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> |
99f9b243 | 35 | #include <linux/kthread.h> |
1da177e4 | 36 | #include <asm/uaccess.h> |
1da177e4 | 37 | |
356d70f1 | 38 | #include "mtdcore.h" |
1da177e4 | 39 | |
356d70f1 | 40 | static LIST_HEAD(blktrans_majors); |
048d8719 ML |
41 | static DEFINE_MUTEX(blktrans_ref_mutex); |
42 | ||
7f53f12f | 43 | static void blktrans_dev_release(struct kref *kref) |
048d8719 ML |
44 | { |
45 | struct mtd_blktrans_dev *dev = | |
46 | container_of(kref, struct mtd_blktrans_dev, ref); | |
47 | ||
48 | dev->disk->private_data = NULL; | |
e4d64cab | 49 | blk_cleanup_queue(dev->rq); |
048d8719 ML |
50 | put_disk(dev->disk); |
51 | list_del(&dev->list); | |
52 | kfree(dev); | |
53 | } | |
54 | ||
55 | static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk) | |
56 | { | |
57 | struct mtd_blktrans_dev *dev; | |
58 | ||
59 | mutex_lock(&blktrans_ref_mutex); | |
60 | dev = disk->private_data; | |
61 | ||
62 | if (!dev) | |
63 | goto unlock; | |
64 | kref_get(&dev->ref); | |
65 | unlock: | |
66 | mutex_unlock(&blktrans_ref_mutex); | |
67 | return dev; | |
68 | } | |
69 | ||
7f53f12f | 70 | static void blktrans_dev_put(struct mtd_blktrans_dev *dev) |
048d8719 ML |
71 | { |
72 | mutex_lock(&blktrans_ref_mutex); | |
73 | kref_put(&dev->ref, blktrans_dev_release); | |
74 | mutex_unlock(&blktrans_ref_mutex); | |
75 | } | |
1da177e4 | 76 | |
1da177e4 LT |
77 | |
78 | static int do_blktrans_request(struct mtd_blktrans_ops *tr, | |
79 | struct mtd_blktrans_dev *dev, | |
80 | struct request *req) | |
81 | { | |
82 | unsigned long block, nsect; | |
83 | char *buf; | |
84 | ||
83096ebf | 85 | block = blk_rq_pos(req) << 9 >> tr->blkshift; |
1011c1b9 | 86 | nsect = blk_rq_cur_bytes(req) >> tr->blkshift; |
19187672 | 87 | |
1da177e4 LT |
88 | buf = req->buffer; |
89 | ||
33659ebb | 90 | if (req->cmd_type != REQ_TYPE_FS) |
f06d9a2b | 91 | return -EIO; |
1da177e4 | 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 | { | |
124 | if (kthread_should_stop()) | |
125 | return 1; | |
126 | ||
7bf7e370 | 127 | return dev->bg_stop; |
c7519dbf JL |
128 | } |
129 | EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background); | |
130 | ||
1da177e4 LT |
131 | static int mtd_blktrans_thread(void *arg) |
132 | { | |
a8638622 | 133 | struct mtd_blktrans_dev *dev = arg; |
c7519dbf | 134 | struct mtd_blktrans_ops *tr = dev->tr; |
a8638622 | 135 | struct request_queue *rq = dev->rq; |
1498ada7 | 136 | struct request *req = NULL; |
c7519dbf | 137 | int background_done = 0; |
1da177e4 | 138 | |
1da177e4 | 139 | spin_lock_irq(rq->queue_lock); |
1498ada7 | 140 | |
3e67fe45 | 141 | while (!kthread_should_stop()) { |
f06d9a2b | 142 | int res; |
1da177e4 | 143 | |
7bf7e370 | 144 | dev->bg_stop = false; |
9934c8c0 | 145 | if (!req && !(req = blk_fetch_request(rq))) { |
c7519dbf JL |
146 | if (tr->background && !background_done) { |
147 | spin_unlock_irq(rq->queue_lock); | |
148 | mutex_lock(&dev->lock); | |
149 | tr->background(dev); | |
150 | mutex_unlock(&dev->lock); | |
151 | spin_lock_irq(rq->queue_lock); | |
152 | /* | |
153 | * Do background processing just once per idle | |
154 | * period. | |
155 | */ | |
7bf7e370 | 156 | background_done = !dev->bg_stop; |
c7519dbf JL |
157 | continue; |
158 | } | |
1da177e4 | 159 | set_current_state(TASK_INTERRUPTIBLE); |
12aebf3e ML |
160 | |
161 | if (kthread_should_stop()) | |
162 | set_current_state(TASK_RUNNING); | |
163 | ||
1da177e4 | 164 | spin_unlock_irq(rq->queue_lock); |
1da177e4 | 165 | schedule(); |
1da177e4 | 166 | spin_lock_irq(rq->queue_lock); |
1da177e4 LT |
167 | continue; |
168 | } | |
169 | ||
1da177e4 LT |
170 | spin_unlock_irq(rq->queue_lock); |
171 | ||
48b19268 | 172 | mutex_lock(&dev->lock); |
a8638622 | 173 | res = do_blktrans_request(dev->tr, dev, req); |
48b19268 | 174 | mutex_unlock(&dev->lock); |
1da177e4 LT |
175 | |
176 | spin_lock_irq(rq->queue_lock); | |
177 | ||
1498ada7 TH |
178 | if (!__blk_end_request_cur(req, res)) |
179 | req = NULL; | |
c7519dbf JL |
180 | |
181 | background_done = 0; | |
1da177e4 | 182 | } |
1498ada7 TH |
183 | |
184 | if (req) | |
185 | __blk_end_request_all(req, -EIO); | |
186 | ||
1da177e4 LT |
187 | spin_unlock_irq(rq->queue_lock); |
188 | ||
3e67fe45 | 189 | return 0; |
1da177e4 LT |
190 | } |
191 | ||
192 | static void mtd_blktrans_request(struct request_queue *rq) | |
193 | { | |
048d8719 ML |
194 | struct mtd_blktrans_dev *dev; |
195 | struct request *req = NULL; | |
196 | ||
197 | dev = rq->queuedata; | |
1da177e4 | 198 | |
048d8719 ML |
199 | if (!dev) |
200 | while ((req = blk_fetch_request(rq)) != NULL) | |
201 | __blk_end_request_all(req, -ENODEV); | |
7bf7e370 AB |
202 | else { |
203 | dev->bg_stop = true; | |
048d8719 | 204 | wake_up_process(dev->thread); |
7bf7e370 | 205 | } |
048d8719 | 206 | } |
1da177e4 | 207 | |
af0e2a0a | 208 | static int blktrans_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 209 | { |
048d8719 | 210 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
008c751e | 211 | int ret = 0; |
048d8719 ML |
212 | |
213 | if (!dev) | |
6e9624b8 | 214 | return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/ |
048d8719 ML |
215 | |
216 | mutex_lock(&dev->lock); | |
217 | ||
008c751e | 218 | if (dev->open++) |
048d8719 | 219 | goto unlock; |
048d8719 | 220 | |
008c751e ML |
221 | kref_get(&dev->ref); |
222 | __module_get(dev->tr->owner); | |
223 | ||
94735ec4 AB |
224 | if (!dev->mtd) |
225 | goto unlock; | |
226 | ||
227 | if (dev->tr->open) { | |
228 | ret = dev->tr->open(dev); | |
229 | if (ret) | |
230 | goto error_put; | |
008c751e | 231 | } |
048d8719 | 232 | |
94735ec4 AB |
233 | ret = __get_mtd_device(dev->mtd); |
234 | if (ret) | |
235 | goto error_release; | |
236 | ||
048d8719 ML |
237 | unlock: |
238 | mutex_unlock(&dev->lock); | |
239 | blktrans_dev_put(dev); | |
1da177e4 | 240 | return ret; |
94735ec4 AB |
241 | |
242 | error_release: | |
243 | if (dev->tr->release) | |
244 | dev->tr->release(dev); | |
245 | error_put: | |
246 | module_put(dev->tr->owner); | |
247 | kref_put(&dev->ref, blktrans_dev_release); | |
248 | mutex_unlock(&dev->lock); | |
249 | blktrans_dev_put(dev); | |
250 | return ret; | |
1da177e4 LT |
251 | } |
252 | ||
af0e2a0a | 253 | static int blktrans_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 254 | { |
048d8719 | 255 | struct mtd_blktrans_dev *dev = blktrans_dev_get(disk); |
008c751e | 256 | int ret = 0; |
1da177e4 | 257 | |
048d8719 ML |
258 | if (!dev) |
259 | return ret; | |
1da177e4 | 260 | |
048d8719 ML |
261 | mutex_lock(&dev->lock); |
262 | ||
008c751e | 263 | if (--dev->open) |
048d8719 ML |
264 | goto unlock; |
265 | ||
008c751e ML |
266 | kref_put(&dev->ref, blktrans_dev_release); |
267 | module_put(dev->tr->owner); | |
268 | ||
269 | if (dev->mtd) { | |
270 | ret = dev->tr->release ? dev->tr->release(dev) : 0; | |
271 | __put_mtd_device(dev->mtd); | |
272 | } | |
048d8719 ML |
273 | unlock: |
274 | mutex_unlock(&dev->lock); | |
275 | blktrans_dev_put(dev); | |
1da177e4 LT |
276 | return ret; |
277 | } | |
278 | ||
a885c8c4 CH |
279 | static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
280 | { | |
048d8719 ML |
281 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
282 | int ret = -ENXIO; | |
283 | ||
284 | if (!dev) | |
285 | return ret; | |
286 | ||
287 | mutex_lock(&dev->lock); | |
a885c8c4 | 288 | |
048d8719 ML |
289 | if (!dev->mtd) |
290 | goto unlock; | |
291 | ||
292 | ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0; | |
293 | unlock: | |
294 | mutex_unlock(&dev->lock); | |
295 | blktrans_dev_put(dev); | |
296 | return ret; | |
a885c8c4 | 297 | } |
1da177e4 | 298 | |
af0e2a0a | 299 | static int blktrans_ioctl(struct block_device *bdev, fmode_t mode, |
1da177e4 LT |
300 | unsigned int cmd, unsigned long arg) |
301 | { | |
048d8719 ML |
302 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
303 | int ret = -ENXIO; | |
304 | ||
305 | if (!dev) | |
306 | return ret; | |
307 | ||
308 | mutex_lock(&dev->lock); | |
309 | ||
310 | if (!dev->mtd) | |
311 | goto unlock; | |
1da177e4 LT |
312 | |
313 | switch (cmd) { | |
314 | case BLKFLSBUF: | |
048d8719 | 315 | ret = dev->tr->flush ? dev->tr->flush(dev) : 0; |
007c2d87 | 316 | break; |
1da177e4 | 317 | default: |
048d8719 | 318 | ret = -ENOTTY; |
1da177e4 | 319 | } |
048d8719 ML |
320 | unlock: |
321 | mutex_unlock(&dev->lock); | |
322 | blktrans_dev_put(dev); | |
323 | return ret; | |
1da177e4 LT |
324 | } |
325 | ||
83d5cde4 | 326 | static const struct block_device_operations mtd_blktrans_ops = { |
1da177e4 | 327 | .owner = THIS_MODULE, |
af0e2a0a AV |
328 | .open = blktrans_open, |
329 | .release = blktrans_release, | |
8a6cfeb6 | 330 | .ioctl = blktrans_ioctl, |
a885c8c4 | 331 | .getgeo = blktrans_getgeo, |
1da177e4 LT |
332 | }; |
333 | ||
334 | int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) | |
335 | { | |
336 | struct mtd_blktrans_ops *tr = new->tr; | |
71a928c0 | 337 | struct mtd_blktrans_dev *d; |
1da177e4 LT |
338 | int last_devnum = -1; |
339 | struct gendisk *gd; | |
a8638622 | 340 | int ret; |
1da177e4 | 341 | |
b3561ea9 | 342 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 343 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
344 | BUG(); |
345 | } | |
346 | ||
048d8719 | 347 | mutex_lock(&blktrans_ref_mutex); |
71a928c0 | 348 | list_for_each_entry(d, &tr->devs, list) { |
1da177e4 LT |
349 | if (new->devnum == -1) { |
350 | /* Use first free number */ | |
351 | if (d->devnum != last_devnum+1) { | |
352 | /* Found a free devnum. Plug it in here */ | |
353 | new->devnum = last_devnum+1; | |
354 | list_add_tail(&new->list, &d->list); | |
355 | goto added; | |
356 | } | |
357 | } else if (d->devnum == new->devnum) { | |
358 | /* Required number taken */ | |
048d8719 | 359 | mutex_unlock(&blktrans_ref_mutex); |
1da177e4 LT |
360 | return -EBUSY; |
361 | } else if (d->devnum > new->devnum) { | |
362 | /* Required number was free */ | |
363 | list_add_tail(&new->list, &d->list); | |
364 | goto added; | |
97894cda | 365 | } |
1da177e4 LT |
366 | last_devnum = d->devnum; |
367 | } | |
a8638622 ML |
368 | |
369 | ret = -EBUSY; | |
1da177e4 LT |
370 | if (new->devnum == -1) |
371 | new->devnum = last_devnum+1; | |
372 | ||
4d3a8534 BH |
373 | /* Check that the device and any partitions will get valid |
374 | * minor numbers and that the disk naming code below can cope | |
375 | * with this number. */ | |
376 | if (new->devnum > (MINORMASK >> tr->part_bits) || | |
048d8719 ML |
377 | (tr->part_bits && new->devnum >= 27 * 26)) { |
378 | mutex_unlock(&blktrans_ref_mutex); | |
a8638622 | 379 | goto error1; |
048d8719 | 380 | } |
1da177e4 | 381 | |
1da177e4 LT |
382 | list_add_tail(&new->list, &tr->devs); |
383 | added: | |
048d8719 ML |
384 | mutex_unlock(&blktrans_ref_mutex); |
385 | ||
ce37ab42 | 386 | mutex_init(&new->lock); |
048d8719 | 387 | kref_init(&new->ref); |
1da177e4 LT |
388 | if (!tr->writesect) |
389 | new->readonly = 1; | |
390 | ||
a8638622 ML |
391 | /* Create gendisk */ |
392 | ret = -ENOMEM; | |
1da177e4 | 393 | gd = alloc_disk(1 << tr->part_bits); |
a8638622 ML |
394 | |
395 | if (!gd) | |
396 | goto error2; | |
397 | ||
398 | new->disk = gd; | |
399 | gd->private_data = new; | |
1da177e4 LT |
400 | gd->major = tr->major; |
401 | gd->first_minor = (new->devnum) << tr->part_bits; | |
402 | gd->fops = &mtd_blktrans_ops; | |
97894cda | 403 | |
65a8de36 TP |
404 | if (tr->part_bits) |
405 | if (new->devnum < 26) | |
406 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
407 | "%s%c", tr->name, 'a' + new->devnum); | |
408 | else | |
409 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
410 | "%s%c%c", tr->name, | |
411 | 'a' - 1 + new->devnum / 26, | |
412 | 'a' + new->devnum % 26); | |
413 | else | |
414 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
415 | "%s%d", tr->name, new->devnum); | |
1da177e4 | 416 | |
19187672 | 417 | set_capacity(gd, (new->size * tr->blksize) >> 9); |
1da177e4 | 418 | |
a8638622 ML |
419 | /* Create the request queue */ |
420 | spin_lock_init(&new->queue_lock); | |
421 | new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock); | |
422 | ||
423 | if (!new->rq) | |
424 | goto error3; | |
425 | ||
426 | new->rq->queuedata = new; | |
427 | blk_queue_logical_block_size(new->rq, tr->blksize); | |
428 | ||
115ee88c JL |
429 | if (tr->discard) { |
430 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq); | |
431 | new->rq->limits.max_discard_sectors = UINT_MAX; | |
432 | } | |
a8638622 ML |
433 | |
434 | gd->queue = new->rq; | |
435 | ||
436 | /* Create processing thread */ | |
437 | /* TODO: workqueue ? */ | |
438 | new->thread = kthread_run(mtd_blktrans_thread, new, | |
439 | "%s%d", tr->name, new->mtd->index); | |
440 | if (IS_ERR(new->thread)) { | |
441 | ret = PTR_ERR(new->thread); | |
442 | goto error4; | |
443 | } | |
d694846b | 444 | gd->driverfs_dev = &new->mtd->dev; |
1da177e4 LT |
445 | |
446 | if (new->readonly) | |
447 | set_disk_ro(gd, 1); | |
448 | ||
449 | add_disk(gd); | |
026ec578 | 450 | |
133fa8c7 ML |
451 | if (new->disk_attributes) { |
452 | ret = sysfs_create_group(&disk_to_dev(gd)->kobj, | |
026ec578 | 453 | new->disk_attributes); |
133fa8c7 ML |
454 | WARN_ON(ret); |
455 | } | |
1da177e4 | 456 | return 0; |
a8638622 ML |
457 | error4: |
458 | blk_cleanup_queue(new->rq); | |
459 | error3: | |
460 | put_disk(new->disk); | |
461 | error2: | |
462 | list_del(&new->list); | |
463 | error1: | |
a8638622 | 464 | return ret; |
1da177e4 LT |
465 | } |
466 | ||
467 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) | |
468 | { | |
048d8719 ML |
469 | unsigned long flags; |
470 | ||
b3561ea9 | 471 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 472 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
473 | BUG(); |
474 | } | |
475 | ||
026ec578 ML |
476 | if (old->disk_attributes) |
477 | sysfs_remove_group(&disk_to_dev(old->disk)->kobj, | |
478 | old->disk_attributes); | |
479 | ||
dba76c03 ML |
480 | /* Stop new requests to arrive */ |
481 | del_gendisk(old->disk); | |
482 | ||
483 | ||
a8638622 ML |
484 | /* Stop the thread */ |
485 | kthread_stop(old->thread); | |
486 | ||
048d8719 ML |
487 | /* Kill current requests */ |
488 | spin_lock_irqsave(&old->queue_lock, flags); | |
489 | old->rq->queuedata = NULL; | |
490 | blk_start_queue(old->rq); | |
491 | spin_unlock_irqrestore(&old->queue_lock, flags); | |
048d8719 | 492 | |
008c751e ML |
493 | /* If the device is currently open, tell trans driver to close it, |
494 | then put mtd device, and don't touch it again */ | |
048d8719 | 495 | mutex_lock(&old->lock); |
008c751e ML |
496 | if (old->open) { |
497 | if (old->tr->release) | |
498 | old->tr->release(old); | |
499 | __put_mtd_device(old->mtd); | |
048d8719 ML |
500 | } |
501 | ||
048d8719 ML |
502 | old->mtd = NULL; |
503 | ||
504 | mutex_unlock(&old->lock); | |
505 | blktrans_dev_put(old); | |
1da177e4 LT |
506 | return 0; |
507 | } | |
508 | ||
509 | static void blktrans_notify_remove(struct mtd_info *mtd) | |
510 | { | |
71a928c0 CM |
511 | struct mtd_blktrans_ops *tr; |
512 | struct mtd_blktrans_dev *dev, *next; | |
1da177e4 | 513 | |
71a928c0 CM |
514 | list_for_each_entry(tr, &blktrans_majors, list) |
515 | list_for_each_entry_safe(dev, next, &tr->devs, list) | |
1da177e4 LT |
516 | if (dev->mtd == mtd) |
517 | tr->remove_dev(dev); | |
1da177e4 LT |
518 | } |
519 | ||
520 | static void blktrans_notify_add(struct mtd_info *mtd) | |
521 | { | |
71a928c0 | 522 | struct mtd_blktrans_ops *tr; |
1da177e4 LT |
523 | |
524 | if (mtd->type == MTD_ABSENT) | |
525 | return; | |
526 | ||
71a928c0 | 527 | list_for_each_entry(tr, &blktrans_majors, list) |
1da177e4 | 528 | tr->add_mtd(tr, mtd); |
1da177e4 LT |
529 | } |
530 | ||
531 | static struct mtd_notifier blktrans_notifier = { | |
532 | .add = blktrans_notify_add, | |
533 | .remove = blktrans_notify_remove, | |
534 | }; | |
97894cda | 535 | |
1da177e4 LT |
536 | int register_mtd_blktrans(struct mtd_blktrans_ops *tr) |
537 | { | |
f1332ba2 BH |
538 | struct mtd_info *mtd; |
539 | int ret; | |
1da177e4 | 540 | |
97894cda | 541 | /* Register the notifier if/when the first device type is |
1da177e4 LT |
542 | registered, to prevent the link/init ordering from fucking |
543 | us over. */ | |
544 | if (!blktrans_notifier.list.next) | |
545 | register_mtd_user(&blktrans_notifier); | |
546 | ||
1da177e4 | 547 | |
48b19268 | 548 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
549 | |
550 | ret = register_blkdev(tr->major, tr->name); | |
6fe4c590 | 551 | if (ret < 0) { |
1da177e4 LT |
552 | printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", |
553 | tr->name, tr->major, ret); | |
48b19268 | 554 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
555 | return ret; |
556 | } | |
eae9acd1 | 557 | |
6fe4c590 FL |
558 | if (ret) |
559 | tr->major = ret; | |
560 | ||
19187672 | 561 | tr->blkshift = ffs(tr->blksize) - 1; |
1da177e4 | 562 | |
1da177e4 LT |
563 | INIT_LIST_HEAD(&tr->devs); |
564 | list_add(&tr->list, &blktrans_majors); | |
565 | ||
f1332ba2 BH |
566 | mtd_for_each_device(mtd) |
567 | if (mtd->type != MTD_ABSENT) | |
568 | tr->add_mtd(tr, mtd); | |
1da177e4 | 569 | |
48b19268 | 570 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
571 | return 0; |
572 | } | |
573 | ||
574 | int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) | |
575 | { | |
71a928c0 | 576 | struct mtd_blktrans_dev *dev, *next; |
1da177e4 | 577 | |
48b19268 | 578 | mutex_lock(&mtd_table_mutex); |
1da177e4 | 579 | |
1da177e4 LT |
580 | /* Remove it from the list of active majors */ |
581 | list_del(&tr->list); | |
582 | ||
71a928c0 | 583 | list_for_each_entry_safe(dev, next, &tr->devs, list) |
1da177e4 | 584 | tr->remove_dev(dev); |
1da177e4 | 585 | |
1da177e4 | 586 | unregister_blkdev(tr->major, tr->name); |
48b19268 | 587 | mutex_unlock(&mtd_table_mutex); |
1da177e4 | 588 | |
373ebfbf | 589 | BUG_ON(!list_empty(&tr->devs)); |
1da177e4 LT |
590 | return 0; |
591 | } | |
592 | ||
593 | static void __exit mtd_blktrans_exit(void) | |
594 | { | |
595 | /* No race here -- if someone's currently in register_mtd_blktrans | |
596 | we're screwed anyway. */ | |
597 | if (blktrans_notifier.list.next) | |
598 | unregister_mtd_user(&blktrans_notifier); | |
599 | } | |
600 | ||
601 | module_exit(mtd_blktrans_exit); | |
602 | ||
603 | EXPORT_SYMBOL_GPL(register_mtd_blktrans); | |
604 | EXPORT_SYMBOL_GPL(deregister_mtd_blktrans); | |
605 | EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev); | |
606 | EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev); | |
607 | ||
608 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
609 | MODULE_LICENSE("GPL"); | |
610 | MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'"); |