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> |
7c0f6ba6 | 34 | #include <linux/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 | 75 | |
2a842aca | 76 | static blk_status_t do_blktrans_request(struct mtd_blktrans_ops *tr, |
1da177e4 LT |
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; |
1da177e4 | 85 | |
2a842aca CH |
86 | if (req_op(req) == REQ_OP_FLUSH) { |
87 | if (tr->flush(dev)) | |
88 | return BLK_STS_IOERR; | |
89 | return BLK_STS_OK; | |
90 | } | |
566c0d6a | 91 | |
83096ebf TH |
92 | if (blk_rq_pos(req) + blk_rq_cur_sectors(req) > |
93 | get_capacity(req->rq_disk)) | |
2a842aca | 94 | return BLK_STS_IOERR; |
1da177e4 | 95 | |
aebf526b CH |
96 | switch (req_op(req)) { |
97 | case REQ_OP_DISCARD: | |
2a842aca CH |
98 | if (tr->discard(dev, block, nsect)) |
99 | return BLK_STS_IOERR; | |
100 | return BLK_STS_OK; | |
aebf526b | 101 | case REQ_OP_READ: |
34ab96e6 CH |
102 | buf = kmap(bio_page(req->bio)) + bio_offset(req->bio); |
103 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) { | |
104 | if (tr->readsect(dev, block, buf)) { | |
105 | kunmap(bio_page(req->bio)); | |
2a842aca | 106 | return BLK_STS_IOERR; |
34ab96e6 CH |
107 | } |
108 | } | |
109 | kunmap(bio_page(req->bio)); | |
2d4dc890 | 110 | rq_flush_dcache_pages(req); |
2a842aca | 111 | return BLK_STS_OK; |
aebf526b | 112 | case REQ_OP_WRITE: |
1da177e4 | 113 | if (!tr->writesect) |
2a842aca | 114 | return BLK_STS_IOERR; |
1da177e4 | 115 | |
2d4dc890 | 116 | rq_flush_dcache_pages(req); |
34ab96e6 CH |
117 | buf = kmap(bio_page(req->bio)) + bio_offset(req->bio); |
118 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) { | |
119 | if (tr->writesect(dev, block, buf)) { | |
120 | kunmap(bio_page(req->bio)); | |
2a842aca | 121 | return BLK_STS_IOERR; |
34ab96e6 CH |
122 | } |
123 | } | |
124 | kunmap(bio_page(req->bio)); | |
9a515447 | 125 | return BLK_STS_OK; |
aebf526b | 126 | default: |
2a842aca | 127 | return BLK_STS_IOERR; |
1da177e4 LT |
128 | } |
129 | } | |
130 | ||
c7519dbf JL |
131 | int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev) |
132 | { | |
7bf7e370 | 133 | return dev->bg_stop; |
c7519dbf JL |
134 | } |
135 | EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background); | |
136 | ||
22a8578f | 137 | static void mtd_blktrans_work(struct work_struct *work) |
1da177e4 | 138 | { |
22a8578f EG |
139 | struct mtd_blktrans_dev *dev = |
140 | container_of(work, struct mtd_blktrans_dev, work); | |
c7519dbf | 141 | struct mtd_blktrans_ops *tr = dev->tr; |
a8638622 | 142 | struct request_queue *rq = dev->rq; |
1498ada7 | 143 | struct request *req = NULL; |
c7519dbf | 144 | int background_done = 0; |
1da177e4 | 145 | |
1da177e4 | 146 | spin_lock_irq(rq->queue_lock); |
1498ada7 | 147 | |
22a8578f | 148 | while (1) { |
2a842aca | 149 | blk_status_t res; |
1da177e4 | 150 | |
7bf7e370 | 151 | dev->bg_stop = false; |
9934c8c0 | 152 | if (!req && !(req = blk_fetch_request(rq))) { |
c7519dbf JL |
153 | if (tr->background && !background_done) { |
154 | spin_unlock_irq(rq->queue_lock); | |
155 | mutex_lock(&dev->lock); | |
156 | tr->background(dev); | |
157 | mutex_unlock(&dev->lock); | |
158 | spin_lock_irq(rq->queue_lock); | |
159 | /* | |
160 | * Do background processing just once per idle | |
161 | * period. | |
162 | */ | |
7bf7e370 | 163 | background_done = !dev->bg_stop; |
c7519dbf JL |
164 | continue; |
165 | } | |
22a8578f | 166 | break; |
1da177e4 LT |
167 | } |
168 | ||
1da177e4 LT |
169 | spin_unlock_irq(rq->queue_lock); |
170 | ||
48b19268 | 171 | mutex_lock(&dev->lock); |
a8638622 | 172 | res = do_blktrans_request(dev->tr, dev, req); |
48b19268 | 173 | mutex_unlock(&dev->lock); |
1da177e4 LT |
174 | |
175 | spin_lock_irq(rq->queue_lock); | |
176 | ||
1498ada7 TH |
177 | if (!__blk_end_request_cur(req, res)) |
178 | req = NULL; | |
c7519dbf JL |
179 | |
180 | background_done = 0; | |
1da177e4 | 181 | } |
1498ada7 | 182 | |
1da177e4 | 183 | spin_unlock_irq(rq->queue_lock); |
1da177e4 LT |
184 | } |
185 | ||
186 | static void mtd_blktrans_request(struct request_queue *rq) | |
187 | { | |
048d8719 ML |
188 | struct mtd_blktrans_dev *dev; |
189 | struct request *req = NULL; | |
190 | ||
191 | dev = rq->queuedata; | |
1da177e4 | 192 | |
048d8719 ML |
193 | if (!dev) |
194 | while ((req = blk_fetch_request(rq)) != NULL) | |
2a842aca | 195 | __blk_end_request_all(req, BLK_STS_IOERR); |
22a8578f EG |
196 | else |
197 | queue_work(dev->wq, &dev->work); | |
048d8719 | 198 | } |
1da177e4 | 199 | |
af0e2a0a | 200 | static int blktrans_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 201 | { |
048d8719 | 202 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
008c751e | 203 | int ret = 0; |
048d8719 ML |
204 | |
205 | if (!dev) | |
6e9624b8 | 206 | return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/ |
048d8719 | 207 | |
073db4a5 | 208 | mutex_lock(&mtd_table_mutex); |
f3c63795 | 209 | mutex_lock(&dev->lock); |
048d8719 | 210 | |
342ff28f | 211 | if (dev->open) |
048d8719 | 212 | goto unlock; |
048d8719 | 213 | |
008c751e ML |
214 | kref_get(&dev->ref); |
215 | __module_get(dev->tr->owner); | |
216 | ||
94735ec4 AB |
217 | if (!dev->mtd) |
218 | goto unlock; | |
219 | ||
220 | if (dev->tr->open) { | |
221 | ret = dev->tr->open(dev); | |
222 | if (ret) | |
223 | goto error_put; | |
008c751e | 224 | } |
048d8719 | 225 | |
94735ec4 AB |
226 | ret = __get_mtd_device(dev->mtd); |
227 | if (ret) | |
228 | goto error_release; | |
70d5098a | 229 | dev->file_mode = mode; |
94735ec4 | 230 | |
048d8719 | 231 | unlock: |
342ff28f | 232 | dev->open++; |
048d8719 | 233 | mutex_unlock(&dev->lock); |
f3c63795 | 234 | mutex_unlock(&mtd_table_mutex); |
048d8719 | 235 | blktrans_dev_put(dev); |
1da177e4 | 236 | return ret; |
94735ec4 AB |
237 | |
238 | error_release: | |
239 | if (dev->tr->release) | |
240 | dev->tr->release(dev); | |
241 | error_put: | |
242 | module_put(dev->tr->owner); | |
243 | kref_put(&dev->ref, blktrans_dev_release); | |
244 | mutex_unlock(&dev->lock); | |
f3c63795 | 245 | mutex_unlock(&mtd_table_mutex); |
94735ec4 AB |
246 | blktrans_dev_put(dev); |
247 | return ret; | |
1da177e4 LT |
248 | } |
249 | ||
db2a144b | 250 | static void blktrans_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 251 | { |
048d8719 | 252 | struct mtd_blktrans_dev *dev = blktrans_dev_get(disk); |
1da177e4 | 253 | |
048d8719 | 254 | if (!dev) |
db2a144b | 255 | return; |
1da177e4 | 256 | |
073db4a5 | 257 | mutex_lock(&mtd_table_mutex); |
f3c63795 | 258 | mutex_lock(&dev->lock); |
048d8719 | 259 | |
008c751e | 260 | if (--dev->open) |
048d8719 ML |
261 | goto unlock; |
262 | ||
008c751e ML |
263 | kref_put(&dev->ref, blktrans_dev_release); |
264 | module_put(dev->tr->owner); | |
265 | ||
266 | if (dev->mtd) { | |
a8ca889e AV |
267 | if (dev->tr->release) |
268 | dev->tr->release(dev); | |
008c751e ML |
269 | __put_mtd_device(dev->mtd); |
270 | } | |
048d8719 ML |
271 | unlock: |
272 | mutex_unlock(&dev->lock); | |
f3c63795 | 273 | mutex_unlock(&mtd_table_mutex); |
048d8719 | 274 | blktrans_dev_put(dev); |
1da177e4 LT |
275 | } |
276 | ||
a885c8c4 CH |
277 | static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
278 | { | |
048d8719 ML |
279 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
280 | int ret = -ENXIO; | |
281 | ||
282 | if (!dev) | |
283 | return ret; | |
284 | ||
285 | mutex_lock(&dev->lock); | |
a885c8c4 | 286 | |
048d8719 ML |
287 | if (!dev->mtd) |
288 | goto unlock; | |
289 | ||
c4a3f13c | 290 | ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENOTTY; |
048d8719 ML |
291 | unlock: |
292 | mutex_unlock(&dev->lock); | |
293 | blktrans_dev_put(dev); | |
294 | return ret; | |
a885c8c4 | 295 | } |
1da177e4 | 296 | |
af0e2a0a | 297 | static int blktrans_ioctl(struct block_device *bdev, fmode_t mode, |
1da177e4 LT |
298 | unsigned int cmd, unsigned long arg) |
299 | { | |
048d8719 ML |
300 | struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); |
301 | int ret = -ENXIO; | |
302 | ||
303 | if (!dev) | |
304 | return ret; | |
305 | ||
306 | mutex_lock(&dev->lock); | |
307 | ||
308 | if (!dev->mtd) | |
309 | goto unlock; | |
1da177e4 LT |
310 | |
311 | switch (cmd) { | |
312 | case BLKFLSBUF: | |
048d8719 | 313 | ret = dev->tr->flush ? dev->tr->flush(dev) : 0; |
007c2d87 | 314 | break; |
1da177e4 | 315 | default: |
048d8719 | 316 | ret = -ENOTTY; |
1da177e4 | 317 | } |
048d8719 ML |
318 | unlock: |
319 | mutex_unlock(&dev->lock); | |
320 | blktrans_dev_put(dev); | |
321 | return ret; | |
1da177e4 LT |
322 | } |
323 | ||
9329c5eb | 324 | static const struct block_device_operations mtd_block_ops = { |
1da177e4 | 325 | .owner = THIS_MODULE, |
af0e2a0a AV |
326 | .open = blktrans_open, |
327 | .release = blktrans_release, | |
8a6cfeb6 | 328 | .ioctl = blktrans_ioctl, |
a885c8c4 | 329 | .getgeo = blktrans_getgeo, |
1da177e4 LT |
330 | }; |
331 | ||
332 | int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) | |
333 | { | |
334 | struct mtd_blktrans_ops *tr = new->tr; | |
71a928c0 | 335 | struct mtd_blktrans_dev *d; |
1da177e4 LT |
336 | int last_devnum = -1; |
337 | struct gendisk *gd; | |
a8638622 | 338 | int ret; |
1da177e4 | 339 | |
b3561ea9 | 340 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 341 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
342 | BUG(); |
343 | } | |
344 | ||
048d8719 | 345 | mutex_lock(&blktrans_ref_mutex); |
71a928c0 | 346 | list_for_each_entry(d, &tr->devs, list) { |
1da177e4 LT |
347 | if (new->devnum == -1) { |
348 | /* Use first free number */ | |
349 | if (d->devnum != last_devnum+1) { | |
350 | /* Found a free devnum. Plug it in here */ | |
351 | new->devnum = last_devnum+1; | |
352 | list_add_tail(&new->list, &d->list); | |
353 | goto added; | |
354 | } | |
355 | } else if (d->devnum == new->devnum) { | |
356 | /* Required number taken */ | |
048d8719 | 357 | mutex_unlock(&blktrans_ref_mutex); |
1da177e4 LT |
358 | return -EBUSY; |
359 | } else if (d->devnum > new->devnum) { | |
360 | /* Required number was free */ | |
361 | list_add_tail(&new->list, &d->list); | |
362 | goto added; | |
97894cda | 363 | } |
1da177e4 LT |
364 | last_devnum = d->devnum; |
365 | } | |
a8638622 ML |
366 | |
367 | ret = -EBUSY; | |
1da177e4 LT |
368 | if (new->devnum == -1) |
369 | new->devnum = last_devnum+1; | |
370 | ||
4d3a8534 BH |
371 | /* Check that the device and any partitions will get valid |
372 | * minor numbers and that the disk naming code below can cope | |
373 | * with this number. */ | |
374 | if (new->devnum > (MINORMASK >> tr->part_bits) || | |
048d8719 ML |
375 | (tr->part_bits && new->devnum >= 27 * 26)) { |
376 | mutex_unlock(&blktrans_ref_mutex); | |
a8638622 | 377 | goto error1; |
048d8719 | 378 | } |
1da177e4 | 379 | |
1da177e4 LT |
380 | list_add_tail(&new->list, &tr->devs); |
381 | added: | |
048d8719 ML |
382 | mutex_unlock(&blktrans_ref_mutex); |
383 | ||
ce37ab42 | 384 | mutex_init(&new->lock); |
048d8719 | 385 | kref_init(&new->ref); |
1da177e4 LT |
386 | if (!tr->writesect) |
387 | new->readonly = 1; | |
388 | ||
a8638622 ML |
389 | /* Create gendisk */ |
390 | ret = -ENOMEM; | |
1da177e4 | 391 | gd = alloc_disk(1 << tr->part_bits); |
a8638622 ML |
392 | |
393 | if (!gd) | |
394 | goto error2; | |
395 | ||
396 | new->disk = gd; | |
397 | gd->private_data = new; | |
1da177e4 LT |
398 | gd->major = tr->major; |
399 | gd->first_minor = (new->devnum) << tr->part_bits; | |
9329c5eb | 400 | gd->fops = &mtd_block_ops; |
97894cda | 401 | |
65a8de36 TP |
402 | if (tr->part_bits) |
403 | if (new->devnum < 26) | |
404 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
405 | "%s%c", tr->name, 'a' + new->devnum); | |
406 | else | |
407 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
408 | "%s%c%c", tr->name, | |
409 | 'a' - 1 + new->devnum / 26, | |
410 | 'a' + new->devnum % 26); | |
411 | else | |
412 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
413 | "%s%d", tr->name, new->devnum); | |
1da177e4 | 414 | |
2ce401d5 | 415 | set_capacity(gd, ((u64)new->size * tr->blksize) >> 9); |
1da177e4 | 416 | |
a8638622 ML |
417 | /* Create the request queue */ |
418 | spin_lock_init(&new->queue_lock); | |
419 | new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock); | |
420 | ||
421 | if (!new->rq) | |
422 | goto error3; | |
423 | ||
566c0d6a | 424 | if (tr->flush) |
fec3ff5d | 425 | blk_queue_write_cache(new->rq, true, false); |
566c0d6a | 426 | |
a8638622 ML |
427 | new->rq->queuedata = new; |
428 | blk_queue_logical_block_size(new->rq, tr->blksize); | |
429 | ||
8b904b5b BVA |
430 | blk_queue_flag_set(QUEUE_FLAG_NONROT, new->rq); |
431 | blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, new->rq); | |
16f7eca5 | 432 | |
115ee88c | 433 | if (tr->discard) { |
8b904b5b | 434 | blk_queue_flag_set(QUEUE_FLAG_DISCARD, new->rq); |
2bb4cd5c | 435 | blk_queue_max_discard_sectors(new->rq, UINT_MAX); |
115ee88c | 436 | } |
a8638622 ML |
437 | |
438 | gd->queue = new->rq; | |
439 | ||
22a8578f EG |
440 | /* Create processing workqueue */ |
441 | new->wq = alloc_workqueue("%s%d", 0, 0, | |
442 | tr->name, new->mtd->index); | |
443 | if (!new->wq) | |
a8638622 | 444 | goto error4; |
22a8578f EG |
445 | INIT_WORK(&new->work, mtd_blktrans_work); |
446 | ||
1da177e4 LT |
447 | if (new->readonly) |
448 | set_disk_ro(gd, 1); | |
449 | ||
0d52c756 | 450 | device_add_disk(&new->mtd->dev, gd); |
026ec578 | 451 | |
133fa8c7 ML |
452 | if (new->disk_attributes) { |
453 | ret = sysfs_create_group(&disk_to_dev(gd)->kobj, | |
026ec578 | 454 | new->disk_attributes); |
133fa8c7 ML |
455 | WARN_ON(ret); |
456 | } | |
1da177e4 | 457 | return 0; |
a8638622 ML |
458 | error4: |
459 | blk_cleanup_queue(new->rq); | |
460 | error3: | |
461 | put_disk(new->disk); | |
462 | error2: | |
463 | list_del(&new->list); | |
464 | error1: | |
a8638622 | 465 | return ret; |
1da177e4 LT |
466 | } |
467 | ||
468 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) | |
469 | { | |
048d8719 ML |
470 | unsigned long flags; |
471 | ||
b3561ea9 | 472 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 473 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
474 | BUG(); |
475 | } | |
476 | ||
026ec578 ML |
477 | if (old->disk_attributes) |
478 | sysfs_remove_group(&disk_to_dev(old->disk)->kobj, | |
479 | old->disk_attributes); | |
480 | ||
dba76c03 ML |
481 | /* Stop new requests to arrive */ |
482 | del_gendisk(old->disk); | |
483 | ||
22a8578f EG |
484 | /* Stop workqueue. This will perform any pending request. */ |
485 | destroy_workqueue(old->wq); | |
a8638622 | 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'"); |