50 | kfree(dev); | |
51 | } | |
52 | ||
53 | static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk) | |
54 | { | |
55 | struct mtd_blktrans_dev *dev; | |
56 | ||
57 | mutex_lock(&blktrans_ref_mutex); | |
58 | dev = disk->private_data; | |
59 | ||
60 | if (!dev) | |
61 | goto unlock; | |
62 | kref_get(&dev->ref); | |
63 | unlock: | |
64 | mutex_unlock(&blktrans_ref_mutex); | |
65 | return dev; | |
66 | } | |
67 | ||
7f53f12f | 68 | static void blktrans_dev_put(struct mtd_blktrans_dev *dev) |
048d8719 ML |
69 | { |
70 | mutex_lock(&blktrans_ref_mutex); | |
71 | kref_put(&dev->ref, blktrans_dev_release); | |
72 | mutex_unlock(&blktrans_ref_mutex); | |
73 | } | |
1da177e4 | 74 | |
1da177e4 LT |
75 | |
76 | static int do_blktrans_request(struct mtd_blktrans_ops *tr, | |
77 | struct mtd_blktrans_dev *dev, | |
78 | struct request *req) | |
79 | { | |
80 | unsigned long block, nsect; | |
81 | char *buf; | |
82 | ||
83096ebf | 83 | block = blk_rq_pos(req) << 9 >> tr->blkshift; |
1011c1b9 | 84 | nsect = blk_rq_cur_bytes(req) >> tr->blkshift; |
b4f42e28 | 85 | buf = bio_data(req->bio); |
1da177e4 | 86 | |
3a5e02ce | 87 | if (req_op(req) == REQ_OP_FLUSH) |
566c0d6a RP |
88 | return tr->flush(dev); |
89 | ||
83096ebf TH |
90 | if (blk_rq_pos(req) + blk_rq_cur_sectors(req) > |
91 | get_capacity(req->rq_disk)) | |
f06d9a2b | 92 | return -EIO; |
1da177e4 | 93 | |
aebf526b CH |
94 | switch (req_op(req)) { |
95 | case REQ_OP_DISCARD: | |
1122a26f | 96 | return tr->discard(dev, block, nsect); |
aebf526b | 97 | case REQ_OP_READ: |
19187672 | 98 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 99 | if (tr->readsect(dev, block, buf)) |
f06d9a2b | 100 | return -EIO; |
2d4dc890 | 101 | rq_flush_dcache_pages(req); |
f06d9a2b | 102 | return 0; |
aebf526b | 103 | case REQ_OP_WRITE: |
1da177e4 | 104 | if (!tr->writesect) |
f06d9a2b | 105 | return -EIO; |
1da177e4 | 106 | |
2d4dc890 | 107 | rq_flush_dcache_pages(req); |
19187672 | 108 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 109 | if (tr->writesect(dev, block, buf)) |
f06d9a2b TH |
110 | return -EIO; |
111 | return 0; | |
aebf526b CH |
112 | default: |
113 | return -EIO; | |
1da177e4 LT |
114 | } |
115 | } | |
116 | ||
c7519dbf JL |
117 | int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev) |
118 | { | |
7bf7e370 | 119 | return dev->bg_stop; |
c7519dbf JL |
120 | } |
121 | EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background); | |
122 | ||
22a8578f | 123 | static void mtd_blktrans_work(struct work_struct *work) |
1da177e4 | 124 | { |
22a8578f EG |
125 | struct mtd_blktrans_dev *dev = |
126 | container_of(work, struct mtd_blktrans_dev, work); | |
c7519dbf | 127 | struct mtd_blktrans_ops *tr = dev->tr; |
a8638622 | 128 | struct request_queue *rq = dev->rq; |
1498ada7 | 129 | struct request *req = NULL; |
c7519dbf | 130 | int background_done = 0; |
1da177e4 | 131 | |
1da177e4 | 132 | spin_lock_irq(rq->queue_lock); |
1498ada7 | 133 | |
22a8578f | 134 | while (1) { |
f06d9a2b | 135 | int res; |
1da177e4 | 136 | |
7bf7e370 | 137 | dev->bg_stop = false; |
9934c8c0 | 138 | if (!req && !(req = blk_fetch_request(rq))) { |
c7519dbf JL |
139 | if (tr->background && !background_done) { |
140 | spin_unlock_irq(rq->queue_lock); | |
141 | mutex_lock(&dev->lock); | |
142 | tr->background(dev); | |
143 | mutex_unlock(&dev->lock); | |
144 | spin_lock_irq(rq->queue_lock); | |
145 | /* | |
146 | * Do background processing just once per idle | |
147 | * period. | |
148 | */ | |
7bf7e370 | 149 | background_done = !dev->bg_stop; |
c7519dbf JL |
150 | continue; |
151 | } | |
22a8578f | 152 | break; |
1da177e4 LT |
153 | } |
154 | ||
1da177e4 LT |
155 | spin_unlock_irq(rq->queue_lock); |
156 | ||
48b19268 | 157 | mutex_lock(&dev->lock); |
a8638622 | 158 | res = do_blktrans_request(dev->tr, dev, req); |
48b19268 | 159 | mutex_unlock(&dev->lock); |
1da177e4 LT |
160 | |
161 | spin_lock_irq(rq->queue_lock); | |
162 | ||
1498ada7 TH |
163 | if (!__blk_end_request_cur(req, res)) |
164 | req = NULL; | |
c7519dbf JL |
165 | |
166 | background_done = 0; | |
1da177e4 | 167 | } |
1498ada7 | 168 | |
1da177e4 | 169 | spin_unlock_irq(rq->queue_lock); |
1da177e4 LT |
170 | } |
171 | ||
172 | static void mtd_blktrans_request(struct request_queue *rq) | |
173 | { | |
048d8719 ML |
174 | struct mtd_blktrans_dev *dev; |
175 | struct request *req = NULL; | |
176 | ||
177 | dev = rq->queuedata; | |
1da177e4 | 178 | |
048d8719 ML |
179 | if (!dev) |
180 | while ((req = blk_fetch_request(rq)) != NULL) | |
181 | __blk_end_request_all(req, -ENODEV); | |
22a8578f EG |
182 | else |
183 | queue_work(dev->wq, &dev->work); | |
048d8719 | 184 | } |
1da177e4 | 185 | |
af0e2a0a | 186 | static int blktrans_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 187 | { |
048d8719 | 188 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
008c751e | 189 | int ret = 0; |
048d8719 ML |
190 | |
191 | if (!dev) | |
6e9624b8 | 192 | return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/ |
048d8719 | 193 | |
073db4a5 | 194 | mutex_lock(&mtd_table_mutex); |
f3c63795 | 195 | mutex_lock(&dev->lock); |
048d8719 | 196 | |
342ff28f | 197 | if (dev->open) |
048d8719 | 198 | goto unlock; |
048d8719 | 199 | |
008c751e ML |
200 | kref_get(&dev->ref); |
201 | __module_get(dev->tr->owner); | |
202 | ||
94735ec4 AB |
203 | if (!dev->mtd) |
204 | goto unlock; | |
205 | ||
206 | if (dev->tr->open) { | |
207 | ret = dev->tr->open(dev); | |
208 | if (ret) | |
209 | goto error_put; | |
008c751e | 210 | } |
048d8719 | 211 | |
94735ec4 AB |
212 | ret = __get_mtd_device(dev->mtd); |
213 | if (ret) | |
214 | goto error_release; | |
70d5098a | 215 | dev->file_mode = mode; |
94735ec4 | 216 | |
048d8719 | 217 | unlock: |
342ff28f | 218 | dev->open++; |
048d8719 | 219 | mutex_unlock(&dev->lock); |
f3c63795 | 220 | mutex_unlock(&mtd_table_mutex); |
048d8719 | 221 | blktrans_dev_put(dev); |
1da177e4 | 222 | return ret; |
94735ec4 AB |
223 | |
224 | error_release: | |
225 | if (dev->tr->release) | |
226 | dev->tr->release(dev); | |
227 | error_put: | |
228 | module_put(dev->tr->owner); | |
229 | kref_put(&dev->ref, blktrans_dev_release); | |
230 | mutex_unlock(&dev->lock); | |
f3c63795 | 231 | mutex_unlock(&mtd_table_mutex); |
94735ec4 AB |
232 | blktrans_dev_put(dev); |
233 | return ret; | |
1da177e4 LT |
234 | } |
235 | ||
db2a144b | 236 | static void blktrans_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 237 | { |
048d8719 | 238 | struct mtd_blktrans_dev *dev = blktrans_dev_get(disk); |
1da177e4 | 239 | |
048d8719 | 240 | if (!dev) |
db2a144b | 241 | return; |
1da177e4 | 242 | |
073db4a5 | 243 | mutex_lock(&mtd_table_mutex); |
f3c63795 | 244 | mutex_lock(&dev->lock); |
048d8719 | 245 | |
008c751e | 246 | if (--dev->open) |
048d8719 ML |
247 | goto unlock; |
248 | ||
008c751e ML |
249 | kref_put(&dev->ref, blktrans_dev_release); |
250 | module_put(dev->tr->owner); | |
251 | ||
252 | if (dev->mtd) { | |
a8ca889e AV |
253 | if (dev->tr->release) |
254 | dev->tr->release(dev); | |
008c751e ML |
255 | __put_mtd_device(dev->mtd); |
256 | } | |
048d8719 ML |
257 | unlock: |
258 | mutex_unlock(&dev->lock); | |
f3c63795 | 259 | mutex_unlock(&mtd_table_mutex); |
048d8719 | 260 | blktrans_dev_put(dev); |
1da177e4 LT |
261 | } |
262 | ||
a885c8c4 CH |
263 | static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
264 | { | |
048d8719 ML |
265 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
266 | int ret = -ENXIO; | |
267 | ||
268 | if (!dev) | |
269 | return ret; | |
270 | ||
271 | mutex_lock(&dev->lock); | |
a885c8c4 | 272 | |
048d8719 ML |
273 | if (!dev->mtd) |
274 | goto unlock; | |
275 | ||
c4a3f13c | 276 | ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENOTTY; |
048d8719 ML |
277 | unlock: |
278 | mutex_unlock(&dev->lock); | |
279 | blktrans_dev_put(dev); | |
280 | return ret; | |
a885c8c4 | 281 | } |
1da177e4 | 282 | |
af0e2a0a | 283 | static int blktrans_ioctl(struct block_device *bdev, fmode_t mode, |
1da177e4 LT |
284 | unsigned int cmd, unsigned long arg) |
285 | { | |
048d8719 ML |
286 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
287 | int ret = -ENXIO; | |
288 | ||
289 | if (!dev) | |
290 | return ret; | |
291 | ||
292 | mutex_lock(&dev->lock); | |
293 | ||
294 | if (!dev->mtd) | |
295 | goto unlock; | |
1da177e4 LT |
296 | |
297 | switch (cmd) { | |
298 | case BLKFLSBUF: | |
048d8719 | 299 | ret = dev->tr->flush ? dev->tr->flush(dev) : 0; |
007c2d87 | 300 | break; |
1da177e4 | 301 | default: |
048d8719 | 302 | ret = -ENOTTY; |
1da177e4 | 303 | } |
048d8719 ML |
304 | unlock: |
305 | mutex_unlock(&dev->lock); | |
306 | blktrans_dev_put(dev); | |
307 | return ret; | |
1da177e4 LT |
308 | } |
309 | ||
9329c5eb | 310 | static const struct block_device_operations mtd_block_ops = { |
1da177e4 | 311 | .owner = THIS_MODULE, |
af0e2a0a AV |
312 | .open = blktrans_open, |
313 | .release = blktrans_release, | |
8a6cfeb6 | 314 | .ioctl = blktrans_ioctl, |
a885c8c4 | 315 | .getgeo = blktrans_getgeo, |
1da177e4 LT |
316 | }; |
317 | ||
318 | int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) | |
319 | { | |
320 | struct mtd_blktrans_ops *tr = new->tr; | |
71a928c0 | 321 | struct mtd_blktrans_dev *d; |
1da177e4 LT |
322 | int last_devnum = -1; |
323 | struct gendisk *gd; | |
a8638622 | 324 | int ret; |
1da177e4 | 325 | |
b3561ea9 | 326 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 327 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
328 | BUG(); |
329 | } | |
330 | ||
048d8719 | 331 | mutex_lock(&blktrans_ref_mutex); |
71a928c0 | 332 | list_for_each_entry(d, &tr->devs, list) { |
1da177e4 LT |
333 | if (new->devnum == -1) { |
334 | /* Use first free number */ | |
335 | if (d->devnum != last_devnum+1) { | |
336 | /* Found a free devnum. Plug it in here */ | |
337 | new->devnum = last_devnum+1; | |
338 | list_add_tail(&new->list, &d->list); | |
339 | goto added; | |
340 | } | |
341 | } else if (d->devnum == new->devnum) { | |
342 | /* Required number taken */ | |
048d8719 | 343 | mutex_unlock(&blktrans_ref_mutex); |
1da177e4 LT |
344 | return -EBUSY; |
345 | } else if (d->devnum > new->devnum) { | |
346 | /* Required number was free */ | |
347 | list_add_tail(&new->list, &d->list); | |
348 | goto added; | |
97894cda | 349 | } |
1da177e4 LT |
350 | last_devnum = d->devnum; |
351 | } | |
a8638622 ML |
352 | |
353 | ret = -EBUSY; | |
1da177e4 LT |
354 | if (new->devnum == -1) |
355 | new->devnum = last_devnum+1; | |
356 | ||
4d3a8534 BH |
357 | /* Check that the device and any partitions will get valid |
358 | * minor numbers and that the disk naming code below can cope | |
359 | * with this number. */ | |
360 | if (new->devnum > (MINORMASK >> tr->part_bits) || | |
048d8719 ML |
361 | (tr->part_bits && new->devnum >= 27 * 26)) { |
362 | mutex_unlock(&blktrans_ref_mutex); | |
a8638622 | 363 | goto error1; |
048d8719 | 364 | } |
1da177e4 | 365 | |
1da177e4 LT |
366 | list_add_tail(&new->list, &tr->devs); |
367 | added: | |
048d8719 ML |
368 | mutex_unlock(&blktrans_ref_mutex); |
369 | ||
ce37ab42 | 370 | mutex_init(&new->lock); |
048d8719 | 371 | kref_init(&new->ref); |
1da177e4 LT |
372 | if (!tr->writesect) |
373 | new->readonly = 1; | |
374 | ||
a8638622 ML |
375 | /* Create gendisk */ |
376 | ret = -ENOMEM; | |
1da177e4 | 377 | gd = alloc_disk(1 << tr->part_bits); |
a8638622 ML |
378 | |
379 | if (!gd) | |
380 | goto error2; | |
381 | ||
382 | new->disk = gd; | |
383 | gd->private_data = new; | |
1da177e4 LT |
384 | gd->major = tr->major; |
385 | gd->first_minor = (new->devnum) << tr->part_bits; | |
9329c5eb | 386 | gd->fops = &mtd_block_ops; |
97894cda | 387 | |
65a8de36 TP |
388 | if (tr->part_bits) |
389 | if (new->devnum < 26) | |
390 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
391 | "%s%c", tr->name, 'a' + new->devnum); | |
392 | else | |
393 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
394 | "%s%c%c", tr->name, | |
395 | 'a' - 1 + new->devnum / 26, | |
396 | 'a' + new->devnum % 26); | |
397 | else | |
398 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
399 | "%s%d", tr->name, new->devnum); | |
1da177e4 | 400 | |
2ce401d5 | 401 | set_capacity(gd, ((u64)new->size * tr->blksize) >> 9); |
1da177e4 | 402 | |
a8638622 ML |
403 | /* Create the request queue */ |
404 | spin_lock_init(&new->queue_lock); | |
405 | new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock); | |
406 | ||
407 | if (!new->rq) | |
408 | goto error3; | |
409 | ||
566c0d6a | 410 | if (tr->flush) |
fec3ff5d | 411 | blk_queue_write_cache(new->rq, true, false); |
566c0d6a | 412 | |
a8638622 ML |
413 | new->rq->queuedata = new; |
414 | blk_queue_logical_block_size(new->rq, tr->blksize); | |
415 | ||
16f7eca5 | 416 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq); |
b277da0a | 417 | queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, new->rq); |
16f7eca5 | 418 | |
115ee88c JL |
419 | if (tr->discard) { |
420 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq); | |
2bb4cd5c | 421 | blk_queue_max_discard_sectors(new->rq, UINT_MAX); |
115ee88c | 422 | } |
a8638622 ML |
423 | |
424 | gd->queue = new->rq; | |
425 | ||
22a8578f EG |
426 | /* Create processing workqueue */ |
427 | new->wq = alloc_workqueue("%s%d", 0, 0, | |
428 | tr->name, new->mtd->index); | |
429 | if (!new->wq) | |
a8638622 | 430 | goto error4; |
22a8578f EG |
431 | INIT_WORK(&new->work, mtd_blktrans_work); |
432 | ||
1da177e4 LT |
433 | if (new->readonly) |
434 | set_disk_ro(gd, 1); | |
435 | ||
0d52c756 | 436 | device_add_disk(&new->mtd->dev, gd); |
026ec578 | 437 | |
133fa8c7 ML |
438 | if (new->disk_attributes) { |
439 | ret = sysfs_create_group(&disk_to_dev(gd)->kobj, | |
026ec578 | 440 | new->disk_attributes); |
133fa8c7 ML |
441 | WARN_ON(ret); |
442 | } | |
1da177e4 | 443 | return 0; |
a8638622 ML |
444 | error4: |
445 | blk_cleanup_queue(new->rq); | |
446 | error3: | |
447 | put_disk(new->disk); | |
448 | error2: | |
449 | list_del(&new->list); | |
450 | error1: | |
a8638622 | 451 | return ret; |
1da177e4 LT |
452 | } |
453 | ||
454 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) | |
455 | { | |
048d8719 ML |
456 | unsigned long flags; |
457 | ||
b3561ea9 | 458 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 459 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
460 | BUG(); |
461 | } | |
462 | ||
026ec578 ML |
463 | if (old->disk_attributes) |
464 | sysfs_remove_group(&disk_to_dev(old->disk)->kobj, | |
465 | old->disk_attributes); | |
466 | ||
dba76c03 ML |
467 | /* Stop new requests to arrive */ |
468 | del_gendisk(old->disk); | |
469 | ||
22a8578f EG |
470 | /* Stop workqueue. This will perform any pending request. */ |
471 | destroy_workqueue(old->wq); | |
a8638622 | 472 | |
048d8719 ML |
473 | /* Kill current requests */ |
474 | spin_lock_irqsave(&old->queue_lock, flags); | |
475 | old->rq->queuedata = NULL; | |
476 | blk_start_queue(old->rq); | |
477 | spin_unlock_irqrestore(&old->queue_lock, flags); | |
048d8719 | 478 | |
008c751e ML |
479 | /* If the device is currently open, tell trans driver to close it, |
480 | then put mtd device, and don't touch it again */ | |
048d8719 | 481 | mutex_lock(&old->lock); |
008c751e ML |
482 | if (old->open) { |
483 | if (old->tr->release) | |
484 | old->tr->release(old); | |
485 | __put_mtd_device(old->mtd); | |
048d8719 ML |
486 | } |
487 | ||
048d8719 ML |
488 | old->mtd = NULL; |
489 | ||
490 | mutex_unlock(&old->lock); | |
491 | blktrans_dev_put(old); | |
1da177e4 LT |
492 | return 0; |
493 | } | |
494 | ||
495 | static void blktrans_notify_remove(struct mtd_info *mtd) | |
496 | { | |
71a928c0 CM |
497 | struct mtd_blktrans_ops *tr; |
498 | struct mtd_blktrans_dev *dev, *next; | |
1da177e4 | 499 | |
71a928c0 CM |
500 | list_for_each_entry(tr, &blktrans_majors, list) |
501 | list_for_each_entry_safe(dev, next, &tr->devs, list) | |
1da177e4 LT |
502 | if (dev->mtd == mtd) |
503 | tr->remove_dev(dev); | |
1da177e4 LT |
504 | } |
505 | ||
506 | static void blktrans_notify_add(struct mtd_info *mtd) | |
507 | { | |
71a928c0 | 508 | struct mtd_blktrans_ops *tr; |
1da177e4 LT |
509 | |
510 | if (mtd->type == MTD_ABSENT) | |
511 | return; | |
512 | ||
71a928c0 | 513 | list_for_each_entry(tr, &blktrans_majors, list) |
1da177e4 | 514 | tr->add_mtd(tr, mtd); |
1da177e4 LT |
515 | } |
516 | ||
517 | static struct mtd_notifier blktrans_notifier = { | |
518 | .add = blktrans_notify_add, | |
519 | .remove = blktrans_notify_remove, | |
520 | }; | |
97894cda | 521 | |
1da177e4 LT |
522 | int register_mtd_blktrans(struct mtd_blktrans_ops *tr) |
523 | { | |
f1332ba2 BH |
524 | struct mtd_info *mtd; |
525 | int ret; | |
1da177e4 | 526 | |
97894cda | 527 | /* Register the notifier if/when the first device type is |
1da177e4 LT |
528 | registered, to prevent the link/init ordering from fucking |
529 | us over. */ | |
530 | if (!blktrans_notifier.list.next) | |
531 | register_mtd_user(&blktrans_notifier); | |
532 | ||
1da177e4 | 533 | |
48b19268 | 534 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
535 | |
536 | ret = register_blkdev(tr->major, tr->name); | |
6fe4c590 | 537 | if (ret < 0) { |
1da177e4 LT |
538 | printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", |
539 | tr->name, tr->major, ret); | |
48b19268 | 540 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
541 | return ret; |
542 | } | |
eae9acd1 | 543 | |
6fe4c590 FL |
544 | if (ret) |
545 | tr->major = ret; | |
546 | ||
19187672 | 547 | tr->blkshift = ffs(tr->blksize) - 1; |
1da177e4 | 548 | |
1da177e4 LT |
549 | INIT_LIST_HEAD(&tr->devs); |
550 | list_add(&tr->list, &blktrans_majors); | |
551 | ||
f1332ba2 BH |
552 | mtd_for_each_device(mtd) |
553 | if (mtd->type != MTD_ABSENT) | |
554 | tr->add_mtd(tr, mtd); | |
1da177e4 | 555 | |
48b19268 | 556 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
557 | return 0; |
558 | } | |
559 | ||
560 | int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) | |
561 | { | |
71a928c0 | 562 | struct mtd_blktrans_dev *dev, *next; |
1da177e4 | 563 | |
48b19268 | 564 | mutex_lock(&mtd_table_mutex); |
1da177e4 | 565 | |
1da177e4 LT |
566 | /* Remove it from the list of active majors */ |
567 | list_del(&tr->list); | |
568 | ||
71a928c0 | 569 | list_for_each_entry_safe(dev, next, &tr->devs, list) |
1da177e4 | 570 | tr->remove_dev(dev); |
1da177e4 | 571 | |
1da177e4 | 572 | unregister_blkdev(tr->major, tr->name); |
48b19268 | 573 | mutex_unlock(&mtd_table_mutex); |
1da177e4 | 574 | |
373ebfbf | 575 | BUG_ON(!list_empty(&tr->devs)); |
1da177e4 LT |
576 | return 0; |
577 | } | |
578 | ||
579 | static void __exit mtd_blktrans_exit(void) | |
580 | { | |
581 | /* No race here -- if someone's currently in register_mtd_blktrans | |
582 | we're screwed anyway. */ | |
583 | if (blktrans_notifier.list.next) | |
584 | unregister_mtd_user(&blktrans_notifier); | |
585 | } | |
586 | ||
587 | module_exit(mtd_blktrans_exit); | |
588 | ||
589 | EXPORT_SYMBOL_GPL(register_mtd_blktrans); | |
590 | EXPORT_SYMBOL_GPL(deregister_mtd_blktrans); | |
591 | EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev); | |
592 | EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev); | |
593 | ||
594 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
595 | MODULE_LICENSE("GPL"); | |
596 | MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'"); |