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 <linux/kthread.h>
36#include <asm/uaccess.h>
37
38#include "mtdcore.h"
39
40static LIST_HEAD(blktrans_majors);
41static DEFINE_MUTEX(blktrans_ref_mutex);
42
43void blktrans_dev_release(struct kref *kref)
44{
45 struct mtd_blktrans_dev *dev =
46 container_of(kref, struct mtd_blktrans_dev, ref);
47
48 dev->disk->private_data = NULL;
49 blk_cleanup_queue(dev->rq);
50 put_disk(dev->disk);
51 list_del(&dev->list);
52 kfree(dev);
53}
54
55static 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);
65unlock:
66 mutex_unlock(&blktrans_ref_mutex);
67 return dev;
68}
69
70void blktrans_dev_put(struct mtd_blktrans_dev *dev)
71{
72 mutex_lock(&blktrans_ref_mutex);
73 kref_put(&dev->ref, blktrans_dev_release);
74 mutex_unlock(&blktrans_ref_mutex);
75}
76
77
78static 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
85 block = blk_rq_pos(req) << 9 >> tr->blkshift;
86 nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
87
88 buf = req->buffer;
89
90 if (req->cmd_type != REQ_TYPE_FS)
91 return -EIO;
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
122static int mtd_blktrans_thread(void *arg)
123{
124 struct mtd_blktrans_dev *dev = arg;
125 struct request_queue *rq = dev->rq;
126 struct request *req = NULL;
127
128 spin_lock_irq(rq->queue_lock);
129
130 while (!kthread_should_stop()) {
131 int res;
132
133 if (!req && !(req = blk_fetch_request(rq))) {
134 set_current_state(TASK_INTERRUPTIBLE);
135
136 if (kthread_should_stop())
137 set_current_state(TASK_RUNNING);
138
139 spin_unlock_irq(rq->queue_lock);
140 schedule();
141 spin_lock_irq(rq->queue_lock);
142 continue;
143 }
144
145 spin_unlock_irq(rq->queue_lock);
146
147 mutex_lock(&dev->lock);
148 res = do_blktrans_request(dev->tr, dev, req);
149 mutex_unlock(&dev->lock);
150
151 spin_lock_irq(rq->queue_lock);
152
153 if (!__blk_end_request_cur(req, res))
154 req = NULL;
155 }
156
157 if (req)
158 __blk_end_request_all(req, -EIO);
159
160 spin_unlock_irq(rq->queue_lock);
161
162 return 0;
163}
164
165static void mtd_blktrans_request(struct request_queue *rq)
166{
167 struct mtd_blktrans_dev *dev;
168 struct request *req = NULL;
169
170 dev = rq->queuedata;
171
172 if (!dev)
173 while ((req = blk_fetch_request(rq)) != NULL)
174 __blk_end_request_all(req, -ENODEV);
175 else
176 wake_up_process(dev->thread);
177}
178
179static int blktrans_open(struct block_device *bdev, fmode_t mode)
180{
181 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
182 int ret = 0;
183
184 if (!dev)
185 return -ERESTARTSYS;
186
187 mutex_lock(&dev->lock);
188
189 if (dev->open++)
190 goto unlock;
191
192 kref_get(&dev->ref);
193 __module_get(dev->tr->owner);
194
195 if (dev->mtd) {
196 ret = dev->tr->open ? dev->tr->open(dev) : 0;
197 __get_mtd_device(dev->mtd);
198 }
199
200unlock:
201 mutex_unlock(&dev->lock);
202 blktrans_dev_put(dev);
203 return ret;
204}
205
206static int blktrans_release(struct gendisk *disk, fmode_t mode)
207{
208 struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
209 int ret = 0;
210
211 if (!dev)
212 return ret;
213
214 mutex_lock(&dev->lock);
215
216 if (--dev->open)
217 goto unlock;
218
219 kref_put(&dev->ref, blktrans_dev_release);
220 module_put(dev->tr->owner);
221
222 if (dev->mtd) {
223 ret = dev->tr->release ? dev->tr->release(dev) : 0;
224 __put_mtd_device(dev->mtd);
225 }
226unlock:
227 mutex_unlock(&dev->lock);
228 blktrans_dev_put(dev);
229 return ret;
230}
231
232static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
233{
234 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
235 int ret = -ENXIO;
236
237 if (!dev)
238 return ret;
239
240 mutex_lock(&dev->lock);
241
242 if (!dev->mtd)
243 goto unlock;
244
245 ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0;
246unlock:
247 mutex_unlock(&dev->lock);
248 blktrans_dev_put(dev);
249 return ret;
250}
251
252static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
253 unsigned int cmd, unsigned long arg)
254{
255 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
256 int ret = -ENXIO;
257
258 if (!dev)
259 return ret;
260
261 mutex_lock(&dev->lock);
262
263 if (!dev->mtd)
264 goto unlock;
265
266 switch (cmd) {
267 case BLKFLSBUF:
268 ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
269 break;
270 default:
271 ret = -ENOTTY;
272 }
273unlock:
274 mutex_unlock(&dev->lock);
275 blktrans_dev_put(dev);
276 return ret;
277}
278
279static const struct block_device_operations mtd_blktrans_ops = {
280 .owner = THIS_MODULE,
281 .open = blktrans_open,
282 .release = blktrans_release,
283 .ioctl = blktrans_ioctl,
284 .getgeo = blktrans_getgeo,
285};
286
287int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
288{
289 struct mtd_blktrans_ops *tr = new->tr;
290 struct mtd_blktrans_dev *d;
291 int last_devnum = -1;
292 struct gendisk *gd;
293 int ret;
294
295 if (mutex_trylock(&mtd_table_mutex)) {
296 mutex_unlock(&mtd_table_mutex);
297 BUG();
298 }
299
300 mutex_lock(&blktrans_ref_mutex);
301 list_for_each_entry(d, &tr->devs, list) {
302 if (new->devnum == -1) {
303
304 if (d->devnum != last_devnum+1) {
305
306 new->devnum = last_devnum+1;
307 list_add_tail(&new->list, &d->list);
308 goto added;
309 }
310 } else if (d->devnum == new->devnum) {
311
312 mutex_unlock(&blktrans_ref_mutex);
313 return -EBUSY;
314 } else if (d->devnum > new->devnum) {
315
316 list_add_tail(&new->list, &d->list);
317 goto added;
318 }
319 last_devnum = d->devnum;
320 }
321
322 ret = -EBUSY;
323 if (new->devnum == -1)
324 new->devnum = last_devnum+1;
325
326
327
328
329 if (new->devnum > (MINORMASK >> tr->part_bits) ||
330 (tr->part_bits && new->devnum >= 27 * 26)) {
331 mutex_unlock(&blktrans_ref_mutex);
332 goto error1;
333 }
334
335 list_add_tail(&new->list, &tr->devs);
336 added:
337 mutex_unlock(&blktrans_ref_mutex);
338
339 mutex_init(&new->lock);
340 kref_init(&new->ref);
341 if (!tr->writesect)
342 new->readonly = 1;
343
344
345 ret = -ENOMEM;
346 gd = alloc_disk(1 << tr->part_bits);
347
348 if (!gd)
349 goto error2;
350
351 new->disk = gd;
352 gd->private_data = new;
353 gd->major = tr->major;
354 gd->first_minor = (new->devnum) << tr->part_bits;
355 gd->fops = &mtd_blktrans_ops;
356
357 if (tr->part_bits)
358 if (new->devnum < 26)
359 snprintf(gd->disk_name, sizeof(gd->disk_name),
360 "%s%c", tr->name, 'a' + new->devnum);
361 else
362 snprintf(gd->disk_name, sizeof(gd->disk_name),
363 "%s%c%c", tr->name,
364 'a' - 1 + new->devnum / 26,
365 'a' + new->devnum % 26);
366 else
367 snprintf(gd->disk_name, sizeof(gd->disk_name),
368 "%s%d", tr->name, new->devnum);
369
370 set_capacity(gd, (new->size * tr->blksize) >> 9);
371
372
373 spin_lock_init(&new->queue_lock);
374 new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock);
375
376 if (!new->rq)
377 goto error3;
378
379 new->rq->queuedata = new;
380 blk_queue_logical_block_size(new->rq, tr->blksize);
381
382 if (tr->discard)
383 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
384 new->rq);
385
386 gd->queue = new->rq;
387
388
389
390 new->thread = kthread_run(mtd_blktrans_thread, new,
391 "%s%d", tr->name, new->mtd->index);
392 if (IS_ERR(new->thread)) {
393 ret = PTR_ERR(new->thread);
394 goto error4;
395 }
396 gd->driverfs_dev = &new->mtd->dev;
397
398 if (new->readonly)
399 set_disk_ro(gd, 1);
400
401 add_disk(gd);
402
403 if (new->disk_attributes) {
404 ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
405 new->disk_attributes);
406 WARN_ON(ret);
407 }
408 return 0;
409error4:
410 blk_cleanup_queue(new->rq);
411error3:
412 put_disk(new->disk);
413error2:
414 list_del(&new->list);
415error1:
416 return ret;
417}
418
419int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
420{
421 unsigned long flags;
422
423 if (mutex_trylock(&mtd_table_mutex)) {
424 mutex_unlock(&mtd_table_mutex);
425 BUG();
426 }
427
428 if (old->disk_attributes)
429 sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
430 old->disk_attributes);
431
432
433 del_gendisk(old->disk);
434
435
436
437 kthread_stop(old->thread);
438
439
440 spin_lock_irqsave(&old->queue_lock, flags);
441 old->rq->queuedata = NULL;
442 blk_start_queue(old->rq);
443 spin_unlock_irqrestore(&old->queue_lock, flags);
444
445
446
447 mutex_lock(&old->lock);
448 if (old->open) {
449 if (old->tr->release)
450 old->tr->release(old);
451 __put_mtd_device(old->mtd);
452 }
453
454 old->mtd = NULL;
455
456 mutex_unlock(&old->lock);
457 blktrans_dev_put(old);
458 return 0;
459}
460
461static void blktrans_notify_remove(struct mtd_info *mtd)
462{
463 struct mtd_blktrans_ops *tr;
464 struct mtd_blktrans_dev *dev, *next;
465
466 list_for_each_entry(tr, &blktrans_majors, list)
467 list_for_each_entry_safe(dev, next, &tr->devs, list)
468 if (dev->mtd == mtd)
469 tr->remove_dev(dev);
470}
471
472static void blktrans_notify_add(struct mtd_info *mtd)
473{
474 struct mtd_blktrans_ops *tr;
475
476 if (mtd->type == MTD_ABSENT)
477 return;
478
479 list_for_each_entry(tr, &blktrans_majors, list)
480 tr->add_mtd(tr, mtd);
481}
482
483static struct mtd_notifier blktrans_notifier = {
484 .add = blktrans_notify_add,
485 .remove = blktrans_notify_remove,
486};
487
488int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
489{
490 struct mtd_info *mtd;
491 int ret;
492
493
494
495
496 if (!blktrans_notifier.list.next)
497 register_mtd_user(&blktrans_notifier);
498
499
500 mutex_lock(&mtd_table_mutex);
501
502 ret = register_blkdev(tr->major, tr->name);
503 if (ret < 0) {
504 printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
505 tr->name, tr->major, ret);
506 mutex_unlock(&mtd_table_mutex);
507 return ret;
508 }
509
510 if (ret)
511 tr->major = ret;
512
513 tr->blkshift = ffs(tr->blksize) - 1;
514
515 INIT_LIST_HEAD(&tr->devs);
516 list_add(&tr->list, &blktrans_majors);
517
518 mtd_for_each_device(mtd)
519 if (mtd->type != MTD_ABSENT)
520 tr->add_mtd(tr, mtd);
521
522 mutex_unlock(&mtd_table_mutex);
523 return 0;
524}
525
526int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
527{
528 struct mtd_blktrans_dev *dev, *next;
529
530 mutex_lock(&mtd_table_mutex);
531
532
533 list_del(&tr->list);
534
535 list_for_each_entry_safe(dev, next, &tr->devs, list)
536 tr->remove_dev(dev);
537
538 unregister_blkdev(tr->major, tr->name);
539 mutex_unlock(&mtd_table_mutex);
540
541 BUG_ON(!list_empty(&tr->devs));
542 return 0;
543}
544
545static void __exit mtd_blktrans_exit(void)
546{
547
548
549 if (blktrans_notifier.list.next)
550 unregister_mtd_user(&blktrans_notifier);
551}
552
553module_exit(mtd_blktrans_exit);
554
555EXPORT_SYMBOL_GPL(register_mtd_blktrans);
556EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
557EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
558EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
559
560MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
561MODULE_LICENSE("GPL");
562MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");
563
