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1/*
2 * Interface to Linux block layer for MTD 'translation layers'.
3 *
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
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
43static void 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
70static void 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
122int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
123{
124 if (kthread_should_stop())
125 return 1;
126
127 return dev->bg_stop;
128}
129EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
130
131static int mtd_blktrans_thread(void *arg)
132{
133 struct mtd_blktrans_dev *dev = arg;
134 struct mtd_blktrans_ops *tr = dev->tr;
135 struct request_queue *rq = dev->rq;
136 struct request *req = NULL;
137 int background_done = 0;
138
139 spin_lock_irq(rq->queue_lock);
140
141 while (!kthread_should_stop()) {
142 int res;
143
144 dev->bg_stop = false;
145 if (!req && !(req = blk_fetch_request(rq))) {
146 if (tr->background && !background_done) {
147 spin_unlock_irq(rq->queue_lock);
148 mutex_lock(&dev->lock);
149 tr->background(dev);
150 mutex_unlock(&dev->lock);
151 spin_lock_irq(rq->queue_lock);
152 /*
153 * Do background processing just once per idle
154 * period.
155 */
156 background_done = !dev->bg_stop;
157 continue;
158 }
159 set_current_state(TASK_INTERRUPTIBLE);
160
161 if (kthread_should_stop())
162 set_current_state(TASK_RUNNING);
163
164 spin_unlock_irq(rq->queue_lock);
165 schedule();
166 spin_lock_irq(rq->queue_lock);
167 continue;
168 }
169
170 spin_unlock_irq(rq->queue_lock);
171
172 mutex_lock(&dev->lock);
173 res = do_blktrans_request(dev->tr, dev, req);
174 mutex_unlock(&dev->lock);
175
176 spin_lock_irq(rq->queue_lock);
177
178 if (!__blk_end_request_cur(req, res))
179 req = NULL;
180
181 background_done = 0;
182 }
183
184 if (req)
185 __blk_end_request_all(req, -EIO);
186
187 spin_unlock_irq(rq->queue_lock);
188
189 return 0;
190}
191
192static void mtd_blktrans_request(struct request_queue *rq)
193{
194 struct mtd_blktrans_dev *dev;
195 struct request *req = NULL;
196
197 dev = rq->queuedata;
198
199 if (!dev)
200 while ((req = blk_fetch_request(rq)) != NULL)
201 __blk_end_request_all(req, -ENODEV);
202 else {
203 dev->bg_stop = true;
204 wake_up_process(dev->thread);
205 }
206}
207
208static int blktrans_open(struct block_device *bdev, fmode_t mode)
209{
210 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
211 int ret = 0;
212
213 if (!dev)
214 return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/
215
216 mutex_lock(&dev->lock);
217
218 if (dev->open++)
219 goto unlock;
220
221 kref_get(&dev->ref);
222 __module_get(dev->tr->owner);
223
224 if (!dev->mtd)
225 goto unlock;
226
227 if (dev->tr->open) {
228 ret = dev->tr->open(dev);
229 if (ret)
230 goto error_put;
231 }
232
233 ret = __get_mtd_device(dev->mtd);
234 if (ret)
235 goto error_release;
236
237unlock:
238 mutex_unlock(&dev->lock);
239 blktrans_dev_put(dev);
240 return ret;
241
242error_release:
243 if (dev->tr->release)
244 dev->tr->release(dev);
245error_put:
246 module_put(dev->tr->owner);
247 kref_put(&dev->ref, blktrans_dev_release);
248 mutex_unlock(&dev->lock);
249 blktrans_dev_put(dev);
250 return ret;
251}
252
253static int blktrans_release(struct gendisk *disk, fmode_t mode)
254{
255 struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
256 int ret = 0;
257
258 if (!dev)
259 return ret;
260
261 mutex_lock(&dev->lock);
262
263 if (--dev->open)
264 goto unlock;
265
266 kref_put(&dev->ref, blktrans_dev_release);
267 module_put(dev->tr->owner);
268
269 if (dev->mtd) {
270 ret = dev->tr->release ? dev->tr->release(dev) : 0;
271 __put_mtd_device(dev->mtd);
272 }
273unlock:
274 mutex_unlock(&dev->lock);
275 blktrans_dev_put(dev);
276 return ret;
277}
278
279static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
280{
281 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
282 int ret = -ENXIO;
283
284 if (!dev)
285 return ret;
286
287 mutex_lock(&dev->lock);
288
289 if (!dev->mtd)
290 goto unlock;
291
292 ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0;
293unlock:
294 mutex_unlock(&dev->lock);
295 blktrans_dev_put(dev);
296 return ret;
297}
298
299static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
300 unsigned int cmd, unsigned long arg)
301{
302 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
303 int ret = -ENXIO;
304
305 if (!dev)
306 return ret;
307
308 mutex_lock(&dev->lock);
309
310 if (!dev->mtd)
311 goto unlock;
312
313 switch (cmd) {
314 case BLKFLSBUF:
315 ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
316 break;
317 default:
318 ret = -ENOTTY;
319 }
320unlock:
321 mutex_unlock(&dev->lock);
322 blktrans_dev_put(dev);
323 return ret;
324}
325
326static const struct block_device_operations mtd_blktrans_ops = {
327 .owner = THIS_MODULE,
328 .open = blktrans_open,
329 .release = blktrans_release,
330 .ioctl = blktrans_ioctl,
331 .getgeo = blktrans_getgeo,
332};
333
334int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
335{
336 struct mtd_blktrans_ops *tr = new->tr;
337 struct mtd_blktrans_dev *d;
338 int last_devnum = -1;
339 struct gendisk *gd;
340 int ret;
341
342 if (mutex_trylock(&mtd_table_mutex)) {
343 mutex_unlock(&mtd_table_mutex);
344 BUG();
345 }
346
347 mutex_lock(&blktrans_ref_mutex);
348 list_for_each_entry(d, &tr->devs, list) {
349 if (new->devnum == -1) {
350 /* Use first free number */
351 if (d->devnum != last_devnum+1) {
352 /* Found a free devnum. Plug it in here */
353 new->devnum = last_devnum+1;
354 list_add_tail(&new->list, &d->list);
355 goto added;
356 }
357 } else if (d->devnum == new->devnum) {
358 /* Required number taken */
359 mutex_unlock(&blktrans_ref_mutex);
360 return -EBUSY;
361 } else if (d->devnum > new->devnum) {
362 /* Required number was free */
363 list_add_tail(&new->list, &d->list);
364 goto added;
365 }
366 last_devnum = d->devnum;
367 }
368
369 ret = -EBUSY;
370 if (new->devnum == -1)
371 new->devnum = last_devnum+1;
372
373 /* Check that the device and any partitions will get valid
374 * minor numbers and that the disk naming code below can cope
375 * with this number. */
376 if (new->devnum > (MINORMASK >> tr->part_bits) ||
377 (tr->part_bits && new->devnum >= 27 * 26)) {
378 mutex_unlock(&blktrans_ref_mutex);
379 goto error1;
380 }
381
382 list_add_tail(&new->list, &tr->devs);
383 added:
384 mutex_unlock(&blktrans_ref_mutex);
385
386 mutex_init(&new->lock);
387 kref_init(&new->ref);
388 if (!tr->writesect)
389 new->readonly = 1;
390
391 /* Create gendisk */
392 ret = -ENOMEM;
393 gd = alloc_disk(1 << tr->part_bits);
394
395 if (!gd)
396 goto error2;
397
398 new->disk = gd;
399 gd->private_data = new;
400 gd->major = tr->major;
401 gd->first_minor = (new->devnum) << tr->part_bits;
402 gd->fops = &mtd_blktrans_ops;
403
404 if (tr->part_bits)
405 if (new->devnum < 26)
406 snprintf(gd->disk_name, sizeof(gd->disk_name),
407 "%s%c", tr->name, 'a' + new->devnum);
408 else
409 snprintf(gd->disk_name, sizeof(gd->disk_name),
410 "%s%c%c", tr->name,
411 'a' - 1 + new->devnum / 26,
412 'a' + new->devnum % 26);
413 else
414 snprintf(gd->disk_name, sizeof(gd->disk_name),
415 "%s%d", tr->name, new->devnum);
416
417 set_capacity(gd, (new->size * tr->blksize) >> 9);
418
419 /* Create the request queue */
420 spin_lock_init(&new->queue_lock);
421 new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock);
422
423 if (!new->rq)
424 goto error3;
425
426 new->rq->queuedata = new;
427 blk_queue_logical_block_size(new->rq, tr->blksize);
428
429 if (tr->discard) {
430 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq);
431 new->rq->limits.max_discard_sectors = UINT_MAX;
432 }
433
434 gd->queue = new->rq;
435
436 /* Create processing thread */
437 /* TODO: workqueue ? */
438 new->thread = kthread_run(mtd_blktrans_thread, new,
439 "%s%d", tr->name, new->mtd->index);
440 if (IS_ERR(new->thread)) {
441 ret = PTR_ERR(new->thread);
442 goto error4;
443 }
444 gd->driverfs_dev = &new->mtd->dev;
445
446 if (new->readonly)
447 set_disk_ro(gd, 1);
448
449 add_disk(gd);
450
451 if (new->disk_attributes) {
452 ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
453 new->disk_attributes);
454 WARN_ON(ret);
455 }
456 return 0;
457error4:
458 blk_cleanup_queue(new->rq);
459error3:
460 put_disk(new->disk);
461error2:
462 list_del(&new->list);
463error1:
464 return ret;
465}
466
467int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
468{
469 unsigned long flags;
470
471 if (mutex_trylock(&mtd_table_mutex)) {
472 mutex_unlock(&mtd_table_mutex);
473 BUG();
474 }
475
476 if (old->disk_attributes)
477 sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
478 old->disk_attributes);
479
480 /* Stop new requests to arrive */
481 del_gendisk(old->disk);
482
483
484 /* Stop the thread */
485 kthread_stop(old->thread);
486
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);
492
493 /* If the device is currently open, tell trans driver to close it,
494 then put mtd device, and don't touch it again */
495 mutex_lock(&old->lock);
496 if (old->open) {
497 if (old->tr->release)
498 old->tr->release(old);
499 __put_mtd_device(old->mtd);
500 }
501
502 old->mtd = NULL;
503
504 mutex_unlock(&old->lock);
505 blktrans_dev_put(old);
506 return 0;
507}
508
509static void blktrans_notify_remove(struct mtd_info *mtd)
510{
511 struct mtd_blktrans_ops *tr;
512 struct mtd_blktrans_dev *dev, *next;
513
514 list_for_each_entry(tr, &blktrans_majors, list)
515 list_for_each_entry_safe(dev, next, &tr->devs, list)
516 if (dev->mtd == mtd)
517 tr->remove_dev(dev);
518}
519
520static void blktrans_notify_add(struct mtd_info *mtd)
521{
522 struct mtd_blktrans_ops *tr;
523
524 if (mtd->type == MTD_ABSENT)
525 return;
526
527 list_for_each_entry(tr, &blktrans_majors, list)
528 tr->add_mtd(tr, mtd);
529}
530
531static struct mtd_notifier blktrans_notifier = {
532 .add = blktrans_notify_add,
533 .remove = blktrans_notify_remove,
534};
535
536int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
537{
538 struct mtd_info *mtd;
539 int ret;
540
541 /* Register the notifier if/when the first device type is
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
547
548 mutex_lock(&mtd_table_mutex);
549
550 ret = register_blkdev(tr->major, tr->name);
551 if (ret < 0) {
552 printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
553 tr->name, tr->major, ret);
554 mutex_unlock(&mtd_table_mutex);
555 return ret;
556 }
557
558 if (ret)
559 tr->major = ret;
560
561 tr->blkshift = ffs(tr->blksize) - 1;
562
563 INIT_LIST_HEAD(&tr->devs);
564 list_add(&tr->list, &blktrans_majors);
565
566 mtd_for_each_device(mtd)
567 if (mtd->type != MTD_ABSENT)
568 tr->add_mtd(tr, mtd);
569
570 mutex_unlock(&mtd_table_mutex);
571 return 0;
572}
573
574int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
575{
576 struct mtd_blktrans_dev *dev, *next;
577
578 mutex_lock(&mtd_table_mutex);
579
580 /* Remove it from the list of active majors */
581 list_del(&tr->list);
582
583 list_for_each_entry_safe(dev, next, &tr->devs, list)
584 tr->remove_dev(dev);
585
586 unregister_blkdev(tr->major, tr->name);
587 mutex_unlock(&mtd_table_mutex);
588
589 BUG_ON(!list_empty(&tr->devs));
590 return 0;
591}
592
593static 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
601module_exit(mtd_blktrans_exit);
602
603EXPORT_SYMBOL_GPL(register_mtd_blktrans);
604EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
605EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
606EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
607
608MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
609MODULE_LICENSE("GPL");
610MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");
1/*
2 * Interface to Linux block layer for MTD 'translation layers'.
3 *
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
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/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
86 buf = req->buffer;
87
88 if (req->cmd_type != REQ_TYPE_FS)
89 return -EIO;
90
91 if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
92 get_capacity(req->rq_disk))
93 return -EIO;
94
95 if (req->cmd_flags & REQ_DISCARD)
96 return tr->discard(dev, block, nsect);
97
98 switch(rq_data_dir(req)) {
99 case READ:
100 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
101 if (tr->readsect(dev, block, buf))
102 return -EIO;
103 rq_flush_dcache_pages(req);
104 return 0;
105 case WRITE:
106 if (!tr->writesect)
107 return -EIO;
108
109 rq_flush_dcache_pages(req);
110 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
111 if (tr->writesect(dev, block, buf))
112 return -EIO;
113 return 0;
114 default:
115 printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
116 return -EIO;
117 }
118}
119
120int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
121{
122 return dev->bg_stop;
123}
124EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
125
126static void mtd_blktrans_work(struct work_struct *work)
127{
128 struct mtd_blktrans_dev *dev =
129 container_of(work, struct mtd_blktrans_dev, work);
130 struct mtd_blktrans_ops *tr = dev->tr;
131 struct request_queue *rq = dev->rq;
132 struct request *req = NULL;
133 int background_done = 0;
134
135 spin_lock_irq(rq->queue_lock);
136
137 while (1) {
138 int res;
139
140 dev->bg_stop = false;
141 if (!req && !(req = blk_fetch_request(rq))) {
142 if (tr->background && !background_done) {
143 spin_unlock_irq(rq->queue_lock);
144 mutex_lock(&dev->lock);
145 tr->background(dev);
146 mutex_unlock(&dev->lock);
147 spin_lock_irq(rq->queue_lock);
148 /*
149 * Do background processing just once per idle
150 * period.
151 */
152 background_done = !dev->bg_stop;
153 continue;
154 }
155 break;
156 }
157
158 spin_unlock_irq(rq->queue_lock);
159
160 mutex_lock(&dev->lock);
161 res = do_blktrans_request(dev->tr, dev, req);
162 mutex_unlock(&dev->lock);
163
164 spin_lock_irq(rq->queue_lock);
165
166 if (!__blk_end_request_cur(req, res))
167 req = NULL;
168
169 background_done = 0;
170 }
171
172 if (req)
173 __blk_end_request_all(req, -EIO);
174
175 spin_unlock_irq(rq->queue_lock);
176}
177
178static void mtd_blktrans_request(struct request_queue *rq)
179{
180 struct mtd_blktrans_dev *dev;
181 struct request *req = NULL;
182
183 dev = rq->queuedata;
184
185 if (!dev)
186 while ((req = blk_fetch_request(rq)) != NULL)
187 __blk_end_request_all(req, -ENODEV);
188 else
189 queue_work(dev->wq, &dev->work);
190}
191
192static int blktrans_open(struct block_device *bdev, fmode_t mode)
193{
194 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
195 int ret = 0;
196
197 if (!dev)
198 return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/
199
200 mutex_lock(&dev->lock);
201
202 if (dev->open)
203 goto unlock;
204
205 kref_get(&dev->ref);
206 __module_get(dev->tr->owner);
207
208 if (!dev->mtd)
209 goto unlock;
210
211 if (dev->tr->open) {
212 ret = dev->tr->open(dev);
213 if (ret)
214 goto error_put;
215 }
216
217 ret = __get_mtd_device(dev->mtd);
218 if (ret)
219 goto error_release;
220 dev->file_mode = mode;
221
222unlock:
223 dev->open++;
224 mutex_unlock(&dev->lock);
225 blktrans_dev_put(dev);
226 return ret;
227
228error_release:
229 if (dev->tr->release)
230 dev->tr->release(dev);
231error_put:
232 module_put(dev->tr->owner);
233 kref_put(&dev->ref, blktrans_dev_release);
234 mutex_unlock(&dev->lock);
235 blktrans_dev_put(dev);
236 return ret;
237}
238
239static void blktrans_release(struct gendisk *disk, fmode_t mode)
240{
241 struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
242
243 if (!dev)
244 return;
245
246 mutex_lock(&dev->lock);
247
248 if (--dev->open)
249 goto unlock;
250
251 kref_put(&dev->ref, blktrans_dev_release);
252 module_put(dev->tr->owner);
253
254 if (dev->mtd) {
255 if (dev->tr->release)
256 dev->tr->release(dev);
257 __put_mtd_device(dev->mtd);
258 }
259unlock:
260 mutex_unlock(&dev->lock);
261 blktrans_dev_put(dev);
262}
263
264static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
265{
266 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
267 int ret = -ENXIO;
268
269 if (!dev)
270 return ret;
271
272 mutex_lock(&dev->lock);
273
274 if (!dev->mtd)
275 goto unlock;
276
277 ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0;
278unlock:
279 mutex_unlock(&dev->lock);
280 blktrans_dev_put(dev);
281 return ret;
282}
283
284static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
285 unsigned int cmd, unsigned long arg)
286{
287 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
288 int ret = -ENXIO;
289
290 if (!dev)
291 return ret;
292
293 mutex_lock(&dev->lock);
294
295 if (!dev->mtd)
296 goto unlock;
297
298 switch (cmd) {
299 case BLKFLSBUF:
300 ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
301 break;
302 default:
303 ret = -ENOTTY;
304 }
305unlock:
306 mutex_unlock(&dev->lock);
307 blktrans_dev_put(dev);
308 return ret;
309}
310
311static const struct block_device_operations mtd_block_ops = {
312 .owner = THIS_MODULE,
313 .open = blktrans_open,
314 .release = blktrans_release,
315 .ioctl = blktrans_ioctl,
316 .getgeo = blktrans_getgeo,
317};
318
319int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
320{
321 struct mtd_blktrans_ops *tr = new->tr;
322 struct mtd_blktrans_dev *d;
323 int last_devnum = -1;
324 struct gendisk *gd;
325 int ret;
326
327 if (mutex_trylock(&mtd_table_mutex)) {
328 mutex_unlock(&mtd_table_mutex);
329 BUG();
330 }
331
332 mutex_lock(&blktrans_ref_mutex);
333 list_for_each_entry(d, &tr->devs, list) {
334 if (new->devnum == -1) {
335 /* Use first free number */
336 if (d->devnum != last_devnum+1) {
337 /* Found a free devnum. Plug it in here */
338 new->devnum = last_devnum+1;
339 list_add_tail(&new->list, &d->list);
340 goto added;
341 }
342 } else if (d->devnum == new->devnum) {
343 /* Required number taken */
344 mutex_unlock(&blktrans_ref_mutex);
345 return -EBUSY;
346 } else if (d->devnum > new->devnum) {
347 /* Required number was free */
348 list_add_tail(&new->list, &d->list);
349 goto added;
350 }
351 last_devnum = d->devnum;
352 }
353
354 ret = -EBUSY;
355 if (new->devnum == -1)
356 new->devnum = last_devnum+1;
357
358 /* Check that the device and any partitions will get valid
359 * minor numbers and that the disk naming code below can cope
360 * with this number. */
361 if (new->devnum > (MINORMASK >> tr->part_bits) ||
362 (tr->part_bits && new->devnum >= 27 * 26)) {
363 mutex_unlock(&blktrans_ref_mutex);
364 goto error1;
365 }
366
367 list_add_tail(&new->list, &tr->devs);
368 added:
369 mutex_unlock(&blktrans_ref_mutex);
370
371 mutex_init(&new->lock);
372 kref_init(&new->ref);
373 if (!tr->writesect)
374 new->readonly = 1;
375
376 /* Create gendisk */
377 ret = -ENOMEM;
378 gd = alloc_disk(1 << tr->part_bits);
379
380 if (!gd)
381 goto error2;
382
383 new->disk = gd;
384 gd->private_data = new;
385 gd->major = tr->major;
386 gd->first_minor = (new->devnum) << tr->part_bits;
387 gd->fops = &mtd_block_ops;
388
389 if (tr->part_bits)
390 if (new->devnum < 26)
391 snprintf(gd->disk_name, sizeof(gd->disk_name),
392 "%s%c", tr->name, 'a' + new->devnum);
393 else
394 snprintf(gd->disk_name, sizeof(gd->disk_name),
395 "%s%c%c", tr->name,
396 'a' - 1 + new->devnum / 26,
397 'a' + new->devnum % 26);
398 else
399 snprintf(gd->disk_name, sizeof(gd->disk_name),
400 "%s%d", tr->name, new->devnum);
401
402 set_capacity(gd, (new->size * tr->blksize) >> 9);
403
404 /* Create the request queue */
405 spin_lock_init(&new->queue_lock);
406 new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock);
407
408 if (!new->rq)
409 goto error3;
410
411 new->rq->queuedata = new;
412 blk_queue_logical_block_size(new->rq, tr->blksize);
413
414 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq);
415
416 if (tr->discard) {
417 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq);
418 new->rq->limits.max_discard_sectors = UINT_MAX;
419 }
420
421 gd->queue = new->rq;
422
423 /* Create processing workqueue */
424 new->wq = alloc_workqueue("%s%d", 0, 0,
425 tr->name, new->mtd->index);
426 if (!new->wq)
427 goto error4;
428 INIT_WORK(&new->work, mtd_blktrans_work);
429
430 gd->driverfs_dev = &new->mtd->dev;
431
432 if (new->readonly)
433 set_disk_ro(gd, 1);
434
435 add_disk(gd);
436
437 if (new->disk_attributes) {
438 ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
439 new->disk_attributes);
440 WARN_ON(ret);
441 }
442 return 0;
443error4:
444 blk_cleanup_queue(new->rq);
445error3:
446 put_disk(new->disk);
447error2:
448 list_del(&new->list);
449error1:
450 return ret;
451}
452
453int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
454{
455 unsigned long flags;
456
457 if (mutex_trylock(&mtd_table_mutex)) {
458 mutex_unlock(&mtd_table_mutex);
459 BUG();
460 }
461
462 if (old->disk_attributes)
463 sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
464 old->disk_attributes);
465
466 /* Stop new requests to arrive */
467 del_gendisk(old->disk);
468
469 /* Stop workqueue. This will perform any pending request. */
470 destroy_workqueue(old->wq);
471
472 /* Kill current requests */
473 spin_lock_irqsave(&old->queue_lock, flags);
474 old->rq->queuedata = NULL;
475 blk_start_queue(old->rq);
476 spin_unlock_irqrestore(&old->queue_lock, flags);
477
478 /* If the device is currently open, tell trans driver to close it,
479 then put mtd device, and don't touch it again */
480 mutex_lock(&old->lock);
481 if (old->open) {
482 if (old->tr->release)
483 old->tr->release(old);
484 __put_mtd_device(old->mtd);
485 }
486
487 old->mtd = NULL;
488
489 mutex_unlock(&old->lock);
490 blktrans_dev_put(old);
491 return 0;
492}
493
494static void blktrans_notify_remove(struct mtd_info *mtd)
495{
496 struct mtd_blktrans_ops *tr;
497 struct mtd_blktrans_dev *dev, *next;
498
499 list_for_each_entry(tr, &blktrans_majors, list)
500 list_for_each_entry_safe(dev, next, &tr->devs, list)
501 if (dev->mtd == mtd)
502 tr->remove_dev(dev);
503}
504
505static void blktrans_notify_add(struct mtd_info *mtd)
506{
507 struct mtd_blktrans_ops *tr;
508
509 if (mtd->type == MTD_ABSENT)
510 return;
511
512 list_for_each_entry(tr, &blktrans_majors, list)
513 tr->add_mtd(tr, mtd);
514}
515
516static struct mtd_notifier blktrans_notifier = {
517 .add = blktrans_notify_add,
518 .remove = blktrans_notify_remove,
519};
520
521int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
522{
523 struct mtd_info *mtd;
524 int ret;
525
526 /* Register the notifier if/when the first device type is
527 registered, to prevent the link/init ordering from fucking
528 us over. */
529 if (!blktrans_notifier.list.next)
530 register_mtd_user(&blktrans_notifier);
531
532
533 mutex_lock(&mtd_table_mutex);
534
535 ret = register_blkdev(tr->major, tr->name);
536 if (ret < 0) {
537 printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
538 tr->name, tr->major, ret);
539 mutex_unlock(&mtd_table_mutex);
540 return ret;
541 }
542
543 if (ret)
544 tr->major = ret;
545
546 tr->blkshift = ffs(tr->blksize) - 1;
547
548 INIT_LIST_HEAD(&tr->devs);
549 list_add(&tr->list, &blktrans_majors);
550
551 mtd_for_each_device(mtd)
552 if (mtd->type != MTD_ABSENT)
553 tr->add_mtd(tr, mtd);
554
555 mutex_unlock(&mtd_table_mutex);
556 return 0;
557}
558
559int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
560{
561 struct mtd_blktrans_dev *dev, *next;
562
563 mutex_lock(&mtd_table_mutex);
564
565 /* Remove it from the list of active majors */
566 list_del(&tr->list);
567
568 list_for_each_entry_safe(dev, next, &tr->devs, list)
569 tr->remove_dev(dev);
570
571 unregister_blkdev(tr->major, tr->name);
572 mutex_unlock(&mtd_table_mutex);
573
574 BUG_ON(!list_empty(&tr->devs));
575 return 0;
576}
577
578static void __exit mtd_blktrans_exit(void)
579{
580 /* No race here -- if someone's currently in register_mtd_blktrans
581 we're screwed anyway. */
582 if (blktrans_notifier.list.next)
583 unregister_mtd_user(&blktrans_notifier);
584}
585
586module_exit(mtd_blktrans_exit);
587
588EXPORT_SYMBOL_GPL(register_mtd_blktrans);
589EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
590EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
591EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
592
593MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
594MODULE_LICENSE("GPL");
595MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");