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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/mutex.h>
34#include <linux/uaccess.h>
35
36#include "mtdcore.h"
37
38static LIST_HEAD(blktrans_majors);
39static DEFINE_MUTEX(blktrans_ref_mutex);
40
41static void blktrans_dev_release(struct kref *kref)
42{
43 struct mtd_blktrans_dev *dev =
44 container_of(kref, struct mtd_blktrans_dev, ref);
45
46 dev->disk->private_data = NULL;
47 blk_cleanup_queue(dev->rq);
48 put_disk(dev->disk);
49 list_del(&dev->list);
50 kfree(dev);
51}
52
53static 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);
63unlock:
64 mutex_unlock(&blktrans_ref_mutex);
65 return dev;
66}
67
68static void blktrans_dev_put(struct mtd_blktrans_dev *dev)
69{
70 mutex_lock(&blktrans_ref_mutex);
71 kref_put(&dev->ref, blktrans_dev_release);
72 mutex_unlock(&blktrans_ref_mutex);
73}
74
75
76static 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
83 block = blk_rq_pos(req) << 9 >> tr->blkshift;
84 nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
85 buf = bio_data(req->bio);
86
87 if (req_op(req) == REQ_OP_FLUSH)
88 return tr->flush(dev);
89
90 if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
91 get_capacity(req->rq_disk))
92 return -EIO;
93
94 switch (req_op(req)) {
95 case REQ_OP_DISCARD:
96 return tr->discard(dev, block, nsect);
97 case REQ_OP_READ:
98 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
99 if (tr->readsect(dev, block, buf))
100 return -EIO;
101 rq_flush_dcache_pages(req);
102 return 0;
103 case REQ_OP_WRITE:
104 if (!tr->writesect)
105 return -EIO;
106
107 rq_flush_dcache_pages(req);
108 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
109 if (tr->writesect(dev, block, buf))
110 return -EIO;
111 return 0;
112 default:
113 return -EIO;
114 }
115}
116
117int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
118{
119 return dev->bg_stop;
120}
121EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
122
123static void mtd_blktrans_work(struct work_struct *work)
124{
125 struct mtd_blktrans_dev *dev =
126 container_of(work, struct mtd_blktrans_dev, work);
127 struct mtd_blktrans_ops *tr = dev->tr;
128 struct request_queue *rq = dev->rq;
129 struct request *req = NULL;
130 int background_done = 0;
131
132 spin_lock_irq(rq->queue_lock);
133
134 while (1) {
135 int res;
136
137 dev->bg_stop = false;
138 if (!req && !(req = blk_fetch_request(rq))) {
139 if (tr->background && !background_done) {
140 spin_unlock_irq(rq->queue_lock);
141 mutex_lock(&dev->lock);
142 tr->background(dev);
143 mutex_unlock(&dev->lock);
144 spin_lock_irq(rq->queue_lock);
145
146
147
148
149 background_done = !dev->bg_stop;
150 continue;
151 }
152 break;
153 }
154
155 spin_unlock_irq(rq->queue_lock);
156
157 mutex_lock(&dev->lock);
158 res = do_blktrans_request(dev->tr, dev, req);
159 mutex_unlock(&dev->lock);
160
161 spin_lock_irq(rq->queue_lock);
162
163 if (!__blk_end_request_cur(req, res))
164 req = NULL;
165
166 background_done = 0;
167 }
168
169 spin_unlock_irq(rq->queue_lock);
170}
171
172static void mtd_blktrans_request(struct request_queue *rq)
173{
174 struct mtd_blktrans_dev *dev;
175 struct request *req = NULL;
176
177 dev = rq->queuedata;
178
179 if (!dev)
180 while ((req = blk_fetch_request(rq)) != NULL)
181 __blk_end_request_all(req, -ENODEV);
182 else
183 queue_work(dev->wq, &dev->work);
184}
185
186static int blktrans_open(struct block_device *bdev, fmode_t mode)
187{
188 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
189 int ret = 0;
190
191 if (!dev)
192 return -ERESTARTSYS;
193
194 mutex_lock(&mtd_table_mutex);
195 mutex_lock(&dev->lock);
196
197 if (dev->open)
198 goto unlock;
199
200 kref_get(&dev->ref);
201 __module_get(dev->tr->owner);
202
203 if (!dev->mtd)
204 goto unlock;
205
206 if (dev->tr->open) {
207 ret = dev->tr->open(dev);
208 if (ret)
209 goto error_put;
210 }
211
212 ret = __get_mtd_device(dev->mtd);
213 if (ret)
214 goto error_release;
215 dev->file_mode = mode;
216
217unlock:
218 dev->open++;
219 mutex_unlock(&dev->lock);
220 mutex_unlock(&mtd_table_mutex);
221 blktrans_dev_put(dev);
222 return ret;
223
224error_release:
225 if (dev->tr->release)
226 dev->tr->release(dev);
227error_put:
228 module_put(dev->tr->owner);
229 kref_put(&dev->ref, blktrans_dev_release);
230 mutex_unlock(&dev->lock);
231 mutex_unlock(&mtd_table_mutex);
232 blktrans_dev_put(dev);
233 return ret;
234}
235
236static void blktrans_release(struct gendisk *disk, fmode_t mode)
237{
238 struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
239
240 if (!dev)
241 return;
242
243 mutex_lock(&mtd_table_mutex);
244 mutex_lock(&dev->lock);
245
246 if (--dev->open)
247 goto unlock;
248
249 kref_put(&dev->ref, blktrans_dev_release);
250 module_put(dev->tr->owner);
251
252 if (dev->mtd) {
253 if (dev->tr->release)
254 dev->tr->release(dev);
255 __put_mtd_device(dev->mtd);
256 }
257unlock:
258 mutex_unlock(&dev->lock);
259 mutex_unlock(&mtd_table_mutex);
260 blktrans_dev_put(dev);
261}
262
263static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
264{
265 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
266 int ret = -ENXIO;
267
268 if (!dev)
269 return ret;
270
271 mutex_lock(&dev->lock);
272
273 if (!dev->mtd)
274 goto unlock;
275
276 ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENOTTY;
277unlock:
278 mutex_unlock(&dev->lock);
279 blktrans_dev_put(dev);
280 return ret;
281}
282
283static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
284 unsigned int cmd, unsigned long arg)
285{
286 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
287 int ret = -ENXIO;
288
289 if (!dev)
290 return ret;
291
292 mutex_lock(&dev->lock);
293
294 if (!dev->mtd)
295 goto unlock;
296
297 switch (cmd) {
298 case BLKFLSBUF:
299 ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
300 break;
301 default:
302 ret = -ENOTTY;
303 }
304unlock:
305 mutex_unlock(&dev->lock);
306 blktrans_dev_put(dev);
307 return ret;
308}
309
310static const struct block_device_operations mtd_block_ops = {
311 .owner = THIS_MODULE,
312 .open = blktrans_open,
313 .release = blktrans_release,
314 .ioctl = blktrans_ioctl,
315 .getgeo = blktrans_getgeo,
316};
317
318int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
319{
320 struct mtd_blktrans_ops *tr = new->tr;
321 struct mtd_blktrans_dev *d;
322 int last_devnum = -1;
323 struct gendisk *gd;
324 int ret;
325
326 if (mutex_trylock(&mtd_table_mutex)) {
327 mutex_unlock(&mtd_table_mutex);
328 BUG();
329 }
330
331 mutex_lock(&blktrans_ref_mutex);
332 list_for_each_entry(d, &tr->devs, list) {
333 if (new->devnum == -1) {
334
335 if (d->devnum != last_devnum+1) {
336
337 new->devnum = last_devnum+1;
338 list_add_tail(&new->list, &d->list);
339 goto added;
340 }
341 } else if (d->devnum == new->devnum) {
342
343 mutex_unlock(&blktrans_ref_mutex);
344 return -EBUSY;
345 } else if (d->devnum > new->devnum) {
346
347 list_add_tail(&new->list, &d->list);
348 goto added;
349 }
350 last_devnum = d->devnum;
351 }
352
353 ret = -EBUSY;
354 if (new->devnum == -1)
355 new->devnum = last_devnum+1;
356
357
358
359
360 if (new->devnum > (MINORMASK >> tr->part_bits) ||
361 (tr->part_bits && new->devnum >= 27 * 26)) {
362 mutex_unlock(&blktrans_ref_mutex);
363 goto error1;
364 }
365
366 list_add_tail(&new->list, &tr->devs);
367 added:
368 mutex_unlock(&blktrans_ref_mutex);
369
370 mutex_init(&new->lock);
371 kref_init(&new->ref);
372 if (!tr->writesect)
373 new->readonly = 1;
374
375
376 ret = -ENOMEM;
377 gd = alloc_disk(1 << tr->part_bits);
378
379 if (!gd)
380 goto error2;
381
382 new->disk = gd;
383 gd->private_data = new;
384 gd->major = tr->major;
385 gd->first_minor = (new->devnum) << tr->part_bits;
386 gd->fops = &mtd_block_ops;
387
388 if (tr->part_bits)
389 if (new->devnum < 26)
390 snprintf(gd->disk_name, sizeof(gd->disk_name),
391 "%s%c", tr->name, 'a' + new->devnum);
392 else
393 snprintf(gd->disk_name, sizeof(gd->disk_name),
394 "%s%c%c", tr->name,
395 'a' - 1 + new->devnum / 26,
396 'a' + new->devnum % 26);
397 else
398 snprintf(gd->disk_name, sizeof(gd->disk_name),
399 "%s%d", tr->name, new->devnum);
400
401 set_capacity(gd, ((u64)new->size * tr->blksize) >> 9);
402
403
404 spin_lock_init(&new->queue_lock);
405 new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock);
406
407 if (!new->rq)
408 goto error3;
409
410 if (tr->flush)
411 blk_queue_write_cache(new->rq, true, false);
412
413 new->rq->queuedata = new;
414 blk_queue_logical_block_size(new->rq, tr->blksize);
415
416 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq);
417 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, new->rq);
418
419 if (tr->discard) {
420 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq);
421 blk_queue_max_discard_sectors(new->rq, UINT_MAX);
422 }
423
424 gd->queue = new->rq;
425
426
427 new->wq = alloc_workqueue("%s%d", 0, 0,
428 tr->name, new->mtd->index);
429 if (!new->wq)
430 goto error4;
431 INIT_WORK(&new->work, mtd_blktrans_work);
432
433 if (new->readonly)
434 set_disk_ro(gd, 1);
435
436 device_add_disk(&new->mtd->dev, gd);
437
438 if (new->disk_attributes) {
439 ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
440 new->disk_attributes);
441 WARN_ON(ret);
442 }
443 return 0;
444error4:
445 blk_cleanup_queue(new->rq);
446error3:
447 put_disk(new->disk);
448error2:
449 list_del(&new->list);
450error1:
451 return ret;
452}
453
454int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
455{
456 unsigned long flags;
457
458 if (mutex_trylock(&mtd_table_mutex)) {
459 mutex_unlock(&mtd_table_mutex);
460 BUG();
461 }
462
463 if (old->disk_attributes)
464 sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
465 old->disk_attributes);
466
467
468 del_gendisk(old->disk);
469
470
471 destroy_workqueue(old->wq);
472
473
474 spin_lock_irqsave(&old->queue_lock, flags);
475 old->rq->queuedata = NULL;
476 blk_start_queue(old->rq);
477 spin_unlock_irqrestore(&old->queue_lock, flags);
478
479
480
481 mutex_lock(&old->lock);
482 if (old->open) {
483 if (old->tr->release)
484 old->tr->release(old);
485 __put_mtd_device(old->mtd);
486 }
487
488 old->mtd = NULL;
489
490 mutex_unlock(&old->lock);
491 blktrans_dev_put(old);
492 return 0;
493}
494
495static void blktrans_notify_remove(struct mtd_info *mtd)
496{
497 struct mtd_blktrans_ops *tr;
498 struct mtd_blktrans_dev *dev, *next;
499
500 list_for_each_entry(tr, &blktrans_majors, list)
501 list_for_each_entry_safe(dev, next, &tr->devs, list)
502 if (dev->mtd == mtd)
503 tr->remove_dev(dev);
504}
505
506static void blktrans_notify_add(struct mtd_info *mtd)
507{
508 struct mtd_blktrans_ops *tr;
509
510 if (mtd->type == MTD_ABSENT)
511 return;
512
513 list_for_each_entry(tr, &blktrans_majors, list)
514 tr->add_mtd(tr, mtd);
515}
516
517static struct mtd_notifier blktrans_notifier = {
518 .add = blktrans_notify_add,
519 .remove = blktrans_notify_remove,
520};
521
522int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
523{
524 struct mtd_info *mtd;
525 int ret;
526
527
528
529
530 if (!blktrans_notifier.list.next)
531 register_mtd_user(&blktrans_notifier);
532
533
534 mutex_lock(&mtd_table_mutex);
535
536 ret = register_blkdev(tr->major, tr->name);
537 if (ret < 0) {
538 printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
539 tr->name, tr->major, ret);
540 mutex_unlock(&mtd_table_mutex);
541 return ret;
542 }
543
544 if (ret)
545 tr->major = ret;
546
547 tr->blkshift = ffs(tr->blksize) - 1;
548
549 INIT_LIST_HEAD(&tr->devs);
550 list_add(&tr->list, &blktrans_majors);
551
552 mtd_for_each_device(mtd)
553 if (mtd->type != MTD_ABSENT)
554 tr->add_mtd(tr, mtd);
555
556 mutex_unlock(&mtd_table_mutex);
557 return 0;
558}
559
560int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
561{
562 struct mtd_blktrans_dev *dev, *next;
563
564 mutex_lock(&mtd_table_mutex);
565
566
567 list_del(&tr->list);
568
569 list_for_each_entry_safe(dev, next, &tr->devs, list)
570 tr->remove_dev(dev);
571
572 unregister_blkdev(tr->major, tr->name);
573 mutex_unlock(&mtd_table_mutex);
574
575 BUG_ON(!list_empty(&tr->devs));
576 return 0;
577}
578
579static void __exit mtd_blktrans_exit(void)
580{
581
582
583 if (blktrans_notifier.list.next)
584 unregister_mtd_user(&blktrans_notifier);
585}
586
587module_exit(mtd_blktrans_exit);
588
589EXPORT_SYMBOL_GPL(register_mtd_blktrans);
590EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
591EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
592EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
593
594MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
595MODULE_LICENSE("GPL");
596MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");
597
