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> | |
33 | #include <linux/init.h> | |
48b19268 | 34 | #include <linux/mutex.h> |
1da177e4 | 35 | #include <asm/uaccess.h> |
1da177e4 | 36 | |
356d70f1 | 37 | #include "mtdcore.h" |
1da177e4 | 38 | |
356d70f1 | 39 | static LIST_HEAD(blktrans_majors); |
048d8719 ML |
40 | static DEFINE_MUTEX(blktrans_ref_mutex); |
41 | ||
7f53f12f | 42 | static void blktrans_dev_release(struct kref *kref) |
048d8719 ML |
43 | { |
44 | struct mtd_blktrans_dev *dev = | |
45 | container_of(kref, struct mtd_blktrans_dev, ref); | |
46 | ||
47 | dev->disk->private_data = NULL; | |
e4d64cab | 48 | blk_cleanup_queue(dev->rq); |
048d8719 ML |
49 | put_disk(dev->disk); |
50 | list_del(&dev->list); | |
51 | kfree(dev); | |
52 | } | |
53 | ||
54 | static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk) | |
55 | { | |
56 | struct mtd_blktrans_dev *dev; | |
57 | ||
58 | mutex_lock(&blktrans_ref_mutex); | |
59 | dev = disk->private_data; | |
60 | ||
61 | if (!dev) | |
62 | goto unlock; | |
63 | kref_get(&dev->ref); | |
64 | unlock: | |
65 | mutex_unlock(&blktrans_ref_mutex); | |
66 | return dev; | |
67 | } | |
68 | ||
7f53f12f | 69 | static void blktrans_dev_put(struct mtd_blktrans_dev *dev) |
048d8719 ML |
70 | { |
71 | mutex_lock(&blktrans_ref_mutex); | |
72 | kref_put(&dev->ref, blktrans_dev_release); | |
73 | mutex_unlock(&blktrans_ref_mutex); | |
74 | } | |
1da177e4 | 75 | |
1da177e4 LT |
76 | |
77 | static int do_blktrans_request(struct mtd_blktrans_ops *tr, | |
78 | struct mtd_blktrans_dev *dev, | |
79 | struct request *req) | |
80 | { | |
81 | unsigned long block, nsect; | |
82 | char *buf; | |
83 | ||
83096ebf | 84 | block = blk_rq_pos(req) << 9 >> tr->blkshift; |
1011c1b9 | 85 | nsect = blk_rq_cur_bytes(req) >> tr->blkshift; |
19187672 | 86 | |
1da177e4 LT |
87 | buf = req->buffer; |
88 | ||
33659ebb | 89 | if (req->cmd_type != REQ_TYPE_FS) |
f06d9a2b | 90 | return -EIO; |
1da177e4 | 91 | |
83096ebf TH |
92 | if (blk_rq_pos(req) + blk_rq_cur_sectors(req) > |
93 | get_capacity(req->rq_disk)) | |
f06d9a2b | 94 | return -EIO; |
1da177e4 | 95 | |
33659ebb | 96 | if (req->cmd_flags & REQ_DISCARD) |
1122a26f CH |
97 | return tr->discard(dev, block, nsect); |
98 | ||
1da177e4 LT |
99 | switch(rq_data_dir(req)) { |
100 | case READ: | |
19187672 | 101 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 102 | if (tr->readsect(dev, block, buf)) |
f06d9a2b | 103 | return -EIO; |
2d4dc890 | 104 | rq_flush_dcache_pages(req); |
f06d9a2b | 105 | return 0; |
1da177e4 LT |
106 | case WRITE: |
107 | if (!tr->writesect) | |
f06d9a2b | 108 | return -EIO; |
1da177e4 | 109 | |
2d4dc890 | 110 | rq_flush_dcache_pages(req); |
19187672 | 111 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 112 | if (tr->writesect(dev, block, buf)) |
f06d9a2b TH |
113 | return -EIO; |
114 | return 0; | |
1da177e4 | 115 | default: |
9a292308 | 116 | printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req)); |
f06d9a2b | 117 | return -EIO; |
1da177e4 LT |
118 | } |
119 | } | |
120 | ||
c7519dbf JL |
121 | int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev) |
122 | { | |
7bf7e370 | 123 | return dev->bg_stop; |
c7519dbf JL |
124 | } |
125 | EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background); | |
126 | ||
22a8578f | 127 | static void mtd_blktrans_work(struct work_struct *work) |
1da177e4 | 128 | { |
22a8578f EG |
129 | struct mtd_blktrans_dev *dev = |
130 | container_of(work, struct mtd_blktrans_dev, work); | |
c7519dbf | 131 | struct mtd_blktrans_ops *tr = dev->tr; |
a8638622 | 132 | struct request_queue *rq = dev->rq; |
1498ada7 | 133 | struct request *req = NULL; |
c7519dbf | 134 | int background_done = 0; |
1da177e4 | 135 | |
1da177e4 | 136 | spin_lock_irq(rq->queue_lock); |
1498ada7 | 137 | |
22a8578f | 138 | while (1) { |
f06d9a2b | 139 | int res; |
1da177e4 | 140 | |
7bf7e370 | 141 | dev->bg_stop = false; |
9934c8c0 | 142 | if (!req && !(req = blk_fetch_request(rq))) { |
c7519dbf JL |
143 | if (tr->background && !background_done) { |
144 | spin_unlock_irq(rq->queue_lock); | |
145 | mutex_lock(&dev->lock); | |
146 | tr->background(dev); | |
147 | mutex_unlock(&dev->lock); | |
148 | spin_lock_irq(rq->queue_lock); | |
149 | /* | |
150 | * Do background processing just once per idle | |
151 | * period. | |
152 | */ | |
7bf7e370 | 153 | background_done = !dev->bg_stop; |
c7519dbf JL |
154 | continue; |
155 | } | |
22a8578f | 156 | break; |
1da177e4 LT |
157 | } |
158 | ||
1da177e4 LT |
159 | spin_unlock_irq(rq->queue_lock); |
160 | ||
48b19268 | 161 | mutex_lock(&dev->lock); |
a8638622 | 162 | res = do_blktrans_request(dev->tr, dev, req); |
48b19268 | 163 | mutex_unlock(&dev->lock); |
1da177e4 LT |
164 | |
165 | spin_lock_irq(rq->queue_lock); | |
166 | ||
1498ada7 TH |
167 | if (!__blk_end_request_cur(req, res)) |
168 | req = NULL; | |
c7519dbf JL |
169 | |
170 | background_done = 0; | |
1da177e4 | 171 | } |
1498ada7 TH |
172 | |
173 | if (req) | |
174 | __blk_end_request_all(req, -EIO); | |
175 | ||
1da177e4 | 176 | spin_unlock_irq(rq->queue_lock); |
1da177e4 LT |
177 | } |
178 | ||
179 | static void mtd_blktrans_request(struct request_queue *rq) | |
180 | { | |
048d8719 ML |
181 | struct mtd_blktrans_dev *dev; |
182 | struct request *req = NULL; | |
183 | ||
184 | dev = rq->queuedata; | |
1da177e4 | 185 | |
048d8719 ML |
186 | if (!dev) |
187 | while ((req = blk_fetch_request(rq)) != NULL) | |
188 | __blk_end_request_all(req, -ENODEV); | |
22a8578f EG |
189 | else |
190 | queue_work(dev->wq, &dev->work); | |
048d8719 | 191 | } |
1da177e4 | 192 | |
af0e2a0a | 193 | static int blktrans_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 194 | { |
048d8719 | 195 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
008c751e | 196 | int ret = 0; |
048d8719 ML |
197 | |
198 | if (!dev) | |
6e9624b8 | 199 | return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/ |
048d8719 ML |
200 | |
201 | mutex_lock(&dev->lock); | |
202 | ||
342ff28f | 203 | if (dev->open) |
048d8719 | 204 | goto unlock; |
048d8719 | 205 | |
008c751e ML |
206 | kref_get(&dev->ref); |
207 | __module_get(dev->tr->owner); | |
208 | ||
94735ec4 AB |
209 | if (!dev->mtd) |
210 | goto unlock; | |
211 | ||
212 | if (dev->tr->open) { | |
213 | ret = dev->tr->open(dev); | |
214 | if (ret) | |
215 | goto error_put; | |
008c751e | 216 | } |
048d8719 | 217 | |
94735ec4 AB |
218 | ret = __get_mtd_device(dev->mtd); |
219 | if (ret) | |
220 | goto error_release; | |
70d5098a | 221 | dev->file_mode = mode; |
94735ec4 | 222 | |
048d8719 | 223 | unlock: |
342ff28f | 224 | dev->open++; |
048d8719 ML |
225 | mutex_unlock(&dev->lock); |
226 | blktrans_dev_put(dev); | |
1da177e4 | 227 | return ret; |
94735ec4 AB |
228 | |
229 | error_release: | |
230 | if (dev->tr->release) | |
231 | dev->tr->release(dev); | |
232 | error_put: | |
233 | module_put(dev->tr->owner); | |
234 | kref_put(&dev->ref, blktrans_dev_release); | |
235 | mutex_unlock(&dev->lock); | |
236 | blktrans_dev_put(dev); | |
237 | return ret; | |
1da177e4 LT |
238 | } |
239 | ||
af0e2a0a | 240 | static int blktrans_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 241 | { |
048d8719 | 242 | struct mtd_blktrans_dev *dev = blktrans_dev_get(disk); |
008c751e | 243 | int ret = 0; |
1da177e4 | 244 | |
048d8719 ML |
245 | if (!dev) |
246 | return ret; | |
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) { | |
257 | ret = dev->tr->release ? dev->tr->release(dev) : 0; | |
258 | __put_mtd_device(dev->mtd); | |
259 | } | |
048d8719 ML |
260 | unlock: |
261 | mutex_unlock(&dev->lock); | |
262 | blktrans_dev_put(dev); | |
1da177e4 LT |
263 | return ret; |
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 | ||
413 | new->rq->queuedata = new; | |
414 | blk_queue_logical_block_size(new->rq, tr->blksize); | |
415 | ||
16f7eca5 DM |
416 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq); |
417 | ||
115ee88c JL |
418 | if (tr->discard) { |
419 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq); | |
420 | new->rq->limits.max_discard_sectors = UINT_MAX; | |
421 | } | |
a8638622 ML |
422 | |
423 | gd->queue = new->rq; | |
424 | ||
22a8578f EG |
425 | /* Create processing workqueue */ |
426 | new->wq = alloc_workqueue("%s%d", 0, 0, | |
427 | tr->name, new->mtd->index); | |
428 | if (!new->wq) | |
a8638622 | 429 | goto error4; |
22a8578f EG |
430 | INIT_WORK(&new->work, mtd_blktrans_work); |
431 | ||
d694846b | 432 | gd->driverfs_dev = &new->mtd->dev; |
1da177e4 LT |
433 | |
434 | if (new->readonly) | |
435 | set_disk_ro(gd, 1); | |
436 | ||
437 | add_disk(gd); | |
026ec578 | 438 | |
133fa8c7 ML |
439 | if (new->disk_attributes) { |
440 | ret = sysfs_create_group(&disk_to_dev(gd)->kobj, | |
026ec578 | 441 | new->disk_attributes); |
133fa8c7 ML |
442 | WARN_ON(ret); |
443 | } | |
1da177e4 | 444 | return 0; |
a8638622 ML |
445 | error4: |
446 | blk_cleanup_queue(new->rq); | |
447 | error3: | |
448 | put_disk(new->disk); | |
449 | error2: | |
450 | list_del(&new->list); | |
451 | error1: | |
a8638622 | 452 | return ret; |
1da177e4 LT |
453 | } |
454 | ||
455 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) | |
456 | { | |
048d8719 ML |
457 | unsigned long flags; |
458 | ||
b3561ea9 | 459 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 460 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
461 | BUG(); |
462 | } | |
463 | ||
026ec578 ML |
464 | if (old->disk_attributes) |
465 | sysfs_remove_group(&disk_to_dev(old->disk)->kobj, | |
466 | old->disk_attributes); | |
467 | ||
dba76c03 ML |
468 | /* Stop new requests to arrive */ |
469 | del_gendisk(old->disk); | |
470 | ||
22a8578f EG |
471 | /* Stop workqueue. This will perform any pending request. */ |
472 | destroy_workqueue(old->wq); | |
a8638622 | 473 | |
048d8719 ML |
474 | /* Kill current requests */ |
475 | spin_lock_irqsave(&old->queue_lock, flags); | |
476 | old->rq->queuedata = NULL; | |
477 | blk_start_queue(old->rq); | |
478 | spin_unlock_irqrestore(&old->queue_lock, flags); | |
048d8719 | 479 | |
008c751e ML |
480 | /* If the device is currently open, tell trans driver to close it, |
481 | then put mtd device, and don't touch it again */ | |
048d8719 | 482 | mutex_lock(&old->lock); |
008c751e ML |
483 | if (old->open) { |
484 | if (old->tr->release) | |
485 | old->tr->release(old); | |
486 | __put_mtd_device(old->mtd); | |
048d8719 ML |
487 | } |
488 | ||
048d8719 ML |
489 | old->mtd = NULL; |
490 | ||
491 | mutex_unlock(&old->lock); | |
492 | blktrans_dev_put(old); | |
1da177e4 LT |
493 | return 0; |
494 | } | |
495 | ||
496 | static void blktrans_notify_remove(struct mtd_info *mtd) | |
497 | { | |
71a928c0 CM |
498 | struct mtd_blktrans_ops *tr; |
499 | struct mtd_blktrans_dev *dev, *next; | |
1da177e4 | 500 | |
71a928c0 CM |
501 | list_for_each_entry(tr, &blktrans_majors, list) |
502 | list_for_each_entry_safe(dev, next, &tr->devs, list) | |
1da177e4 LT |
503 | if (dev->mtd == mtd) |
504 | tr->remove_dev(dev); | |
1da177e4 LT |
505 | } |
506 | ||
507 | static void blktrans_notify_add(struct mtd_info *mtd) | |
508 | { | |
71a928c0 | 509 | struct mtd_blktrans_ops *tr; |
1da177e4 LT |
510 | |
511 | if (mtd->type == MTD_ABSENT) | |
512 | return; | |
513 | ||
71a928c0 | 514 | list_for_each_entry(tr, &blktrans_majors, list) |
1da177e4 | 515 | tr->add_mtd(tr, mtd); |
1da177e4 LT |
516 | } |
517 | ||
518 | static struct mtd_notifier blktrans_notifier = { | |
519 | .add = blktrans_notify_add, | |
520 | .remove = blktrans_notify_remove, | |
521 | }; | |
97894cda | 522 | |
1da177e4 LT |
523 | int register_mtd_blktrans(struct mtd_blktrans_ops *tr) |
524 | { | |
f1332ba2 BH |
525 | struct mtd_info *mtd; |
526 | int ret; | |
1da177e4 | 527 | |
97894cda | 528 | /* Register the notifier if/when the first device type is |
1da177e4 LT |
529 | registered, to prevent the link/init ordering from fucking |
530 | us over. */ | |
531 | if (!blktrans_notifier.list.next) | |
532 | register_mtd_user(&blktrans_notifier); | |
533 | ||
1da177e4 | 534 | |
48b19268 | 535 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
536 | |
537 | ret = register_blkdev(tr->major, tr->name); | |
6fe4c590 | 538 | if (ret < 0) { |
1da177e4 LT |
539 | printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", |
540 | tr->name, tr->major, ret); | |
48b19268 | 541 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
542 | return ret; |
543 | } | |
eae9acd1 | 544 | |
6fe4c590 FL |
545 | if (ret) |
546 | tr->major = ret; | |
547 | ||
19187672 | 548 | tr->blkshift = ffs(tr->blksize) - 1; |
1da177e4 | 549 | |
1da177e4 LT |
550 | INIT_LIST_HEAD(&tr->devs); |
551 | list_add(&tr->list, &blktrans_majors); | |
552 | ||
f1332ba2 BH |
553 | mtd_for_each_device(mtd) |
554 | if (mtd->type != MTD_ABSENT) | |
555 | tr->add_mtd(tr, mtd); | |
1da177e4 | 556 | |
48b19268 | 557 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
558 | return 0; |
559 | } | |
560 | ||
561 | int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) | |
562 | { | |
71a928c0 | 563 | struct mtd_blktrans_dev *dev, *next; |
1da177e4 | 564 | |
48b19268 | 565 | mutex_lock(&mtd_table_mutex); |
1da177e4 | 566 | |
1da177e4 LT |
567 | /* Remove it from the list of active majors */ |
568 | list_del(&tr->list); | |
569 | ||
71a928c0 | 570 | list_for_each_entry_safe(dev, next, &tr->devs, list) |
1da177e4 | 571 | tr->remove_dev(dev); |
1da177e4 | 572 | |
1da177e4 | 573 | unregister_blkdev(tr->major, tr->name); |
48b19268 | 574 | mutex_unlock(&mtd_table_mutex); |
1da177e4 | 575 | |
373ebfbf | 576 | BUG_ON(!list_empty(&tr->devs)); |
1da177e4 LT |
577 | return 0; |
578 | } | |
579 | ||
580 | static void __exit mtd_blktrans_exit(void) | |
581 | { | |
582 | /* No race here -- if someone's currently in register_mtd_blktrans | |
583 | we're screwed anyway. */ | |
584 | if (blktrans_notifier.list.next) | |
585 | unregister_mtd_user(&blktrans_notifier); | |
586 | } | |
587 | ||
588 | module_exit(mtd_blktrans_exit); | |
589 | ||
590 | EXPORT_SYMBOL_GPL(register_mtd_blktrans); | |
591 | EXPORT_SYMBOL_GPL(deregister_mtd_blktrans); | |
592 | EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev); | |
593 | EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev); | |
594 | ||
595 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
596 | MODULE_LICENSE("GPL"); | |
597 | MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'"); |