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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 <asm/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->cmd_type != REQ_TYPE_FS)
88 return -EIO;
89
90 if (req->cmd_flags & REQ_FLUSH)
91 return tr->flush(dev);
92
93 if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
94 get_capacity(req->rq_disk))
95 return -EIO;
96
97 if (req->cmd_flags & REQ_DISCARD)
98 return tr->discard(dev, block, nsect);
99
100 switch(rq_data_dir(req)) {
101 case READ:
102 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
103 if (tr->readsect(dev, block, buf))
104 return -EIO;
105 rq_flush_dcache_pages(req);
106 return 0;
107 case WRITE:
108 if (!tr->writesect)
109 return -EIO;
110
111 rq_flush_dcache_pages(req);
112 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
113 if (tr->writesect(dev, block, buf))
114 return -EIO;
115 return 0;
116 default:
117 printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
118 return -EIO;
119 }
120}
121
122int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
123{
124 return dev->bg_stop;
125}
126EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
127
128static void mtd_blktrans_work(struct work_struct *work)
129{
130 struct mtd_blktrans_dev *dev =
131 container_of(work, struct mtd_blktrans_dev, work);
132 struct mtd_blktrans_ops *tr = dev->tr;
133 struct request_queue *rq = dev->rq;
134 struct request *req = NULL;
135 int background_done = 0;
136
137 spin_lock_irq(rq->queue_lock);
138
139 while (1) {
140 int res;
141
142 dev->bg_stop = false;
143 if (!req && !(req = blk_fetch_request(rq))) {
144 if (tr->background && !background_done) {
145 spin_unlock_irq(rq->queue_lock);
146 mutex_lock(&dev->lock);
147 tr->background(dev);
148 mutex_unlock(&dev->lock);
149 spin_lock_irq(rq->queue_lock);
150
151
152
153
154 background_done = !dev->bg_stop;
155 continue;
156 }
157 break;
158 }
159
160 spin_unlock_irq(rq->queue_lock);
161
162 mutex_lock(&dev->lock);
163 res = do_blktrans_request(dev->tr, dev, req);
164 mutex_unlock(&dev->lock);
165
166 spin_lock_irq(rq->queue_lock);
167
168 if (!__blk_end_request_cur(req, res))
169 req = NULL;
170
171 background_done = 0;
172 }
173
174 if (req)
175 __blk_end_request_all(req, -EIO);
176
177 spin_unlock_irq(rq->queue_lock);
178}
179
180static void mtd_blktrans_request(struct request_queue *rq)
181{
182 struct mtd_blktrans_dev *dev;
183 struct request *req = NULL;
184
185 dev = rq->queuedata;
186
187 if (!dev)
188 while ((req = blk_fetch_request(rq)) != NULL)
189 __blk_end_request_all(req, -ENODEV);
190 else
191 queue_work(dev->wq, &dev->work);
192}
193
194static int blktrans_open(struct block_device *bdev, fmode_t mode)
195{
196 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
197 int ret = 0;
198
199 if (!dev)
200 return -ERESTARTSYS;
201
202 mutex_lock(&dev->lock);
203
204 if (dev->open)
205 goto unlock;
206
207 kref_get(&dev->ref);
208 __module_get(dev->tr->owner);
209
210 if (!dev->mtd)
211 goto unlock;
212
213 if (dev->tr->open) {
214 ret = dev->tr->open(dev);
215 if (ret)
216 goto error_put;
217 }
218
219 ret = __get_mtd_device(dev->mtd);
220 if (ret)
221 goto error_release;
222 dev->file_mode = mode;
223
224unlock:
225 dev->open++;
226 mutex_unlock(&dev->lock);
227 blktrans_dev_put(dev);
228 return ret;
229
230error_release:
231 if (dev->tr->release)
232 dev->tr->release(dev);
233error_put:
234 module_put(dev->tr->owner);
235 kref_put(&dev->ref, blktrans_dev_release);
236 mutex_unlock(&dev->lock);
237 blktrans_dev_put(dev);
238 return ret;
239}
240
241static void blktrans_release(struct gendisk *disk, fmode_t mode)
242{
243 struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
244
245 if (!dev)
246 return;
247
248 mutex_lock(&dev->lock);
249
250 if (--dev->open)
251 goto unlock;
252
253 kref_put(&dev->ref, blktrans_dev_release);
254 module_put(dev->tr->owner);
255
256 if (dev->mtd) {
257 if (dev->tr->release)
258 dev->tr->release(dev);
259 __put_mtd_device(dev->mtd);
260 }
261unlock:
262 mutex_unlock(&dev->lock);
263 blktrans_dev_put(dev);
264}
265
266static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
267{
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);
275
276 if (!dev->mtd)
277 goto unlock;
278
279 ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0;
280unlock:
281 mutex_unlock(&dev->lock);
282 blktrans_dev_put(dev);
283 return ret;
284}
285
286static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
287 unsigned int cmd, unsigned long arg)
288{
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;
299
300 switch (cmd) {
301 case BLKFLSBUF:
302 ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
303 break;
304 default:
305 ret = -ENOTTY;
306 }
307unlock:
308 mutex_unlock(&dev->lock);
309 blktrans_dev_put(dev);
310 return ret;
311}
312
313static const struct block_device_operations mtd_block_ops = {
314 .owner = THIS_MODULE,
315 .open = blktrans_open,
316 .release = blktrans_release,
317 .ioctl = blktrans_ioctl,
318 .getgeo = blktrans_getgeo,
319};
320
321int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
322{
323 struct mtd_blktrans_ops *tr = new->tr;
324 struct mtd_blktrans_dev *d;
325 int last_devnum = -1;
326 struct gendisk *gd;
327 int ret;
328
329 if (mutex_trylock(&mtd_table_mutex)) {
330 mutex_unlock(&mtd_table_mutex);
331 BUG();
332 }
333
334 mutex_lock(&blktrans_ref_mutex);
335 list_for_each_entry(d, &tr->devs, list) {
336 if (new->devnum == -1) {
337
338 if (d->devnum != last_devnum+1) {
339
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
346 mutex_unlock(&blktrans_ref_mutex);
347 return -EBUSY;
348 } else if (d->devnum > new->devnum) {
349
350 list_add_tail(&new->list, &d->list);
351 goto added;
352 }
353 last_devnum = d->devnum;
354 }
355
356 ret = -EBUSY;
357 if (new->devnum == -1)
358 new->devnum = last_devnum+1;
359
360
361
362
363 if (new->devnum > (MINORMASK >> tr->part_bits) ||
364 (tr->part_bits && new->devnum >= 27 * 26)) {
365 mutex_unlock(&blktrans_ref_mutex);
366 goto error1;
367 }
368
369 list_add_tail(&new->list, &tr->devs);
370 added:
371 mutex_unlock(&blktrans_ref_mutex);
372
373 mutex_init(&new->lock);
374 kref_init(&new->ref);
375 if (!tr->writesect)
376 new->readonly = 1;
377
378
379 ret = -ENOMEM;
380 gd = alloc_disk(1 << tr->part_bits);
381
382 if (!gd)
383 goto error2;
384
385 new->disk = gd;
386 gd->private_data = new;
387 gd->major = tr->major;
388 gd->first_minor = (new->devnum) << tr->part_bits;
389 gd->fops = &mtd_block_ops;
390
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);
403
404 set_capacity(gd, (new->size * tr->blksize) >> 9);
405
406
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 if (tr->flush)
414 blk_queue_flush(new->rq, REQ_FLUSH);
415
416 new->rq->queuedata = new;
417 blk_queue_logical_block_size(new->rq, tr->blksize);
418
419 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq);
420 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, new->rq);
421
422 if (tr->discard) {
423 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq);
424 new->rq->limits.max_discard_sectors = UINT_MAX;
425 }
426
427 gd->queue = new->rq;
428
429
430 new->wq = alloc_workqueue("%s%d", 0, 0,
431 tr->name, new->mtd->index);
432 if (!new->wq)
433 goto error4;
434 INIT_WORK(&new->work, mtd_blktrans_work);
435
436 gd->driverfs_dev = &new->mtd->dev;
437
438 if (new->readonly)
439 set_disk_ro(gd, 1);
440
441 add_disk(gd);
442
443 if (new->disk_attributes) {
444 ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
445 new->disk_attributes);
446 WARN_ON(ret);
447 }
448 return 0;
449error4:
450 blk_cleanup_queue(new->rq);
451error3:
452 put_disk(new->disk);
453error2:
454 list_del(&new->list);
455error1:
456 return ret;
457}
458
459int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
460{
461 unsigned long flags;
462
463 if (mutex_trylock(&mtd_table_mutex)) {
464 mutex_unlock(&mtd_table_mutex);
465 BUG();
466 }
467
468 if (old->disk_attributes)
469 sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
470 old->disk_attributes);
471
472
473 del_gendisk(old->disk);
474
475
476 destroy_workqueue(old->wq);
477
478
479 spin_lock_irqsave(&old->queue_lock, flags);
480 old->rq->queuedata = NULL;
481 blk_start_queue(old->rq);
482 spin_unlock_irqrestore(&old->queue_lock, flags);
483
484
485
486 mutex_lock(&old->lock);
487 if (old->open) {
488 if (old->tr->release)
489 old->tr->release(old);
490 __put_mtd_device(old->mtd);
491 }
492
493 old->mtd = NULL;
494
495 mutex_unlock(&old->lock);
496 blktrans_dev_put(old);
497 return 0;
498}
499
500static void blktrans_notify_remove(struct mtd_info *mtd)
501{
502 struct mtd_blktrans_ops *tr;
503 struct mtd_blktrans_dev *dev, *next;
504
505 list_for_each_entry(tr, &blktrans_majors, list)
506 list_for_each_entry_safe(dev, next, &tr->devs, list)
507 if (dev->mtd == mtd)
508 tr->remove_dev(dev);
509}
510
511static void blktrans_notify_add(struct mtd_info *mtd)
512{
513 struct mtd_blktrans_ops *tr;
514
515 if (mtd->type == MTD_ABSENT)
516 return;
517
518 list_for_each_entry(tr, &blktrans_majors, list)
519 tr->add_mtd(tr, mtd);
520}
521
522static struct mtd_notifier blktrans_notifier = {
523 .add = blktrans_notify_add,
524 .remove = blktrans_notify_remove,
525};
526
527int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
528{
529 struct mtd_info *mtd;
530 int ret;
531
532
533
534
535 if (!blktrans_notifier.list.next)
536 register_mtd_user(&blktrans_notifier);
537
538
539 mutex_lock(&mtd_table_mutex);
540
541 ret = register_blkdev(tr->major, tr->name);
542 if (ret < 0) {
543 printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
544 tr->name, tr->major, ret);
545 mutex_unlock(&mtd_table_mutex);
546 return ret;
547 }
548
549 if (ret)
550 tr->major = ret;
551
552 tr->blkshift = ffs(tr->blksize) - 1;
553
554 INIT_LIST_HEAD(&tr->devs);
555 list_add(&tr->list, &blktrans_majors);
556
557 mtd_for_each_device(mtd)
558 if (mtd->type != MTD_ABSENT)
559 tr->add_mtd(tr, mtd);
560
561 mutex_unlock(&mtd_table_mutex);
562 return 0;
563}
564
565int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
566{
567 struct mtd_blktrans_dev *dev, *next;
568
569 mutex_lock(&mtd_table_mutex);
570
571
572 list_del(&tr->list);
573
574 list_for_each_entry_safe(dev, next, &tr->devs, list)
575 tr->remove_dev(dev);
576
577 unregister_blkdev(tr->major, tr->name);
578 mutex_unlock(&mtd_table_mutex);
579
580 BUG_ON(!list_empty(&tr->devs));
581 return 0;
582}
583
584static void __exit mtd_blktrans_exit(void)
585{
586
587
588 if (blktrans_notifier.list.next)
589 unregister_mtd_user(&blktrans_notifier);
590}
591
592module_exit(mtd_blktrans_exit);
593
594EXPORT_SYMBOL_GPL(register_mtd_blktrans);
595EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
596EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
597EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
598
599MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
600MODULE_LICENSE("GPL");
601MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");
602
