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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 int last_devnum = -1;
281 struct gendisk *gd;
282 int ret;
283
284 lockdep_assert_held(&mtd_table_mutex);
285
286 list_for_each_entry(d, &tr->devs, list) {
287 if (new->devnum == -1) {
288 /* Use first free number */
289 if (d->devnum != last_devnum+1) {
290 /* Found a free devnum. Plug it in here */
291 new->devnum = last_devnum+1;
292 list_add_tail(&new->list, &d->list);
293 goto added;
294 }
295 } else if (d->devnum == new->devnum) {
296 /* Required number taken */
297 return -EBUSY;
298 } else if (d->devnum > new->devnum) {
299 /* Required number was free */
300 list_add_tail(&new->list, &d->list);
301 goto added;
302 }
303 last_devnum = d->devnum;
304 }
305
306 ret = -EBUSY;
307 if (new->devnum == -1)
308 new->devnum = last_devnum+1;
309
310 /* Check that the device and any partitions will get valid
311 * minor numbers and that the disk naming code below can cope
312 * with this number. */
313 if (new->devnum > (MINORMASK >> tr->part_bits) ||
314 (tr->part_bits && new->devnum >= 27 * 26))
315 return ret;
316
317 list_add_tail(&new->list, &tr->devs);
318 added:
319
320 mutex_init(&new->lock);
321 kref_init(&new->ref);
322 if (!tr->writesect)
323 new->readonly = 1;
324
325 ret = -ENOMEM;
326 new->tag_set = kzalloc(sizeof(*new->tag_set), GFP_KERNEL);
327 if (!new->tag_set)
328 goto out_list_del;
329
330 ret = blk_mq_alloc_sq_tag_set(new->tag_set, &mtd_mq_ops, 2,
331 BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING);
332 if (ret)
333 goto out_kfree_tag_set;
334
335 /* Create gendisk */
336 gd = blk_mq_alloc_disk(new->tag_set, new);
337 if (IS_ERR(gd)) {
338 ret = PTR_ERR(gd);
339 goto out_free_tag_set;
340 }
341
342 new->disk = gd;
343 new->rq = new->disk->queue;
344 gd->private_data = new;
345 gd->major = tr->major;
346 gd->first_minor = (new->devnum) << tr->part_bits;
347 gd->minors = 1 << tr->part_bits;
348 gd->fops = &mtd_block_ops;
349
350 if (tr->part_bits) {
351 if (new->devnum < 26)
352 snprintf(gd->disk_name, sizeof(gd->disk_name),
353 "%s%c", tr->name, 'a' + new->devnum);
354 else
355 snprintf(gd->disk_name, sizeof(gd->disk_name),
356 "%s%c%c", tr->name,
357 'a' - 1 + new->devnum / 26,
358 'a' + new->devnum % 26);
359 } else {
360 snprintf(gd->disk_name, sizeof(gd->disk_name),
361 "%s%d", tr->name, new->devnum);
362 gd->flags |= GENHD_FL_NO_PART;
363 }
364
365 set_capacity(gd, ((u64)new->size * tr->blksize) >> 9);
366
367 /* Create the request queue */
368 spin_lock_init(&new->queue_lock);
369 INIT_LIST_HEAD(&new->rq_list);
370
371 if (tr->flush)
372 blk_queue_write_cache(new->rq, true, false);
373
374 blk_queue_logical_block_size(new->rq, tr->blksize);
375
376 blk_queue_flag_set(QUEUE_FLAG_NONROT, new->rq);
377 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, new->rq);
378
379 if (tr->discard)
380 blk_queue_max_discard_sectors(new->rq, UINT_MAX);
381
382 gd->queue = new->rq;
383
384 if (new->readonly)
385 set_disk_ro(gd, 1);
386
387 ret = device_add_disk(&new->mtd->dev, gd, NULL);
388 if (ret)
389 goto out_cleanup_disk;
390
391 if (new->disk_attributes) {
392 ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
393 new->disk_attributes);
394 WARN_ON(ret);
395 }
396 return 0;
397
398out_cleanup_disk:
399 put_disk(new->disk);
400out_free_tag_set:
401 blk_mq_free_tag_set(new->tag_set);
402out_kfree_tag_set:
403 kfree(new->tag_set);
404out_list_del:
405 list_del(&new->list);
406 return ret;
407}
408
409int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
410{
411 unsigned long flags;
412
413 lockdep_assert_held(&mtd_table_mutex);
414
415 if (old->disk_attributes)
416 sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
417 old->disk_attributes);
418
419 /* Stop new requests to arrive */
420 del_gendisk(old->disk);
421
422 /* Kill current requests */
423 spin_lock_irqsave(&old->queue_lock, flags);
424 old->rq->queuedata = NULL;
425 spin_unlock_irqrestore(&old->queue_lock, flags);
426
427 /* freeze+quiesce queue to ensure all requests are flushed */
428 blk_mq_freeze_queue(old->rq);
429 blk_mq_quiesce_queue(old->rq);
430 blk_mq_unquiesce_queue(old->rq);
431 blk_mq_unfreeze_queue(old->rq);
432
433 /* If the device is currently open, tell trans driver to close it,
434 then put mtd device, and don't touch it again */
435 mutex_lock(&old->lock);
436 if (old->open) {
437 if (old->tr->release)
438 old->tr->release(old);
439 __put_mtd_device(old->mtd);
440 }
441
442 old->mtd = NULL;
443
444 mutex_unlock(&old->lock);
445 blktrans_dev_put(old);
446 return 0;
447}
448
449static void blktrans_notify_remove(struct mtd_info *mtd)
450{
451 struct mtd_blktrans_ops *tr;
452 struct mtd_blktrans_dev *dev, *next;
453
454 list_for_each_entry(tr, &blktrans_majors, list)
455 list_for_each_entry_safe(dev, next, &tr->devs, list)
456 if (dev->mtd == mtd)
457 tr->remove_dev(dev);
458}
459
460static void blktrans_notify_add(struct mtd_info *mtd)
461{
462 struct mtd_blktrans_ops *tr;
463
464 if (mtd->type == MTD_ABSENT || mtd->type == MTD_UBIVOLUME)
465 return;
466
467 list_for_each_entry(tr, &blktrans_majors, list)
468 tr->add_mtd(tr, mtd);
469}
470
471static struct mtd_notifier blktrans_notifier = {
472 .add = blktrans_notify_add,
473 .remove = blktrans_notify_remove,
474};
475
476int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
477{
478 struct mtd_info *mtd;
479 int ret;
480
481 /* Register the notifier if/when the first device type is
482 registered, to prevent the link/init ordering from fucking
483 us over. */
484 if (!blktrans_notifier.list.next)
485 register_mtd_user(&blktrans_notifier);
486
487 ret = register_blkdev(tr->major, tr->name);
488 if (ret < 0) {
489 printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
490 tr->name, tr->major, ret);
491 return ret;
492 }
493
494 if (ret)
495 tr->major = ret;
496
497 tr->blkshift = ffs(tr->blksize) - 1;
498
499 INIT_LIST_HEAD(&tr->devs);
500
501 mutex_lock(&mtd_table_mutex);
502 list_add(&tr->list, &blktrans_majors);
503 mtd_for_each_device(mtd)
504 if (mtd->type != MTD_ABSENT && mtd->type != MTD_UBIVOLUME)
505 tr->add_mtd(tr, mtd);
506 mutex_unlock(&mtd_table_mutex);
507 return 0;
508}
509
510int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
511{
512 struct mtd_blktrans_dev *dev, *next;
513
514 mutex_lock(&mtd_table_mutex);
515
516 /* Remove it from the list of active majors */
517 list_del(&tr->list);
518
519 list_for_each_entry_safe(dev, next, &tr->devs, list)
520 tr->remove_dev(dev);
521
522 mutex_unlock(&mtd_table_mutex);
523 unregister_blkdev(tr->major, tr->name);
524
525 BUG_ON(!list_empty(&tr->devs));
526 return 0;
527}
528
529static void __exit mtd_blktrans_exit(void)
530{
531 /* No race here -- if someone's currently in register_mtd_blktrans
532 we're screwed anyway. */
533 if (blktrans_notifier.list.next)
534 unregister_mtd_user(&blktrans_notifier);
535}
536
537module_exit(mtd_blktrans_exit);
538
539EXPORT_SYMBOL_GPL(register_mtd_blktrans);
540EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
541EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
542EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
543
544MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
545MODULE_LICENSE("GPL");
546MODULE_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 <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 blk_status_t 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 if (tr->flush(dev))
89 return BLK_STS_IOERR;
90 return BLK_STS_OK;
91 }
92
93 if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
94 get_capacity(req->rq_disk))
95 return BLK_STS_IOERR;
96
97 switch (req_op(req)) {
98 case REQ_OP_DISCARD:
99 if (tr->discard(dev, block, nsect))
100 return BLK_STS_IOERR;
101 return BLK_STS_OK;
102 case REQ_OP_READ:
103 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
104 if (tr->readsect(dev, block, buf))
105 return BLK_STS_IOERR;
106 rq_flush_dcache_pages(req);
107 return BLK_STS_OK;
108 case REQ_OP_WRITE:
109 if (!tr->writesect)
110 return BLK_STS_IOERR;
111
112 rq_flush_dcache_pages(req);
113 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
114 if (tr->writesect(dev, block, buf))
115 return BLK_STS_IOERR;
116 return BLK_STS_OK;
117 default:
118 return BLK_STS_IOERR;
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 blk_status_t 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 * Do background processing just once per idle
152 * period.
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 spin_unlock_irq(rq->queue_lock);
175}
176
177static void mtd_blktrans_request(struct request_queue *rq)
178{
179 struct mtd_blktrans_dev *dev;
180 struct request *req = NULL;
181
182 dev = rq->queuedata;
183
184 if (!dev)
185 while ((req = blk_fetch_request(rq)) != NULL)
186 __blk_end_request_all(req, BLK_STS_IOERR);
187 else
188 queue_work(dev->wq, &dev->work);
189}
190
191static int blktrans_open(struct block_device *bdev, fmode_t mode)
192{
193 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
194 int ret = 0;
195
196 if (!dev)
197 return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/
198
199 mutex_lock(&mtd_table_mutex);
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 mutex_unlock(&mtd_table_mutex);
226 blktrans_dev_put(dev);
227 return ret;
228
229error_release:
230 if (dev->tr->release)
231 dev->tr->release(dev);
232error_put:
233 module_put(dev->tr->owner);
234 kref_put(&dev->ref, blktrans_dev_release);
235 mutex_unlock(&dev->lock);
236 mutex_unlock(&mtd_table_mutex);
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(&mtd_table_mutex);
249 mutex_lock(&dev->lock);
250
251 if (--dev->open)
252 goto unlock;
253
254 kref_put(&dev->ref, blktrans_dev_release);
255 module_put(dev->tr->owner);
256
257 if (dev->mtd) {
258 if (dev->tr->release)
259 dev->tr->release(dev);
260 __put_mtd_device(dev->mtd);
261 }
262unlock:
263 mutex_unlock(&dev->lock);
264 mutex_unlock(&mtd_table_mutex);
265 blktrans_dev_put(dev);
266}
267
268static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
269{
270 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
271 int ret = -ENXIO;
272
273 if (!dev)
274 return ret;
275
276 mutex_lock(&dev->lock);
277
278 if (!dev->mtd)
279 goto unlock;
280
281 ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENOTTY;
282unlock:
283 mutex_unlock(&dev->lock);
284 blktrans_dev_put(dev);
285 return ret;
286}
287
288static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
289 unsigned int cmd, unsigned long arg)
290{
291 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
292 int ret = -ENXIO;
293
294 if (!dev)
295 return ret;
296
297 mutex_lock(&dev->lock);
298
299 if (!dev->mtd)
300 goto unlock;
301
302 switch (cmd) {
303 case BLKFLSBUF:
304 ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
305 break;
306 default:
307 ret = -ENOTTY;
308 }
309unlock:
310 mutex_unlock(&dev->lock);
311 blktrans_dev_put(dev);
312 return ret;
313}
314
315static const struct block_device_operations mtd_block_ops = {
316 .owner = THIS_MODULE,
317 .open = blktrans_open,
318 .release = blktrans_release,
319 .ioctl = blktrans_ioctl,
320 .getgeo = blktrans_getgeo,
321};
322
323int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
324{
325 struct mtd_blktrans_ops *tr = new->tr;
326 struct mtd_blktrans_dev *d;
327 int last_devnum = -1;
328 struct gendisk *gd;
329 int ret;
330
331 if (mutex_trylock(&mtd_table_mutex)) {
332 mutex_unlock(&mtd_table_mutex);
333 BUG();
334 }
335
336 mutex_lock(&blktrans_ref_mutex);
337 list_for_each_entry(d, &tr->devs, list) {
338 if (new->devnum == -1) {
339 /* Use first free number */
340 if (d->devnum != last_devnum+1) {
341 /* Found a free devnum. Plug it in here */
342 new->devnum = last_devnum+1;
343 list_add_tail(&new->list, &d->list);
344 goto added;
345 }
346 } else if (d->devnum == new->devnum) {
347 /* Required number taken */
348 mutex_unlock(&blktrans_ref_mutex);
349 return -EBUSY;
350 } else if (d->devnum > new->devnum) {
351 /* Required number was free */
352 list_add_tail(&new->list, &d->list);
353 goto added;
354 }
355 last_devnum = d->devnum;
356 }
357
358 ret = -EBUSY;
359 if (new->devnum == -1)
360 new->devnum = last_devnum+1;
361
362 /* Check that the device and any partitions will get valid
363 * minor numbers and that the disk naming code below can cope
364 * with this number. */
365 if (new->devnum > (MINORMASK >> tr->part_bits) ||
366 (tr->part_bits && new->devnum >= 27 * 26)) {
367 mutex_unlock(&blktrans_ref_mutex);
368 goto error1;
369 }
370
371 list_add_tail(&new->list, &tr->devs);
372 added:
373 mutex_unlock(&blktrans_ref_mutex);
374
375 mutex_init(&new->lock);
376 kref_init(&new->ref);
377 if (!tr->writesect)
378 new->readonly = 1;
379
380 /* Create gendisk */
381 ret = -ENOMEM;
382 gd = alloc_disk(1 << tr->part_bits);
383
384 if (!gd)
385 goto error2;
386
387 new->disk = gd;
388 gd->private_data = new;
389 gd->major = tr->major;
390 gd->first_minor = (new->devnum) << tr->part_bits;
391 gd->fops = &mtd_block_ops;
392
393 if (tr->part_bits)
394 if (new->devnum < 26)
395 snprintf(gd->disk_name, sizeof(gd->disk_name),
396 "%s%c", tr->name, 'a' + new->devnum);
397 else
398 snprintf(gd->disk_name, sizeof(gd->disk_name),
399 "%s%c%c", tr->name,
400 'a' - 1 + new->devnum / 26,
401 'a' + new->devnum % 26);
402 else
403 snprintf(gd->disk_name, sizeof(gd->disk_name),
404 "%s%d", tr->name, new->devnum);
405
406 set_capacity(gd, ((u64)new->size * tr->blksize) >> 9);
407
408 /* Create the request queue */
409 spin_lock_init(&new->queue_lock);
410 new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock);
411
412 if (!new->rq)
413 goto error3;
414
415 if (tr->flush)
416 blk_queue_write_cache(new->rq, true, false);
417
418 new->rq->queuedata = new;
419 blk_queue_logical_block_size(new->rq, tr->blksize);
420
421 blk_queue_bounce_limit(new->rq, BLK_BOUNCE_HIGH);
422 blk_queue_flag_set(QUEUE_FLAG_NONROT, new->rq);
423 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, new->rq);
424
425 if (tr->discard) {
426 blk_queue_flag_set(QUEUE_FLAG_DISCARD, new->rq);
427 blk_queue_max_discard_sectors(new->rq, UINT_MAX);
428 }
429
430 gd->queue = new->rq;
431
432 /* Create processing workqueue */
433 new->wq = alloc_workqueue("%s%d", 0, 0,
434 tr->name, new->mtd->index);
435 if (!new->wq)
436 goto error4;
437 INIT_WORK(&new->work, mtd_blktrans_work);
438
439 if (new->readonly)
440 set_disk_ro(gd, 1);
441
442 device_add_disk(&new->mtd->dev, gd);
443
444 if (new->disk_attributes) {
445 ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
446 new->disk_attributes);
447 WARN_ON(ret);
448 }
449 return 0;
450error4:
451 blk_cleanup_queue(new->rq);
452error3:
453 put_disk(new->disk);
454error2:
455 list_del(&new->list);
456error1:
457 return ret;
458}
459
460int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
461{
462 unsigned long flags;
463
464 if (mutex_trylock(&mtd_table_mutex)) {
465 mutex_unlock(&mtd_table_mutex);
466 BUG();
467 }
468
469 if (old->disk_attributes)
470 sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
471 old->disk_attributes);
472
473 /* Stop new requests to arrive */
474 del_gendisk(old->disk);
475
476 /* Stop workqueue. This will perform any pending request. */
477 destroy_workqueue(old->wq);
478
479 /* Kill current requests */
480 spin_lock_irqsave(&old->queue_lock, flags);
481 old->rq->queuedata = NULL;
482 blk_start_queue(old->rq);
483 spin_unlock_irqrestore(&old->queue_lock, flags);
484
485 /* If the device is currently open, tell trans driver to close it,
486 then put mtd device, and don't touch it again */
487 mutex_lock(&old->lock);
488 if (old->open) {
489 if (old->tr->release)
490 old->tr->release(old);
491 __put_mtd_device(old->mtd);
492 }
493
494 old->mtd = NULL;
495
496 mutex_unlock(&old->lock);
497 blktrans_dev_put(old);
498 return 0;
499}
500
501static void blktrans_notify_remove(struct mtd_info *mtd)
502{
503 struct mtd_blktrans_ops *tr;
504 struct mtd_blktrans_dev *dev, *next;
505
506 list_for_each_entry(tr, &blktrans_majors, list)
507 list_for_each_entry_safe(dev, next, &tr->devs, list)
508 if (dev->mtd == mtd)
509 tr->remove_dev(dev);
510}
511
512static void blktrans_notify_add(struct mtd_info *mtd)
513{
514 struct mtd_blktrans_ops *tr;
515
516 if (mtd->type == MTD_ABSENT)
517 return;
518
519 list_for_each_entry(tr, &blktrans_majors, list)
520 tr->add_mtd(tr, mtd);
521}
522
523static struct mtd_notifier blktrans_notifier = {
524 .add = blktrans_notify_add,
525 .remove = blktrans_notify_remove,
526};
527
528int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
529{
530 struct mtd_info *mtd;
531 int ret;
532
533 /* Register the notifier if/when the first device type is
534 registered, to prevent the link/init ordering from fucking
535 us over. */
536 if (!blktrans_notifier.list.next)
537 register_mtd_user(&blktrans_notifier);
538
539
540 mutex_lock(&mtd_table_mutex);
541
542 ret = register_blkdev(tr->major, tr->name);
543 if (ret < 0) {
544 printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
545 tr->name, tr->major, ret);
546 mutex_unlock(&mtd_table_mutex);
547 return ret;
548 }
549
550 if (ret)
551 tr->major = ret;
552
553 tr->blkshift = ffs(tr->blksize) - 1;
554
555 INIT_LIST_HEAD(&tr->devs);
556 list_add(&tr->list, &blktrans_majors);
557
558 mtd_for_each_device(mtd)
559 if (mtd->type != MTD_ABSENT)
560 tr->add_mtd(tr, mtd);
561
562 mutex_unlock(&mtd_table_mutex);
563 return 0;
564}
565
566int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
567{
568 struct mtd_blktrans_dev *dev, *next;
569
570 mutex_lock(&mtd_table_mutex);
571
572 /* Remove it from the list of active majors */
573 list_del(&tr->list);
574
575 list_for_each_entry_safe(dev, next, &tr->devs, list)
576 tr->remove_dev(dev);
577
578 unregister_blkdev(tr->major, tr->name);
579 mutex_unlock(&mtd_table_mutex);
580
581 BUG_ON(!list_empty(&tr->devs));
582 return 0;
583}
584
585static void __exit mtd_blktrans_exit(void)
586{
587 /* No race here -- if someone's currently in register_mtd_blktrans
588 we're screwed anyway. */
589 if (blktrans_notifier.list.next)
590 unregister_mtd_user(&blktrans_notifier);
591}
592
593module_exit(mtd_blktrans_exit);
594
595EXPORT_SYMBOL_GPL(register_mtd_blktrans);
596EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
597EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
598EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
599
600MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
601MODULE_LICENSE("GPL");
602MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");