1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) International Business Machines Corp., 2006
4 * Copyright (c) Nokia Corporation, 2007
5 *
6 * Author: Artem Bityutskiy (Битюцкий Артём),
7 * Frank Haverkamp
8 */
9
10 /*
11 * This file includes UBI initialization and building of UBI devices.
12 *
13 * When UBI is initialized, it attaches all the MTD devices specified as the
14 * module load parameters or the kernel boot parameters. If MTD devices were
15 * specified, UBI does not attach any MTD device, but it is possible to do
16 * later using the "UBI control device".
17 */
18
19 #include <linux/err.h>
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <linux/stringify.h>
23 #include <linux/namei.h>
24 #include <linux/stat.h>
25 #include <linux/miscdevice.h>
26 #include <linux/mtd/partitions.h>
27 #include <linux/log2.h>
28 #include <linux/kthread.h>
29 #include <linux/kernel.h>
30 #include <linux/slab.h>
31 #include <linux/major.h>
32 #include "ubi.h"
33
34 /* Maximum length of the 'mtd=' parameter */
35 #define MTD_PARAM_LEN_MAX 64
36
37 /* Maximum number of comma-separated items in the 'mtd=' parameter */
38 #define MTD_PARAM_MAX_COUNT 4
39
40 /* Maximum value for the number of bad PEBs per 1024 PEBs */
41 #define MAX_MTD_UBI_BEB_LIMIT 768
42
43 #ifdef CONFIG_MTD_UBI_MODULE
44 #define ubi_is_module() 1
45 #else
46 #define ubi_is_module() 0
47 #endif
48
49 /**
50 * struct mtd_dev_param - MTD device parameter description data structure.
51 * @name: MTD character device node path, MTD device name, or MTD device number
52 * string
53 * @vid_hdr_offs: VID header offset
54 * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
55 */
56 struct mtd_dev_param {
57 char name[MTD_PARAM_LEN_MAX];
58 int ubi_num;
59 int vid_hdr_offs;
60 int max_beb_per1024;
61 };
62
63 /* Numbers of elements set in the @mtd_dev_param array */
64 static int mtd_devs;
65
66 /* MTD devices specification parameters */
67 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
68 #ifdef CONFIG_MTD_UBI_FASTMAP
69 /* UBI module parameter to enable fastmap automatically on non-fastmap images */
70 static bool fm_autoconvert;
71 static bool fm_debug;
72 #endif
73
74 /* Slab cache for wear-leveling entries */
75 struct kmem_cache *ubi_wl_entry_slab;
76
77 /* UBI control character device */
78 static struct miscdevice ubi_ctrl_cdev = {
79 .minor = MISC_DYNAMIC_MINOR,
80 .name = "ubi_ctrl",
81 .fops = &ubi_ctrl_cdev_operations,
82 };
83
84 /* All UBI devices in system */
85 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
86
87 /* Serializes UBI devices creations and removals */
88 DEFINE_MUTEX(ubi_devices_mutex);
89
90 /* Protects @ubi_devices and @ubi->ref_count */
91 static DEFINE_SPINLOCK(ubi_devices_lock);
92
93 /* "Show" method for files in '/<sysfs>/class/ubi/' */
94 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
version_show(struct class * class,struct class_attribute * attr,char * buf)95 static ssize_t version_show(struct class *class, struct class_attribute *attr,
96 char *buf)
97 {
98 return sprintf(buf, "%d\n", UBI_VERSION);
99 }
100 static CLASS_ATTR_RO(version);
101
102 static struct attribute *ubi_class_attrs[] = {
103 &class_attr_version.attr,
104 NULL,
105 };
106 ATTRIBUTE_GROUPS(ubi_class);
107
108 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
109 struct class ubi_class = {
110 .name = UBI_NAME_STR,
111 .owner = THIS_MODULE,
112 .class_groups = ubi_class_groups,
113 };
114
115 static ssize_t dev_attribute_show(struct device *dev,
116 struct device_attribute *attr, char *buf);
117
118 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
119 static struct device_attribute dev_eraseblock_size =
120 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
121 static struct device_attribute dev_avail_eraseblocks =
122 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
123 static struct device_attribute dev_total_eraseblocks =
124 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
125 static struct device_attribute dev_volumes_count =
126 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
127 static struct device_attribute dev_max_ec =
128 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
129 static struct device_attribute dev_reserved_for_bad =
130 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
131 static struct device_attribute dev_bad_peb_count =
132 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
133 static struct device_attribute dev_max_vol_count =
134 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
135 static struct device_attribute dev_min_io_size =
136 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
137 static struct device_attribute dev_bgt_enabled =
138 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
139 static struct device_attribute dev_mtd_num =
140 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
141 static struct device_attribute dev_ro_mode =
142 __ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
143
144 /**
145 * ubi_volume_notify - send a volume change notification.
146 * @ubi: UBI device description object
147 * @vol: volume description object of the changed volume
148 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
149 *
150 * This is a helper function which notifies all subscribers about a volume
151 * change event (creation, removal, re-sizing, re-naming, updating). Returns
152 * zero in case of success and a negative error code in case of failure.
153 */
ubi_volume_notify(struct ubi_device * ubi,struct ubi_volume * vol,int ntype)154 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
155 {
156 int ret;
157 struct ubi_notification nt;
158
159 ubi_do_get_device_info(ubi, &nt.di);
160 ubi_do_get_volume_info(ubi, vol, &nt.vi);
161
162 switch (ntype) {
163 case UBI_VOLUME_ADDED:
164 case UBI_VOLUME_REMOVED:
165 case UBI_VOLUME_RESIZED:
166 case UBI_VOLUME_RENAMED:
167 ret = ubi_update_fastmap(ubi);
168 if (ret)
169 ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
170 }
171
172 return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
173 }
174
175 /**
176 * ubi_notify_all - send a notification to all volumes.
177 * @ubi: UBI device description object
178 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
179 * @nb: the notifier to call
180 *
181 * This function walks all volumes of UBI device @ubi and sends the @ntype
182 * notification for each volume. If @nb is %NULL, then all registered notifiers
183 * are called, otherwise only the @nb notifier is called. Returns the number of
184 * sent notifications.
185 */
ubi_notify_all(struct ubi_device * ubi,int ntype,struct notifier_block * nb)186 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
187 {
188 struct ubi_notification nt;
189 int i, count = 0;
190
191 ubi_do_get_device_info(ubi, &nt.di);
192
193 mutex_lock(&ubi->device_mutex);
194 for (i = 0; i < ubi->vtbl_slots; i++) {
195 /*
196 * Since the @ubi->device is locked, and we are not going to
197 * change @ubi->volumes, we do not have to lock
198 * @ubi->volumes_lock.
199 */
200 if (!ubi->volumes[i])
201 continue;
202
203 ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
204 if (nb)
205 nb->notifier_call(nb, ntype, &nt);
206 else
207 blocking_notifier_call_chain(&ubi_notifiers, ntype,
208 &nt);
209 count += 1;
210 }
211 mutex_unlock(&ubi->device_mutex);
212
213 return count;
214 }
215
216 /**
217 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
218 * @nb: the notifier to call
219 *
220 * This function walks all UBI devices and volumes and sends the
221 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
222 * registered notifiers are called, otherwise only the @nb notifier is called.
223 * Returns the number of sent notifications.
224 */
ubi_enumerate_volumes(struct notifier_block * nb)225 int ubi_enumerate_volumes(struct notifier_block *nb)
226 {
227 int i, count = 0;
228
229 /*
230 * Since the @ubi_devices_mutex is locked, and we are not going to
231 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
232 */
233 for (i = 0; i < UBI_MAX_DEVICES; i++) {
234 struct ubi_device *ubi = ubi_devices[i];
235
236 if (!ubi)
237 continue;
238 count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
239 }
240
241 return count;
242 }
243
244 /**
245 * ubi_get_device - get UBI device.
246 * @ubi_num: UBI device number
247 *
248 * This function returns UBI device description object for UBI device number
249 * @ubi_num, or %NULL if the device does not exist. This function increases the
250 * device reference count to prevent removal of the device. In other words, the
251 * device cannot be removed if its reference count is not zero.
252 */
ubi_get_device(int ubi_num)253 struct ubi_device *ubi_get_device(int ubi_num)
254 {
255 struct ubi_device *ubi;
256
257 spin_lock(&ubi_devices_lock);
258 ubi = ubi_devices[ubi_num];
259 if (ubi) {
260 ubi_assert(ubi->ref_count >= 0);
261 ubi->ref_count += 1;
262 get_device(&ubi->dev);
263 }
264 spin_unlock(&ubi_devices_lock);
265
266 return ubi;
267 }
268
269 /**
270 * ubi_put_device - drop an UBI device reference.
271 * @ubi: UBI device description object
272 */
ubi_put_device(struct ubi_device * ubi)273 void ubi_put_device(struct ubi_device *ubi)
274 {
275 spin_lock(&ubi_devices_lock);
276 ubi->ref_count -= 1;
277 put_device(&ubi->dev);
278 spin_unlock(&ubi_devices_lock);
279 }
280
281 /**
282 * ubi_get_by_major - get UBI device by character device major number.
283 * @major: major number
284 *
285 * This function is similar to 'ubi_get_device()', but it searches the device
286 * by its major number.
287 */
ubi_get_by_major(int major)288 struct ubi_device *ubi_get_by_major(int major)
289 {
290 int i;
291 struct ubi_device *ubi;
292
293 spin_lock(&ubi_devices_lock);
294 for (i = 0; i < UBI_MAX_DEVICES; i++) {
295 ubi = ubi_devices[i];
296 if (ubi && MAJOR(ubi->cdev.dev) == major) {
297 ubi_assert(ubi->ref_count >= 0);
298 ubi->ref_count += 1;
299 get_device(&ubi->dev);
300 spin_unlock(&ubi_devices_lock);
301 return ubi;
302 }
303 }
304 spin_unlock(&ubi_devices_lock);
305
306 return NULL;
307 }
308
309 /**
310 * ubi_major2num - get UBI device number by character device major number.
311 * @major: major number
312 *
313 * This function searches UBI device number object by its major number. If UBI
314 * device was not found, this function returns -ENODEV, otherwise the UBI device
315 * number is returned.
316 */
ubi_major2num(int major)317 int ubi_major2num(int major)
318 {
319 int i, ubi_num = -ENODEV;
320
321 spin_lock(&ubi_devices_lock);
322 for (i = 0; i < UBI_MAX_DEVICES; i++) {
323 struct ubi_device *ubi = ubi_devices[i];
324
325 if (ubi && MAJOR(ubi->cdev.dev) == major) {
326 ubi_num = ubi->ubi_num;
327 break;
328 }
329 }
330 spin_unlock(&ubi_devices_lock);
331
332 return ubi_num;
333 }
334
335 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
dev_attribute_show(struct device * dev,struct device_attribute * attr,char * buf)336 static ssize_t dev_attribute_show(struct device *dev,
337 struct device_attribute *attr, char *buf)
338 {
339 ssize_t ret;
340 struct ubi_device *ubi;
341
342 /*
343 * The below code looks weird, but it actually makes sense. We get the
344 * UBI device reference from the contained 'struct ubi_device'. But it
345 * is unclear if the device was removed or not yet. Indeed, if the
346 * device was removed before we increased its reference count,
347 * 'ubi_get_device()' will return -ENODEV and we fail.
348 *
349 * Remember, 'struct ubi_device' is freed in the release function, so
350 * we still can use 'ubi->ubi_num'.
351 */
352 ubi = container_of(dev, struct ubi_device, dev);
353
354 if (attr == &dev_eraseblock_size)
355 ret = sprintf(buf, "%d\n", ubi->leb_size);
356 else if (attr == &dev_avail_eraseblocks)
357 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
358 else if (attr == &dev_total_eraseblocks)
359 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
360 else if (attr == &dev_volumes_count)
361 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
362 else if (attr == &dev_max_ec)
363 ret = sprintf(buf, "%d\n", ubi->max_ec);
364 else if (attr == &dev_reserved_for_bad)
365 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
366 else if (attr == &dev_bad_peb_count)
367 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
368 else if (attr == &dev_max_vol_count)
369 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
370 else if (attr == &dev_min_io_size)
371 ret = sprintf(buf, "%d\n", ubi->min_io_size);
372 else if (attr == &dev_bgt_enabled)
373 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
374 else if (attr == &dev_mtd_num)
375 ret = sprintf(buf, "%d\n", ubi->mtd->index);
376 else if (attr == &dev_ro_mode)
377 ret = sprintf(buf, "%d\n", ubi->ro_mode);
378 else
379 ret = -EINVAL;
380
381 return ret;
382 }
383
384 static struct attribute *ubi_dev_attrs[] = {
385 &dev_eraseblock_size.attr,
386 &dev_avail_eraseblocks.attr,
387 &dev_total_eraseblocks.attr,
388 &dev_volumes_count.attr,
389 &dev_max_ec.attr,
390 &dev_reserved_for_bad.attr,
391 &dev_bad_peb_count.attr,
392 &dev_max_vol_count.attr,
393 &dev_min_io_size.attr,
394 &dev_bgt_enabled.attr,
395 &dev_mtd_num.attr,
396 &dev_ro_mode.attr,
397 NULL
398 };
399 ATTRIBUTE_GROUPS(ubi_dev);
400
dev_release(struct device * dev)401 static void dev_release(struct device *dev)
402 {
403 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
404
405 kfree(ubi);
406 }
407
408 /**
409 * kill_volumes - destroy all user volumes.
410 * @ubi: UBI device description object
411 */
kill_volumes(struct ubi_device * ubi)412 static void kill_volumes(struct ubi_device *ubi)
413 {
414 int i;
415
416 for (i = 0; i < ubi->vtbl_slots; i++)
417 if (ubi->volumes[i])
418 ubi_free_volume(ubi, ubi->volumes[i]);
419 }
420
421 /**
422 * uif_init - initialize user interfaces for an UBI device.
423 * @ubi: UBI device description object
424 *
425 * This function initializes various user interfaces for an UBI device. If the
426 * initialization fails at an early stage, this function frees all the
427 * resources it allocated, returns an error.
428 *
429 * This function returns zero in case of success and a negative error code in
430 * case of failure.
431 */
uif_init(struct ubi_device * ubi)432 static int uif_init(struct ubi_device *ubi)
433 {
434 int i, err;
435 dev_t dev;
436
437 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
438
439 /*
440 * Major numbers for the UBI character devices are allocated
441 * dynamically. Major numbers of volume character devices are
442 * equivalent to ones of the corresponding UBI character device. Minor
443 * numbers of UBI character devices are 0, while minor numbers of
444 * volume character devices start from 1. Thus, we allocate one major
445 * number and ubi->vtbl_slots + 1 minor numbers.
446 */
447 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
448 if (err) {
449 ubi_err(ubi, "cannot register UBI character devices");
450 return err;
451 }
452
453 ubi->dev.devt = dev;
454
455 ubi_assert(MINOR(dev) == 0);
456 cdev_init(&ubi->cdev, &ubi_cdev_operations);
457 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
458 ubi->cdev.owner = THIS_MODULE;
459
460 dev_set_name(&ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
461 err = cdev_device_add(&ubi->cdev, &ubi->dev);
462 if (err)
463 goto out_unreg;
464
465 for (i = 0; i < ubi->vtbl_slots; i++)
466 if (ubi->volumes[i]) {
467 err = ubi_add_volume(ubi, ubi->volumes[i]);
468 if (err) {
469 ubi_err(ubi, "cannot add volume %d", i);
470 goto out_volumes;
471 }
472 }
473
474 return 0;
475
476 out_volumes:
477 kill_volumes(ubi);
478 cdev_device_del(&ubi->cdev, &ubi->dev);
479 out_unreg:
480 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
481 ubi_err(ubi, "cannot initialize UBI %s, error %d",
482 ubi->ubi_name, err);
483 return err;
484 }
485
486 /**
487 * uif_close - close user interfaces for an UBI device.
488 * @ubi: UBI device description object
489 *
490 * Note, since this function un-registers UBI volume device objects (@vol->dev),
491 * the memory allocated voe the volumes is freed as well (in the release
492 * function).
493 */
uif_close(struct ubi_device * ubi)494 static void uif_close(struct ubi_device *ubi)
495 {
496 kill_volumes(ubi);
497 cdev_device_del(&ubi->cdev, &ubi->dev);
498 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
499 }
500
501 /**
502 * ubi_free_volumes_from - free volumes from specific index.
503 * @ubi: UBI device description object
504 * @from: the start index used for volume free.
505 */
ubi_free_volumes_from(struct ubi_device * ubi,int from)506 static void ubi_free_volumes_from(struct ubi_device *ubi, int from)
507 {
508 int i;
509
510 for (i = from; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
511 if (!ubi->volumes[i])
512 continue;
513 ubi_eba_replace_table(ubi->volumes[i], NULL);
514 ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
515 kfree(ubi->volumes[i]);
516 ubi->volumes[i] = NULL;
517 }
518 }
519
520 /**
521 * ubi_free_all_volumes - free all volumes.
522 * @ubi: UBI device description object
523 */
ubi_free_all_volumes(struct ubi_device * ubi)524 void ubi_free_all_volumes(struct ubi_device *ubi)
525 {
526 ubi_free_volumes_from(ubi, 0);
527 }
528
529 /**
530 * ubi_free_internal_volumes - free internal volumes.
531 * @ubi: UBI device description object
532 */
ubi_free_internal_volumes(struct ubi_device * ubi)533 void ubi_free_internal_volumes(struct ubi_device *ubi)
534 {
535 ubi_free_volumes_from(ubi, ubi->vtbl_slots);
536 }
537
get_bad_peb_limit(const struct ubi_device * ubi,int max_beb_per1024)538 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
539 {
540 int limit, device_pebs;
541 uint64_t device_size;
542
543 if (!max_beb_per1024) {
544 /*
545 * Since max_beb_per1024 has not been set by the user in either
546 * the cmdline or Kconfig, use mtd_max_bad_blocks to set the
547 * limit if it is supported by the device.
548 */
549 limit = mtd_max_bad_blocks(ubi->mtd, 0, ubi->mtd->size);
550 if (limit < 0)
551 return 0;
552 return limit;
553 }
554
555 /*
556 * Here we are using size of the entire flash chip and
557 * not just the MTD partition size because the maximum
558 * number of bad eraseblocks is a percentage of the
559 * whole device and bad eraseblocks are not fairly
560 * distributed over the flash chip. So the worst case
561 * is that all the bad eraseblocks of the chip are in
562 * the MTD partition we are attaching (ubi->mtd).
563 */
564 device_size = mtd_get_device_size(ubi->mtd);
565 device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
566 limit = mult_frac(device_pebs, max_beb_per1024, 1024);
567
568 /* Round it up */
569 if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
570 limit += 1;
571
572 return limit;
573 }
574
575 /**
576 * io_init - initialize I/O sub-system for a given UBI device.
577 * @ubi: UBI device description object
578 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
579 *
580 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
581 * assumed:
582 * o EC header is always at offset zero - this cannot be changed;
583 * o VID header starts just after the EC header at the closest address
584 * aligned to @io->hdrs_min_io_size;
585 * o data starts just after the VID header at the closest address aligned to
586 * @io->min_io_size
587 *
588 * This function returns zero in case of success and a negative error code in
589 * case of failure.
590 */
io_init(struct ubi_device * ubi,int max_beb_per1024)591 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
592 {
593 dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
594 dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
595
596 if (ubi->mtd->numeraseregions != 0) {
597 /*
598 * Some flashes have several erase regions. Different regions
599 * may have different eraseblock size and other
600 * characteristics. It looks like mostly multi-region flashes
601 * have one "main" region and one or more small regions to
602 * store boot loader code or boot parameters or whatever. I
603 * guess we should just pick the largest region. But this is
604 * not implemented.
605 */
606 ubi_err(ubi, "multiple regions, not implemented");
607 return -EINVAL;
608 }
609
610 if (ubi->vid_hdr_offset < 0)
611 return -EINVAL;
612
613 /*
614 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
615 * physical eraseblocks maximum.
616 */
617
618 ubi->peb_size = ubi->mtd->erasesize;
619 ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
620 ubi->flash_size = ubi->mtd->size;
621
622 if (mtd_can_have_bb(ubi->mtd)) {
623 ubi->bad_allowed = 1;
624 ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
625 }
626
627 if (ubi->mtd->type == MTD_NORFLASH) {
628 ubi_assert(ubi->mtd->writesize == 1);
629 ubi->nor_flash = 1;
630 }
631
632 ubi->min_io_size = ubi->mtd->writesize;
633 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
634
635 /*
636 * Make sure minimal I/O unit is power of 2. Note, there is no
637 * fundamental reason for this assumption. It is just an optimization
638 * which allows us to avoid costly division operations.
639 */
640 if (!is_power_of_2(ubi->min_io_size)) {
641 ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
642 ubi->min_io_size);
643 return -EINVAL;
644 }
645
646 ubi_assert(ubi->hdrs_min_io_size > 0);
647 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
648 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
649
650 ubi->max_write_size = ubi->mtd->writebufsize;
651 /*
652 * Maximum write size has to be greater or equivalent to min. I/O
653 * size, and be multiple of min. I/O size.
654 */
655 if (ubi->max_write_size < ubi->min_io_size ||
656 ubi->max_write_size % ubi->min_io_size ||
657 !is_power_of_2(ubi->max_write_size)) {
658 ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
659 ubi->max_write_size, ubi->min_io_size);
660 return -EINVAL;
661 }
662
663 /* Calculate default aligned sizes of EC and VID headers */
664 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
665 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
666
667 dbg_gen("min_io_size %d", ubi->min_io_size);
668 dbg_gen("max_write_size %d", ubi->max_write_size);
669 dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
670 dbg_gen("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
671 dbg_gen("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
672
673 if (ubi->vid_hdr_offset == 0)
674 /* Default offset */
675 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
676 ubi->ec_hdr_alsize;
677 else {
678 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
679 ~(ubi->hdrs_min_io_size - 1);
680 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
681 ubi->vid_hdr_aloffset;
682 }
683
684 /* Similar for the data offset */
685 ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
686 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
687
688 dbg_gen("vid_hdr_offset %d", ubi->vid_hdr_offset);
689 dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
690 dbg_gen("vid_hdr_shift %d", ubi->vid_hdr_shift);
691 dbg_gen("leb_start %d", ubi->leb_start);
692
693 /* The shift must be aligned to 32-bit boundary */
694 if (ubi->vid_hdr_shift % 4) {
695 ubi_err(ubi, "unaligned VID header shift %d",
696 ubi->vid_hdr_shift);
697 return -EINVAL;
698 }
699
700 /* Check sanity */
701 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
702 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
703 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
704 ubi->leb_start & (ubi->min_io_size - 1)) {
705 ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
706 ubi->vid_hdr_offset, ubi->leb_start);
707 return -EINVAL;
708 }
709
710 /*
711 * Set maximum amount of physical erroneous eraseblocks to be 10%.
712 * Erroneous PEB are those which have read errors.
713 */
714 ubi->max_erroneous = ubi->peb_count / 10;
715 if (ubi->max_erroneous < 16)
716 ubi->max_erroneous = 16;
717 dbg_gen("max_erroneous %d", ubi->max_erroneous);
718
719 /*
720 * It may happen that EC and VID headers are situated in one minimal
721 * I/O unit. In this case we can only accept this UBI image in
722 * read-only mode.
723 */
724 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
725 ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
726 ubi->ro_mode = 1;
727 }
728
729 ubi->leb_size = ubi->peb_size - ubi->leb_start;
730
731 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
732 ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
733 ubi->mtd->index);
734 ubi->ro_mode = 1;
735 }
736
737 /*
738 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
739 * unfortunately, MTD does not provide this information. We should loop
740 * over all physical eraseblocks and invoke mtd->block_is_bad() for
741 * each physical eraseblock. So, we leave @ubi->bad_peb_count
742 * uninitialized so far.
743 */
744
745 return 0;
746 }
747
748 /**
749 * autoresize - re-size the volume which has the "auto-resize" flag set.
750 * @ubi: UBI device description object
751 * @vol_id: ID of the volume to re-size
752 *
753 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
754 * the volume table to the largest possible size. See comments in ubi-header.h
755 * for more description of the flag. Returns zero in case of success and a
756 * negative error code in case of failure.
757 */
autoresize(struct ubi_device * ubi,int vol_id)758 static int autoresize(struct ubi_device *ubi, int vol_id)
759 {
760 struct ubi_volume_desc desc;
761 struct ubi_volume *vol = ubi->volumes[vol_id];
762 int err, old_reserved_pebs = vol->reserved_pebs;
763
764 if (ubi->ro_mode) {
765 ubi_warn(ubi, "skip auto-resize because of R/O mode");
766 return 0;
767 }
768
769 /*
770 * Clear the auto-resize flag in the volume in-memory copy of the
771 * volume table, and 'ubi_resize_volume()' will propagate this change
772 * to the flash.
773 */
774 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
775
776 if (ubi->avail_pebs == 0) {
777 struct ubi_vtbl_record vtbl_rec;
778
779 /*
780 * No available PEBs to re-size the volume, clear the flag on
781 * flash and exit.
782 */
783 vtbl_rec = ubi->vtbl[vol_id];
784 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
785 if (err)
786 ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
787 vol_id);
788 } else {
789 desc.vol = vol;
790 err = ubi_resize_volume(&desc,
791 old_reserved_pebs + ubi->avail_pebs);
792 if (err)
793 ubi_err(ubi, "cannot auto-resize volume %d",
794 vol_id);
795 }
796
797 if (err)
798 return err;
799
800 ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
801 vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
802 return 0;
803 }
804
805 /**
806 * ubi_attach_mtd_dev - attach an MTD device.
807 * @mtd: MTD device description object
808 * @ubi_num: number to assign to the new UBI device
809 * @vid_hdr_offset: VID header offset
810 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
811 *
812 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
813 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
814 * which case this function finds a vacant device number and assigns it
815 * automatically. Returns the new UBI device number in case of success and a
816 * negative error code in case of failure.
817 *
818 * Note, the invocations of this function has to be serialized by the
819 * @ubi_devices_mutex.
820 */
ubi_attach_mtd_dev(struct mtd_info * mtd,int ubi_num,int vid_hdr_offset,int max_beb_per1024)821 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
822 int vid_hdr_offset, int max_beb_per1024)
823 {
824 struct ubi_device *ubi;
825 int i, err;
826
827 if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
828 return -EINVAL;
829
830 if (!max_beb_per1024)
831 max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
832
833 /*
834 * Check if we already have the same MTD device attached.
835 *
836 * Note, this function assumes that UBI devices creations and deletions
837 * are serialized, so it does not take the &ubi_devices_lock.
838 */
839 for (i = 0; i < UBI_MAX_DEVICES; i++) {
840 ubi = ubi_devices[i];
841 if (ubi && mtd->index == ubi->mtd->index) {
842 pr_err("ubi: mtd%d is already attached to ubi%d\n",
843 mtd->index, i);
844 return -EEXIST;
845 }
846 }
847
848 /*
849 * Make sure this MTD device is not emulated on top of an UBI volume
850 * already. Well, generally this recursion works fine, but there are
851 * different problems like the UBI module takes a reference to itself
852 * by attaching (and thus, opening) the emulated MTD device. This
853 * results in inability to unload the module. And in general it makes
854 * no sense to attach emulated MTD devices, so we prohibit this.
855 */
856 if (mtd->type == MTD_UBIVOLUME) {
857 pr_err("ubi: refuse attaching mtd%d - it is already emulated on top of UBI\n",
858 mtd->index);
859 return -EINVAL;
860 }
861
862 /*
863 * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
864 * MLC NAND is different and needs special care, otherwise UBI or UBIFS
865 * will die soon and you will lose all your data.
866 * Relax this rule if the partition we're attaching to operates in SLC
867 * mode.
868 */
869 if (mtd->type == MTD_MLCNANDFLASH &&
870 !(mtd->flags & MTD_SLC_ON_MLC_EMULATION)) {
871 pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
872 mtd->index);
873 return -EINVAL;
874 }
875
876 /* UBI cannot work on flashes with zero erasesize. */
877 if (!mtd->erasesize) {
878 pr_err("ubi: refuse attaching mtd%d - zero erasesize flash is not supported\n",
879 mtd->index);
880 return -EINVAL;
881 }
882
883 if (ubi_num == UBI_DEV_NUM_AUTO) {
884 /* Search for an empty slot in the @ubi_devices array */
885 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
886 if (!ubi_devices[ubi_num])
887 break;
888 if (ubi_num == UBI_MAX_DEVICES) {
889 pr_err("ubi: only %d UBI devices may be created\n",
890 UBI_MAX_DEVICES);
891 return -ENFILE;
892 }
893 } else {
894 if (ubi_num >= UBI_MAX_DEVICES)
895 return -EINVAL;
896
897 /* Make sure ubi_num is not busy */
898 if (ubi_devices[ubi_num]) {
899 pr_err("ubi: ubi%i already exists\n", ubi_num);
900 return -EEXIST;
901 }
902 }
903
904 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
905 if (!ubi)
906 return -ENOMEM;
907
908 device_initialize(&ubi->dev);
909 ubi->dev.release = dev_release;
910 ubi->dev.class = &ubi_class;
911 ubi->dev.groups = ubi_dev_groups;
912
913 ubi->mtd = mtd;
914 ubi->ubi_num = ubi_num;
915 ubi->vid_hdr_offset = vid_hdr_offset;
916 ubi->autoresize_vol_id = -1;
917
918 #ifdef CONFIG_MTD_UBI_FASTMAP
919 ubi->fm_pool.used = ubi->fm_pool.size = 0;
920 ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
921
922 /*
923 * fm_pool.max_size is 5% of the total number of PEBs but it's also
924 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
925 */
926 ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
927 ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
928 ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
929 UBI_FM_MIN_POOL_SIZE);
930
931 ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
932 ubi->fm_disabled = !fm_autoconvert;
933 if (fm_debug)
934 ubi_enable_dbg_chk_fastmap(ubi);
935
936 if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
937 <= UBI_FM_MAX_START) {
938 ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
939 UBI_FM_MAX_START);
940 ubi->fm_disabled = 1;
941 }
942
943 ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
944 ubi_msg(ubi, "default fastmap WL pool size: %d",
945 ubi->fm_wl_pool.max_size);
946 #else
947 ubi->fm_disabled = 1;
948 #endif
949 mutex_init(&ubi->buf_mutex);
950 mutex_init(&ubi->ckvol_mutex);
951 mutex_init(&ubi->device_mutex);
952 spin_lock_init(&ubi->volumes_lock);
953 init_rwsem(&ubi->fm_protect);
954 init_rwsem(&ubi->fm_eba_sem);
955
956 ubi_msg(ubi, "attaching mtd%d", mtd->index);
957
958 err = io_init(ubi, max_beb_per1024);
959 if (err)
960 goto out_free;
961
962 err = -ENOMEM;
963 ubi->peb_buf = vmalloc(ubi->peb_size);
964 if (!ubi->peb_buf)
965 goto out_free;
966
967 #ifdef CONFIG_MTD_UBI_FASTMAP
968 ubi->fm_size = ubi_calc_fm_size(ubi);
969 ubi->fm_buf = vzalloc(ubi->fm_size);
970 if (!ubi->fm_buf)
971 goto out_free;
972 #endif
973 err = ubi_attach(ubi, 0);
974 if (err) {
975 ubi_err(ubi, "failed to attach mtd%d, error %d",
976 mtd->index, err);
977 goto out_free;
978 }
979
980 if (ubi->autoresize_vol_id != -1) {
981 err = autoresize(ubi, ubi->autoresize_vol_id);
982 if (err)
983 goto out_detach;
984 }
985
986 err = uif_init(ubi);
987 if (err)
988 goto out_detach;
989
990 err = ubi_debugfs_init_dev(ubi);
991 if (err)
992 goto out_uif;
993
994 ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
995 if (IS_ERR(ubi->bgt_thread)) {
996 err = PTR_ERR(ubi->bgt_thread);
997 ubi_err(ubi, "cannot spawn \"%s\", error %d",
998 ubi->bgt_name, err);
999 goto out_debugfs;
1000 }
1001
1002 ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
1003 mtd->index, mtd->name, ubi->flash_size >> 20);
1004 ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
1005 ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
1006 ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
1007 ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1008 ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1009 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1010 ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1011 ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1012 ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1013 ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1014 ubi->vtbl_slots);
1015 ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1016 ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1017 ubi->image_seq);
1018 ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1019 ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1020
1021 /*
1022 * The below lock makes sure we do not race with 'ubi_thread()' which
1023 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1024 */
1025 spin_lock(&ubi->wl_lock);
1026 ubi->thread_enabled = 1;
1027 wake_up_process(ubi->bgt_thread);
1028 spin_unlock(&ubi->wl_lock);
1029
1030 ubi_devices[ubi_num] = ubi;
1031 ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1032 return ubi_num;
1033
1034 out_debugfs:
1035 ubi_debugfs_exit_dev(ubi);
1036 out_uif:
1037 uif_close(ubi);
1038 out_detach:
1039 ubi_wl_close(ubi);
1040 ubi_free_all_volumes(ubi);
1041 vfree(ubi->vtbl);
1042 out_free:
1043 vfree(ubi->peb_buf);
1044 vfree(ubi->fm_buf);
1045 put_device(&ubi->dev);
1046 return err;
1047 }
1048
1049 /**
1050 * ubi_detach_mtd_dev - detach an MTD device.
1051 * @ubi_num: UBI device number to detach from
1052 * @anyway: detach MTD even if device reference count is not zero
1053 *
1054 * This function destroys an UBI device number @ubi_num and detaches the
1055 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1056 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1057 * exist.
1058 *
1059 * Note, the invocations of this function has to be serialized by the
1060 * @ubi_devices_mutex.
1061 */
ubi_detach_mtd_dev(int ubi_num,int anyway)1062 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1063 {
1064 struct ubi_device *ubi;
1065
1066 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1067 return -EINVAL;
1068
1069 ubi = ubi_get_device(ubi_num);
1070 if (!ubi)
1071 return -EINVAL;
1072
1073 spin_lock(&ubi_devices_lock);
1074 put_device(&ubi->dev);
1075 ubi->ref_count -= 1;
1076 if (ubi->ref_count) {
1077 if (!anyway) {
1078 spin_unlock(&ubi_devices_lock);
1079 return -EBUSY;
1080 }
1081 /* This may only happen if there is a bug */
1082 ubi_err(ubi, "%s reference count %d, destroy anyway",
1083 ubi->ubi_name, ubi->ref_count);
1084 }
1085 ubi_devices[ubi_num] = NULL;
1086 spin_unlock(&ubi_devices_lock);
1087
1088 ubi_assert(ubi_num == ubi->ubi_num);
1089 ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1090 ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1091 #ifdef CONFIG_MTD_UBI_FASTMAP
1092 /* If we don't write a new fastmap at detach time we lose all
1093 * EC updates that have been made since the last written fastmap.
1094 * In case of fastmap debugging we omit the update to simulate an
1095 * unclean shutdown. */
1096 if (!ubi_dbg_chk_fastmap(ubi))
1097 ubi_update_fastmap(ubi);
1098 #endif
1099 /*
1100 * Before freeing anything, we have to stop the background thread to
1101 * prevent it from doing anything on this device while we are freeing.
1102 */
1103 if (ubi->bgt_thread)
1104 kthread_stop(ubi->bgt_thread);
1105
1106 #ifdef CONFIG_MTD_UBI_FASTMAP
1107 cancel_work_sync(&ubi->fm_work);
1108 #endif
1109 ubi_debugfs_exit_dev(ubi);
1110 uif_close(ubi);
1111
1112 ubi_wl_close(ubi);
1113 ubi_free_internal_volumes(ubi);
1114 vfree(ubi->vtbl);
1115 vfree(ubi->peb_buf);
1116 vfree(ubi->fm_buf);
1117 ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1118 put_mtd_device(ubi->mtd);
1119 put_device(&ubi->dev);
1120 return 0;
1121 }
1122
1123 /**
1124 * open_mtd_by_chdev - open an MTD device by its character device node path.
1125 * @mtd_dev: MTD character device node path
1126 *
1127 * This helper function opens an MTD device by its character node device path.
1128 * Returns MTD device description object in case of success and a negative
1129 * error code in case of failure.
1130 */
open_mtd_by_chdev(const char * mtd_dev)1131 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1132 {
1133 int err, minor;
1134 struct path path;
1135 struct kstat stat;
1136
1137 /* Probably this is an MTD character device node path */
1138 err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1139 if (err)
1140 return ERR_PTR(err);
1141
1142 err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
1143 path_put(&path);
1144 if (err)
1145 return ERR_PTR(err);
1146
1147 /* MTD device number is defined by the major / minor numbers */
1148 if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
1149 return ERR_PTR(-EINVAL);
1150
1151 minor = MINOR(stat.rdev);
1152
1153 if (minor & 1)
1154 /*
1155 * Just do not think the "/dev/mtdrX" devices support is need,
1156 * so do not support them to avoid doing extra work.
1157 */
1158 return ERR_PTR(-EINVAL);
1159
1160 return get_mtd_device(NULL, minor / 2);
1161 }
1162
1163 /**
1164 * open_mtd_device - open MTD device by name, character device path, or number.
1165 * @mtd_dev: name, character device node path, or MTD device device number
1166 *
1167 * This function tries to open and MTD device described by @mtd_dev string,
1168 * which is first treated as ASCII MTD device number, and if it is not true, it
1169 * is treated as MTD device name, and if that is also not true, it is treated
1170 * as MTD character device node path. Returns MTD device description object in
1171 * case of success and a negative error code in case of failure.
1172 */
open_mtd_device(const char * mtd_dev)1173 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1174 {
1175 struct mtd_info *mtd;
1176 int mtd_num;
1177 char *endp;
1178
1179 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1180 if (*endp != '\0' || mtd_dev == endp) {
1181 /*
1182 * This does not look like an ASCII integer, probably this is
1183 * MTD device name.
1184 */
1185 mtd = get_mtd_device_nm(mtd_dev);
1186 if (PTR_ERR(mtd) == -ENODEV)
1187 /* Probably this is an MTD character device node path */
1188 mtd = open_mtd_by_chdev(mtd_dev);
1189 } else
1190 mtd = get_mtd_device(NULL, mtd_num);
1191
1192 return mtd;
1193 }
1194
ubi_init(void)1195 static int __init ubi_init(void)
1196 {
1197 int err, i, k;
1198
1199 /* Ensure that EC and VID headers have correct size */
1200 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1201 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1202
1203 if (mtd_devs > UBI_MAX_DEVICES) {
1204 pr_err("UBI error: too many MTD devices, maximum is %d\n",
1205 UBI_MAX_DEVICES);
1206 return -EINVAL;
1207 }
1208
1209 /* Create base sysfs directory and sysfs files */
1210 err = class_register(&ubi_class);
1211 if (err < 0)
1212 return err;
1213
1214 err = misc_register(&ubi_ctrl_cdev);
1215 if (err) {
1216 pr_err("UBI error: cannot register device\n");
1217 goto out;
1218 }
1219
1220 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1221 sizeof(struct ubi_wl_entry),
1222 0, 0, NULL);
1223 if (!ubi_wl_entry_slab) {
1224 err = -ENOMEM;
1225 goto out_dev_unreg;
1226 }
1227
1228 err = ubi_debugfs_init();
1229 if (err)
1230 goto out_slab;
1231
1232
1233 /* Attach MTD devices */
1234 for (i = 0; i < mtd_devs; i++) {
1235 struct mtd_dev_param *p = &mtd_dev_param[i];
1236 struct mtd_info *mtd;
1237
1238 cond_resched();
1239
1240 mtd = open_mtd_device(p->name);
1241 if (IS_ERR(mtd)) {
1242 err = PTR_ERR(mtd);
1243 pr_err("UBI error: cannot open mtd %s, error %d\n",
1244 p->name, err);
1245 /* See comment below re-ubi_is_module(). */
1246 if (ubi_is_module())
1247 goto out_detach;
1248 continue;
1249 }
1250
1251 mutex_lock(&ubi_devices_mutex);
1252 err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1253 p->vid_hdr_offs, p->max_beb_per1024);
1254 mutex_unlock(&ubi_devices_mutex);
1255 if (err < 0) {
1256 pr_err("UBI error: cannot attach mtd%d\n",
1257 mtd->index);
1258 put_mtd_device(mtd);
1259
1260 /*
1261 * Originally UBI stopped initializing on any error.
1262 * However, later on it was found out that this
1263 * behavior is not very good when UBI is compiled into
1264 * the kernel and the MTD devices to attach are passed
1265 * through the command line. Indeed, UBI failure
1266 * stopped whole boot sequence.
1267 *
1268 * To fix this, we changed the behavior for the
1269 * non-module case, but preserved the old behavior for
1270 * the module case, just for compatibility. This is a
1271 * little inconsistent, though.
1272 */
1273 if (ubi_is_module())
1274 goto out_detach;
1275 }
1276 }
1277
1278 err = ubiblock_init();
1279 if (err) {
1280 pr_err("UBI error: block: cannot initialize, error %d\n", err);
1281
1282 /* See comment above re-ubi_is_module(). */
1283 if (ubi_is_module())
1284 goto out_detach;
1285 }
1286
1287 return 0;
1288
1289 out_detach:
1290 for (k = 0; k < i; k++)
1291 if (ubi_devices[k]) {
1292 mutex_lock(&ubi_devices_mutex);
1293 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1294 mutex_unlock(&ubi_devices_mutex);
1295 }
1296 ubi_debugfs_exit();
1297 out_slab:
1298 kmem_cache_destroy(ubi_wl_entry_slab);
1299 out_dev_unreg:
1300 misc_deregister(&ubi_ctrl_cdev);
1301 out:
1302 class_unregister(&ubi_class);
1303 pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1304 return err;
1305 }
1306 late_initcall(ubi_init);
1307
ubi_exit(void)1308 static void __exit ubi_exit(void)
1309 {
1310 int i;
1311
1312 ubiblock_exit();
1313
1314 for (i = 0; i < UBI_MAX_DEVICES; i++)
1315 if (ubi_devices[i]) {
1316 mutex_lock(&ubi_devices_mutex);
1317 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1318 mutex_unlock(&ubi_devices_mutex);
1319 }
1320 ubi_debugfs_exit();
1321 kmem_cache_destroy(ubi_wl_entry_slab);
1322 misc_deregister(&ubi_ctrl_cdev);
1323 class_unregister(&ubi_class);
1324 }
1325 module_exit(ubi_exit);
1326
1327 /**
1328 * bytes_str_to_int - convert a number of bytes string into an integer.
1329 * @str: the string to convert
1330 *
1331 * This function returns positive resulting integer in case of success and a
1332 * negative error code in case of failure.
1333 */
bytes_str_to_int(const char * str)1334 static int bytes_str_to_int(const char *str)
1335 {
1336 char *endp;
1337 unsigned long result;
1338
1339 result = simple_strtoul(str, &endp, 0);
1340 if (str == endp || result >= INT_MAX) {
1341 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1342 return -EINVAL;
1343 }
1344
1345 switch (*endp) {
1346 case 'G':
1347 result *= 1024;
1348 fallthrough;
1349 case 'M':
1350 result *= 1024;
1351 fallthrough;
1352 case 'K':
1353 result *= 1024;
1354 if (endp[1] == 'i' && endp[2] == 'B')
1355 endp += 2;
1356 case '\0':
1357 break;
1358 default:
1359 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1360 return -EINVAL;
1361 }
1362
1363 return result;
1364 }
1365
1366 /**
1367 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1368 * @val: the parameter value to parse
1369 * @kp: not used
1370 *
1371 * This function returns zero in case of success and a negative error code in
1372 * case of error.
1373 */
ubi_mtd_param_parse(const char * val,const struct kernel_param * kp)1374 static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1375 {
1376 int i, len;
1377 struct mtd_dev_param *p;
1378 char buf[MTD_PARAM_LEN_MAX];
1379 char *pbuf = &buf[0];
1380 char *tokens[MTD_PARAM_MAX_COUNT], *token;
1381
1382 if (!val)
1383 return -EINVAL;
1384
1385 if (mtd_devs == UBI_MAX_DEVICES) {
1386 pr_err("UBI error: too many parameters, max. is %d\n",
1387 UBI_MAX_DEVICES);
1388 return -EINVAL;
1389 }
1390
1391 len = strnlen(val, MTD_PARAM_LEN_MAX);
1392 if (len == MTD_PARAM_LEN_MAX) {
1393 pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1394 val, MTD_PARAM_LEN_MAX);
1395 return -EINVAL;
1396 }
1397
1398 if (len == 0) {
1399 pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1400 return 0;
1401 }
1402
1403 strcpy(buf, val);
1404
1405 /* Get rid of the final newline */
1406 if (buf[len - 1] == '\n')
1407 buf[len - 1] = '\0';
1408
1409 for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1410 tokens[i] = strsep(&pbuf, ",");
1411
1412 if (pbuf) {
1413 pr_err("UBI error: too many arguments at \"%s\"\n", val);
1414 return -EINVAL;
1415 }
1416
1417 p = &mtd_dev_param[mtd_devs];
1418 strcpy(&p->name[0], tokens[0]);
1419
1420 token = tokens[1];
1421 if (token) {
1422 p->vid_hdr_offs = bytes_str_to_int(token);
1423
1424 if (p->vid_hdr_offs < 0)
1425 return p->vid_hdr_offs;
1426 }
1427
1428 token = tokens[2];
1429 if (token) {
1430 int err = kstrtoint(token, 10, &p->max_beb_per1024);
1431
1432 if (err) {
1433 pr_err("UBI error: bad value for max_beb_per1024 parameter: %s",
1434 token);
1435 return -EINVAL;
1436 }
1437 }
1438
1439 token = tokens[3];
1440 if (token) {
1441 int err = kstrtoint(token, 10, &p->ubi_num);
1442
1443 if (err) {
1444 pr_err("UBI error: bad value for ubi_num parameter: %s",
1445 token);
1446 return -EINVAL;
1447 }
1448 } else
1449 p->ubi_num = UBI_DEV_NUM_AUTO;
1450
1451 mtd_devs += 1;
1452 return 0;
1453 }
1454
1455 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1456 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1457 "Multiple \"mtd\" parameters may be specified.\n"
1458 "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1459 "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1460 "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1461 __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1462 "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1463 "\n"
1464 "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1465 "Example 2: mtd=content,1984 mtd=4 - attach MTD device with name \"content\" using VID header offset 1984, and MTD device number 4 with default VID header offset.\n"
1466 "Example 3: mtd=/dev/mtd1,0,25 - attach MTD device /dev/mtd1 using default VID header offset and reserve 25*nand_size_in_blocks/1024 erase blocks for bad block handling.\n"
1467 "Example 4: mtd=/dev/mtd1,0,0,5 - attach MTD device /dev/mtd1 to UBI 5 and using default values for the other fields.\n"
1468 "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1469 #ifdef CONFIG_MTD_UBI_FASTMAP
1470 module_param(fm_autoconvert, bool, 0644);
1471 MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1472 module_param(fm_debug, bool, 0);
1473 MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1474 #endif
1475 MODULE_VERSION(__stringify(UBI_VERSION));
1476 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1477 MODULE_AUTHOR("Artem Bityutskiy");
1478 MODULE_LICENSE("GPL");
1479