1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
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>
34#include <linux/mutex.h>
35#include <asm/uaccess.h>
36
37#include "mtdcore.h"
38
39static LIST_HEAD(blktrans_majors);
40static DEFINE_MUTEX(blktrans_ref_mutex);
41
42static void blktrans_dev_release(struct kref *kref)
43{
44 struct mtd_blktrans_dev *dev =
45 container_of(kref, struct mtd_blktrans_dev, ref);
46
47 dev->disk->private_data = NULL;
48 blk_cleanup_queue(dev->rq);
49 put_disk(dev->disk);
50 list_del(&dev->list);
51 kfree(dev);
52}
53
54static 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);
64unlock:
65 mutex_unlock(&blktrans_ref_mutex);
66 return dev;
67}
68
69static void blktrans_dev_put(struct mtd_blktrans_dev *dev)
70{
71 mutex_lock(&blktrans_ref_mutex);
72 kref_put(&dev->ref, blktrans_dev_release);
73 mutex_unlock(&blktrans_ref_mutex);
74}
75
76
77static 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
84 block = blk_rq_pos(req) << 9 >> tr->blkshift;
85 nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
86
87 buf = req->buffer;
88
89 if (req->cmd_type != REQ_TYPE_FS)
90 return -EIO;
91
92 if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
93 get_capacity(req->rq_disk))
94 return -EIO;
95
96 if (req->cmd_flags & REQ_DISCARD)
97 return tr->discard(dev, block, nsect);
98
99 switch(rq_data_dir(req)) {
100 case READ:
101 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
102 if (tr->readsect(dev, block, buf))
103 return -EIO;
104 rq_flush_dcache_pages(req);
105 return 0;
106 case WRITE:
107 if (!tr->writesect)
108 return -EIO;
109
110 rq_flush_dcache_pages(req);
111 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
112 if (tr->writesect(dev, block, buf))
113 return -EIO;
114 return 0;
115 default:
116 printk(KERN_NOTICE "Unknown request %llu\n", rq_data_dir(req));
117 return -EIO;
118 }
119}
120
121int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
122{
123 return dev->bg_stop;
124}
125EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
126
127static void mtd_blktrans_work(struct work_struct *work)
128{
129 struct mtd_blktrans_dev *dev =
130 container_of(work, struct mtd_blktrans_dev, work);
131 struct mtd_blktrans_ops *tr = dev->tr;
132 struct request_queue *rq = dev->rq;
133 struct request *req = NULL;
134 int background_done = 0;
135
136 spin_lock_irq(rq->queue_lock);
137
138 while (1) {
139 int res;
140
141 dev->bg_stop = false;
142 if (!req && !(req = blk_fetch_request(rq))) {
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
151
152
153 background_done = !dev->bg_stop;
154 continue;
155 }
156 break;
157 }
158
159 spin_unlock_irq(rq->queue_lock);
160
161 mutex_lock(&dev->lock);
162 res = do_blktrans_request(dev->tr, dev, req);
163 mutex_unlock(&dev->lock);
164
165 spin_lock_irq(rq->queue_lock);
166
167 if (!__blk_end_request_cur(req, res))
168 req = NULL;
169
170 background_done = 0;
171 }
172
173 if (req)
174 __blk_end_request_all(req, -EIO);
175
176 spin_unlock_irq(rq->queue_lock);
177}
178
179static void mtd_blktrans_request(struct request_queue *rq)
180{
181 struct mtd_blktrans_dev *dev;
182 struct request *req = NULL;
183
184 dev = rq->queuedata;
185
186 if (!dev)
187 while ((req = blk_fetch_request(rq)) != NULL)
188 __blk_end_request_all(req, -ENODEV);
189 else
190 queue_work(dev->wq, &dev->work);
191}
192
193static int blktrans_open(struct block_device *bdev, fmode_t mode)
194{
195 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
196 int ret = 0;
197
198 if (!dev)
199 return -ERESTARTSYS;
200
201 mutex_lock(&dev->lock);
202
203 if (dev->open)
204 goto unlock;
205
206 kref_get(&dev->ref);
207 __module_get(dev->tr->owner);
208
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;
216 }
217
218 ret = __get_mtd_device(dev->mtd);
219 if (ret)
220 goto error_release;
221 dev->file_mode = mode;
222
223unlock:
224 dev->open++;
225 mutex_unlock(&dev->lock);
226 blktrans_dev_put(dev);
227 return ret;
228
229error_release:
230 if (dev->tr->release)
231 dev->tr->release(dev);
232error_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;
238}
239
240static void blktrans_release(struct gendisk *disk, fmode_t mode)
241{
242 struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
243
244 if (!dev)
245 return;
246
247 mutex_lock(&dev->lock);
248
249 if (--dev->open)
250 goto unlock;
251
252 kref_put(&dev->ref, blktrans_dev_release);
253 module_put(dev->tr->owner);
254
255 if (dev->mtd) {
256 if (dev->tr->release)
257 dev->tr->release(dev);
258 __put_mtd_device(dev->mtd);
259 }
260unlock:
261 mutex_unlock(&dev->lock);
262 blktrans_dev_put(dev);
263}
264
265static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
266{
267 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
268 int ret = -ENXIO;
269
270 if (!dev)
271 return ret;
272
273 mutex_lock(&dev->lock);
274
275 if (!dev->mtd)
276 goto unlock;
277
278 ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0;
279unlock:
280 mutex_unlock(&dev->lock);
281 blktrans_dev_put(dev);
282 return ret;
283}
284
285static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
286 unsigned int cmd, unsigned long arg)
287{
288 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
289 int ret = -ENXIO;
290
291 if (!dev)
292 return ret;
293
294 mutex_lock(&dev->lock);
295
296 if (!dev->mtd)
297 goto unlock;
298
299 switch (cmd) {
300 case BLKFLSBUF:
301 ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
302 break;
303 default:
304 ret = -ENOTTY;
305 }
306unlock:
307 mutex_unlock(&dev->lock);
308 blktrans_dev_put(dev);
309 return ret;
310}
311
312static const struct block_device_operations mtd_block_ops = {
313 .owner = THIS_MODULE,
314 .open = blktrans_open,
315 .release = blktrans_release,
316 .ioctl = blktrans_ioctl,
317 .getgeo = blktrans_getgeo,
318};
319
320int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
321{
322 struct mtd_blktrans_ops *tr = new->tr;
323 struct mtd_blktrans_dev *d;
324 int last_devnum = -1;
325 struct gendisk *gd;
326 int ret;
327
328 if (mutex_trylock(&mtd_table_mutex)) {
329 mutex_unlock(&mtd_table_mutex);
330 BUG();
331 }
332
333 mutex_lock(&blktrans_ref_mutex);
334 list_for_each_entry(d, &tr->devs, list) {
335 if (new->devnum == -1) {
336
337 if (d->devnum != last_devnum+1) {
338
339 new->devnum = last_devnum+1;
340 list_add_tail(&new->list, &d->list);
341 goto added;
342 }
343 } else if (d->devnum == new->devnum) {
344
345 mutex_unlock(&blktrans_ref_mutex);
346 return -EBUSY;
347 } else if (d->devnum > new->devnum) {
348
349 list_add_tail(&new->list, &d->list);
350 goto added;
351 }
352 last_devnum = d->devnum;
353 }
354
355 ret = -EBUSY;
356 if (new->devnum == -1)
357 new->devnum = last_devnum+1;
358
359
360
361
362 if (new->devnum > (MINORMASK >> tr->part_bits) ||
363 (tr->part_bits && new->devnum >= 27 * 26)) {
364 mutex_unlock(&blktrans_ref_mutex);
365 goto error1;
366 }
367
368 list_add_tail(&new->list, &tr->devs);
369 added:
370 mutex_unlock(&blktrans_ref_mutex);
371
372 mutex_init(&new->lock);
373 kref_init(&new->ref);
374 if (!tr->writesect)
375 new->readonly = 1;
376
377
378 ret = -ENOMEM;
379 gd = alloc_disk(1 << tr->part_bits);
380
381 if (!gd)
382 goto error2;
383
384 new->disk = gd;
385 gd->private_data = new;
386 gd->major = tr->major;
387 gd->first_minor = (new->devnum) << tr->part_bits;
388 gd->fops = &mtd_block_ops;
389
390 if (tr->part_bits)
391 if (new->devnum < 26)
392 snprintf(gd->disk_name, sizeof(gd->disk_name),
393 "%s%c", tr->name, 'a' + new->devnum);
394 else
395 snprintf(gd->disk_name, sizeof(gd->disk_name),
396 "%s%c%c", tr->name,
397 'a' - 1 + new->devnum / 26,
398 'a' + new->devnum % 26);
399 else
400 snprintf(gd->disk_name, sizeof(gd->disk_name),
401 "%s%d", tr->name, new->devnum);
402
403 set_capacity(gd, (new->size * tr->blksize) >> 9);
404
405
406 spin_lock_init(&new->queue_lock);
407 new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock);
408
409 if (!new->rq)
410 goto error3;
411
412 new->rq->queuedata = new;
413 blk_queue_logical_block_size(new->rq, tr->blksize);
414
415 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq);
416 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, new->rq);
417
418 if (tr->discard) {
419 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq);
420 new->rq->limits.max_discard_sectors = UINT_MAX;
421 }
422
423 gd->queue = new->rq;
424
425
426 new->wq = alloc_workqueue("%s%d", 0, 0,
427 tr->name, new->mtd->index);
428 if (!new->wq)
429 goto error4;
430 INIT_WORK(&new->work, mtd_blktrans_work);
431
432 gd->driverfs_dev = &new->mtd->dev;
433
434 if (new->readonly)
435 set_disk_ro(gd, 1);
436
437 add_disk(gd);
438
439 if (new->disk_attributes) {
440 ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
441 new->disk_attributes);
442 WARN_ON(ret);
443 }
444 return 0;
445error4:
446 blk_cleanup_queue(new->rq);
447error3:
448 put_disk(new->disk);
449error2:
450 list_del(&new->list);
451error1:
452 return ret;
453}
454
455int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
456{
457 unsigned long flags;
458
459 if (mutex_trylock(&mtd_table_mutex)) {
460 mutex_unlock(&mtd_table_mutex);
461 BUG();
462 }
463
464 if (old->disk_attributes)
465 sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
466 old->disk_attributes);
467
468
469 del_gendisk(old->disk);
470
471
472 destroy_workqueue(old->wq);
473
474
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);
479
480
481
482 mutex_lock(&old->lock);
483 if (old->open) {
484 if (old->tr->release)
485 old->tr->release(old);
486 __put_mtd_device(old->mtd);
487 }
488
489 old->mtd = NULL;
490
491 mutex_unlock(&old->lock);
492 blktrans_dev_put(old);
493 return 0;
494}
495
496static void blktrans_notify_remove(struct mtd_info *mtd)
497{
498 struct mtd_blktrans_ops *tr;
499 struct mtd_blktrans_dev *dev, *next;
500
501 list_for_each_entry(tr, &blktrans_majors, list)
502 list_for_each_entry_safe(dev, next, &tr->devs, list)
503 if (dev->mtd == mtd)
504 tr->remove_dev(dev);
505}
506
507static void blktrans_notify_add(struct mtd_info *mtd)
508{
509 struct mtd_blktrans_ops *tr;
510
511 if (mtd->type == MTD_ABSENT)
512 return;
513
514 list_for_each_entry(tr, &blktrans_majors, list)
515 tr->add_mtd(tr, mtd);
516}
517
518static struct mtd_notifier blktrans_notifier = {
519 .add = blktrans_notify_add,
520 .remove = blktrans_notify_remove,
521};
522
523int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
524{
525 struct mtd_info *mtd;
526 int ret;
527
528
529
530
531 if (!blktrans_notifier.list.next)
532 register_mtd_user(&blktrans_notifier);
533
534
535 mutex_lock(&mtd_table_mutex);
536
537 ret = register_blkdev(tr->major, tr->name);
538 if (ret < 0) {
539 printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
540 tr->name, tr->major, ret);
541 mutex_unlock(&mtd_table_mutex);
542 return ret;
543 }
544
545 if (ret)
546 tr->major = ret;
547
548 tr->blkshift = ffs(tr->blksize) - 1;
549
550 INIT_LIST_HEAD(&tr->devs);
551 list_add(&tr->list, &blktrans_majors);
552
553 mtd_for_each_device(mtd)
554 if (mtd->type != MTD_ABSENT)
555 tr->add_mtd(tr, mtd);
556
557 mutex_unlock(&mtd_table_mutex);
558 return 0;
559}
560
561int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
562{
563 struct mtd_blktrans_dev *dev, *next;
564
565 mutex_lock(&mtd_table_mutex);
566
567
568 list_del(&tr->list);
569
570 list_for_each_entry_safe(dev, next, &tr->devs, list)
571 tr->remove_dev(dev);
572
573 unregister_blkdev(tr->major, tr->name);
574 mutex_unlock(&mtd_table_mutex);
575
576 BUG_ON(!list_empty(&tr->devs));
577 return 0;
578}
579
580static void __exit mtd_blktrans_exit(void)
581{
582
583
584 if (blktrans_notifier.list.next)
585 unregister_mtd_user(&blktrans_notifier);
586}
587
588module_exit(mtd_blktrans_exit);
589
590EXPORT_SYMBOL_GPL(register_mtd_blktrans);
591EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
592EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
593EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
594
595MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
596MODULE_LICENSE("GPL");
597MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");
598
