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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Interface to Linux block layer for MTD 'translation layers'.
4 *
5 * Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org>
6 */
7
8#include <linux/kernel.h>
9#include <linux/slab.h>
10#include <linux/module.h>
11#include <linux/list.h>
12#include <linux/fs.h>
13#include <linux/mtd/blktrans.h>
14#include <linux/mtd/mtd.h>
15#include <linux/blkdev.h>
16#include <linux/blk-mq.h>
17#include <linux/blkpg.h>
18#include <linux/spinlock.h>
19#include <linux/hdreg.h>
20#include <linux/mutex.h>
21#include <linux/uaccess.h>
22
23#include "mtdcore.h"
24
25static LIST_HEAD(blktrans_majors);
26
27static void blktrans_dev_release(struct kref *kref)
28{
29 struct mtd_blktrans_dev *dev =
30 container_of(kref, struct mtd_blktrans_dev, ref);
31
32 put_disk(dev->disk);
33 blk_mq_free_tag_set(dev->tag_set);
34 kfree(dev->tag_set);
35 list_del(&dev->list);
36 kfree(dev);
37}
38
39static void blktrans_dev_put(struct mtd_blktrans_dev *dev)
40{
41 kref_put(&dev->ref, blktrans_dev_release);
42}
43
44
45static blk_status_t do_blktrans_request(struct mtd_blktrans_ops *tr,
46 struct mtd_blktrans_dev *dev,
47 struct request *req)
48{
49 struct req_iterator iter;
50 struct bio_vec bvec;
51 unsigned long block, nsect;
52 char *buf;
53
54 block = blk_rq_pos(req) << 9 >> tr->blkshift;
55 nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
56
57 switch (req_op(req)) {
58 case REQ_OP_FLUSH:
59 if (tr->flush(dev))
60 return BLK_STS_IOERR;
61 return BLK_STS_OK;
62 case REQ_OP_DISCARD:
63 if (tr->discard(dev, block, nsect))
64 return BLK_STS_IOERR;
65 return BLK_STS_OK;
66 case REQ_OP_READ:
67 buf = kmap(bio_page(req->bio)) + bio_offset(req->bio);
68 for (; nsect > 0; nsect--, block++, buf += tr->blksize) {
69 if (tr->readsect(dev, block, buf)) {
70 kunmap(bio_page(req->bio));
71 return BLK_STS_IOERR;
72 }
73 }
74 kunmap(bio_page(req->bio));
75
76 rq_for_each_segment(bvec, req, iter)
77 flush_dcache_page(bvec.bv_page);
78 return BLK_STS_OK;
79 case REQ_OP_WRITE:
80 if (!tr->writesect)
81 return BLK_STS_IOERR;
82
83 rq_for_each_segment(bvec, req, iter)
84 flush_dcache_page(bvec.bv_page);
85
86 buf = kmap(bio_page(req->bio)) + bio_offset(req->bio);
87 for (; nsect > 0; nsect--, block++, buf += tr->blksize) {
88 if (tr->writesect(dev, block, buf)) {
89 kunmap(bio_page(req->bio));
90 return BLK_STS_IOERR;
91 }
92 }
93 kunmap(bio_page(req->bio));
94 return BLK_STS_OK;
95 default:
96 return BLK_STS_IOERR;
97 }
98}
99
100int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
101{
102 return dev->bg_stop;
103}
104EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
105
106static struct request *mtd_next_request(struct mtd_blktrans_dev *dev)
107{
108 struct request *rq;
109
110 rq = list_first_entry_or_null(&dev->rq_list, struct request, queuelist);
111 if (rq) {
112 list_del_init(&rq->queuelist);
113 blk_mq_start_request(rq);
114 return rq;
115 }
116
117 return NULL;
118}
119
120static void mtd_blktrans_work(struct mtd_blktrans_dev *dev)
121 __releases(&dev->queue_lock)
122 __acquires(&dev->queue_lock)
123{
124 struct mtd_blktrans_ops *tr = dev->tr;
125 struct request *req = NULL;
126 int background_done = 0;
127
128 while (1) {
129 blk_status_t res;
130
131 dev->bg_stop = false;
132 if (!req && !(req = mtd_next_request(dev))) {
133 if (tr->background && !background_done) {
134 spin_unlock_irq(&dev->queue_lock);
135 mutex_lock(&dev->lock);
136 tr->background(dev);
137 mutex_unlock(&dev->lock);
138 spin_lock_irq(&dev->queue_lock);
139 /*
140 * Do background processing just once per idle
141 * period.
142 */
143 background_done = !dev->bg_stop;
144 continue;
145 }
146 break;
147 }
148
149 spin_unlock_irq(&dev->queue_lock);
150
151 mutex_lock(&dev->lock);
152 res = do_blktrans_request(dev->tr, dev, req);
153 mutex_unlock(&dev->lock);
154
155 if (!blk_update_request(req, res, blk_rq_cur_bytes(req))) {
156 __blk_mq_end_request(req, res);
157 req = NULL;
158 }
159
160 background_done = 0;
161 cond_resched();
162 spin_lock_irq(&dev->queue_lock);
163 }
164}
165
166static blk_status_t mtd_queue_rq(struct blk_mq_hw_ctx *hctx,
167 const struct blk_mq_queue_data *bd)
168{
169 struct mtd_blktrans_dev *dev;
170
171 dev = hctx->queue->queuedata;
172 if (!dev) {
173 blk_mq_start_request(bd->rq);
174 return BLK_STS_IOERR;
175 }
176
177 spin_lock_irq(&dev->queue_lock);
178 list_add_tail(&bd->rq->queuelist, &dev->rq_list);
179 mtd_blktrans_work(dev);
180 spin_unlock_irq(&dev->queue_lock);
181
182 return BLK_STS_OK;
183}
184
185static int blktrans_open(struct gendisk *disk, blk_mode_t mode)
186{
187 struct mtd_blktrans_dev *dev = disk->private_data;
188 int ret = 0;
189
190 kref_get(&dev->ref);
191
192 mutex_lock(&dev->lock);
193
194 if (dev->open)
195 goto unlock;
196
197 __module_get(dev->tr->owner);
198
199 if (!dev->mtd)
200 goto unlock;
201
202 if (dev->tr->open) {
203 ret = dev->tr->open(dev);
204 if (ret)
205 goto error_put;
206 }
207
208 ret = __get_mtd_device(dev->mtd);
209 if (ret)
210 goto error_release;
211 dev->writable = mode & BLK_OPEN_WRITE;
212
213unlock:
214 dev->open++;
215 mutex_unlock(&dev->lock);
216 return ret;
217
218error_release:
219 if (dev->tr->release)
220 dev->tr->release(dev);
221error_put:
222 module_put(dev->tr->owner);
223 mutex_unlock(&dev->lock);
224 blktrans_dev_put(dev);
225 return ret;
226}
227
228static void blktrans_release(struct gendisk *disk)
229{
230 struct mtd_blktrans_dev *dev = disk->private_data;
231
232 mutex_lock(&dev->lock);
233
234 if (--dev->open)
235 goto unlock;
236
237 module_put(dev->tr->owner);
238
239 if (dev->mtd) {
240 if (dev->tr->release)
241 dev->tr->release(dev);
242 __put_mtd_device(dev->mtd);
243 }
244unlock:
245 mutex_unlock(&dev->lock);
246 blktrans_dev_put(dev);
247}
248
249static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
250{
251 struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
252 int ret = -ENXIO;
253
254 mutex_lock(&dev->lock);
255
256 if (!dev->mtd)
257 goto unlock;
258
259 ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENOTTY;
260unlock:
261 mutex_unlock(&dev->lock);
262 return ret;
263}
264
265static const struct block_device_operations mtd_block_ops = {
266 .owner = THIS_MODULE,
267 .open = blktrans_open,
268 .release = blktrans_release,
269 .getgeo = blktrans_getgeo,
270};
271
272static const struct blk_mq_ops mtd_mq_ops = {
273 .queue_rq = mtd_queue_rq,
274};
275
276int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
277{
278 struct mtd_blktrans_ops *tr = new->tr;
279 struct mtd_blktrans_dev *d;
280 struct queue_limits lim = { };
281 int last_devnum = -1;
282 struct gendisk *gd;
283 int ret;
284
285 lockdep_assert_held(&mtd_table_mutex);
286
287 list_for_each_entry(d, &tr->devs, list) {
288 if (new->devnum == -1) {
289 /* Use first free number */
290 if (d->devnum != last_devnum+1) {
291 /* Found a free devnum. Plug it in here */
292 new->devnum = last_devnum+1;
293 list_add_tail(&new->list, &d->list);
294 goto added;
295 }
296 } else if (d->devnum == new->devnum) {
297 /* Required number taken */
298 return -EBUSY;
299 } else if (d->devnum > new->devnum) {
300 /* Required number was free */
301 list_add_tail(&new->list, &d->list);
302 goto added;
303 }
304 last_devnum = d->devnum;
305 }
306
307 ret = -EBUSY;
308 if (new->devnum == -1)
309 new->devnum = last_devnum+1;
310
311 /* Check that the device and any partitions will get valid
312 * minor numbers and that the disk naming code below can cope
313 * with this number. */
314 if (new->devnum > (MINORMASK >> tr->part_bits) ||
315 (tr->part_bits && new->devnum >= 27 * 26))
316 return ret;
317
318 list_add_tail(&new->list, &tr->devs);
319 added:
320
321 mutex_init(&new->lock);
322 kref_init(&new->ref);
323 if (!tr->writesect)
324 new->readonly = 1;
325
326 ret = -ENOMEM;
327 new->tag_set = kzalloc(sizeof(*new->tag_set), GFP_KERNEL);
328 if (!new->tag_set)
329 goto out_list_del;
330
331 ret = blk_mq_alloc_sq_tag_set(new->tag_set, &mtd_mq_ops, 2,
332 BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING);
333 if (ret)
334 goto out_kfree_tag_set;
335
336 lim.logical_block_size = tr->blksize;
337 if (tr->discard)
338 lim.max_hw_discard_sectors = UINT_MAX;
339 if (tr->flush)
340 lim.features |= BLK_FEAT_WRITE_CACHE;
341
342 /* Create gendisk */
343 gd = blk_mq_alloc_disk(new->tag_set, &lim, new);
344 if (IS_ERR(gd)) {
345 ret = PTR_ERR(gd);
346 goto out_free_tag_set;
347 }
348
349 new->disk = gd;
350 new->rq = new->disk->queue;
351 gd->private_data = new;
352 gd->major = tr->major;
353 gd->first_minor = (new->devnum) << tr->part_bits;
354 gd->minors = 1 << tr->part_bits;
355 gd->fops = &mtd_block_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 gd->flags |= GENHD_FL_NO_PART;
370 }
371
372 set_capacity(gd, ((u64)new->size * tr->blksize) >> 9);
373
374 /* Create the request queue */
375 spin_lock_init(&new->queue_lock);
376 INIT_LIST_HEAD(&new->rq_list);
377 gd->queue = new->rq;
378
379 if (new->readonly)
380 set_disk_ro(gd, 1);
381
382 ret = device_add_disk(&new->mtd->dev, gd, NULL);
383 if (ret)
384 goto out_cleanup_disk;
385
386 if (new->disk_attributes) {
387 ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
388 new->disk_attributes);
389 WARN_ON(ret);
390 }
391 return 0;
392
393out_cleanup_disk:
394 put_disk(new->disk);
395out_free_tag_set:
396 blk_mq_free_tag_set(new->tag_set);
397out_kfree_tag_set:
398 kfree(new->tag_set);
399out_list_del:
400 list_del(&new->list);
401 return ret;
402}
403
404int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
405{
406 unsigned long flags;
407
408 lockdep_assert_held(&mtd_table_mutex);
409
410 if (old->disk_attributes)
411 sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
412 old->disk_attributes);
413
414 /* Stop new requests to arrive */
415 del_gendisk(old->disk);
416
417 /* Kill current requests */
418 spin_lock_irqsave(&old->queue_lock, flags);
419 old->rq->queuedata = NULL;
420 spin_unlock_irqrestore(&old->queue_lock, flags);
421
422 /* freeze+quiesce queue to ensure all requests are flushed */
423 blk_mq_freeze_queue(old->rq);
424 blk_mq_quiesce_queue(old->rq);
425 blk_mq_unquiesce_queue(old->rq);
426 blk_mq_unfreeze_queue(old->rq);
427
428 /* If the device is currently open, tell trans driver to close it,
429 then put mtd device, and don't touch it again */
430 mutex_lock(&old->lock);
431 if (old->open) {
432 if (old->tr->release)
433 old->tr->release(old);
434 __put_mtd_device(old->mtd);
435 }
436
437 old->mtd = NULL;
438
439 mutex_unlock(&old->lock);
440 blktrans_dev_put(old);
441 return 0;
442}
443
444static void blktrans_notify_remove(struct mtd_info *mtd)
445{
446 struct mtd_blktrans_ops *tr;
447 struct mtd_blktrans_dev *dev, *next;
448
449 list_for_each_entry(tr, &blktrans_majors, list)
450 list_for_each_entry_safe(dev, next, &tr->devs, list)
451 if (dev->mtd == mtd)
452 tr->remove_dev(dev);
453}
454
455static void blktrans_notify_add(struct mtd_info *mtd)
456{
457 struct mtd_blktrans_ops *tr;
458
459 if (mtd->type == MTD_ABSENT || mtd->type == MTD_UBIVOLUME)
460 return;
461
462 list_for_each_entry(tr, &blktrans_majors, list)
463 tr->add_mtd(tr, mtd);
464}
465
466static struct mtd_notifier blktrans_notifier = {
467 .add = blktrans_notify_add,
468 .remove = blktrans_notify_remove,
469};
470
471int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
472{
473 struct mtd_info *mtd;
474 int ret;
475
476 /* Register the notifier if/when the first device type is
477 registered, to prevent the link/init ordering from fucking
478 us over. */
479 if (!blktrans_notifier.list.next)
480 register_mtd_user(&blktrans_notifier);
481
482 ret = register_blkdev(tr->major, tr->name);
483 if (ret < 0) {
484 printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
485 tr->name, tr->major, ret);
486 return ret;
487 }
488
489 if (ret)
490 tr->major = ret;
491
492 tr->blkshift = ffs(tr->blksize) - 1;
493
494 INIT_LIST_HEAD(&tr->devs);
495
496 mutex_lock(&mtd_table_mutex);
497 list_add(&tr->list, &blktrans_majors);
498 mtd_for_each_device(mtd)
499 if (mtd->type != MTD_ABSENT && mtd->type != MTD_UBIVOLUME)
500 tr->add_mtd(tr, mtd);
501 mutex_unlock(&mtd_table_mutex);
502 return 0;
503}
504
505int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
506{
507 struct mtd_blktrans_dev *dev, *next;
508
509 mutex_lock(&mtd_table_mutex);
510
511 /* Remove it from the list of active majors */
512 list_del(&tr->list);
513
514 list_for_each_entry_safe(dev, next, &tr->devs, list)
515 tr->remove_dev(dev);
516
517 mutex_unlock(&mtd_table_mutex);
518 unregister_blkdev(tr->major, tr->name);
519
520 BUG_ON(!list_empty(&tr->devs));
521 return 0;
522}
523
524static void __exit mtd_blktrans_exit(void)
525{
526 /* No race here -- if someone's currently in register_mtd_blktrans
527 we're screwed anyway. */
528 if (blktrans_notifier.list.next)
529 unregister_mtd_user(&blktrans_notifier);
530}
531
532module_exit(mtd_blktrans_exit);
533
534EXPORT_SYMBOL_GPL(register_mtd_blktrans);
535EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
536EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
537EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
538
539MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
540MODULE_LICENSE("GPL");
541MODULE_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'");