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 6
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 * @ubi_num: UBI number
54 * @vid_hdr_offs: VID header offset
55 * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
56 * @enable_fm: enable fastmap when value is non-zero
57 * @need_resv_pool: reserve pool->max_size pebs when value is none-zero
58 */
59 struct mtd_dev_param {
60 char name[MTD_PARAM_LEN_MAX];
61 int ubi_num;
62 int vid_hdr_offs;
63 int max_beb_per1024;
64 int enable_fm;
65 int need_resv_pool;
66 };
67
68 /* Numbers of elements set in the @mtd_dev_param array */
69 static int mtd_devs;
70
71 /* MTD devices specification parameters */
72 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
73 #ifdef CONFIG_MTD_UBI_FASTMAP
74 /* UBI module parameter to enable fastmap automatically on non-fastmap images */
75 static bool fm_autoconvert;
76 static bool fm_debug;
77 #endif
78
79 /* Slab cache for wear-leveling entries */
80 struct kmem_cache *ubi_wl_entry_slab;
81
82 /* UBI control character device */
83 static struct miscdevice ubi_ctrl_cdev = {
84 .minor = MISC_DYNAMIC_MINOR,
85 .name = "ubi_ctrl",
86 .fops = &ubi_ctrl_cdev_operations,
87 };
88
89 /* All UBI devices in system */
90 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
91
92 /* Serializes UBI devices creations and removals */
93 DEFINE_MUTEX(ubi_devices_mutex);
94
95 /* Protects @ubi_devices and @ubi->ref_count */
96 static DEFINE_SPINLOCK(ubi_devices_lock);
97
98 /* "Show" method for files in '/<sysfs>/class/ubi/' */
99 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
version_show(const struct class * class,const struct class_attribute * attr,char * buf)100 static ssize_t version_show(const struct class *class, const struct class_attribute *attr,
101 char *buf)
102 {
103 return sprintf(buf, "%d\n", UBI_VERSION);
104 }
105 static CLASS_ATTR_RO(version);
106
107 static struct attribute *ubi_class_attrs[] = {
108 &class_attr_version.attr,
109 NULL,
110 };
111 ATTRIBUTE_GROUPS(ubi_class);
112
113 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
114 struct class ubi_class = {
115 .name = UBI_NAME_STR,
116 .class_groups = ubi_class_groups,
117 };
118
119 static ssize_t dev_attribute_show(struct device *dev,
120 struct device_attribute *attr, char *buf);
121
122 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
123 static struct device_attribute dev_eraseblock_size =
124 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
125 static struct device_attribute dev_avail_eraseblocks =
126 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
127 static struct device_attribute dev_total_eraseblocks =
128 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
129 static struct device_attribute dev_volumes_count =
130 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
131 static struct device_attribute dev_max_ec =
132 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
133 static struct device_attribute dev_reserved_for_bad =
134 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
135 static struct device_attribute dev_bad_peb_count =
136 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
137 static struct device_attribute dev_max_vol_count =
138 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
139 static struct device_attribute dev_min_io_size =
140 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
141 static struct device_attribute dev_bgt_enabled =
142 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
143 static struct device_attribute dev_mtd_num =
144 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
145 static struct device_attribute dev_ro_mode =
146 __ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
147
148 /**
149 * ubi_volume_notify - send a volume change notification.
150 * @ubi: UBI device description object
151 * @vol: volume description object of the changed volume
152 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
153 *
154 * This is a helper function which notifies all subscribers about a volume
155 * change event (creation, removal, re-sizing, re-naming, updating). Returns
156 * zero in case of success and a negative error code in case of failure.
157 */
ubi_volume_notify(struct ubi_device * ubi,struct ubi_volume * vol,int ntype)158 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
159 {
160 int ret;
161 struct ubi_notification nt;
162
163 ubi_do_get_device_info(ubi, &nt.di);
164 ubi_do_get_volume_info(ubi, vol, &nt.vi);
165
166 switch (ntype) {
167 case UBI_VOLUME_ADDED:
168 case UBI_VOLUME_REMOVED:
169 case UBI_VOLUME_RESIZED:
170 case UBI_VOLUME_RENAMED:
171 ret = ubi_update_fastmap(ubi);
172 if (ret)
173 ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
174 }
175
176 return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
177 }
178
179 /**
180 * ubi_notify_all - send a notification to all volumes.
181 * @ubi: UBI device description object
182 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
183 * @nb: the notifier to call
184 *
185 * This function walks all volumes of UBI device @ubi and sends the @ntype
186 * notification for each volume. If @nb is %NULL, then all registered notifiers
187 * are called, otherwise only the @nb notifier is called. Returns the number of
188 * sent notifications.
189 */
ubi_notify_all(struct ubi_device * ubi,int ntype,struct notifier_block * nb)190 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
191 {
192 struct ubi_notification nt;
193 int i, count = 0;
194
195 ubi_do_get_device_info(ubi, &nt.di);
196
197 mutex_lock(&ubi->device_mutex);
198 for (i = 0; i < ubi->vtbl_slots; i++) {
199 /*
200 * Since the @ubi->device is locked, and we are not going to
201 * change @ubi->volumes, we do not have to lock
202 * @ubi->volumes_lock.
203 */
204 if (!ubi->volumes[i])
205 continue;
206
207 ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
208 if (nb)
209 nb->notifier_call(nb, ntype, &nt);
210 else
211 blocking_notifier_call_chain(&ubi_notifiers, ntype,
212 &nt);
213 count += 1;
214 }
215 mutex_unlock(&ubi->device_mutex);
216
217 return count;
218 }
219
220 /**
221 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
222 * @nb: the notifier to call
223 *
224 * This function walks all UBI devices and volumes and sends the
225 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
226 * registered notifiers are called, otherwise only the @nb notifier is called.
227 * Returns the number of sent notifications.
228 */
ubi_enumerate_volumes(struct notifier_block * nb)229 int ubi_enumerate_volumes(struct notifier_block *nb)
230 {
231 int i, count = 0;
232
233 /*
234 * Since the @ubi_devices_mutex is locked, and we are not going to
235 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
236 */
237 for (i = 0; i < UBI_MAX_DEVICES; i++) {
238 struct ubi_device *ubi = ubi_devices[i];
239
240 if (!ubi)
241 continue;
242 count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
243 }
244
245 return count;
246 }
247
248 /**
249 * ubi_get_device - get UBI device.
250 * @ubi_num: UBI device number
251 *
252 * This function returns UBI device description object for UBI device number
253 * @ubi_num, or %NULL if the device does not exist. This function increases the
254 * device reference count to prevent removal of the device. In other words, the
255 * device cannot be removed if its reference count is not zero.
256 */
ubi_get_device(int ubi_num)257 struct ubi_device *ubi_get_device(int ubi_num)
258 {
259 struct ubi_device *ubi;
260
261 spin_lock(&ubi_devices_lock);
262 ubi = ubi_devices[ubi_num];
263 if (ubi) {
264 ubi_assert(ubi->ref_count >= 0);
265 ubi->ref_count += 1;
266 get_device(&ubi->dev);
267 }
268 spin_unlock(&ubi_devices_lock);
269
270 return ubi;
271 }
272
273 /**
274 * ubi_put_device - drop an UBI device reference.
275 * @ubi: UBI device description object
276 */
ubi_put_device(struct ubi_device * ubi)277 void ubi_put_device(struct ubi_device *ubi)
278 {
279 spin_lock(&ubi_devices_lock);
280 ubi->ref_count -= 1;
281 put_device(&ubi->dev);
282 spin_unlock(&ubi_devices_lock);
283 }
284
285 /**
286 * ubi_get_by_major - get UBI device by character device major number.
287 * @major: major number
288 *
289 * This function is similar to 'ubi_get_device()', but it searches the device
290 * by its major number.
291 */
ubi_get_by_major(int major)292 struct ubi_device *ubi_get_by_major(int major)
293 {
294 int i;
295 struct ubi_device *ubi;
296
297 spin_lock(&ubi_devices_lock);
298 for (i = 0; i < UBI_MAX_DEVICES; i++) {
299 ubi = ubi_devices[i];
300 if (ubi && MAJOR(ubi->cdev.dev) == major) {
301 ubi_assert(ubi->ref_count >= 0);
302 ubi->ref_count += 1;
303 get_device(&ubi->dev);
304 spin_unlock(&ubi_devices_lock);
305 return ubi;
306 }
307 }
308 spin_unlock(&ubi_devices_lock);
309
310 return NULL;
311 }
312
313 /**
314 * ubi_major2num - get UBI device number by character device major number.
315 * @major: major number
316 *
317 * This function searches UBI device number object by its major number. If UBI
318 * device was not found, this function returns -ENODEV, otherwise the UBI device
319 * number is returned.
320 */
ubi_major2num(int major)321 int ubi_major2num(int major)
322 {
323 int i, ubi_num = -ENODEV;
324
325 spin_lock(&ubi_devices_lock);
326 for (i = 0; i < UBI_MAX_DEVICES; i++) {
327 struct ubi_device *ubi = ubi_devices[i];
328
329 if (ubi && MAJOR(ubi->cdev.dev) == major) {
330 ubi_num = ubi->ubi_num;
331 break;
332 }
333 }
334 spin_unlock(&ubi_devices_lock);
335
336 return ubi_num;
337 }
338
339 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
dev_attribute_show(struct device * dev,struct device_attribute * attr,char * buf)340 static ssize_t dev_attribute_show(struct device *dev,
341 struct device_attribute *attr, char *buf)
342 {
343 ssize_t ret;
344 struct ubi_device *ubi;
345
346 /*
347 * The below code looks weird, but it actually makes sense. We get the
348 * UBI device reference from the contained 'struct ubi_device'. But it
349 * is unclear if the device was removed or not yet. Indeed, if the
350 * device was removed before we increased its reference count,
351 * 'ubi_get_device()' will return -ENODEV and we fail.
352 *
353 * Remember, 'struct ubi_device' is freed in the release function, so
354 * we still can use 'ubi->ubi_num'.
355 */
356 ubi = container_of(dev, struct ubi_device, dev);
357
358 if (attr == &dev_eraseblock_size)
359 ret = sprintf(buf, "%d\n", ubi->leb_size);
360 else if (attr == &dev_avail_eraseblocks)
361 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
362 else if (attr == &dev_total_eraseblocks)
363 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
364 else if (attr == &dev_volumes_count)
365 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
366 else if (attr == &dev_max_ec)
367 ret = sprintf(buf, "%d\n", ubi->max_ec);
368 else if (attr == &dev_reserved_for_bad)
369 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
370 else if (attr == &dev_bad_peb_count)
371 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
372 else if (attr == &dev_max_vol_count)
373 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
374 else if (attr == &dev_min_io_size)
375 ret = sprintf(buf, "%d\n", ubi->min_io_size);
376 else if (attr == &dev_bgt_enabled)
377 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
378 else if (attr == &dev_mtd_num)
379 ret = sprintf(buf, "%d\n", ubi->mtd->index);
380 else if (attr == &dev_ro_mode)
381 ret = sprintf(buf, "%d\n", ubi->ro_mode);
382 else
383 ret = -EINVAL;
384
385 return ret;
386 }
387
388 static struct attribute *ubi_dev_attrs[] = {
389 &dev_eraseblock_size.attr,
390 &dev_avail_eraseblocks.attr,
391 &dev_total_eraseblocks.attr,
392 &dev_volumes_count.attr,
393 &dev_max_ec.attr,
394 &dev_reserved_for_bad.attr,
395 &dev_bad_peb_count.attr,
396 &dev_max_vol_count.attr,
397 &dev_min_io_size.attr,
398 &dev_bgt_enabled.attr,
399 &dev_mtd_num.attr,
400 &dev_ro_mode.attr,
401 NULL
402 };
403 ATTRIBUTE_GROUPS(ubi_dev);
404
dev_release(struct device * dev)405 static void dev_release(struct device *dev)
406 {
407 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
408
409 kfree(ubi);
410 }
411
412 /**
413 * kill_volumes - destroy all user volumes.
414 * @ubi: UBI device description object
415 */
kill_volumes(struct ubi_device * ubi)416 static void kill_volumes(struct ubi_device *ubi)
417 {
418 int i;
419
420 for (i = 0; i < ubi->vtbl_slots; i++)
421 if (ubi->volumes[i])
422 ubi_free_volume(ubi, ubi->volumes[i]);
423 }
424
425 /**
426 * uif_init - initialize user interfaces for an UBI device.
427 * @ubi: UBI device description object
428 *
429 * This function initializes various user interfaces for an UBI device. If the
430 * initialization fails at an early stage, this function frees all the
431 * resources it allocated, returns an error.
432 *
433 * This function returns zero in case of success and a negative error code in
434 * case of failure.
435 */
uif_init(struct ubi_device * ubi)436 static int uif_init(struct ubi_device *ubi)
437 {
438 int i, err;
439 dev_t dev;
440
441 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
442
443 /*
444 * Major numbers for the UBI character devices are allocated
445 * dynamically. Major numbers of volume character devices are
446 * equivalent to ones of the corresponding UBI character device. Minor
447 * numbers of UBI character devices are 0, while minor numbers of
448 * volume character devices start from 1. Thus, we allocate one major
449 * number and ubi->vtbl_slots + 1 minor numbers.
450 */
451 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
452 if (err) {
453 ubi_err(ubi, "cannot register UBI character devices");
454 return err;
455 }
456
457 ubi->dev.devt = dev;
458
459 ubi_assert(MINOR(dev) == 0);
460 cdev_init(&ubi->cdev, &ubi_cdev_operations);
461 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
462 ubi->cdev.owner = THIS_MODULE;
463
464 dev_set_name(&ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
465 err = cdev_device_add(&ubi->cdev, &ubi->dev);
466 if (err)
467 goto out_unreg;
468
469 for (i = 0; i < ubi->vtbl_slots; i++)
470 if (ubi->volumes[i]) {
471 err = ubi_add_volume(ubi, ubi->volumes[i]);
472 if (err) {
473 ubi_err(ubi, "cannot add volume %d", i);
474 ubi->volumes[i] = NULL;
475 goto out_volumes;
476 }
477 }
478
479 return 0;
480
481 out_volumes:
482 kill_volumes(ubi);
483 cdev_device_del(&ubi->cdev, &ubi->dev);
484 out_unreg:
485 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
486 ubi_err(ubi, "cannot initialize UBI %s, error %d",
487 ubi->ubi_name, err);
488 return err;
489 }
490
491 /**
492 * uif_close - close user interfaces for an UBI device.
493 * @ubi: UBI device description object
494 *
495 * Note, since this function un-registers UBI volume device objects (@vol->dev),
496 * the memory allocated voe the volumes is freed as well (in the release
497 * function).
498 */
uif_close(struct ubi_device * ubi)499 static void uif_close(struct ubi_device *ubi)
500 {
501 kill_volumes(ubi);
502 cdev_device_del(&ubi->cdev, &ubi->dev);
503 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
504 }
505
506 /**
507 * ubi_free_volumes_from - free volumes from specific index.
508 * @ubi: UBI device description object
509 * @from: the start index used for volume free.
510 */
ubi_free_volumes_from(struct ubi_device * ubi,int from)511 static void ubi_free_volumes_from(struct ubi_device *ubi, int from)
512 {
513 int i;
514
515 for (i = from; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
516 if (!ubi->volumes[i])
517 continue;
518 ubi_eba_replace_table(ubi->volumes[i], NULL);
519 ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
520 kfree(ubi->volumes[i]);
521 ubi->volumes[i] = NULL;
522 }
523 }
524
525 /**
526 * ubi_free_all_volumes - free all volumes.
527 * @ubi: UBI device description object
528 */
ubi_free_all_volumes(struct ubi_device * ubi)529 void ubi_free_all_volumes(struct ubi_device *ubi)
530 {
531 ubi_free_volumes_from(ubi, 0);
532 }
533
534 /**
535 * ubi_free_internal_volumes - free internal volumes.
536 * @ubi: UBI device description object
537 */
ubi_free_internal_volumes(struct ubi_device * ubi)538 void ubi_free_internal_volumes(struct ubi_device *ubi)
539 {
540 ubi_free_volumes_from(ubi, ubi->vtbl_slots);
541 }
542
get_bad_peb_limit(const struct ubi_device * ubi,int max_beb_per1024)543 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
544 {
545 int limit, device_pebs;
546 uint64_t device_size;
547
548 if (!max_beb_per1024) {
549 /*
550 * Since max_beb_per1024 has not been set by the user in either
551 * the cmdline or Kconfig, use mtd_max_bad_blocks to set the
552 * limit if it is supported by the device.
553 */
554 limit = mtd_max_bad_blocks(ubi->mtd, 0, ubi->mtd->size);
555 if (limit < 0)
556 return 0;
557 return limit;
558 }
559
560 /*
561 * Here we are using size of the entire flash chip and
562 * not just the MTD partition size because the maximum
563 * number of bad eraseblocks is a percentage of the
564 * whole device and bad eraseblocks are not fairly
565 * distributed over the flash chip. So the worst case
566 * is that all the bad eraseblocks of the chip are in
567 * the MTD partition we are attaching (ubi->mtd).
568 */
569 device_size = mtd_get_device_size(ubi->mtd);
570 device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
571 limit = mult_frac(device_pebs, max_beb_per1024, 1024);
572
573 /* Round it up */
574 if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
575 limit += 1;
576
577 return limit;
578 }
579
580 /**
581 * io_init - initialize I/O sub-system for a given UBI device.
582 * @ubi: UBI device description object
583 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
584 *
585 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
586 * assumed:
587 * o EC header is always at offset zero - this cannot be changed;
588 * o VID header starts just after the EC header at the closest address
589 * aligned to @io->hdrs_min_io_size;
590 * o data starts just after the VID header at the closest address aligned to
591 * @io->min_io_size
592 *
593 * This function returns zero in case of success and a negative error code in
594 * case of failure.
595 */
io_init(struct ubi_device * ubi,int max_beb_per1024)596 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
597 {
598 dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
599 dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
600
601 if (ubi->mtd->numeraseregions != 0) {
602 /*
603 * Some flashes have several erase regions. Different regions
604 * may have different eraseblock size and other
605 * characteristics. It looks like mostly multi-region flashes
606 * have one "main" region and one or more small regions to
607 * store boot loader code or boot parameters or whatever. I
608 * guess we should just pick the largest region. But this is
609 * not implemented.
610 */
611 ubi_err(ubi, "multiple regions, not implemented");
612 return -EINVAL;
613 }
614
615 if (ubi->vid_hdr_offset < 0)
616 return -EINVAL;
617
618 /*
619 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
620 * physical eraseblocks maximum.
621 */
622
623 ubi->peb_size = ubi->mtd->erasesize;
624 ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
625 ubi->flash_size = ubi->mtd->size;
626
627 if (mtd_can_have_bb(ubi->mtd)) {
628 ubi->bad_allowed = 1;
629 ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
630 }
631
632 if (ubi->mtd->type == MTD_NORFLASH)
633 ubi->nor_flash = 1;
634
635 ubi->min_io_size = ubi->mtd->writesize;
636 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
637
638 /*
639 * Make sure minimal I/O unit is power of 2. Note, there is no
640 * fundamental reason for this assumption. It is just an optimization
641 * which allows us to avoid costly division operations.
642 */
643 if (!is_power_of_2(ubi->min_io_size)) {
644 ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
645 ubi->min_io_size);
646 return -EINVAL;
647 }
648
649 ubi_assert(ubi->hdrs_min_io_size > 0);
650 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
651 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
652
653 ubi->max_write_size = ubi->mtd->writebufsize;
654 /*
655 * Maximum write size has to be greater or equivalent to min. I/O
656 * size, and be multiple of min. I/O size.
657 */
658 if (ubi->max_write_size < ubi->min_io_size ||
659 ubi->max_write_size % ubi->min_io_size ||
660 !is_power_of_2(ubi->max_write_size)) {
661 ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
662 ubi->max_write_size, ubi->min_io_size);
663 return -EINVAL;
664 }
665
666 /* Calculate default aligned sizes of EC and VID headers */
667 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
668 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
669
670 dbg_gen("min_io_size %d", ubi->min_io_size);
671 dbg_gen("max_write_size %d", ubi->max_write_size);
672 dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
673 dbg_gen("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
674 dbg_gen("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
675
676 if (ubi->vid_hdr_offset == 0)
677 /* Default offset */
678 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
679 ubi->ec_hdr_alsize;
680 else {
681 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
682 ~(ubi->hdrs_min_io_size - 1);
683 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
684 ubi->vid_hdr_aloffset;
685 }
686
687 /*
688 * Memory allocation for VID header is ubi->vid_hdr_alsize
689 * which is described in comments in io.c.
690 * Make sure VID header shift + UBI_VID_HDR_SIZE not exceeds
691 * ubi->vid_hdr_alsize, so that all vid header operations
692 * won't access memory out of bounds.
693 */
694 if ((ubi->vid_hdr_shift + UBI_VID_HDR_SIZE) > ubi->vid_hdr_alsize) {
695 ubi_err(ubi, "Invalid VID header offset %d, VID header shift(%d)"
696 " + VID header size(%zu) > VID header aligned size(%d).",
697 ubi->vid_hdr_offset, ubi->vid_hdr_shift,
698 UBI_VID_HDR_SIZE, ubi->vid_hdr_alsize);
699 return -EINVAL;
700 }
701
702 /* Similar for the data offset */
703 ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
704 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
705
706 dbg_gen("vid_hdr_offset %d", ubi->vid_hdr_offset);
707 dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
708 dbg_gen("vid_hdr_shift %d", ubi->vid_hdr_shift);
709 dbg_gen("leb_start %d", ubi->leb_start);
710
711 /* The shift must be aligned to 32-bit boundary */
712 if (ubi->vid_hdr_shift % 4) {
713 ubi_err(ubi, "unaligned VID header shift %d",
714 ubi->vid_hdr_shift);
715 return -EINVAL;
716 }
717
718 /* Check sanity */
719 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
720 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
721 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
722 ubi->leb_start & (ubi->min_io_size - 1)) {
723 ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
724 ubi->vid_hdr_offset, ubi->leb_start);
725 return -EINVAL;
726 }
727
728 /*
729 * Set maximum amount of physical erroneous eraseblocks to be 10%.
730 * Erroneous PEB are those which have read errors.
731 */
732 ubi->max_erroneous = ubi->peb_count / 10;
733 if (ubi->max_erroneous < 16)
734 ubi->max_erroneous = 16;
735 dbg_gen("max_erroneous %d", ubi->max_erroneous);
736
737 /*
738 * It may happen that EC and VID headers are situated in one minimal
739 * I/O unit. In this case we can only accept this UBI image in
740 * read-only mode.
741 */
742 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
743 ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
744 ubi->ro_mode = 1;
745 }
746
747 ubi->leb_size = ubi->peb_size - ubi->leb_start;
748
749 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
750 ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
751 ubi->mtd->index);
752 ubi->ro_mode = 1;
753 }
754
755 /*
756 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
757 * unfortunately, MTD does not provide this information. We should loop
758 * over all physical eraseblocks and invoke mtd->block_is_bad() for
759 * each physical eraseblock. So, we leave @ubi->bad_peb_count
760 * uninitialized so far.
761 */
762
763 return 0;
764 }
765
766 /**
767 * autoresize - re-size the volume which has the "auto-resize" flag set.
768 * @ubi: UBI device description object
769 * @vol_id: ID of the volume to re-size
770 *
771 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
772 * the volume table to the largest possible size. See comments in ubi-header.h
773 * for more description of the flag. Returns zero in case of success and a
774 * negative error code in case of failure.
775 */
autoresize(struct ubi_device * ubi,int vol_id)776 static int autoresize(struct ubi_device *ubi, int vol_id)
777 {
778 struct ubi_volume_desc desc;
779 struct ubi_volume *vol = ubi->volumes[vol_id];
780 int err, old_reserved_pebs = vol->reserved_pebs;
781
782 if (ubi->ro_mode) {
783 ubi_warn(ubi, "skip auto-resize because of R/O mode");
784 return 0;
785 }
786
787 /*
788 * Clear the auto-resize flag in the volume in-memory copy of the
789 * volume table, and 'ubi_resize_volume()' will propagate this change
790 * to the flash.
791 */
792 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
793
794 if (ubi->avail_pebs == 0) {
795 struct ubi_vtbl_record vtbl_rec;
796
797 /*
798 * No available PEBs to re-size the volume, clear the flag on
799 * flash and exit.
800 */
801 vtbl_rec = ubi->vtbl[vol_id];
802 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
803 if (err)
804 ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
805 vol_id);
806 } else {
807 desc.vol = vol;
808 err = ubi_resize_volume(&desc,
809 old_reserved_pebs + ubi->avail_pebs);
810 if (err)
811 ubi_err(ubi, "cannot auto-resize volume %d",
812 vol_id);
813 }
814
815 if (err)
816 return err;
817
818 ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
819 vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
820 return 0;
821 }
822
823 /**
824 * ubi_attach_mtd_dev - attach an MTD device.
825 * @mtd: MTD device description object
826 * @ubi_num: number to assign to the new UBI device
827 * @vid_hdr_offset: VID header offset
828 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
829 * @disable_fm: whether disable fastmap
830 * @need_resv_pool: whether reserve pebs to fill fm_pool
831 *
832 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
833 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
834 * which case this function finds a vacant device number and assigns it
835 * automatically. Returns the new UBI device number in case of success and a
836 * negative error code in case of failure.
837 *
838 * If @disable_fm is true, ubi doesn't create new fastmap even the module param
839 * 'fm_autoconvert' is set, and existed old fastmap will be destroyed after
840 * doing full scanning.
841 *
842 * Note, the invocations of this function has to be serialized by the
843 * @ubi_devices_mutex.
844 */
ubi_attach_mtd_dev(struct mtd_info * mtd,int ubi_num,int vid_hdr_offset,int max_beb_per1024,bool disable_fm,bool need_resv_pool)845 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
846 int vid_hdr_offset, int max_beb_per1024, bool disable_fm,
847 bool need_resv_pool)
848 {
849 struct ubi_device *ubi;
850 int i, err;
851
852 if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
853 return -EINVAL;
854
855 if (!max_beb_per1024)
856 max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
857
858 /*
859 * Check if we already have the same MTD device attached.
860 *
861 * Note, this function assumes that UBI devices creations and deletions
862 * are serialized, so it does not take the &ubi_devices_lock.
863 */
864 for (i = 0; i < UBI_MAX_DEVICES; i++) {
865 ubi = ubi_devices[i];
866 if (ubi && mtd->index == ubi->mtd->index) {
867 pr_err("ubi: mtd%d is already attached to ubi%d\n",
868 mtd->index, i);
869 return -EEXIST;
870 }
871 }
872
873 /*
874 * Make sure this MTD device is not emulated on top of an UBI volume
875 * already. Well, generally this recursion works fine, but there are
876 * different problems like the UBI module takes a reference to itself
877 * by attaching (and thus, opening) the emulated MTD device. This
878 * results in inability to unload the module. And in general it makes
879 * no sense to attach emulated MTD devices, so we prohibit this.
880 */
881 if (mtd->type == MTD_UBIVOLUME) {
882 pr_err("ubi: refuse attaching mtd%d - it is already emulated on top of UBI\n",
883 mtd->index);
884 return -EINVAL;
885 }
886
887 /*
888 * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
889 * MLC NAND is different and needs special care, otherwise UBI or UBIFS
890 * will die soon and you will lose all your data.
891 * Relax this rule if the partition we're attaching to operates in SLC
892 * mode.
893 */
894 if (mtd->type == MTD_MLCNANDFLASH &&
895 !(mtd->flags & MTD_SLC_ON_MLC_EMULATION)) {
896 pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
897 mtd->index);
898 return -EINVAL;
899 }
900
901 /* UBI cannot work on flashes with zero erasesize. */
902 if (!mtd->erasesize) {
903 pr_err("ubi: refuse attaching mtd%d - zero erasesize flash is not supported\n",
904 mtd->index);
905 return -EINVAL;
906 }
907
908 if (ubi_num == UBI_DEV_NUM_AUTO) {
909 /* Search for an empty slot in the @ubi_devices array */
910 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
911 if (!ubi_devices[ubi_num])
912 break;
913 if (ubi_num == UBI_MAX_DEVICES) {
914 pr_err("ubi: only %d UBI devices may be created\n",
915 UBI_MAX_DEVICES);
916 return -ENFILE;
917 }
918 } else {
919 if (ubi_num >= UBI_MAX_DEVICES)
920 return -EINVAL;
921
922 /* Make sure ubi_num is not busy */
923 if (ubi_devices[ubi_num]) {
924 pr_err("ubi: ubi%i already exists\n", ubi_num);
925 return -EEXIST;
926 }
927 }
928
929 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
930 if (!ubi)
931 return -ENOMEM;
932
933 device_initialize(&ubi->dev);
934 ubi->dev.release = dev_release;
935 ubi->dev.class = &ubi_class;
936 ubi->dev.groups = ubi_dev_groups;
937 ubi->dev.parent = &mtd->dev;
938
939 ubi->mtd = mtd;
940 ubi->ubi_num = ubi_num;
941 ubi->vid_hdr_offset = vid_hdr_offset;
942 ubi->autoresize_vol_id = -1;
943
944 #ifdef CONFIG_MTD_UBI_FASTMAP
945 ubi->fm_pool.used = ubi->fm_pool.size = 0;
946 ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
947
948 /*
949 * fm_pool.max_size is 5% of the total number of PEBs but it's also
950 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
951 */
952 ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
953 ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
954 ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
955 UBI_FM_MIN_POOL_SIZE);
956
957 ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
958 ubi->fm_pool_rsv_cnt = need_resv_pool ? ubi->fm_pool.max_size : 0;
959 ubi->fm_disabled = (!fm_autoconvert || disable_fm) ? 1 : 0;
960 if (fm_debug)
961 ubi_enable_dbg_chk_fastmap(ubi);
962
963 if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
964 <= UBI_FM_MAX_START) {
965 ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
966 UBI_FM_MAX_START);
967 ubi->fm_disabled = 1;
968 }
969
970 ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
971 ubi_msg(ubi, "default fastmap WL pool size: %d",
972 ubi->fm_wl_pool.max_size);
973 #else
974 ubi->fm_disabled = 1;
975 #endif
976 mutex_init(&ubi->buf_mutex);
977 mutex_init(&ubi->ckvol_mutex);
978 mutex_init(&ubi->device_mutex);
979 spin_lock_init(&ubi->volumes_lock);
980 init_rwsem(&ubi->fm_protect);
981 init_rwsem(&ubi->fm_eba_sem);
982
983 ubi_msg(ubi, "attaching mtd%d", mtd->index);
984
985 err = io_init(ubi, max_beb_per1024);
986 if (err)
987 goto out_free;
988
989 err = -ENOMEM;
990 ubi->peb_buf = vmalloc(ubi->peb_size);
991 if (!ubi->peb_buf)
992 goto out_free;
993
994 #ifdef CONFIG_MTD_UBI_FASTMAP
995 ubi->fm_size = ubi_calc_fm_size(ubi);
996 ubi->fm_buf = vzalloc(ubi->fm_size);
997 if (!ubi->fm_buf)
998 goto out_free;
999 #endif
1000 err = ubi_attach(ubi, disable_fm ? 1 : 0);
1001 if (err) {
1002 ubi_err(ubi, "failed to attach mtd%d, error %d",
1003 mtd->index, err);
1004 goto out_free;
1005 }
1006
1007 if (ubi->autoresize_vol_id != -1) {
1008 err = autoresize(ubi, ubi->autoresize_vol_id);
1009 if (err)
1010 goto out_detach;
1011 }
1012
1013 err = uif_init(ubi);
1014 if (err)
1015 goto out_detach;
1016
1017 err = ubi_debugfs_init_dev(ubi);
1018 if (err)
1019 goto out_uif;
1020
1021 ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
1022 if (IS_ERR(ubi->bgt_thread)) {
1023 err = PTR_ERR(ubi->bgt_thread);
1024 ubi_err(ubi, "cannot spawn \"%s\", error %d",
1025 ubi->bgt_name, err);
1026 goto out_debugfs;
1027 }
1028
1029 ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
1030 mtd->index, mtd->name, ubi->flash_size >> 20);
1031 ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
1032 ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
1033 ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
1034 ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1035 ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1036 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1037 ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1038 ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1039 ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1040 ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1041 ubi->vtbl_slots);
1042 ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1043 ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1044 ubi->image_seq);
1045 ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1046 ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1047
1048 /*
1049 * The below lock makes sure we do not race with 'ubi_thread()' which
1050 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1051 */
1052 spin_lock(&ubi->wl_lock);
1053 ubi->thread_enabled = 1;
1054 wake_up_process(ubi->bgt_thread);
1055 spin_unlock(&ubi->wl_lock);
1056
1057 ubi_devices[ubi_num] = ubi;
1058 ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1059 return ubi_num;
1060
1061 out_debugfs:
1062 ubi_debugfs_exit_dev(ubi);
1063 out_uif:
1064 uif_close(ubi);
1065 out_detach:
1066 ubi_wl_close(ubi);
1067 ubi_free_all_volumes(ubi);
1068 vfree(ubi->vtbl);
1069 out_free:
1070 vfree(ubi->peb_buf);
1071 vfree(ubi->fm_buf);
1072 put_device(&ubi->dev);
1073 return err;
1074 }
1075
1076 /**
1077 * ubi_detach_mtd_dev - detach an MTD device.
1078 * @ubi_num: UBI device number to detach from
1079 * @anyway: detach MTD even if device reference count is not zero
1080 *
1081 * This function destroys an UBI device number @ubi_num and detaches the
1082 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1083 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1084 * exist.
1085 *
1086 * Note, the invocations of this function has to be serialized by the
1087 * @ubi_devices_mutex.
1088 */
ubi_detach_mtd_dev(int ubi_num,int anyway)1089 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1090 {
1091 struct ubi_device *ubi;
1092
1093 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1094 return -EINVAL;
1095
1096 ubi = ubi_get_device(ubi_num);
1097 if (!ubi)
1098 return -EINVAL;
1099
1100 spin_lock(&ubi_devices_lock);
1101 put_device(&ubi->dev);
1102 ubi->ref_count -= 1;
1103 if (ubi->ref_count) {
1104 if (!anyway) {
1105 spin_unlock(&ubi_devices_lock);
1106 return -EBUSY;
1107 }
1108 /* This may only happen if there is a bug */
1109 ubi_err(ubi, "%s reference count %d, destroy anyway",
1110 ubi->ubi_name, ubi->ref_count);
1111 }
1112 ubi_devices[ubi_num] = NULL;
1113 spin_unlock(&ubi_devices_lock);
1114
1115 ubi_assert(ubi_num == ubi->ubi_num);
1116 ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1117 ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1118 #ifdef CONFIG_MTD_UBI_FASTMAP
1119 /* If we don't write a new fastmap at detach time we lose all
1120 * EC updates that have been made since the last written fastmap.
1121 * In case of fastmap debugging we omit the update to simulate an
1122 * unclean shutdown. */
1123 if (!ubi_dbg_chk_fastmap(ubi))
1124 ubi_update_fastmap(ubi);
1125 #endif
1126 /*
1127 * Before freeing anything, we have to stop the background thread to
1128 * prevent it from doing anything on this device while we are freeing.
1129 */
1130 if (ubi->bgt_thread)
1131 kthread_stop(ubi->bgt_thread);
1132
1133 #ifdef CONFIG_MTD_UBI_FASTMAP
1134 cancel_work_sync(&ubi->fm_work);
1135 #endif
1136 ubi_debugfs_exit_dev(ubi);
1137 uif_close(ubi);
1138
1139 ubi_wl_close(ubi);
1140 ubi_free_internal_volumes(ubi);
1141 vfree(ubi->vtbl);
1142 vfree(ubi->peb_buf);
1143 vfree(ubi->fm_buf);
1144 ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1145 put_mtd_device(ubi->mtd);
1146 put_device(&ubi->dev);
1147 return 0;
1148 }
1149
1150 /**
1151 * open_mtd_by_chdev - open an MTD device by its character device node path.
1152 * @mtd_dev: MTD character device node path
1153 *
1154 * This helper function opens an MTD device by its character node device path.
1155 * Returns MTD device description object in case of success and a negative
1156 * error code in case of failure.
1157 */
open_mtd_by_chdev(const char * mtd_dev)1158 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1159 {
1160 int err, minor;
1161 struct path path;
1162 struct kstat stat;
1163
1164 /* Probably this is an MTD character device node path */
1165 err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1166 if (err)
1167 return ERR_PTR(err);
1168
1169 err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
1170 path_put(&path);
1171 if (err)
1172 return ERR_PTR(err);
1173
1174 /* MTD device number is defined by the major / minor numbers */
1175 if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
1176 return ERR_PTR(-EINVAL);
1177
1178 minor = MINOR(stat.rdev);
1179
1180 if (minor & 1)
1181 /*
1182 * Just do not think the "/dev/mtdrX" devices support is need,
1183 * so do not support them to avoid doing extra work.
1184 */
1185 return ERR_PTR(-EINVAL);
1186
1187 return get_mtd_device(NULL, minor / 2);
1188 }
1189
1190 /**
1191 * open_mtd_device - open MTD device by name, character device path, or number.
1192 * @mtd_dev: name, character device node path, or MTD device device number
1193 *
1194 * This function tries to open and MTD device described by @mtd_dev string,
1195 * which is first treated as ASCII MTD device number, and if it is not true, it
1196 * is treated as MTD device name, and if that is also not true, it is treated
1197 * as MTD character device node path. Returns MTD device description object in
1198 * case of success and a negative error code in case of failure.
1199 */
open_mtd_device(const char * mtd_dev)1200 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1201 {
1202 struct mtd_info *mtd;
1203 int mtd_num;
1204 char *endp;
1205
1206 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1207 if (*endp != '\0' || mtd_dev == endp) {
1208 /*
1209 * This does not look like an ASCII integer, probably this is
1210 * MTD device name.
1211 */
1212 mtd = get_mtd_device_nm(mtd_dev);
1213 if (PTR_ERR(mtd) == -ENODEV)
1214 /* Probably this is an MTD character device node path */
1215 mtd = open_mtd_by_chdev(mtd_dev);
1216 } else
1217 mtd = get_mtd_device(NULL, mtd_num);
1218
1219 return mtd;
1220 }
1221
ubi_init(void)1222 static int __init ubi_init(void)
1223 {
1224 int err, i, k;
1225
1226 /* Ensure that EC and VID headers have correct size */
1227 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1228 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1229
1230 if (mtd_devs > UBI_MAX_DEVICES) {
1231 pr_err("UBI error: too many MTD devices, maximum is %d\n",
1232 UBI_MAX_DEVICES);
1233 return -EINVAL;
1234 }
1235
1236 /* Create base sysfs directory and sysfs files */
1237 err = class_register(&ubi_class);
1238 if (err < 0)
1239 return err;
1240
1241 err = misc_register(&ubi_ctrl_cdev);
1242 if (err) {
1243 pr_err("UBI error: cannot register device\n");
1244 goto out;
1245 }
1246
1247 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1248 sizeof(struct ubi_wl_entry),
1249 0, 0, NULL);
1250 if (!ubi_wl_entry_slab) {
1251 err = -ENOMEM;
1252 goto out_dev_unreg;
1253 }
1254
1255 err = ubi_debugfs_init();
1256 if (err)
1257 goto out_slab;
1258
1259
1260 /* Attach MTD devices */
1261 for (i = 0; i < mtd_devs; i++) {
1262 struct mtd_dev_param *p = &mtd_dev_param[i];
1263 struct mtd_info *mtd;
1264
1265 cond_resched();
1266
1267 mtd = open_mtd_device(p->name);
1268 if (IS_ERR(mtd)) {
1269 err = PTR_ERR(mtd);
1270 pr_err("UBI error: cannot open mtd %s, error %d\n",
1271 p->name, err);
1272 /* See comment below re-ubi_is_module(). */
1273 if (ubi_is_module())
1274 goto out_detach;
1275 continue;
1276 }
1277
1278 mutex_lock(&ubi_devices_mutex);
1279 err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1280 p->vid_hdr_offs, p->max_beb_per1024,
1281 p->enable_fm == 0,
1282 p->need_resv_pool != 0);
1283 mutex_unlock(&ubi_devices_mutex);
1284 if (err < 0) {
1285 pr_err("UBI error: cannot attach mtd%d\n",
1286 mtd->index);
1287 put_mtd_device(mtd);
1288
1289 /*
1290 * Originally UBI stopped initializing on any error.
1291 * However, later on it was found out that this
1292 * behavior is not very good when UBI is compiled into
1293 * the kernel and the MTD devices to attach are passed
1294 * through the command line. Indeed, UBI failure
1295 * stopped whole boot sequence.
1296 *
1297 * To fix this, we changed the behavior for the
1298 * non-module case, but preserved the old behavior for
1299 * the module case, just for compatibility. This is a
1300 * little inconsistent, though.
1301 */
1302 if (ubi_is_module())
1303 goto out_detach;
1304 }
1305 }
1306
1307 err = ubiblock_init();
1308 if (err) {
1309 pr_err("UBI error: block: cannot initialize, error %d\n", err);
1310
1311 /* See comment above re-ubi_is_module(). */
1312 if (ubi_is_module())
1313 goto out_detach;
1314 }
1315
1316 return 0;
1317
1318 out_detach:
1319 for (k = 0; k < i; k++)
1320 if (ubi_devices[k]) {
1321 mutex_lock(&ubi_devices_mutex);
1322 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1323 mutex_unlock(&ubi_devices_mutex);
1324 }
1325 ubi_debugfs_exit();
1326 out_slab:
1327 kmem_cache_destroy(ubi_wl_entry_slab);
1328 out_dev_unreg:
1329 misc_deregister(&ubi_ctrl_cdev);
1330 out:
1331 class_unregister(&ubi_class);
1332 pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1333 return err;
1334 }
1335 late_initcall(ubi_init);
1336
ubi_exit(void)1337 static void __exit ubi_exit(void)
1338 {
1339 int i;
1340
1341 ubiblock_exit();
1342
1343 for (i = 0; i < UBI_MAX_DEVICES; i++)
1344 if (ubi_devices[i]) {
1345 mutex_lock(&ubi_devices_mutex);
1346 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1347 mutex_unlock(&ubi_devices_mutex);
1348 }
1349 ubi_debugfs_exit();
1350 kmem_cache_destroy(ubi_wl_entry_slab);
1351 misc_deregister(&ubi_ctrl_cdev);
1352 class_unregister(&ubi_class);
1353 }
1354 module_exit(ubi_exit);
1355
1356 /**
1357 * bytes_str_to_int - convert a number of bytes string into an integer.
1358 * @str: the string to convert
1359 *
1360 * This function returns positive resulting integer in case of success and a
1361 * negative error code in case of failure.
1362 */
bytes_str_to_int(const char * str)1363 static int bytes_str_to_int(const char *str)
1364 {
1365 char *endp;
1366 unsigned long result;
1367
1368 result = simple_strtoul(str, &endp, 0);
1369 if (str == endp || result >= INT_MAX) {
1370 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1371 return -EINVAL;
1372 }
1373
1374 switch (*endp) {
1375 case 'G':
1376 result *= 1024;
1377 fallthrough;
1378 case 'M':
1379 result *= 1024;
1380 fallthrough;
1381 case 'K':
1382 result *= 1024;
1383 break;
1384 case '\0':
1385 break;
1386 default:
1387 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1388 return -EINVAL;
1389 }
1390
1391 return result;
1392 }
1393
1394 /**
1395 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1396 * @val: the parameter value to parse
1397 * @kp: not used
1398 *
1399 * This function returns zero in case of success and a negative error code in
1400 * case of error.
1401 */
ubi_mtd_param_parse(const char * val,const struct kernel_param * kp)1402 static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1403 {
1404 int i, len;
1405 struct mtd_dev_param *p;
1406 char buf[MTD_PARAM_LEN_MAX];
1407 char *pbuf = &buf[0];
1408 char *tokens[MTD_PARAM_MAX_COUNT], *token;
1409
1410 if (!val)
1411 return -EINVAL;
1412
1413 if (mtd_devs == UBI_MAX_DEVICES) {
1414 pr_err("UBI error: too many parameters, max. is %d\n",
1415 UBI_MAX_DEVICES);
1416 return -EINVAL;
1417 }
1418
1419 len = strnlen(val, MTD_PARAM_LEN_MAX);
1420 if (len == MTD_PARAM_LEN_MAX) {
1421 pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1422 val, MTD_PARAM_LEN_MAX);
1423 return -EINVAL;
1424 }
1425
1426 if (len == 0) {
1427 pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1428 return 0;
1429 }
1430
1431 strcpy(buf, val);
1432
1433 /* Get rid of the final newline */
1434 if (buf[len - 1] == '\n')
1435 buf[len - 1] = '\0';
1436
1437 for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1438 tokens[i] = strsep(&pbuf, ",");
1439
1440 if (pbuf) {
1441 pr_err("UBI error: too many arguments at \"%s\"\n", val);
1442 return -EINVAL;
1443 }
1444
1445 p = &mtd_dev_param[mtd_devs];
1446 strcpy(&p->name[0], tokens[0]);
1447
1448 token = tokens[1];
1449 if (token) {
1450 p->vid_hdr_offs = bytes_str_to_int(token);
1451
1452 if (p->vid_hdr_offs < 0)
1453 return p->vid_hdr_offs;
1454 }
1455
1456 token = tokens[2];
1457 if (token) {
1458 int err = kstrtoint(token, 10, &p->max_beb_per1024);
1459
1460 if (err) {
1461 pr_err("UBI error: bad value for max_beb_per1024 parameter: %s\n",
1462 token);
1463 return -EINVAL;
1464 }
1465 }
1466
1467 token = tokens[3];
1468 if (token) {
1469 int err = kstrtoint(token, 10, &p->ubi_num);
1470
1471 if (err) {
1472 pr_err("UBI error: bad value for ubi_num parameter: %s\n",
1473 token);
1474 return -EINVAL;
1475 }
1476 } else
1477 p->ubi_num = UBI_DEV_NUM_AUTO;
1478
1479 token = tokens[4];
1480 if (token) {
1481 int err = kstrtoint(token, 10, &p->enable_fm);
1482
1483 if (err) {
1484 pr_err("UBI error: bad value for enable_fm parameter: %s\n",
1485 token);
1486 return -EINVAL;
1487 }
1488 } else
1489 p->enable_fm = 0;
1490
1491 token = tokens[5];
1492 if (token) {
1493 int err = kstrtoint(token, 10, &p->need_resv_pool);
1494
1495 if (err) {
1496 pr_err("UBI error: bad value for need_resv_pool parameter: %s\n",
1497 token);
1498 return -EINVAL;
1499 }
1500 } else
1501 p->need_resv_pool = 0;
1502
1503 mtd_devs += 1;
1504 return 0;
1505 }
1506
1507 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1508 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1509 "Multiple \"mtd\" parameters may be specified.\n"
1510 "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1511 "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1512 "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1513 __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1514 "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1515 "Optional \"enable_fm\" parameter determines whether to enable fastmap during attach. If the value is non-zero, fastmap is enabled. Default value is 0.\n"
1516 "Optional \"need_resv_pool\" parameter determines whether to reserve pool->max_size pebs during attach. If the value is non-zero, peb reservation is enabled. Default value is 0.\n"
1517 "\n"
1518 "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1519 "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"
1520 "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"
1521 "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"
1522 "example 5: mtd=1,0,0,5 mtd=2,0,0,6,1 - attach MTD device /dev/mtd1 to UBI 5 and disable fastmap; attach MTD device /dev/mtd2 to UBI 6 and enable fastmap.(only works when fastmap is enabled and fm_autoconvert=Y).\n"
1523 "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1524 #ifdef CONFIG_MTD_UBI_FASTMAP
1525 module_param(fm_autoconvert, bool, 0644);
1526 MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1527 module_param(fm_debug, bool, 0);
1528 MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1529 #endif
1530 MODULE_VERSION(__stringify(UBI_VERSION));
1531 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1532 MODULE_AUTHOR("Artem Bityutskiy");
1533 MODULE_LICENSE("GPL");
1534