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; |
19187672 | 85 | |
1da177e4 LT |
86 | buf = req->buffer; |
87 | ||
33659ebb | 88 | if (req->cmd_type != REQ_TYPE_FS) |
f06d9a2b | 89 | return -EIO; |
1da177e4 | 90 | |
83096ebf TH |
91 | if (blk_rq_pos(req) + blk_rq_cur_sectors(req) > |
92 | get_capacity(req->rq_disk)) | |
f06d9a2b | 93 | return -EIO; |
1da177e4 | 94 | |
33659ebb | 95 | if (req->cmd_flags & REQ_DISCARD) |
1122a26f CH |
96 | return tr->discard(dev, block, nsect); |
97 | ||
1da177e4 LT |
98 | switch(rq_data_dir(req)) { |
99 | case READ: | |
19187672 | 100 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 101 | if (tr->readsect(dev, block, buf)) |
f06d9a2b | 102 | return -EIO; |
2d4dc890 | 103 | rq_flush_dcache_pages(req); |
f06d9a2b | 104 | return 0; |
1da177e4 LT |
105 | case WRITE: |
106 | if (!tr->writesect) | |
f06d9a2b | 107 | return -EIO; |
1da177e4 | 108 | |
2d4dc890 | 109 | rq_flush_dcache_pages(req); |
19187672 | 110 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 111 | if (tr->writesect(dev, block, buf)) |
f06d9a2b TH |
112 | return -EIO; |
113 | return 0; | |
1da177e4 | 114 | default: |
9a292308 | 115 | printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req)); |
f06d9a2b | 116 | return -EIO; |
1da177e4 LT |
117 | } |
118 | } | |
119 | ||
c7519dbf JL |
120 | int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev) |
121 | { | |
7bf7e370 | 122 | return dev->bg_stop; |
c7519dbf JL |
123 | } |
124 | EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background); | |
125 | ||
22a8578f | 126 | static void mtd_blktrans_work(struct work_struct *work) |
1da177e4 | 127 | { |
22a8578f EG |
128 | struct mtd_blktrans_dev *dev = |
129 | container_of(work, struct mtd_blktrans_dev, work); | |
c7519dbf | 130 | struct mtd_blktrans_ops *tr = dev->tr; |
a8638622 | 131 | struct request_queue *rq = dev->rq; |
1498ada7 | 132 | struct request *req = NULL; |
c7519dbf | 133 | int background_done = 0; |
1da177e4 | 134 | |
1da177e4 | 135 | spin_lock_irq(rq->queue_lock); |
1498ada7 | 136 | |
22a8578f | 137 | while (1) { |
f06d9a2b | 138 | int res; |
1da177e4 | 139 | |
7bf7e370 | 140 | dev->bg_stop = false; |
9934c8c0 | 141 | if (!req && !(req = blk_fetch_request(rq))) { |
c7519dbf JL |
142 | if (tr->background && !background_done) { |
143 | spin_unlock_irq(rq->queue_lock); | |
144 | mutex_lock(&dev->lock); | |
145 | tr->background(dev); | |
146 | mutex_unlock(&dev->lock); | |
147 | spin_lock_irq(rq->queue_lock); | |
148 | /* | |
149 | * Do background processing just once per idle | |
150 | * period. | |
151 | */ | |
7bf7e370 | 152 | background_done = !dev->bg_stop; |
c7519dbf JL |
153 | continue; |
154 | } | |
22a8578f | 155 | break; |
1da177e4 LT |
156 | } |
157 | ||
1da177e4 LT |
158 | spin_unlock_irq(rq->queue_lock); |
159 | ||
48b19268 | 160 | mutex_lock(&dev->lock); |
a8638622 | 161 | res = do_blktrans_request(dev->tr, dev, req); |
48b19268 | 162 | mutex_unlock(&dev->lock); |
1da177e4 LT |
163 | |
164 | spin_lock_irq(rq->queue_lock); | |
165 | ||
1498ada7 TH |
166 | if (!__blk_end_request_cur(req, res)) |
167 | req = NULL; | |
c7519dbf JL |
168 | |
169 | background_done = 0; | |
1da177e4 | 170 | } |
1498ada7 TH |
171 | |
172 | if (req) | |
173 | __blk_end_request_all(req, -EIO); | |
174 | ||
1da177e4 | 175 | spin_unlock_irq(rq->queue_lock); |
1da177e4 LT |
176 | } |
177 | ||
178 | static void mtd_blktrans_request(struct request_queue *rq) | |
179 | { | |
048d8719 ML |
180 | struct mtd_blktrans_dev *dev; |
181 | struct request *req = NULL; | |
182 | ||
183 | dev = rq->queuedata; | |
1da177e4 | 184 | |
048d8719 ML |
185 | if (!dev) |
186 | while ((req = blk_fetch_request(rq)) != NULL) | |
187 | __blk_end_request_all(req, -ENODEV); | |
22a8578f EG |
188 | else |
189 | queue_work(dev->wq, &dev->work); | |
048d8719 | 190 | } |
1da177e4 | 191 | |
af0e2a0a | 192 | static int blktrans_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 193 | { |
048d8719 | 194 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
008c751e | 195 | int ret = 0; |
048d8719 ML |
196 | |
197 | if (!dev) | |
6e9624b8 | 198 | return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/ |
048d8719 ML |
199 | |
200 | mutex_lock(&dev->lock); | |
201 | ||
342ff28f | 202 | if (dev->open) |
048d8719 | 203 | goto unlock; |
048d8719 | 204 | |
008c751e ML |
205 | kref_get(&dev->ref); |
206 | __module_get(dev->tr->owner); | |
207 | ||
94735ec4 AB |
208 | if (!dev->mtd) |
209 | goto unlock; | |
210 | ||
211 | if (dev->tr->open) { | |
212 | ret = dev->tr->open(dev); | |
213 | if (ret) | |
214 | goto error_put; | |
008c751e | 215 | } |
048d8719 | 216 | |
94735ec4 AB |
217 | ret = __get_mtd_device(dev->mtd); |
218 | if (ret) | |
219 | goto error_release; | |
70d5098a | 220 | dev->file_mode = mode; |
94735ec4 | 221 | |
048d8719 | 222 | unlock: |
342ff28f | 223 | dev->open++; |
048d8719 ML |
224 | mutex_unlock(&dev->lock); |
225 | blktrans_dev_put(dev); | |
1da177e4 | 226 | return ret; |
94735ec4 AB |
227 | |
228 | error_release: | |
229 | if (dev->tr->release) | |
230 | dev->tr->release(dev); | |
231 | error_put: | |
232 | module_put(dev->tr->owner); | |
233 | kref_put(&dev->ref, blktrans_dev_release); | |
234 | mutex_unlock(&dev->lock); | |
235 | blktrans_dev_put(dev); | |
236 | return ret; | |
1da177e4 LT |
237 | } |
238 | ||
db2a144b | 239 | static void blktrans_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 240 | { |
048d8719 | 241 | struct mtd_blktrans_dev *dev = blktrans_dev_get(disk); |
1da177e4 | 242 | |
048d8719 | 243 | if (!dev) |
db2a144b | 244 | return; |
1da177e4 | 245 | |
048d8719 ML |
246 | mutex_lock(&dev->lock); |
247 | ||
008c751e | 248 | if (--dev->open) |
048d8719 ML |
249 | goto unlock; |
250 | ||
008c751e ML |
251 | kref_put(&dev->ref, blktrans_dev_release); |
252 | module_put(dev->tr->owner); | |
253 | ||
254 | if (dev->mtd) { | |
a8ca889e AV |
255 | if (dev->tr->release) |
256 | dev->tr->release(dev); | |
008c751e ML |
257 | __put_mtd_device(dev->mtd); |
258 | } | |
048d8719 ML |
259 | unlock: |
260 | mutex_unlock(&dev->lock); | |
261 | blktrans_dev_put(dev); | |
1da177e4 LT |
262 | } |
263 | ||
a885c8c4 CH |
264 | static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
265 | { | |
048d8719 ML |
266 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
267 | int ret = -ENXIO; | |
268 | ||
269 | if (!dev) | |
270 | return ret; | |
271 | ||
272 | mutex_lock(&dev->lock); | |
a885c8c4 | 273 | |
048d8719 ML |
274 | if (!dev->mtd) |
275 | goto unlock; | |
276 | ||
277 | ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0; | |
278 | unlock: | |
279 | mutex_unlock(&dev->lock); | |
280 | blktrans_dev_put(dev); | |
281 | return ret; | |
a885c8c4 | 282 | } |
1da177e4 | 283 | |
af0e2a0a | 284 | static int blktrans_ioctl(struct block_device *bdev, fmode_t mode, |
1da177e4 LT |
285 | unsigned int cmd, unsigned long arg) |
286 | { | |
048d8719 ML |
287 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
288 | int ret = -ENXIO; | |
289 | ||
290 | if (!dev) | |
291 | return ret; | |
292 | ||
293 | mutex_lock(&dev->lock); | |
294 | ||
295 | if (!dev->mtd) | |
296 | goto unlock; | |
1da177e4 LT |
297 | |
298 | switch (cmd) { | |
299 | case BLKFLSBUF: | |
048d8719 | 300 | ret = dev->tr->flush ? dev->tr->flush(dev) : 0; |
007c2d87 | 301 | break; |
1da177e4 | 302 | default: |
048d8719 | 303 | ret = -ENOTTY; |
1da177e4 | 304 | } |
048d8719 ML |
305 | unlock: |
306 | mutex_unlock(&dev->lock); | |
307 | blktrans_dev_put(dev); | |
308 | return ret; | |
1da177e4 LT |
309 | } |
310 | ||
9329c5eb | 311 | static const struct block_device_operations mtd_block_ops = { |
1da177e4 | 312 | .owner = THIS_MODULE, |
af0e2a0a AV |
313 | .open = blktrans_open, |
314 | .release = blktrans_release, | |
8a6cfeb6 | 315 | .ioctl = blktrans_ioctl, |
a885c8c4 | 316 | .getgeo = blktrans_getgeo, |
1da177e4 LT |
317 | }; |
318 | ||
319 | int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) | |
320 | { | |
321 | struct mtd_blktrans_ops *tr = new->tr; | |
71a928c0 | 322 | struct mtd_blktrans_dev *d; |
1da177e4 LT |
323 | int last_devnum = -1; |
324 | struct gendisk *gd; | |
a8638622 | 325 | int ret; |
1da177e4 | 326 | |
b3561ea9 | 327 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 328 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
329 | BUG(); |
330 | } | |
331 | ||
048d8719 | 332 | mutex_lock(&blktrans_ref_mutex); |
71a928c0 | 333 | list_for_each_entry(d, &tr->devs, list) { |
1da177e4 LT |
334 | if (new->devnum == -1) { |
335 | /* Use first free number */ | |
336 | if (d->devnum != last_devnum+1) { | |
337 | /* Found a free devnum. Plug it in here */ | |
338 | new->devnum = last_devnum+1; | |
339 | list_add_tail(&new->list, &d->list); | |
340 | goto added; | |
341 | } | |
342 | } else if (d->devnum == new->devnum) { | |
343 | /* Required number taken */ | |
048d8719 | 344 | mutex_unlock(&blktrans_ref_mutex); |
1da177e4 LT |
345 | return -EBUSY; |
346 | } else if (d->devnum > new->devnum) { | |
347 | /* Required number was free */ | |
348 | list_add_tail(&new->list, &d->list); | |
349 | goto added; | |
97894cda | 350 | } |
1da177e4 LT |
351 | last_devnum = d->devnum; |
352 | } | |
a8638622 ML |
353 | |
354 | ret = -EBUSY; | |
1da177e4 LT |
355 | if (new->devnum == -1) |
356 | new->devnum = last_devnum+1; | |
357 | ||
4d3a8534 BH |
358 | /* Check that the device and any partitions will get valid |
359 | * minor numbers and that the disk naming code below can cope | |
360 | * with this number. */ | |
361 | if (new->devnum > (MINORMASK >> tr->part_bits) || | |
048d8719 ML |
362 | (tr->part_bits && new->devnum >= 27 * 26)) { |
363 | mutex_unlock(&blktrans_ref_mutex); | |
a8638622 | 364 | goto error1; |
048d8719 | 365 | } |
1da177e4 | 366 | |
1da177e4 LT |
367 | list_add_tail(&new->list, &tr->devs); |
368 | added: | |
048d8719 ML |
369 | mutex_unlock(&blktrans_ref_mutex); |
370 | ||
ce37ab42 | 371 | mutex_init(&new->lock); |
048d8719 | 372 | kref_init(&new->ref); |
1da177e4 LT |
373 | if (!tr->writesect) |
374 | new->readonly = 1; | |
375 | ||
a8638622 ML |
376 | /* Create gendisk */ |
377 | ret = -ENOMEM; | |
1da177e4 | 378 | gd = alloc_disk(1 << tr->part_bits); |
a8638622 ML |
379 | |
380 | if (!gd) | |
381 | goto error2; | |
382 | ||
383 | new->disk = gd; | |
384 | gd->private_data = new; | |
1da177e4 LT |
385 | gd->major = tr->major; |
386 | gd->first_minor = (new->devnum) << tr->part_bits; | |
9329c5eb | 387 | gd->fops = &mtd_block_ops; |
97894cda | 388 | |
65a8de36 TP |
389 | if (tr->part_bits) |
390 | if (new->devnum < 26) | |
391 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
392 | "%s%c", tr->name, 'a' + new->devnum); | |
393 | else | |
394 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
395 | "%s%c%c", tr->name, | |
396 | 'a' - 1 + new->devnum / 26, | |
397 | 'a' + new->devnum % 26); | |
398 | else | |
399 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
400 | "%s%d", tr->name, new->devnum); | |
1da177e4 | 401 | |
19187672 | 402 | set_capacity(gd, (new->size * tr->blksize) >> 9); |
1da177e4 | 403 | |
a8638622 ML |
404 | /* Create the request queue */ |
405 | spin_lock_init(&new->queue_lock); | |
406 | new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock); | |
407 | ||
408 | if (!new->rq) | |
409 | goto error3; | |
410 | ||
411 | new->rq->queuedata = new; | |
412 | blk_queue_logical_block_size(new->rq, tr->blksize); | |
413 | ||
16f7eca5 DM |
414 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq); |
415 | ||
115ee88c JL |
416 | if (tr->discard) { |
417 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq); | |
418 | new->rq->limits.max_discard_sectors = UINT_MAX; | |
419 | } | |
a8638622 ML |
420 | |
421 | gd->queue = new->rq; | |
422 | ||
22a8578f EG |
423 | /* Create processing workqueue */ |
424 | new->wq = alloc_workqueue("%s%d", 0, 0, | |
425 | tr->name, new->mtd->index); | |
426 | if (!new->wq) | |
a8638622 | 427 | goto error4; |
22a8578f EG |
428 | INIT_WORK(&new->work, mtd_blktrans_work); |
429 | ||
d694846b | 430 | gd->driverfs_dev = &new->mtd->dev; |
1da177e4 LT |
431 | |
432 | if (new->readonly) | |
433 | set_disk_ro(gd, 1); | |
434 | ||
435 | add_disk(gd); | |
026ec578 | 436 | |
133fa8c7 ML |
437 | if (new->disk_attributes) { |
438 | ret = sysfs_create_group(&disk_to_dev(gd)->kobj, | |
026ec578 | 439 | new->disk_attributes); |
133fa8c7 ML |
440 | WARN_ON(ret); |
441 | } | |
1da177e4 | 442 | return 0; |
a8638622 ML |
443 | error4: |
444 | blk_cleanup_queue(new->rq); | |
445 | error3: | |
446 | put_disk(new->disk); | |
447 | error2: | |
448 | list_del(&new->list); | |
449 | error1: | |
a8638622 | 450 | return ret; |
1da177e4 LT |
451 | } |
452 | ||
453 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) | |
454 | { | |
048d8719 ML |
455 | unsigned long flags; |
456 | ||
b3561ea9 | 457 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 458 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
459 | BUG(); |
460 | } | |
461 | ||
026ec578 ML |
462 | if (old->disk_attributes) |
463 | sysfs_remove_group(&disk_to_dev(old->disk)->kobj, | |
464 | old->disk_attributes); | |
465 | ||
dba76c03 ML |
466 | /* Stop new requests to arrive */ |
467 | del_gendisk(old->disk); | |
468 | ||
22a8578f EG |
469 | /* Stop workqueue. This will perform any pending request. */ |
470 | destroy_workqueue(old->wq); | |
a8638622 | 471 | |
048d8719 ML |
472 | /* Kill current requests */ |
473 | spin_lock_irqsave(&old->queue_lock, flags); | |
474 | old->rq->queuedata = NULL; | |
475 | blk_start_queue(old->rq); | |
476 | spin_unlock_irqrestore(&old->queue_lock, flags); | |
048d8719 | 477 | |
008c751e ML |
478 | /* If the device is currently open, tell trans driver to close it, |
479 | then put mtd device, and don't touch it again */ | |
048d8719 | 480 | mutex_lock(&old->lock); |
008c751e ML |
481 | if (old->open) { |
482 | if (old->tr->release) | |
483 | old->tr->release(old); | |
484 | __put_mtd_device(old->mtd); | |
048d8719 ML |
485 | } |
486 | ||
048d8719 ML |
487 | old->mtd = NULL; |
488 | ||
489 | mutex_unlock(&old->lock); | |
490 | blktrans_dev_put(old); | |
1da177e4 LT |
491 | return 0; |
492 | } | |
493 | ||
494 | static void blktrans_notify_remove(struct mtd_info *mtd) | |
495 | { | |
71a928c0 CM |
496 | struct mtd_blktrans_ops *tr; |
497 | struct mtd_blktrans_dev *dev, *next; | |
1da177e4 | 498 | |
71a928c0 CM |
499 | list_for_each_entry(tr, &blktrans_majors, list) |
500 | list_for_each_entry_safe(dev, next, &tr->devs, list) | |
1da177e4 LT |
501 | if (dev->mtd == mtd) |
502 | tr->remove_dev(dev); | |
1da177e4 LT |
503 | } |
504 | ||
505 | static void blktrans_notify_add(struct mtd_info *mtd) | |
506 | { | |
71a928c0 | 507 | struct mtd_blktrans_ops *tr; |
1da177e4 LT |
508 | |
509 | if (mtd->type == MTD_ABSENT) | |
510 | return; | |
511 | ||
71a928c0 | 512 | list_for_each_entry(tr, &blktrans_majors, list) |
1da177e4 | 513 | tr->add_mtd(tr, mtd); |
1da177e4 LT |
514 | } |
515 | ||
516 | static struct mtd_notifier blktrans_notifier = { | |
517 | .add = blktrans_notify_add, | |
518 | .remove = blktrans_notify_remove, | |
519 | }; | |
97894cda | 520 | |
1da177e4 LT |
521 | int register_mtd_blktrans(struct mtd_blktrans_ops *tr) |
522 | { | |
f1332ba2 BH |
523 | struct mtd_info *mtd; |
524 | int ret; | |
1da177e4 | 525 | |
97894cda | 526 | /* Register the notifier if/when the first device type is |
1da177e4 LT |
527 | registered, to prevent the link/init ordering from fucking |
528 | us over. */ | |
529 | if (!blktrans_notifier.list.next) | |
530 | register_mtd_user(&blktrans_notifier); | |
531 | ||
1da177e4 | 532 | |
48b19268 | 533 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
534 | |
535 | ret = register_blkdev(tr->major, tr->name); | |
6fe4c590 | 536 | if (ret < 0) { |
1da177e4 LT |
537 | printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", |
538 | tr->name, tr->major, ret); | |
48b19268 | 539 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
540 | return ret; |
541 | } | |
eae9acd1 | 542 | |
6fe4c590 FL |
543 | if (ret) |
544 | tr->major = ret; | |
545 | ||
19187672 | 546 | tr->blkshift = ffs(tr->blksize) - 1; |
1da177e4 | 547 | |
1da177e4 LT |
548 | INIT_LIST_HEAD(&tr->devs); |
549 | list_add(&tr->list, &blktrans_majors); | |
550 | ||
f1332ba2 BH |
551 | mtd_for_each_device(mtd) |
552 | if (mtd->type != MTD_ABSENT) | |
553 | tr->add_mtd(tr, mtd); | |
1da177e4 | 554 | |
48b19268 | 555 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
556 | return 0; |
557 | } | |
558 | ||
559 | int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) | |
560 | { | |
71a928c0 | 561 | struct mtd_blktrans_dev *dev, *next; |
1da177e4 | 562 | |
48b19268 | 563 | mutex_lock(&mtd_table_mutex); |
1da177e4 | 564 | |
1da177e4 LT |
565 | /* Remove it from the list of active majors */ |
566 | list_del(&tr->list); | |
567 | ||
71a928c0 | 568 | list_for_each_entry_safe(dev, next, &tr->devs, list) |
1da177e4 | 569 | tr->remove_dev(dev); |
1da177e4 | 570 | |
1da177e4 | 571 | unregister_blkdev(tr->major, tr->name); |
48b19268 | 572 | mutex_unlock(&mtd_table_mutex); |
1da177e4 | 573 | |
373ebfbf | 574 | BUG_ON(!list_empty(&tr->devs)); |
1da177e4 LT |
575 | return 0; |
576 | } | |
577 | ||
578 | static void __exit mtd_blktrans_exit(void) | |
579 | { | |
580 | /* No race here -- if someone's currently in register_mtd_blktrans | |
581 | we're screwed anyway. */ | |
582 | if (blktrans_notifier.list.next) | |
583 | unregister_mtd_user(&blktrans_notifier); | |
584 | } | |
585 | ||
586 | module_exit(mtd_blktrans_exit); | |
587 | ||
588 | EXPORT_SYMBOL_GPL(register_mtd_blktrans); | |
589 | EXPORT_SYMBOL_GPL(deregister_mtd_blktrans); | |
590 | EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev); | |
591 | EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev); | |
592 | ||
593 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
594 | MODULE_LICENSE("GPL"); | |
595 | MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'"); |