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 TH |
173 | |
174 | if (req) | |
175 | __blk_end_request_all(req, -EIO); | |
176 | ||
1da177e4 | 177 | spin_unlock_irq(rq->queue_lock); |
1da177e4 LT |
178 | } |
179 | ||
180 | static void mtd_blktrans_request(struct request_queue *rq) | |
181 | { | |
048d8719 ML |
182 | struct mtd_blktrans_dev *dev; |
183 | struct request *req = NULL; | |
184 | ||
185 | dev = rq->queuedata; | |
1da177e4 | 186 | |
048d8719 ML |
187 | if (!dev) |
188 | while ((req = blk_fetch_request(rq)) != NULL) | |
189 | __blk_end_request_all(req, -ENODEV); | |
22a8578f EG |
190 | else |
191 | queue_work(dev->wq, &dev->work); | |
048d8719 | 192 | } |
1da177e4 | 193 | |
af0e2a0a | 194 | static int blktrans_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 195 | { |
048d8719 | 196 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
008c751e | 197 | int ret = 0; |
048d8719 ML |
198 | |
199 | if (!dev) | |
6e9624b8 | 200 | return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/ |
048d8719 ML |
201 | |
202 | mutex_lock(&dev->lock); | |
203 | ||
342ff28f | 204 | if (dev->open) |
048d8719 | 205 | goto unlock; |
048d8719 | 206 | |
008c751e ML |
207 | kref_get(&dev->ref); |
208 | __module_get(dev->tr->owner); | |
209 | ||
94735ec4 AB |
210 | if (!dev->mtd) |
211 | goto unlock; | |
212 | ||
213 | if (dev->tr->open) { | |
214 | ret = dev->tr->open(dev); | |
215 | if (ret) | |
216 | goto error_put; | |
008c751e | 217 | } |
048d8719 | 218 | |
94735ec4 AB |
219 | ret = __get_mtd_device(dev->mtd); |
220 | if (ret) | |
221 | goto error_release; | |
70d5098a | 222 | dev->file_mode = mode; |
94735ec4 | 223 | |
048d8719 | 224 | unlock: |
342ff28f | 225 | dev->open++; |
048d8719 ML |
226 | mutex_unlock(&dev->lock); |
227 | blktrans_dev_put(dev); | |
1da177e4 | 228 | return ret; |
94735ec4 AB |
229 | |
230 | error_release: | |
231 | if (dev->tr->release) | |
232 | dev->tr->release(dev); | |
233 | error_put: | |
234 | module_put(dev->tr->owner); | |
235 | kref_put(&dev->ref, blktrans_dev_release); | |
236 | mutex_unlock(&dev->lock); | |
237 | blktrans_dev_put(dev); | |
238 | return ret; | |
1da177e4 LT |
239 | } |
240 | ||
db2a144b | 241 | static void blktrans_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 242 | { |
048d8719 | 243 | struct mtd_blktrans_dev *dev = blktrans_dev_get(disk); |
1da177e4 | 244 | |
048d8719 | 245 | if (!dev) |
db2a144b | 246 | return; |
1da177e4 | 247 | |
048d8719 ML |
248 | mutex_lock(&dev->lock); |
249 | ||
008c751e | 250 | if (--dev->open) |
048d8719 ML |
251 | goto unlock; |
252 | ||
008c751e ML |
253 | kref_put(&dev->ref, blktrans_dev_release); |
254 | module_put(dev->tr->owner); | |
255 | ||
256 | if (dev->mtd) { | |
a8ca889e AV |
257 | if (dev->tr->release) |
258 | dev->tr->release(dev); | |
008c751e ML |
259 | __put_mtd_device(dev->mtd); |
260 | } | |
048d8719 ML |
261 | unlock: |
262 | mutex_unlock(&dev->lock); | |
263 | blktrans_dev_put(dev); | |
1da177e4 LT |
264 | } |
265 | ||
a885c8c4 CH |
266 | static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
267 | { | |
048d8719 ML |
268 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
269 | int ret = -ENXIO; | |
270 | ||
271 | if (!dev) | |
272 | return ret; | |
273 | ||
274 | mutex_lock(&dev->lock); | |
a885c8c4 | 275 | |
048d8719 ML |
276 | if (!dev->mtd) |
277 | goto unlock; | |
278 | ||
279 | ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0; | |
280 | unlock: | |
281 | mutex_unlock(&dev->lock); | |
282 | blktrans_dev_put(dev); | |
283 | return ret; | |
a885c8c4 | 284 | } |
1da177e4 | 285 | |
af0e2a0a | 286 | static int blktrans_ioctl(struct block_device *bdev, fmode_t mode, |
1da177e4 LT |
287 | unsigned int cmd, unsigned long arg) |
288 | { | |
048d8719 ML |
289 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
290 | int ret = -ENXIO; | |
291 | ||
292 | if (!dev) | |
293 | return ret; | |
294 | ||
295 | mutex_lock(&dev->lock); | |
296 | ||
297 | if (!dev->mtd) | |
298 | goto unlock; | |
1da177e4 LT |
299 | |
300 | switch (cmd) { | |
301 | case BLKFLSBUF: | |
048d8719 | 302 | ret = dev->tr->flush ? dev->tr->flush(dev) : 0; |
007c2d87 | 303 | break; |
1da177e4 | 304 | default: |
048d8719 | 305 | ret = -ENOTTY; |
1da177e4 | 306 | } |
048d8719 ML |
307 | unlock: |
308 | mutex_unlock(&dev->lock); | |
309 | blktrans_dev_put(dev); | |
310 | return ret; | |
1da177e4 LT |
311 | } |
312 | ||
9329c5eb | 313 | static const struct block_device_operations mtd_block_ops = { |
1da177e4 | 314 | .owner = THIS_MODULE, |
af0e2a0a AV |
315 | .open = blktrans_open, |
316 | .release = blktrans_release, | |
8a6cfeb6 | 317 | .ioctl = blktrans_ioctl, |
a885c8c4 | 318 | .getgeo = blktrans_getgeo, |
1da177e4 LT |
319 | }; |
320 | ||
321 | int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) | |
322 | { | |
323 | struct mtd_blktrans_ops *tr = new->tr; | |
71a928c0 | 324 | struct mtd_blktrans_dev *d; |
1da177e4 LT |
325 | int last_devnum = -1; |
326 | struct gendisk *gd; | |
a8638622 | 327 | int ret; |
1da177e4 | 328 | |
b3561ea9 | 329 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 330 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
331 | BUG(); |
332 | } | |
333 | ||
048d8719 | 334 | mutex_lock(&blktrans_ref_mutex); |
71a928c0 | 335 | list_for_each_entry(d, &tr->devs, list) { |
1da177e4 LT |
336 | if (new->devnum == -1) { |
337 | /* Use first free number */ | |
338 | if (d->devnum != last_devnum+1) { | |
339 | /* Found a free devnum. Plug it in here */ | |
340 | new->devnum = last_devnum+1; | |
341 | list_add_tail(&new->list, &d->list); | |
342 | goto added; | |
343 | } | |
344 | } else if (d->devnum == new->devnum) { | |
345 | /* Required number taken */ | |
048d8719 | 346 | mutex_unlock(&blktrans_ref_mutex); |
1da177e4 LT |
347 | return -EBUSY; |
348 | } else if (d->devnum > new->devnum) { | |
349 | /* Required number was free */ | |
350 | list_add_tail(&new->list, &d->list); | |
351 | goto added; | |
97894cda | 352 | } |
1da177e4 LT |
353 | last_devnum = d->devnum; |
354 | } | |
a8638622 ML |
355 | |
356 | ret = -EBUSY; | |
1da177e4 LT |
357 | if (new->devnum == -1) |
358 | new->devnum = last_devnum+1; | |
359 | ||
4d3a8534 BH |
360 | /* Check that the device and any partitions will get valid |
361 | * minor numbers and that the disk naming code below can cope | |
362 | * with this number. */ | |
363 | if (new->devnum > (MINORMASK >> tr->part_bits) || | |
048d8719 ML |
364 | (tr->part_bits && new->devnum >= 27 * 26)) { |
365 | mutex_unlock(&blktrans_ref_mutex); | |
a8638622 | 366 | goto error1; |
048d8719 | 367 | } |
1da177e4 | 368 | |
1da177e4 LT |
369 | list_add_tail(&new->list, &tr->devs); |
370 | added: | |
048d8719 ML |
371 | mutex_unlock(&blktrans_ref_mutex); |
372 | ||
ce37ab42 | 373 | mutex_init(&new->lock); |
048d8719 | 374 | kref_init(&new->ref); |
1da177e4 LT |
375 | if (!tr->writesect) |
376 | new->readonly = 1; | |
377 | ||
a8638622 ML |
378 | /* Create gendisk */ |
379 | ret = -ENOMEM; | |
1da177e4 | 380 | gd = alloc_disk(1 << tr->part_bits); |
a8638622 ML |
381 | |
382 | if (!gd) | |
383 | goto error2; | |
384 | ||
385 | new->disk = gd; | |
386 | gd->private_data = new; | |
1da177e4 LT |
387 | gd->major = tr->major; |
388 | gd->first_minor = (new->devnum) << tr->part_bits; | |
9329c5eb | 389 | gd->fops = &mtd_block_ops; |
97894cda | 390 | |
65a8de36 TP |
391 | if (tr->part_bits) |
392 | if (new->devnum < 26) | |
393 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
394 | "%s%c", tr->name, 'a' + new->devnum); | |
395 | else | |
396 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
397 | "%s%c%c", tr->name, | |
398 | 'a' - 1 + new->devnum / 26, | |
399 | 'a' + new->devnum % 26); | |
400 | else | |
401 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
402 | "%s%d", tr->name, new->devnum); | |
1da177e4 | 403 | |
19187672 | 404 | set_capacity(gd, (new->size * tr->blksize) >> 9); |
1da177e4 | 405 | |
a8638622 ML |
406 | /* Create the request queue */ |
407 | spin_lock_init(&new->queue_lock); | |
408 | new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock); | |
409 | ||
410 | if (!new->rq) | |
411 | goto error3; | |
412 | ||
566c0d6a RP |
413 | if (tr->flush) |
414 | blk_queue_flush(new->rq, REQ_FLUSH); | |
415 | ||
a8638622 ML |
416 | new->rq->queuedata = new; |
417 | blk_queue_logical_block_size(new->rq, tr->blksize); | |
418 | ||
16f7eca5 | 419 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq); |
b277da0a | 420 | queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, new->rq); |
16f7eca5 | 421 | |
115ee88c JL |
422 | if (tr->discard) { |
423 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq); | |
424 | new->rq->limits.max_discard_sectors = UINT_MAX; | |
425 | } | |
a8638622 ML |
426 | |
427 | gd->queue = new->rq; | |
428 | ||
22a8578f EG |
429 | /* Create processing workqueue */ |
430 | new->wq = alloc_workqueue("%s%d", 0, 0, | |
431 | tr->name, new->mtd->index); | |
432 | if (!new->wq) | |
a8638622 | 433 | goto error4; |
22a8578f EG |
434 | INIT_WORK(&new->work, mtd_blktrans_work); |
435 | ||
d694846b | 436 | gd->driverfs_dev = &new->mtd->dev; |
1da177e4 LT |
437 | |
438 | if (new->readonly) | |
439 | set_disk_ro(gd, 1); | |
440 | ||
441 | add_disk(gd); | |
026ec578 | 442 | |
133fa8c7 ML |
443 | if (new->disk_attributes) { |
444 | ret = sysfs_create_group(&disk_to_dev(gd)->kobj, | |
026ec578 | 445 | new->disk_attributes); |
133fa8c7 ML |
446 | WARN_ON(ret); |
447 | } | |
1da177e4 | 448 | return 0; |
a8638622 ML |
449 | error4: |
450 | blk_cleanup_queue(new->rq); | |
451 | error3: | |
452 | put_disk(new->disk); | |
453 | error2: | |
454 | list_del(&new->list); | |
455 | error1: | |
a8638622 | 456 | return ret; |
1da177e4 LT |
457 | } |
458 | ||
459 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) | |
460 | { | |
048d8719 ML |
461 | unsigned long flags; |
462 | ||
b3561ea9 | 463 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 464 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
465 | BUG(); |
466 | } | |
467 | ||
026ec578 ML |
468 | if (old->disk_attributes) |
469 | sysfs_remove_group(&disk_to_dev(old->disk)->kobj, | |
470 | old->disk_attributes); | |
471 | ||
dba76c03 ML |
472 | /* Stop new requests to arrive */ |
473 | del_gendisk(old->disk); | |
474 | ||
22a8578f EG |
475 | /* Stop workqueue. This will perform any pending request. */ |
476 | destroy_workqueue(old->wq); | |
a8638622 | 477 | |
048d8719 ML |
478 | /* Kill current requests */ |
479 | spin_lock_irqsave(&old->queue_lock, flags); | |
480 | old->rq->queuedata = NULL; | |
481 | blk_start_queue(old->rq); | |
482 | spin_unlock_irqrestore(&old->queue_lock, flags); | |
048d8719 | 483 | |
008c751e ML |
484 | /* If the device is currently open, tell trans driver to close it, |
485 | then put mtd device, and don't touch it again */ | |
048d8719 | 486 | mutex_lock(&old->lock); |
008c751e ML |
487 | if (old->open) { |
488 | if (old->tr->release) | |
489 | old->tr->release(old); | |
490 | __put_mtd_device(old->mtd); | |
048d8719 ML |
491 | } |
492 | ||
048d8719 ML |
493 | old->mtd = NULL; |
494 | ||
495 | mutex_unlock(&old->lock); | |
496 | blktrans_dev_put(old); | |
1da177e4 LT |
497 | return 0; |
498 | } | |
499 | ||
500 | static void blktrans_notify_remove(struct mtd_info *mtd) | |
501 | { | |
71a928c0 CM |
502 | struct mtd_blktrans_ops *tr; |
503 | struct mtd_blktrans_dev *dev, *next; | |
1da177e4 | 504 | |
71a928c0 CM |
505 | list_for_each_entry(tr, &blktrans_majors, list) |
506 | list_for_each_entry_safe(dev, next, &tr->devs, list) | |
1da177e4 LT |
507 | if (dev->mtd == mtd) |
508 | tr->remove_dev(dev); | |
1da177e4 LT |
509 | } |
510 | ||
511 | static void blktrans_notify_add(struct mtd_info *mtd) | |
512 | { | |
71a928c0 | 513 | struct mtd_blktrans_ops *tr; |
1da177e4 LT |
514 | |
515 | if (mtd->type == MTD_ABSENT) | |
516 | return; | |
517 | ||
71a928c0 | 518 | list_for_each_entry(tr, &blktrans_majors, list) |
1da177e4 | 519 | tr->add_mtd(tr, mtd); |
1da177e4 LT |
520 | } |
521 | ||
522 | static struct mtd_notifier blktrans_notifier = { | |
523 | .add = blktrans_notify_add, | |
524 | .remove = blktrans_notify_remove, | |
525 | }; | |
97894cda | 526 | |
1da177e4 LT |
527 | int register_mtd_blktrans(struct mtd_blktrans_ops *tr) |
528 | { | |
f1332ba2 BH |
529 | struct mtd_info *mtd; |
530 | int ret; | |
1da177e4 | 531 | |
97894cda | 532 | /* Register the notifier if/when the first device type is |
1da177e4 LT |
533 | registered, to prevent the link/init ordering from fucking |
534 | us over. */ | |
535 | if (!blktrans_notifier.list.next) | |
536 | register_mtd_user(&blktrans_notifier); | |
537 | ||
1da177e4 | 538 | |
48b19268 | 539 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
540 | |
541 | ret = register_blkdev(tr->major, tr->name); | |
6fe4c590 | 542 | if (ret < 0) { |
1da177e4 LT |
543 | printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", |
544 | tr->name, tr->major, ret); | |
48b19268 | 545 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
546 | return ret; |
547 | } | |
eae9acd1 | 548 | |
6fe4c590 FL |
549 | if (ret) |
550 | tr->major = ret; | |
551 | ||
19187672 | 552 | tr->blkshift = ffs(tr->blksize) - 1; |
1da177e4 | 553 | |
1da177e4 LT |
554 | INIT_LIST_HEAD(&tr->devs); |
555 | list_add(&tr->list, &blktrans_majors); | |
556 | ||
f1332ba2 BH |
557 | mtd_for_each_device(mtd) |
558 | if (mtd->type != MTD_ABSENT) | |
559 | tr->add_mtd(tr, mtd); | |
1da177e4 | 560 | |
48b19268 | 561 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
562 | return 0; |
563 | } | |
564 | ||
565 | int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) | |
566 | { | |
71a928c0 | 567 | struct mtd_blktrans_dev *dev, *next; |
1da177e4 | 568 | |
48b19268 | 569 | mutex_lock(&mtd_table_mutex); |
1da177e4 | 570 | |
1da177e4 LT |
571 | /* Remove it from the list of active majors */ |
572 | list_del(&tr->list); | |
573 | ||
71a928c0 | 574 | list_for_each_entry_safe(dev, next, &tr->devs, list) |
1da177e4 | 575 | tr->remove_dev(dev); |
1da177e4 | 576 | |
1da177e4 | 577 | unregister_blkdev(tr->major, tr->name); |
48b19268 | 578 | mutex_unlock(&mtd_table_mutex); |
1da177e4 | 579 | |
373ebfbf | 580 | BUG_ON(!list_empty(&tr->devs)); |
1da177e4 LT |
581 | return 0; |
582 | } | |
583 | ||
584 | static void __exit mtd_blktrans_exit(void) | |
585 | { | |
586 | /* No race here -- if someone's currently in register_mtd_blktrans | |
587 | we're screwed anyway. */ | |
588 | if (blktrans_notifier.list.next) | |
589 | unregister_mtd_user(&blktrans_notifier); | |
590 | } | |
591 | ||
592 | module_exit(mtd_blktrans_exit); | |
593 | ||
594 | EXPORT_SYMBOL_GPL(register_mtd_blktrans); | |
595 | EXPORT_SYMBOL_GPL(deregister_mtd_blktrans); | |
596 | EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev); | |
597 | EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev); | |
598 | ||
599 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
600 | MODULE_LICENSE("GPL"); | |
601 | MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'"); |