Commit | Line | Data |
---|---|---|
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> |
1da177e4 | 34 | #include <asm/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 | |
33659ebb | 87 | if (req->cmd_type != REQ_TYPE_FS) |
f06d9a2b | 88 | return -EIO; |
1da177e4 | 89 | |
566c0d6a RP |
90 | if (req->cmd_flags & REQ_FLUSH) |
91 | return tr->flush(dev); | |
92 | ||
83096ebf TH |
93 | if (blk_rq_pos(req) + blk_rq_cur_sectors(req) > |
94 | get_capacity(req->rq_disk)) | |
f06d9a2b | 95 | return -EIO; |
1da177e4 | 96 | |
33659ebb | 97 | if (req->cmd_flags & REQ_DISCARD) |
1122a26f CH |
98 | return tr->discard(dev, block, nsect); |
99 | ||
1da177e4 LT |
100 | switch(rq_data_dir(req)) { |
101 | case READ: | |
19187672 | 102 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 103 | if (tr->readsect(dev, block, buf)) |
f06d9a2b | 104 | return -EIO; |
2d4dc890 | 105 | rq_flush_dcache_pages(req); |
f06d9a2b | 106 | return 0; |
1da177e4 LT |
107 | case WRITE: |
108 | if (!tr->writesect) | |
f06d9a2b | 109 | return -EIO; |
1da177e4 | 110 | |
2d4dc890 | 111 | rq_flush_dcache_pages(req); |
19187672 | 112 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 113 | if (tr->writesect(dev, block, buf)) |
f06d9a2b TH |
114 | return -EIO; |
115 | return 0; | |
1da177e4 | 116 | default: |
9a292308 | 117 | printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req)); |
f06d9a2b | 118 | return -EIO; |
1da177e4 LT |
119 | } |
120 | } | |
121 | ||
c7519dbf JL |
122 | int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev) |
123 | { | |
7bf7e370 | 124 | return dev->bg_stop; |
c7519dbf JL |
125 | } |
126 | EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background); | |
127 | ||
22a8578f | 128 | static void mtd_blktrans_work(struct work_struct *work) |
1da177e4 | 129 | { |
22a8578f EG |
130 | struct mtd_blktrans_dev *dev = |
131 | container_of(work, struct mtd_blktrans_dev, work); | |
c7519dbf | 132 | struct mtd_blktrans_ops *tr = dev->tr; |
a8638622 | 133 | struct request_queue *rq = dev->rq; |
1498ada7 | 134 | struct request *req = NULL; |
c7519dbf | 135 | int background_done = 0; |
1da177e4 | 136 | |
1da177e4 | 137 | spin_lock_irq(rq->queue_lock); |
1498ada7 | 138 | |
22a8578f | 139 | while (1) { |
f06d9a2b | 140 | int res; |
1da177e4 | 141 | |
7bf7e370 | 142 | dev->bg_stop = false; |
9934c8c0 | 143 | if (!req && !(req = blk_fetch_request(rq))) { |
c7519dbf JL |
144 | if (tr->background && !background_done) { |
145 | spin_unlock_irq(rq->queue_lock); | |
146 | mutex_lock(&dev->lock); | |
147 | tr->background(dev); | |
148 | mutex_unlock(&dev->lock); | |
149 | spin_lock_irq(rq->queue_lock); | |
150 | /* | |
151 | * Do background processing just once per idle | |
152 | * period. | |
153 | */ | |
7bf7e370 | 154 | background_done = !dev->bg_stop; |
c7519dbf JL |
155 | continue; |
156 | } | |
22a8578f | 157 | break; |
1da177e4 LT |
158 | } |
159 | ||
1da177e4 LT |
160 | spin_unlock_irq(rq->queue_lock); |
161 | ||
48b19268 | 162 | mutex_lock(&dev->lock); |
a8638622 | 163 | res = do_blktrans_request(dev->tr, dev, req); |
48b19268 | 164 | mutex_unlock(&dev->lock); |
1da177e4 LT |
165 | |
166 | spin_lock_irq(rq->queue_lock); | |
167 | ||
1498ada7 TH |
168 | if (!__blk_end_request_cur(req, res)) |
169 | req = NULL; | |
c7519dbf JL |
170 | |
171 | background_done = 0; | |
1da177e4 | 172 | } |
1498ada7 | 173 | |
1da177e4 | 174 | spin_unlock_irq(rq->queue_lock); |
1da177e4 LT |
175 | } |
176 | ||
177 | static void mtd_blktrans_request(struct request_queue *rq) | |
178 | { | |
048d8719 ML |
179 | struct mtd_blktrans_dev *dev; |
180 | struct request *req = NULL; | |
181 | ||
182 | dev = rq->queuedata; | |
1da177e4 | 183 | |
048d8719 ML |
184 | if (!dev) |
185 | while ((req = blk_fetch_request(rq)) != NULL) | |
186 | __blk_end_request_all(req, -ENODEV); | |
22a8578f EG |
187 | else |
188 | queue_work(dev->wq, &dev->work); | |
048d8719 | 189 | } |
1da177e4 | 190 | |
af0e2a0a | 191 | static int blktrans_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 192 | { |
048d8719 | 193 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
008c751e | 194 | int ret = 0; |
048d8719 ML |
195 | |
196 | if (!dev) | |
6e9624b8 | 197 | return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/ |
048d8719 ML |
198 | |
199 | mutex_lock(&dev->lock); | |
200 | ||
342ff28f | 201 | if (dev->open) |
048d8719 | 202 | goto unlock; |
048d8719 | 203 | |
008c751e ML |
204 | kref_get(&dev->ref); |
205 | __module_get(dev->tr->owner); | |
206 | ||
94735ec4 AB |
207 | if (!dev->mtd) |
208 | goto unlock; | |
209 | ||
210 | if (dev->tr->open) { | |
211 | ret = dev->tr->open(dev); | |
212 | if (ret) | |
213 | goto error_put; | |
008c751e | 214 | } |
048d8719 | 215 | |
94735ec4 AB |
216 | ret = __get_mtd_device(dev->mtd); |
217 | if (ret) | |
218 | goto error_release; | |
70d5098a | 219 | dev->file_mode = mode; |
94735ec4 | 220 | |
048d8719 | 221 | unlock: |
342ff28f | 222 | dev->open++; |
048d8719 ML |
223 | mutex_unlock(&dev->lock); |
224 | blktrans_dev_put(dev); | |
1da177e4 | 225 | return ret; |
94735ec4 AB |
226 | |
227 | error_release: | |
228 | if (dev->tr->release) | |
229 | dev->tr->release(dev); | |
230 | error_put: | |
231 | module_put(dev->tr->owner); | |
232 | kref_put(&dev->ref, blktrans_dev_release); | |
233 | mutex_unlock(&dev->lock); | |
234 | blktrans_dev_put(dev); | |
235 | return ret; | |
1da177e4 LT |
236 | } |
237 | ||
db2a144b | 238 | static void blktrans_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 239 | { |
048d8719 | 240 | struct mtd_blktrans_dev *dev = blktrans_dev_get(disk); |
1da177e4 | 241 | |
048d8719 | 242 | if (!dev) |
db2a144b | 243 | return; |
1da177e4 | 244 | |
048d8719 ML |
245 | mutex_lock(&dev->lock); |
246 | ||
008c751e | 247 | if (--dev->open) |
048d8719 ML |
248 | goto unlock; |
249 | ||
008c751e ML |
250 | kref_put(&dev->ref, blktrans_dev_release); |
251 | module_put(dev->tr->owner); | |
252 | ||
253 | if (dev->mtd) { | |
a8ca889e AV |
254 | if (dev->tr->release) |
255 | dev->tr->release(dev); | |
008c751e ML |
256 | __put_mtd_device(dev->mtd); |
257 | } | |
048d8719 ML |
258 | unlock: |
259 | mutex_unlock(&dev->lock); | |
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 | ||
276 | ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0; | |
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 | |
19187672 | 401 | set_capacity(gd, (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 RP |
410 | if (tr->flush) |
411 | blk_queue_flush(new->rq, REQ_FLUSH); | |
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); | |
421 | new->rq->limits.max_discard_sectors = UINT_MAX; | |
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 | ||
d694846b | 433 | gd->driverfs_dev = &new->mtd->dev; |
1da177e4 LT |
434 | |
435 | if (new->readonly) | |
436 | set_disk_ro(gd, 1); | |
437 | ||
438 | add_disk(gd); | |
026ec578 | 439 | |
133fa8c7 ML |
440 | if (new->disk_attributes) { |
441 | ret = sysfs_create_group(&disk_to_dev(gd)->kobj, | |
026ec578 | 442 | new->disk_attributes); |
133fa8c7 ML |
443 | WARN_ON(ret); |
444 | } | |
1da177e4 | 445 | return 0; |
a8638622 ML |
446 | error4: |
447 | blk_cleanup_queue(new->rq); | |
448 | error3: | |
449 | put_disk(new->disk); | |
450 | error2: | |
451 | list_del(&new->list); | |
452 | error1: | |
a8638622 | 453 | return ret; |
1da177e4 LT |
454 | } |
455 | ||
456 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) | |
457 | { | |
048d8719 ML |
458 | unsigned long flags; |
459 | ||
b3561ea9 | 460 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 461 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
462 | BUG(); |
463 | } | |
464 | ||
026ec578 ML |
465 | if (old->disk_attributes) |
466 | sysfs_remove_group(&disk_to_dev(old->disk)->kobj, | |
467 | old->disk_attributes); | |
468 | ||
dba76c03 ML |
469 | /* Stop new requests to arrive */ |
470 | del_gendisk(old->disk); | |
471 | ||
22a8578f EG |
472 | /* Stop workqueue. This will perform any pending request. */ |
473 | destroy_workqueue(old->wq); | |
a8638622 | 474 | |
048d8719 ML |
475 | /* Kill current requests */ |
476 | spin_lock_irqsave(&old->queue_lock, flags); | |
477 | old->rq->queuedata = NULL; | |
478 | blk_start_queue(old->rq); | |
479 | spin_unlock_irqrestore(&old->queue_lock, flags); | |
048d8719 | 480 | |
008c751e ML |
481 | /* If the device is currently open, tell trans driver to close it, |
482 | then put mtd device, and don't touch it again */ | |
048d8719 | 483 | mutex_lock(&old->lock); |
008c751e ML |
484 | if (old->open) { |
485 | if (old->tr->release) | |
486 | old->tr->release(old); | |
487 | __put_mtd_device(old->mtd); | |
048d8719 ML |
488 | } |
489 | ||
048d8719 ML |
490 | old->mtd = NULL; |
491 | ||
492 | mutex_unlock(&old->lock); | |
493 | blktrans_dev_put(old); | |
1da177e4 LT |
494 | return 0; |
495 | } | |
496 | ||
497 | static void blktrans_notify_remove(struct mtd_info *mtd) | |
498 | { | |
71a928c0 CM |
499 | struct mtd_blktrans_ops *tr; |
500 | struct mtd_blktrans_dev *dev, *next; | |
1da177e4 | 501 | |
71a928c0 CM |
502 | list_for_each_entry(tr, &blktrans_majors, list) |
503 | list_for_each_entry_safe(dev, next, &tr->devs, list) | |
1da177e4 LT |
504 | if (dev->mtd == mtd) |
505 | tr->remove_dev(dev); | |
1da177e4 LT |
506 | } |
507 | ||
508 | static void blktrans_notify_add(struct mtd_info *mtd) | |
509 | { | |
71a928c0 | 510 | struct mtd_blktrans_ops *tr; |
1da177e4 LT |
511 | |
512 | if (mtd->type == MTD_ABSENT) | |
513 | return; | |
514 | ||
71a928c0 | 515 | list_for_each_entry(tr, &blktrans_majors, list) |
1da177e4 | 516 | tr->add_mtd(tr, mtd); |
1da177e4 LT |
517 | } |
518 | ||
519 | static struct mtd_notifier blktrans_notifier = { | |
520 | .add = blktrans_notify_add, | |
521 | .remove = blktrans_notify_remove, | |
522 | }; | |
97894cda | 523 | |
1da177e4 LT |
524 | int register_mtd_blktrans(struct mtd_blktrans_ops *tr) |
525 | { | |
f1332ba2 BH |
526 | struct mtd_info *mtd; |
527 | int ret; | |
1da177e4 | 528 | |
97894cda | 529 | /* Register the notifier if/when the first device type is |
1da177e4 LT |
530 | registered, to prevent the link/init ordering from fucking |
531 | us over. */ | |
532 | if (!blktrans_notifier.list.next) | |
533 | register_mtd_user(&blktrans_notifier); | |
534 | ||
1da177e4 | 535 | |
48b19268 | 536 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
537 | |
538 | ret = register_blkdev(tr->major, tr->name); | |
6fe4c590 | 539 | if (ret < 0) { |
1da177e4 LT |
540 | printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", |
541 | tr->name, tr->major, ret); | |
48b19268 | 542 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
543 | return ret; |
544 | } | |
eae9acd1 | 545 | |
6fe4c590 FL |
546 | if (ret) |
547 | tr->major = ret; | |
548 | ||
19187672 | 549 | tr->blkshift = ffs(tr->blksize) - 1; |
1da177e4 | 550 | |
1da177e4 LT |
551 | INIT_LIST_HEAD(&tr->devs); |
552 | list_add(&tr->list, &blktrans_majors); | |
553 | ||
f1332ba2 BH |
554 | mtd_for_each_device(mtd) |
555 | if (mtd->type != MTD_ABSENT) | |
556 | tr->add_mtd(tr, mtd); | |
1da177e4 | 557 | |
48b19268 | 558 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
559 | return 0; |
560 | } | |
561 | ||
562 | int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) | |
563 | { | |
71a928c0 | 564 | struct mtd_blktrans_dev *dev, *next; |
1da177e4 | 565 | |
48b19268 | 566 | mutex_lock(&mtd_table_mutex); |
1da177e4 | 567 | |
1da177e4 LT |
568 | /* Remove it from the list of active majors */ |
569 | list_del(&tr->list); | |
570 | ||
71a928c0 | 571 | list_for_each_entry_safe(dev, next, &tr->devs, list) |
1da177e4 | 572 | tr->remove_dev(dev); |
1da177e4 | 573 | |
1da177e4 | 574 | unregister_blkdev(tr->major, tr->name); |
48b19268 | 575 | mutex_unlock(&mtd_table_mutex); |
1da177e4 | 576 | |
373ebfbf | 577 | BUG_ON(!list_empty(&tr->devs)); |
1da177e4 LT |
578 | return 0; |
579 | } | |
580 | ||
581 | static void __exit mtd_blktrans_exit(void) | |
582 | { | |
583 | /* No race here -- if someone's currently in register_mtd_blktrans | |
584 | we're screwed anyway. */ | |
585 | if (blktrans_notifier.list.next) | |
586 | unregister_mtd_user(&blktrans_notifier); | |
587 | } | |
588 | ||
589 | module_exit(mtd_blktrans_exit); | |
590 | ||
591 | EXPORT_SYMBOL_GPL(register_mtd_blktrans); | |
592 | EXPORT_SYMBOL_GPL(deregister_mtd_blktrans); | |
593 | EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev); | |
594 | EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev); | |
595 | ||
596 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
597 | MODULE_LICENSE("GPL"); | |
598 | MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'"); |